[api] Pass pos by value through encode_varint_raw_loop

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>

.ai/instructions.md

@@ -124,6 +124,28 @@ This document provides essential context for AI models interacting with this pro
     *   **Indentation:** Use spaces (two per indentation level), not tabs
     *   **Type aliases:** Prefer `using type_t = int;` over `typedef int type_t;`
     *   **Line length:** Wrap lines at no more than 120 characters
+    *   **Constructor parameters vs setters:** Component properties that are both **required** and **invariant**
+        (never change after construction) should be constructor parameters rather than set via setter methods.
+        This makes the dependency explicit and prevents use of the object in an incompletely-initialized state.
+        In code generation, when calling `cg.new_Pvariable()` or the relevant helper function to create the component, pass these as arguments.
+        ```cpp
+        // Good - required invariant dependency as constructor parameter
+        class SourceTextSensor : public text_sensor::TextSensor, public Component {
+         public:
+          explicit SourceTextSensor(text::Text *source) : source_(source) {}
+         protected:
+          text::Text *source_;
+        };
+        ```
+        ```cpp
+        // Bad - required invariant dependency as setter
+        class SourceTextSensor : public text_sensor::TextSensor, public Component {
+         public:
+          void set_source(text::Text *source) { this->source_ = source; }
+         protected:
+          text::Text *source_{nullptr};
+        };
+        ```
 
 *   **Component Structure:**
     *   **Standard Files:**
@@ -217,6 +239,123 @@ This document provides essential context for AI models interacting with this pro
               var = await switch.new_switch(config)
           ```
 
+*   **Automations (Triggers, Actions, Conditions):**
+
+    Automations have three building blocks: **Triggers** (fire when something happens), **Actions** (do something), and **Conditions** (check if something is true).
+
+    *   **Triggers -- Callback method (preferred):**
+
+        Use `build_callback_automation()` for simple triggers. This eliminates the need for a C++ Trigger class by using a lightweight pointer-sized forwarder struct registered directly as a callback. No `CONF_TRIGGER_ID` in the schema.
+
+        **Python:**
+        ```python
+        from esphome import automation
+
+        CONFIG_SCHEMA = cv.Schema({
+            cv.GenerateID(): cv.declare_id(MyComponent),
+            cv.Optional(CONF_ON_STATE): automation.validate_automation({}),
+        }).extend(cv.COMPONENT_SCHEMA)
+
+        async def to_code(config):
+            var = cg.new_Pvariable(config[CONF_ID])
+            await cg.register_component(var, config)
+            for conf in config.get(CONF_ON_STATE, []):
+                await automation.build_callback_automation(
+                    var, "add_on_state_callback", [(bool, "x")], conf
+                )
+        ```
+
+        `build_callback_automation` arguments: `parent`, `callback_method` (C++ method name), `args` (template args as `[(type, name)]` tuples), `config`, and optional `forwarder` (defaults to `TriggerForwarder<Ts...>`).
+
+        For boolean filtering (e.g. `on_press`/`on_release`), use built-in forwarders with `args=[]`:
+        ```python
+        for conf_key, forwarder in (
+            (CONF_ON_PRESS, automation.TriggerOnTrueForwarder),
+            (CONF_ON_RELEASE, automation.TriggerOnFalseForwarder),
+        ):
+            for conf in config.get(conf_key, []):
+                await automation.build_callback_automation(
+                    var, "add_on_state_callback", [], conf, forwarder=forwarder
+                )
+        ```
+
+        **C++ -- no trigger class needed.** The callback registration method must be templatized to accept both `std::function` and lightweight forwarder structs (which avoid heap allocation):
+        ```cpp
+        class MyComponent : public Component {
+         public:
+          // Must be a template -- accepts both std::function and pointer-sized forwarder structs
+          template<typename F> void add_on_state_callback(F &&callback) {
+            this->state_callback_.add(std::forward<F>(callback));
+          }
+         protected:
+          // Use CallbackManager when callbacks are always registered (e.g. core components)
+          CallbackManager<void(bool)> state_callback_;
+          // Use LazyCallbackManager when callbacks are often not registered -- saves 8 bytes
+          // (nullptr vs empty std::vector) per instance when no callbacks are added
+          // LazyCallbackManager<void(bool)> state_callback_;
+        };
+        ```
+
+    *   **Triggers -- Trigger class method:**
+
+        Use `build_automation()` with a `Trigger<Ts...>` subclass only when the forwarder needs **mutable state beyond a single `Automation*` pointer** (e.g. edge detection tracking previous state, timing logic).
+
+        **Python:**
+        ```python
+        TurnOnTrigger = my_ns.class_("TurnOnTrigger", automation.Trigger.template())
+
+        CONFIG_SCHEMA = cv.Schema({
+            cv.Optional(CONF_ON_TURN_ON): automation.validate_automation(
+                {cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(TurnOnTrigger)}
+            ),
+        })
+
+        async def to_code(config):
+            for conf in config.get(CONF_ON_TURN_ON, []):
+                trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+                await automation.build_automation(trigger, [], conf)
+        ```
+
+        **C++:**
+        ```cpp
+        class TurnOnTrigger : public Trigger<> {
+         public:
+          explicit TurnOnTrigger(MyComponent *parent) : last_on_{false} {
+            parent->add_on_state_callback([this](bool state) {
+              if (state && !this->last_on_)
+                this->trigger();
+              this->last_on_ = state;
+            });
+          }
+         protected:
+          bool last_on_;
+        };
+        ```
+
+    *   **Actions:**
+        ```cpp
+        template<typename... Ts> class MyAction : public Action<Ts...> {
+         public:
+          explicit MyAction(MyComponent *parent) : parent_(parent) {}
+          void play(const Ts &...) override { this->parent_->do_something(); }
+         protected:
+          MyComponent *parent_;
+        };
+        ```
+        Register with `@automation.register_action("my_component.do_something", MyAction, schema, synchronous=True)`. Use `synchronous=True` for actions that run to completion inside `play()` without deferring. Use `synchronous=False` if the action may suspend/defer execution (e.g. `delay`, `wait_until`, `script.wait`) or store trigger arguments for later use.
+
+    *   **Conditions:**
+        ```cpp
+        template<typename... Ts> class MyCondition : public Condition<Ts...> {
+         public:
+          explicit MyCondition(MyComponent *parent) : parent_(parent) {}
+          bool check(const Ts &...) override { return this->parent_->is_active(); }
+         protected:
+          MyComponent *parent_;
+        };
+        ```
+        Register with `@automation.register_condition("my_component.is_active", MyCondition, schema)`.
+
 *   **Configuration Validation:**
     *   **Common Validators:** `cv.int_`, `cv.float_`, `cv.string`, `cv.boolean`, `cv.int_range(min=0, max=100)`, `cv.positive_int`, `cv.percentage`.
     *   **Complex Validation:** `cv.All(cv.string, cv.Length(min=1, max=50))`, `cv.Any(cv.int_, cv.string)`.
@@ -252,10 +391,39 @@ This document provides essential context for AI models interacting with this pro
     *   **Component Tests:** YAML-based compilation tests are located in `tests/`. The structure is as follows:
         ```
         tests/
-        ├── test_build_components/ # Base test configurations
-        └── components/[component]/ # Component-specific tests
+        ├── test_build_components/
+        │   └── common/          # Shared bus packages (uart, i2c, spi, etc.)
+        │       ├── uart/        # UART at default baud rate
+        │       ├── uart_115200/ # UART at 115200 baud
+        │       ├── i2c/         # I2C bus
+        │       └── spi/         # SPI bus
+        └── components/[component]/
+            ├── common.yaml      # Component-only config (no bus definitions)
+            ├── test.esp32-idf.yaml
+            ├── test.esp8266-ard.yaml
+            └── test.rp2040-ard.yaml
         ```
         Run them using `script/test_build_components`. Use `-c <component>` to test specific components and `-t <target>` for specific platforms.
+
+    *   **Test Grouping with Packages:** Components that use shared bus packages can be grouped together in CI to reduce build count. **Never define buses (uart, i2c, spi, modbus) directly in test YAML files** — always use packages from `test_build_components/common/`:
+        ```yaml
+        # test.esp32-idf.yaml — use packages for buses
+        packages:
+          uart: !include ../../test_build_components/common/uart_115200/esp32-idf.yaml
+
+        <<: !include common.yaml
+        ```
+        ```yaml
+        # common.yaml — component config only, NO bus definitions
+        my_component:
+          id: my_instance
+
+        sensor:
+          - platform: my_component
+            name: My Sensor
+        ```
+        Components that define buses directly are flagged as "NEEDS MIGRATION" and cannot be grouped, increasing CI build time.
+
     *   **Testing All Components Together:** To verify that all components can be tested together without ID conflicts or configuration issues, use:
         ```bash
         ./script/test_component_grouping.py -e config --all
@@ -286,6 +454,7 @@ This document provides essential context for AI models interacting with this pro
 *   **Documentation Contributions:**
     *   Documentation is hosted in the separate `esphome/esphome-docs` repository.
     *   The contribution workflow is the same as for the codebase.
+    *   When editing a component's documentation page, also update the corresponding component index page to ensure both pages remain in sync.
 
 *   **Best Practices:**
     *   **Component Development:** Keep dependencies minimal, provide clear error messages, and write comprehensive docstrings and tests.
@@ -394,6 +563,30 @@ This document provides essential context for AI models interacting with this pro
 
         Note: Avoiding heap allocation after `setup()` is always required regardless of component type. The prioritization above is about the effort spent on container optimization (e.g., migrating from `std::vector` to `StaticVector`).
 
+        **Callback Managers:**
+
+        ESPHome provides two callback manager types in `esphome/core/helpers.h` for the observer pattern. Both support `std::function`, lambdas, and lightweight forwarder structs via their templatized `add()` method.
+
+        | Type | Idle overhead (32-bit) | When to use |
+        |------|----------------------|-------------|
+        | `CallbackManager<void(Ts...)>` | 12 bytes (empty `std::vector`) | Callbacks are always or almost always registered |
+        | `LazyCallbackManager<void(Ts...)>` | 4 bytes (`nullptr`) | Callbacks are often not registered (common case) |
+
+        `LazyCallbackManager` is a drop-in replacement for `CallbackManager` that defers allocation until the first callback is added. Prefer it for entity-level callbacks where most instances have no subscribers.
+
+        **Important:** Registration methods that add to a callback manager **must always be templatized** to accept both `std::function` and pointer-sized forwarder structs (used by `build_callback_automation`). Never use `std::function` in the method signature:
+        ```cpp
+        // Bad -- forces heap allocation for forwarder structs
+        void add_on_state_callback(std::function<void(bool)> &&callback) {
+          this->state_callback_.add(std::move(callback));
+        }
+
+        // Good -- accepts any callable without forcing std::function wrapping
+        template<typename F> void add_on_state_callback(F &&callback) {
+          this->state_callback_.add(std::forward<F>(callback));
+        }
+        ```
+
     *   **State Management:** Use `CORE.data` for component state that needs to persist during configuration generation. Avoid module-level mutable globals.
 
         **Bad Pattern (Module-Level Globals):**

.clang-tidy.hash

@@ -1 +1 @@
-ce05c28e9dc0b12c4f6e7454986ffea5123ac974a949da841be698c535f2083e
+f31f13994768b5b07e29624406c9b053bf4bb26e1623ac2bc1e9d4a9477502d6

.github/PULL_REQUEST_TEMPLATE.md

@@ -6,8 +6,9 @@
 
 - [ ] Bugfix (non-breaking change which fixes an issue)
 - [ ] New feature (non-breaking change which adds functionality)
-- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
-- [ ] Developer breaking change (an API change that could break external components)
+- [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected) — [policy](https://developers.esphome.io/contributing/code/#what-constitutes-a-c-breaking-change)
+- [ ] Developer breaking change (an API change that could break external components) — [policy](https://developers.esphome.io/contributing/code/#what-is-considered-public-c-api)
+- [ ] Undocumented C++ API change (removal or change of undocumented public methods that lambda users may depend on) — [policy](https://developers.esphome.io/contributing/code/#c-user-expectations)
 - [ ] Code quality improvements to existing code or addition of tests
 - [ ] Other
 
@@ -24,7 +25,7 @@
 - [ ] ESP32
 - [ ] ESP32 IDF
 - [ ] ESP8266
-- [ ] RP2040
+- [ ] RP2040/RP2350
 - [ ] BK72xx
 - [ ] RTL87xx
 - [ ] LN882x

.github/actions/build-image/action.yaml

@@ -47,7 +47,7 @@ runs:
 
     - name: Build and push to ghcr by digest
       id: build-ghcr
-      uses: docker/build-push-action@601a80b39c9405e50806ae38af30926f9d957c47 # v6.19.1
+      uses: docker/build-push-action@d08e5c354a6adb9ed34480a06d141179aa583294 # v7.0.0
       env:
         DOCKER_BUILD_SUMMARY: false
         DOCKER_BUILD_RECORD_UPLOAD: false
@@ -73,7 +73,7 @@ runs:
 
     - name: Build and push to dockerhub by digest
       id: build-dockerhub
-      uses: docker/build-push-action@601a80b39c9405e50806ae38af30926f9d957c47 # v6.19.1
+      uses: docker/build-push-action@d08e5c354a6adb9ed34480a06d141179aa583294 # v7.0.0
       env:
         DOCKER_BUILD_SUMMARY: false
         DOCKER_BUILD_RECORD_UPLOAD: false

.github/actions/restore-python/action.yml

@@ -22,7 +22,7 @@ runs:
         python-version: ${{ inputs.python-version }}
     - name: Restore Python virtual environment
       id: cache-venv
-      uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+      uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: venv
         # yamllint disable-line rule:line-length

.github/scripts/auto-label-pr/constants.js

@@ -4,6 +4,7 @@ module.exports = {
   CODEOWNERS_MARKER: '<!-- codeowners-request -->',
   TOO_BIG_MARKER: '<!-- too-big-request -->',
   DEPRECATED_COMPONENT_MARKER: '<!-- deprecated-component-request -->',
+  ORG_FORK_MARKER: '<!-- maintainer-access-warning -->',
 
   MANAGED_LABELS: [
     'new-component',
@@ -14,6 +15,7 @@ module.exports = {
     'chained-pr',
     'core',
     'small-pr',
+    'medium-pr',
     'dashboard',
     'github-actions',
     'by-code-owner',
@@ -27,6 +29,7 @@ module.exports = {
     'new-feature',
     'breaking-change',
     'developer-breaking-change',
+    'undocumented-api-change',
     'code-quality',
     'deprecated-component'
   ],

.github/scripts/auto-label-pr/detectors.js

@@ -1,5 +1,13 @@
 const fs = require('fs');
 const { DOCS_PR_PATTERNS } = require('./constants');
+const {
+  COMPONENT_REGEX,
+  detectComponents,
+  hasCoreChanges,
+  hasDashboardChanges,
+  hasGitHubActionsChanges,
+} = require('../detect-tags');
+const { loadCodeowners, getEffectiveOwners } = require('../codeowners');
 
 // Strategy: Merge branch detection
 async function detectMergeBranch(context) {
@@ -20,15 +28,13 @@ async function detectMergeBranch(context) {
 // Strategy: Component and platform labeling
 async function detectComponentPlatforms(changedFiles, apiData) {
   const labels = new Set();
-  const componentRegex = /^esphome\/components\/([^\/]+)\//;
   const targetPlatformRegex = new RegExp(`^esphome\/components\/(${apiData.targetPlatforms.join('|')})/`);
 
-  for (const file of changedFiles) {
-    const componentMatch = file.match(componentRegex);
-    if (componentMatch) {
-      labels.add(`component: ${componentMatch[1]}`);
-    }
+  for (const comp of detectComponents(changedFiles)) {
+    labels.add(`component: ${comp}`);
+  }
 
+  for (const file of changedFiles) {
     const platformMatch = file.match(targetPlatformRegex);
     if (platformMatch) {
       labels.add(`platform: ${platformMatch[1]}`);
@@ -90,20 +96,14 @@ async function detectNewPlatforms(prFiles, apiData) {
 // Strategy: Core files detection
 async function detectCoreChanges(changedFiles) {
   const labels = new Set();
-  const coreFiles = changedFiles.filter(file =>
-    file.startsWith('esphome/core/') ||
-    (file.startsWith('esphome/') && file.split('/').length === 2)
-  );
-
-  if (coreFiles.length > 0) {
+  if (hasCoreChanges(changedFiles)) {
     labels.add('core');
   }
-
   return labels;
 }
 
 // Strategy: PR size detection
-async function detectPRSize(prFiles, totalAdditions, totalDeletions, totalChanges, isMegaPR, SMALL_PR_THRESHOLD, TOO_BIG_THRESHOLD) {
+async function detectPRSize(prFiles, totalAdditions, totalDeletions, totalChanges, isMegaPR, SMALL_PR_THRESHOLD, MEDIUM_PR_THRESHOLD, TOO_BIG_THRESHOLD) {
   const labels = new Set();
 
   if (totalChanges <= SMALL_PR_THRESHOLD) {
@@ -111,6 +111,11 @@ async function detectPRSize(prFiles, totalAdditions, totalDeletions, totalChange
     return labels;
   }
 
+  if (totalChanges <= MEDIUM_PR_THRESHOLD) {
+    labels.add('medium-pr');
+    return labels;
+  }
+
   const testAdditions = prFiles
     .filter(file => file.filename.startsWith('tests/'))
     .reduce((sum, file) => sum + (file.additions || 0), 0);
@@ -131,80 +136,33 @@ async function detectPRSize(prFiles, totalAdditions, totalDeletions, totalChange
 // Strategy: Dashboard changes
 async function detectDashboardChanges(changedFiles) {
   const labels = new Set();
-  const dashboardFiles = changedFiles.filter(file =>
-    file.startsWith('esphome/dashboard/') ||
-    file.startsWith('esphome/components/dashboard_import/')
-  );
-
-  if (dashboardFiles.length > 0) {
+  if (hasDashboardChanges(changedFiles)) {
     labels.add('dashboard');
   }
-
   return labels;
 }
 
 // Strategy: GitHub Actions changes
 async function detectGitHubActionsChanges(changedFiles) {
   const labels = new Set();
-  const githubActionsFiles = changedFiles.filter(file =>
-    file.startsWith('.github/workflows/')
-  );
-
-  if (githubActionsFiles.length > 0) {
+  if (hasGitHubActionsChanges(changedFiles)) {
     labels.add('github-actions');
   }
-
   return labels;
 }
 
 // Strategy: Code owner detection
 async function detectCodeOwner(github, context, changedFiles) {
   const labels = new Set();
-  const { owner, repo } = context.repo;
 
   try {
-    const { data: codeownersFile } = await github.rest.repos.getContent({
-      owner,
-      repo,
-      path: 'CODEOWNERS',
-    });
-
-    const codeownersContent = Buffer.from(codeownersFile.content, 'base64').toString('utf8');
+    const codeownersPatterns = loadCodeowners();
     const prAuthor = context.payload.pull_request.user.login;
 
-    const codeownersLines = codeownersContent.split('\n')
-      .map(line => line.trim())
-      .filter(line => line && !line.startsWith('#'));
-
-    const codeownersRegexes = codeownersLines.map(line => {
-      const parts = line.split(/\s+/);
-      const pattern = parts[0];
-      const owners = parts.slice(1);
-
-      let regex;
-      if (pattern.endsWith('*')) {
-        const dir = pattern.slice(0, -1);
-        regex = new RegExp(`^${dir.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}`);
-      } else if (pattern.includes('*')) {
-        // First escape all regex special chars except *, then replace * with .*
-        const regexPattern = pattern
-          .replace(/[.+?^${}()|[\]\\]/g, '\\$&')
-          .replace(/\*/g, '.*');
-        regex = new RegExp(`^${regexPattern}$`);
-      } else {
-        regex = new RegExp(`^${pattern.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')}$`);
-      }
-
-      return { regex, owners };
-    });
-
-    for (const file of changedFiles) {
-      for (const { regex, owners } of codeownersRegexes) {
-        if (regex.test(file) && owners.some(owner => owner === `@${prAuthor}`)) {
-          labels.add('by-code-owner');
-          return labels;
-        }
-      }
+    // Check if PR author is a codeowner of any changed file
+    const effective = getEffectiveOwners(changedFiles, codeownersPatterns);
+    if (effective.users.has(prAuthor)) {
+      labels.add('by-code-owner');
     }
   } catch (error) {
     console.log('Failed to read or parse CODEOWNERS file:', error.message);
@@ -238,6 +196,7 @@ async function detectPRTemplateCheckboxes(context) {
     { pattern: /- \[x\] New feature \(non-breaking change which adds functionality\)/i, label: 'new-feature' },
     { pattern: /- \[x\] Breaking change \(fix or feature that would cause existing functionality to not work as expected\)/i, label: 'breaking-change' },
     { pattern: /- \[x\] Developer breaking change \(an API change that could break external components\)/i, label: 'developer-breaking-change' },
+    { pattern: /- \[x\] Undocumented C\+\+ API change \(removal or change of undocumented public methods that lambda users may depend on\)/i, label: 'undocumented-api-change' },
     { pattern: /- \[x\] Code quality improvements to existing code or addition of tests/i, label: 'code-quality' }
   ];
 
@@ -258,7 +217,7 @@ async function detectDeprecatedComponents(github, context, changedFiles) {
   const { owner, repo } = context.repo;
 
   // Compile regex once for better performance
-  const componentFileRegex = /^esphome\/components\/([^\/]+)\//;
+  const componentFileRegex = COMPONENT_REGEX;
 
   // Get files that are modified or added in components directory
   const componentFiles = changedFiles.filter(file => componentFileRegex.test(file));
@@ -276,19 +235,20 @@ async function detectDeprecatedComponents(github, context, changedFiles) {
     }
   }
 
-  // Get PR head to fetch files from the PR branch
-  const prNumber = context.payload.pull_request.number;
+  // Get base branch ref to check if deprecation already exists for the component
+  // This prevents flagging a PR that simply adds deprecation
+  const baseRef = context.payload.pull_request.base.ref;
 
   // Check each component's __init__.py for DEPRECATED_COMPONENT constant
   for (const component of components) {
     const initFile = `esphome/components/${component}/__init__.py`;
     try {
-      // Fetch file content from PR head using GitHub API
+      // Fetch file content from base branch using GitHub API
       const { data: fileData } = await github.rest.repos.getContent({
         owner,
         repo,
         path: initFile,
-        ref: `refs/pull/${prNumber}/head`
+        ref: baseRef
       });
 
       // Decode base64 content
@@ -321,6 +281,24 @@ async function detectDeprecatedComponents(github, context, changedFiles) {
   return { labels, deprecatedInfo };
 }
 
+// Strategy: Detect when maintainers cannot modify the PR branch
+function detectMaintainerAccess(context) {
+  const pr = context.payload.pull_request;
+
+  // Only relevant for cross-repo PRs (forks)
+  if (!pr.head.repo || pr.head.repo.full_name === pr.base.repo.full_name) {
+    return null;
+  }
+
+  if (pr.maintainer_can_modify) {
+    return null;
+  }
+
+  const isOrgFork = pr.head.repo.owner.type === 'Organization';
+  console.log(`Maintainer cannot modify PR branch (${isOrgFork ? 'org fork: ' + pr.head.repo.owner.login : 'user disabled'})`);
+  return { isOrgFork, orgName: pr.head.repo.owner.login };
+}
+
 // Strategy: Requirements detection
 async function detectRequirements(allLabels, prFiles, context) {
   const labels = new Set();
@@ -369,5 +347,6 @@ module.exports = {
   detectTests,
   detectPRTemplateCheckboxes,
   detectDeprecatedComponents,
+  detectMaintainerAccess,
   detectRequirements
 };

.github/scripts/auto-label-pr/index.js

@@ -12,9 +12,10 @@ const {
   detectTests,
   detectPRTemplateCheckboxes,
   detectDeprecatedComponents,
+  detectMaintainerAccess,
   detectRequirements
 } = require('./detectors');
-const { handleReviews } = require('./reviews');
+const { handleReviews, handleMaintainerAccessComment } = require('./reviews');
 const { applyLabels, removeOldLabels } = require('./labels');
 
 // Fetch API data
@@ -35,6 +36,7 @@ async function fetchApiData() {
 module.exports = async ({ github, context }) => {
   // Environment variables
   const SMALL_PR_THRESHOLD = parseInt(process.env.SMALL_PR_THRESHOLD);
+  const MEDIUM_PR_THRESHOLD = parseInt(process.env.MEDIUM_PR_THRESHOLD);
   const MAX_LABELS = parseInt(process.env.MAX_LABELS);
   const TOO_BIG_THRESHOLD = parseInt(process.env.TOO_BIG_THRESHOLD);
   const COMPONENT_LABEL_THRESHOLD = parseInt(process.env.COMPONENT_LABEL_THRESHOLD);
@@ -113,20 +115,22 @@ module.exports = async ({ github, context }) => {
     codeOwnerLabels,
     testLabels,
     checkboxLabels,
-    deprecatedResult
+    deprecatedResult,
+    maintainerAccess
   ] = await Promise.all([
     detectMergeBranch(context),
     detectComponentPlatforms(changedFiles, apiData),
     detectNewComponents(prFiles),
     detectNewPlatforms(prFiles, apiData),
     detectCoreChanges(changedFiles),
-    detectPRSize(prFiles, totalAdditions, totalDeletions, totalChanges, isMegaPR, SMALL_PR_THRESHOLD, TOO_BIG_THRESHOLD),
+    detectPRSize(prFiles, totalAdditions, totalDeletions, totalChanges, isMegaPR, SMALL_PR_THRESHOLD, MEDIUM_PR_THRESHOLD, TOO_BIG_THRESHOLD),
     detectDashboardChanges(changedFiles),
     detectGitHubActionsChanges(changedFiles),
     detectCodeOwner(github, context, changedFiles),
     detectTests(changedFiles),
     detectPRTemplateCheckboxes(context),
-    detectDeprecatedComponents(github, context, changedFiles)
+    detectDeprecatedComponents(github, context, changedFiles),
+    detectMaintainerAccess(context)
   ]);
 
   // Extract deprecated component info
@@ -176,8 +180,11 @@ module.exports = async ({ github, context }) => {
 
   console.log('Computed labels:', finalLabels.join(', '));
 
-  // Handle reviews
-  await handleReviews(github, context, finalLabels, originalLabelCount, deprecatedInfo, prFiles, totalAdditions, totalDeletions, MAX_LABELS, TOO_BIG_THRESHOLD);
+  // Handle reviews and org fork comment
+  await Promise.all([
+    handleReviews(github, context, finalLabels, originalLabelCount, deprecatedInfo, prFiles, totalAdditions, totalDeletions, MAX_LABELS, TOO_BIG_THRESHOLD),
+    handleMaintainerAccessComment(github, context, maintainerAccess)
+  ]);
 
   // Apply labels
   await applyLabels(github, context, finalLabels);

.github/scripts/auto-label-pr/reviews.js

@@ -2,7 +2,8 @@ const {
   BOT_COMMENT_MARKER,
   CODEOWNERS_MARKER,
   TOO_BIG_MARKER,
-  DEPRECATED_COMPONENT_MARKER
+  DEPRECATED_COMPONENT_MARKER,
+  ORG_FORK_MARKER
 } = require('./constants');
 
 // Generate review messages
@@ -136,6 +137,63 @@ async function handleReviews(github, context, finalLabels, originalLabelCount, d
   }
 }
 
+// Handle maintainer access warning comment
+async function handleMaintainerAccessComment(github, context, maintainerAccess) {
+  if (!maintainerAccess) {
+    return;
+  }
+
+  const { owner, repo } = context.repo;
+  const pr_number = context.issue.number;
+  const prAuthor = context.payload.pull_request.user.login;
+
+  // Check if we already posted the warning (iterate pages to exit early)
+  let existingComment;
+  for await (const { data: comments } of github.paginate.iterator(
+    github.rest.issues.listComments,
+    { owner, repo, issue_number: pr_number }
+  )) {
+    existingComment = comments.find(comment =>
+      comment.user.type === 'Bot' &&
+      comment.body && comment.body.includes(ORG_FORK_MARKER)
+    );
+    if (existingComment) {
+      break;
+    }
+  }
+
+  if (existingComment) {
+    console.log('Maintainer access warning comment already exists, skipping');
+    return;
+  }
+
+  let body;
+  if (maintainerAccess.isOrgFork) {
+    body = `${ORG_FORK_MARKER}\n### ⚠️ Organization Fork Detected\n\n` +
+      `Hey there @${prAuthor},\n` +
+      `It looks like this PR was submitted from a fork owned by the **${maintainerAccess.orgName}** organization. ` +
+      `GitHub does not allow maintainers to push changes to pull request branches when the fork is owned by an organization. ` +
+      `This means we won't be able to make small adjustments or fixups to your PR directly.\n\n` +
+      `To allow maintainer collaboration, please re-submit this PR from a personal fork instead.\n\n` +
+      `See: [Setting up the local repository](https://developers.esphome.io/contributing/development-environment/?h=org#set-up-the-local-repository) for more details.`;
+  } else {
+    body = `${ORG_FORK_MARKER}\n### ⚠️ Maintainer Access Disabled\n\n` +
+      `Hey there @${prAuthor},\n` +
+      `It looks like this PR does not have the "Allow edits from maintainers" option enabled. ` +
+      `This means we won't be able to make small adjustments or fixups to your PR directly.\n\n` +
+      `Please enable this option in the PR sidebar to allow maintainer collaboration.`;
+  }
+
+  await github.rest.issues.createComment({
+    owner,
+    repo,
+    issue_number: pr_number,
+    body
+  });
+  console.log('Created maintainer access warning comment');
+}
+
 module.exports = {
-  handleReviews
+  handleReviews,
+  handleMaintainerAccessComment
 };

.github/scripts/codeowners.js

@@ -0,0 +1,227 @@
+// Shared CODEOWNERS parsing and matching utilities.
+//
+// Used by:
+//   - codeowner-review-request.yml
+//   - codeowner-approved-label-update.yml
+//   - auto-label-pr/detectors.js (detectCodeOwner)
+
+/**
+ * Convert a CODEOWNERS glob pattern to a RegExp.
+ *
+ * Handles **, *, and ? wildcards after escaping regex-special characters.
+ */
+function globToRegex(pattern) {
+  let regexStr = pattern
+    .replace(/([.+^=!:${}()|[\]\\])/g, '\\$1')
+    .replace(/\*\*/g, '\x00GLOBSTAR\x00')  // protect ** from next replace
+    .replace(/\*/g, '[^/]*')               // single star
+    .replace(/\x00GLOBSTAR\x00/g, '.*')    // restore globstar
+    .replace(/\?/g, '.');
+  return new RegExp('^' + regexStr + '$');
+}
+
+/**
+ * Parse raw CODEOWNERS file content into an array of
+ * { pattern, regex, owners } objects.
+ *
+ * Each `owners` entry is the raw string from the file (e.g. "@user" or
+ * "@esphome/core").
+ */
+function parseCodeowners(content) {
+  const lines = content
+    .split('\n')
+    .map(line => line.trim())
+    .filter(line => line && !line.startsWith('#'));
+
+  const patterns = [];
+  for (const line of lines) {
+    const parts = line.split(/\s+/);
+    if (parts.length < 2) continue;
+
+    const pattern = parts[0];
+    const owners = parts.slice(1);
+    const regex = globToRegex(pattern);
+    patterns.push({ pattern, regex, owners });
+  }
+  return patterns;
+}
+
+/**
+ * Fetch and parse the CODEOWNERS file via the GitHub API.
+ *
+ * @param {object} github  - octokit instance from actions/github-script
+ * @param {string} owner   - repo owner
+ * @param {string} repo    - repo name
+ * @param {string} [ref]   - git ref (SHA / branch) to read from
+ * @returns {Array<{pattern: string, regex: RegExp, owners: string[]}>}
+ */
+async function fetchCodeowners(github, owner, repo, ref) {
+  const params = { owner, repo, path: 'CODEOWNERS' };
+  if (ref) params.ref = ref;
+
+  const { data: file } = await github.rest.repos.getContent(params);
+  const content = Buffer.from(file.content, 'base64').toString('utf8');
+  return parseCodeowners(content);
+}
+
+/**
+ * Classify raw owner strings into individual users and teams.
+ *
+ * @param {string[]} rawOwners - e.g. ["@user1", "@esphome/core"]
+ * @returns {{ users: string[], teams: string[] }}
+ *   users  – login names without "@"
+ *   teams  – team slugs without the "org/" prefix
+ */
+function classifyOwners(rawOwners) {
+  const users = [];
+  const teams = [];
+  for (const o of rawOwners) {
+    const clean = o.startsWith('@') ? o.slice(1) : o;
+    if (clean.includes('/')) {
+      teams.push(clean.split('/')[1]);
+    } else {
+      users.push(clean);
+    }
+  }
+  return { users, teams };
+}
+
+/**
+ * For each file, find its effective codeowners using GitHub's
+ * "last match wins" semantics, then union across all files.
+ *
+ * @param {string[]} files              - list of file paths
+ * @param {Array}    codeownersPatterns  - from parseCodeowners / fetchCodeowners
+ * @returns {{ users: Set<string>, teams: Set<string>, matchedFileCount: number }}
+ */
+function getEffectiveOwners(files, codeownersPatterns) {
+  const users = new Set();
+  const teams = new Set();
+  let matchedFileCount = 0;
+
+  for (const file of files) {
+    // Last matching pattern wins for each file
+    let effectiveOwners = null;
+    for (const { regex, owners } of codeownersPatterns) {
+      if (regex.test(file)) {
+        effectiveOwners = owners;
+      }
+    }
+    if (effectiveOwners) {
+      matchedFileCount++;
+      const classified = classifyOwners(effectiveOwners);
+      for (const u of classified.users) users.add(u);
+      for (const t of classified.teams) teams.add(t);
+    }
+  }
+
+  return { users, teams, matchedFileCount };
+}
+
+/**
+ * Read and parse the CODEOWNERS file from disk.
+ *
+ * Use this when the repo is already checked out (avoids an API call).
+ *
+ * @param {string} [repoRoot='.'] - path to the repo root
+ * @returns {Array<{pattern: string, regex: RegExp, owners: string[]}>}
+ */
+function loadCodeowners(repoRoot = '.') {
+  const fs = require('fs');
+  const path = require('path');
+  const content = fs.readFileSync(path.join(repoRoot, 'CODEOWNERS'), 'utf8');
+  return parseCodeowners(content);
+}
+
+/** Possible label actions returned by determineLabelAction. */
+const LabelAction = Object.freeze({
+  ADD: 'add',
+  REMOVE: 'remove',
+  NONE: 'none',
+});
+
+/**
+ * Determine what label action is needed for a PR based on codeowner approvals.
+ *
+ * Checks changed files against CODEOWNERS patterns, reviews, and current labels
+ * to decide if the label should be added, removed, or left unchanged.
+ *
+ * @param {object} github              - octokit instance from actions/github-script
+ * @param {string} owner               - repo owner
+ * @param {string} repo                - repo name
+ * @param {number} pr_number           - pull request number
+ * @param {Array}  codeownersPatterns   - from loadCodeowners / fetchCodeowners
+ * @param {string} labelName           - label to manage
+ * @returns {Promise<LabelAction>}
+ */
+async function determineLabelAction(github, owner, repo, pr_number, codeownersPatterns, labelName) {
+  // Get the list of changed files in this PR
+  const prFiles = await github.paginate(
+    github.rest.pulls.listFiles,
+    { owner, repo, pull_number: pr_number }
+  );
+
+  const changedFiles = prFiles.map(file => file.filename);
+  console.log(`Found ${changedFiles.length} changed files`);
+
+  if (changedFiles.length === 0) {
+    console.log('No changed files found');
+    return LabelAction.NONE;
+  }
+
+  // Get effective owners using last-match-wins semantics
+  const effective = getEffectiveOwners(changedFiles, codeownersPatterns);
+  const componentCodeowners = effective.users;
+
+  console.log(`Component-specific codeowners: ${Array.from(componentCodeowners).join(', ') || '(none)'}`);
+
+  // Get current labels
+  const { data: currentLabels } = await github.rest.issues.listLabelsOnIssue({
+    owner, repo, issue_number: pr_number
+  });
+  const hasLabel = currentLabels.some(label => label.name === labelName);
+
+  if (componentCodeowners.size === 0) {
+    console.log('No component-specific codeowners found');
+    return hasLabel ? LabelAction.REMOVE : LabelAction.NONE;
+  }
+
+  // Get all reviews and find latest per user
+  const reviews = await github.paginate(
+    github.rest.pulls.listReviews,
+    { owner, repo, pull_number: pr_number }
+  );
+
+  const latestReviewByUser = new Map();
+  for (const review of reviews) {
+    if (!review.user || review.user.type === 'Bot' || review.state === 'COMMENTED') continue;
+    latestReviewByUser.set(review.user.login, review);
+  }
+
+  // Check if any component-specific codeowner has an active approval
+  let hasCodeownerApproval = false;
+  for (const [login, review] of latestReviewByUser) {
+    if (review.state === 'APPROVED' && componentCodeowners.has(login)) {
+      console.log(`Codeowner '${login}' has approved`);
+      hasCodeownerApproval = true;
+      break;
+    }
+  }
+
+  if (hasCodeownerApproval && !hasLabel) return LabelAction.ADD;
+  if (!hasCodeownerApproval && hasLabel) return LabelAction.REMOVE;
+
+  console.log(`Label already ${hasLabel ? 'present' : 'absent'}, no change needed`);
+  return LabelAction.NONE;
+}
+
+module.exports = {
+  globToRegex,
+  parseCodeowners,
+  fetchCodeowners,
+  loadCodeowners,
+  classifyOwners,
+  getEffectiveOwners,
+  LabelAction,
+  determineLabelAction
+};

.github/scripts/detect-tags.js

@@ -0,0 +1,66 @@
+/**
+ * Shared tag detection from changed file paths.
+ * Used by pr-title-check and auto-label-pr workflows.
+ */
+
+const COMPONENT_REGEX = /^esphome\/components\/([^\/]+)\//;
+
+/**
+ * Detect component names from changed files.
+ * @param {string[]} changedFiles - List of changed file paths
+ * @returns {Set<string>} Set of component names
+ */
+function detectComponents(changedFiles) {
+  const components = new Set();
+  for (const file of changedFiles) {
+    const match = file.match(COMPONENT_REGEX);
+    if (match) {
+      components.add(match[1]);
+    }
+  }
+  return components;
+}
+
+/**
+ * Detect if core files were changed.
+ * Core files are in esphome/core/ or top-level esphome/ directory.
+ * @param {string[]} changedFiles - List of changed file paths
+ * @returns {boolean}
+ */
+function hasCoreChanges(changedFiles) {
+  return changedFiles.some(file =>
+    file.startsWith('esphome/core/') ||
+    (file.startsWith('esphome/') && file.split('/').length === 2)
+  );
+}
+
+/**
+ * Detect if dashboard files were changed.
+ * @param {string[]} changedFiles - List of changed file paths
+ * @returns {boolean}
+ */
+function hasDashboardChanges(changedFiles) {
+  return changedFiles.some(file =>
+    file.startsWith('esphome/dashboard/') ||
+    file.startsWith('esphome/components/dashboard_import/')
+  );
+}
+
+/**
+ * Detect if GitHub Actions files were changed.
+ * @param {string[]} changedFiles - List of changed file paths
+ * @returns {boolean}
+ */
+function hasGitHubActionsChanges(changedFiles) {
+  return changedFiles.some(file =>
+    file.startsWith('.github/workflows/')
+  );
+}
+
+module.exports = {
+  COMPONENT_REGEX,
+  detectComponents,
+  hasCoreChanges,
+  hasDashboardChanges,
+  hasGitHubActionsChanges,
+};

.github/workflows/auto-label-pr.yml

@@ -12,6 +12,7 @@ permissions:
 
 env:
   SMALL_PR_THRESHOLD: 30
+  MEDIUM_PR_THRESHOLD: 100
   MAX_LABELS: 15
   TOO_BIG_THRESHOLD: 1000
   COMPONENT_LABEL_THRESHOLD: 10
@@ -26,7 +27,7 @@ jobs:
 
       - name: Generate a token
         id: generate-token
-        uses: actions/create-github-app-token@29824e69f54612133e76f7eaac726eef6c875baf # v2
+        uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859 # v2
         with:
           app-id: ${{ secrets.ESPHOME_GITHUB_APP_ID }}
           private-key: ${{ secrets.ESPHOME_GITHUB_APP_PRIVATE_KEY }}

.github/workflows/ci-api-proto.yml

@@ -62,7 +62,7 @@ jobs:
         run: git diff
       - if: failure()
         name: Archive artifacts
-        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         with:
           name: generated-proto-files
           path: |

.github/workflows/ci-clang-tidy-hash.yml

@@ -40,7 +40,7 @@ jobs:
           echo "You have modified clang-tidy configuration but have not updated the hash." | tee -a $GITHUB_STEP_SUMMARY
           echo "Please run 'script/clang_tidy_hash.py --update' and commit the changes." | tee -a $GITHUB_STEP_SUMMARY
 
-      - if: failure()
+      - if: failure() && github.event.pull_request.head.repo.full_name == github.repository
         name: Request changes
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:
@@ -53,7 +53,7 @@ jobs:
               body: 'You have modified clang-tidy configuration but have not updated the hash.\nPlease run `script/clang_tidy_hash.py --update` and commit the changes.'
             })
 
-      - if: success()
+      - if: success() && github.event.pull_request.head.repo.full_name == github.repository
         name: Dismiss review
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:

.github/workflows/ci-docker.yml

@@ -49,7 +49,7 @@ jobs:
         with:
           python-version: "3.11"
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
+        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Set TAG
         run: |

.github/workflows/ci.yml

@@ -47,7 +47,7 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
       - name: Restore Python virtual environment
         id: cache-venv
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: venv
           # yamllint disable-line rule:line-length
@@ -106,6 +106,7 @@ jobs:
           script/build_codeowners.py --check
           script/build_language_schema.py --check
           script/generate-esp32-boards.py --check
+          script/generate-rp2040-boards.py --check
 
   pytest:
     name: Run pytest
@@ -153,12 +154,12 @@ jobs:
           . venv/bin/activate
           pytest -vv --cov-report=xml --tb=native -n auto tests --ignore=tests/integration/
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@671740ac38dd9b0130fbe1cec585b89eea48d3de # v5.5.2
+        uses: codecov/codecov-action@57e3a136b779b570ffcdbf80b3bdc90e7fab3de2 # v6.0.0
         with:
           token: ${{ secrets.CODECOV_TOKEN }}
       - name: Save Python virtual environment cache
         if: github.ref == 'refs/heads/dev'
-        uses: actions/cache/save@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/save@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: venv
           key: ${{ runner.os }}-${{ steps.restore-python.outputs.python-version }}-venv-${{ needs.common.outputs.cache-key }}
@@ -170,6 +171,8 @@ jobs:
       - common
     outputs:
       integration-tests: ${{ steps.determine.outputs.integration-tests }}
+      integration-tests-run-all: ${{ steps.determine.outputs.integration-tests-run-all }}
+      integration-test-files: ${{ steps.determine.outputs.integration-test-files }}
       clang-tidy: ${{ steps.determine.outputs.clang-tidy }}
       clang-tidy-mode: ${{ steps.determine.outputs.clang-tidy-mode }}
       python-linters: ${{ steps.determine.outputs.python-linters }}
@@ -182,6 +185,7 @@ jobs:
       cpp-unit-tests-run-all: ${{ steps.determine.outputs.cpp-unit-tests-run-all }}
       cpp-unit-tests-components: ${{ steps.determine.outputs.cpp-unit-tests-components }}
       component-test-batches: ${{ steps.determine.outputs.component-test-batches }}
+      benchmarks: ${{ steps.determine.outputs.benchmarks }}
     steps:
       - name: Check out code from GitHub
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -194,7 +198,7 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
       - name: Restore components graph cache
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: .temp/components_graph.json
           key: components-graph-${{ hashFiles('esphome/components/**/*.py') }}
@@ -210,6 +214,8 @@ jobs:
 
           # Extract individual fields
           echo "integration-tests=$(echo "$output" | jq -r '.integration_tests')" >> $GITHUB_OUTPUT
+          echo "integration-tests-run-all=$(echo "$output" | jq -r '.integration_tests_run_all')" >> $GITHUB_OUTPUT
+          echo "integration-test-files=$(echo "$output" | jq -c '.integration_test_files')" >> $GITHUB_OUTPUT
           echo "clang-tidy=$(echo "$output" | jq -r '.clang_tidy')" >> $GITHUB_OUTPUT
           echo "clang-tidy-mode=$(echo "$output" | jq -r '.clang_tidy_mode')" >> $GITHUB_OUTPUT
           echo "python-linters=$(echo "$output" | jq -r '.python_linters')" >> $GITHUB_OUTPUT
@@ -222,9 +228,10 @@ jobs:
           echo "cpp-unit-tests-run-all=$(echo "$output" | jq -r '.cpp_unit_tests_run_all')" >> $GITHUB_OUTPUT
           echo "cpp-unit-tests-components=$(echo "$output" | jq -c '.cpp_unit_tests_components')" >> $GITHUB_OUTPUT
           echo "component-test-batches=$(echo "$output" | jq -c '.component_test_batches')" >> $GITHUB_OUTPUT
+          echo "benchmarks=$(echo "$output" | jq -r '.benchmarks')" >> $GITHUB_OUTPUT
       - name: Save components graph cache
         if: github.ref == 'refs/heads/dev'
-        uses: actions/cache/save@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/save@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: .temp/components_graph.json
           key: components-graph-${{ hashFiles('esphome/components/**/*.py') }}
@@ -246,7 +253,7 @@ jobs:
           python-version: "3.13"
       - name: Restore Python virtual environment
         id: cache-venv
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: venv
           key: ${{ runner.os }}-${{ steps.python.outputs.python-version }}-venv-${{ needs.common.outputs.cache-key }}
@@ -261,9 +268,20 @@ jobs:
       - name: Register matcher
         run: echo "::add-matcher::.github/workflows/matchers/pytest.json"
       - name: Run integration tests
+        env:
+          INTEGRATION_TEST_FILES: ${{ needs.determine-jobs.outputs.integration-test-files }}
+          INTEGRATION_TESTS_RUN_ALL: ${{ needs.determine-jobs.outputs.integration-tests-run-all }}
         run: |
           . venv/bin/activate
-          pytest -vv --no-cov --tb=native -n auto tests/integration/
+          if [[ "$INTEGRATION_TESTS_RUN_ALL" == "true" ]]; then
+            echo "Running all integration tests"
+            pytest -vv --no-cov --tb=native -n auto tests/integration/
+          else
+            # Parse JSON array into bash array to avoid shell expansion issues
+            mapfile -t test_files < <(echo "$INTEGRATION_TEST_FILES" | jq -r '.[]')
+            echo "Running ${#test_files[@]} specific integration tests"
+            pytest -vv --no-cov --tb=native -n auto "${test_files[@]}"
+          fi
 
   cpp-unit-tests:
     name: Run C++ unit tests
@@ -292,6 +310,40 @@ jobs:
             script/cpp_unit_test.py $ARGS
           fi
 
+  benchmarks:
+    name: Run CodSpeed benchmarks
+    runs-on: ubuntu-24.04
+    needs:
+      - common
+      - determine-jobs
+    if: >-
+      (github.event_name == 'push' && github.ref_name == 'dev') ||
+      (github.event_name == 'pull_request' && needs.determine-jobs.outputs.benchmarks == 'true')
+    steps:
+      - name: Check out code from GitHub
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - name: Restore Python
+        uses: ./.github/actions/restore-python
+        with:
+          python-version: ${{ env.DEFAULT_PYTHON }}
+          cache-key: ${{ needs.common.outputs.cache-key }}
+
+      - name: Build benchmarks
+        id: build
+        run: |
+          . venv/bin/activate
+          export BENCHMARK_LIB_CONFIG=$(python script/setup_codspeed_lib.py)
+          # --build-only prints BUILD_BINARY=<path> to stdout
+          BINARY=$(script/cpp_benchmark.py --all --build-only | grep '^BUILD_BINARY=' | tail -1 | cut -d= -f2-)
+          echo "binary=$BINARY" >> $GITHUB_OUTPUT
+
+      - name: Run CodSpeed benchmarks
+        uses: CodSpeedHQ/action@db35df748deb45fdef0960669f57d627c1956c30 # v4
+        with:
+          run: ${{ steps.build.outputs.binary }}
+          mode: simulation
+
   clang-tidy-single:
     name: ${{ matrix.name }}
     runs-on: ubuntu-24.04
@@ -335,14 +387,14 @@ jobs:
 
       - name: Cache platformio
         if: github.ref == 'refs/heads/dev'
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-${{ matrix.pio_cache_key }}-${{ hashFiles('platformio.ini') }}
 
       - name: Cache platformio
         if: github.ref != 'refs/heads/dev'
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-${{ matrix.pio_cache_key }}-${{ hashFiles('platformio.ini') }}
@@ -414,14 +466,14 @@ jobs:
 
       - name: Cache platformio
         if: github.ref == 'refs/heads/dev'
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-tidyesp32-${{ hashFiles('platformio.ini') }}
 
       - name: Cache platformio
         if: github.ref != 'refs/heads/dev'
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-tidyesp32-${{ hashFiles('platformio.ini') }}
@@ -503,14 +555,14 @@ jobs:
 
       - name: Cache platformio
         if: github.ref == 'refs/heads/dev'
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-tidyesp32-${{ hashFiles('platformio.ini') }}
 
       - name: Cache platformio
         if: github.ref != 'refs/heads/dev'
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-tidyesp32-${{ hashFiles('platformio.ini') }}
@@ -671,7 +723,7 @@ jobs:
           cache-key: ${{ needs.common.outputs.cache-key }}
       - uses: esphome/pre-commit-action@43cd1109c09c544d97196f7730ee5b2e0cc6d81e # v3.0.1 fork with pinned actions/cache
         env:
-          SKIP: pylint,clang-tidy-hash
+          SKIP: pylint,clang-tidy-hash,ci-custom
       - uses: pre-commit-ci/lite-action@5d6cc0eb514c891a40562a58a8e71576c5c7fb43 # v1.1.0
         if: always()
 
@@ -686,7 +738,7 @@ jobs:
       ram_usage: ${{ steps.extract.outputs.ram_usage }}
       flash_usage: ${{ steps.extract.outputs.flash_usage }}
       cache_hit: ${{ steps.cache-memory-analysis.outputs.cache-hit }}
-      skip: ${{ steps.check-script.outputs.skip }}
+      skip: ${{ steps.check-script.outputs.skip || steps.check-tests.outputs.skip }}
     steps:
       - name: Check out target branch
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
@@ -705,10 +757,39 @@ jobs:
             echo "::warning::ci_memory_impact_extract.py not found on target branch, skipping memory impact analysis"
           fi
 
-      # All remaining steps only run if script exists
+      # Check if test files exist on the target branch for the requested
+      # components and platform. When a PR adds new test files for a platform,
+      # the target branch won't have them yet, so skip instead of failing.
+      # This check must be done here (not in determine-jobs.py) because
+      # determine-jobs runs on the PR branch and cannot see what the target
+      # branch has.
+      - name: Check for test files on target branch
+        id: check-tests
+        if: steps.check-script.outputs.skip != 'true'
+        run: |
+          components='${{ toJSON(fromJSON(needs.determine-jobs.outputs.memory_impact).components) }}'
+          platform="${{ fromJSON(needs.determine-jobs.outputs.memory_impact).platform }}"
+          found=false
+          for component in $(echo "$components" | jq -r '.[]'); do
+            # Check for test files matching the platform (test.platform.yaml or test-*.platform.yaml)
+            for f in tests/components/${component}/test*.${platform}.yaml; do
+              if [ -f "$f" ]; then
+                found=true
+                break 2
+              fi
+            done
+          done
+          if [ "$found" = false ]; then
+            echo "skip=true" >> $GITHUB_OUTPUT
+            echo "::warning::No test files found on target branch for platform ${platform}, skipping memory impact analysis"
+          else
+            echo "skip=false" >> $GITHUB_OUTPUT
+          fi
+
+      # All remaining steps only run if script and tests exist
       - name: Generate cache key
         id: cache-key
-        if: steps.check-script.outputs.skip != 'true'
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true'
         run: |
           # Get the commit SHA of the target branch
           target_sha=$(git rev-parse HEAD)
@@ -735,14 +816,14 @@ jobs:
 
       - name: Restore cached memory analysis
         id: cache-memory-analysis
-        if: steps.check-script.outputs.skip != 'true'
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true'
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: memory-analysis-target.json
           key: ${{ steps.cache-key.outputs.cache-key }}
 
       - name: Cache status
-        if: steps.check-script.outputs.skip != 'true'
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true'
         run: |
           if [ "${{ steps.cache-memory-analysis.outputs.cache-hit }}" == "true" ]; then
             echo "✓ Cache hit! Using cached memory analysis results."
@@ -752,21 +833,21 @@ jobs:
           fi
 
       - name: Restore Python
-        if: steps.check-script.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
         uses: ./.github/actions/restore-python
         with:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
 
       - name: Cache platformio
-        if: steps.check-script.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-memory-${{ fromJSON(needs.determine-jobs.outputs.memory_impact).platform }}-${{ hashFiles('platformio.ini') }}
 
       - name: Build, compile, and analyze memory
-        if: steps.check-script.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true'
         id: build
         run: |
           . venv/bin/activate
@@ -787,7 +868,8 @@ jobs:
           python script/test_build_components.py \
             -e compile \
             -c "$component_list" \
-            -t "$platform" 2>&1 | \
+            -t "$platform" \
+            --base-only 2>&1 | \
             tee /dev/stderr | \
             python script/ci_memory_impact_extract.py \
               --output-env \
@@ -800,15 +882,15 @@ jobs:
             --platform "$platform"
 
       - name: Save memory analysis to cache
-        if: steps.check-script.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true' && steps.build.outcome == 'success'
-        uses: actions/cache/save@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true' && steps.cache-memory-analysis.outputs.cache-hit != 'true' && steps.build.outcome == 'success'
+        uses: actions/cache/save@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: memory-analysis-target.json
           key: ${{ steps.cache-key.outputs.cache-key }}
 
       - name: Extract memory usage for outputs
         id: extract
-        if: steps.check-script.outputs.skip != 'true'
+        if: steps.check-script.outputs.skip != 'true' && steps.check-tests.outputs.skip != 'true'
         run: |
           if [ -f memory-analysis-target.json ]; then
             ram=$(jq -r '.ram_bytes' memory-analysis-target.json)
@@ -822,7 +904,7 @@ jobs:
           fi
 
       - name: Upload memory analysis JSON
-        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         with:
           name: memory-analysis-target
           path: memory-analysis-target.json
@@ -848,7 +930,7 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
       - name: Cache platformio
-        uses: actions/cache/restore@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5.0.3
+        uses: actions/cache/restore@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: ~/.platformio
           key: platformio-memory-${{ fromJSON(needs.determine-jobs.outputs.memory_impact).platform }}-${{ hashFiles('platformio.ini') }}
@@ -873,7 +955,8 @@ jobs:
           python script/test_build_components.py \
             -e compile \
             -c "$component_list" \
-            -t "$platform" 2>&1 | \
+            -t "$platform" \
+            --base-only 2>&1 | \
             tee /dev/stderr | \
             python script/ci_memory_impact_extract.py \
               --output-env \
@@ -886,7 +969,7 @@ jobs:
             --platform "$platform"
 
       - name: Upload memory analysis JSON
-        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         with:
           name: memory-analysis-pr
           path: memory-analysis-pr.json
@@ -916,13 +999,13 @@ jobs:
           python-version: ${{ env.DEFAULT_PYTHON }}
           cache-key: ${{ needs.common.outputs.cache-key }}
       - name: Download target analysis JSON
-        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7.0.0
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           name: memory-analysis-target
           path: ./memory-analysis
         continue-on-error: true
       - name: Download PR analysis JSON
-        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7.0.0
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           name: memory-analysis-pr
           path: ./memory-analysis

.github/workflows/codeowner-approved-label-update.yml

@@ -0,0 +1,81 @@
+# Adds/removes a 'code-owner-approved' label when a component-specific
+# codeowner approves (or dismisses) a PR.
+#
+# Uses pull_request_target so that fork PRs do not require workflow approval.
+# The label is reconciled on every PR update; for review events specifically,
+# this means the label is applied on the next push after a codeowner review.
+
+name: Codeowner Approved Label
+
+on:
+  pull_request_target:
+    types: [opened, synchronize, reopened, ready_for_review]
+    branches-ignore:
+      - release
+      - beta
+
+permissions:
+  issues: write
+  pull-requests: read
+  contents: read
+
+jobs:
+  codeowner-approved:
+    name: Run
+    if: ${{ github.repository == 'esphome/esphome' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout base branch
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          ref: ${{ github.event.pull_request.base.sha }}
+          sparse-checkout: |
+            .github/scripts/codeowners.js
+            CODEOWNERS
+
+      - name: Check codeowner approval and update label
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        env:
+          PR_NUMBER: ${{ github.event.pull_request.number }}
+        with:
+          script: |
+            const { loadCodeowners, determineLabelAction, LabelAction } = require('./.github/scripts/codeowners.js');
+
+            const owner = context.repo.owner;
+            const repo = context.repo.repo;
+            const pr_number = parseInt(process.env.PR_NUMBER, 10);
+            const LABEL_NAME = 'code-owner-approved';
+
+            console.log(`Processing PR #${pr_number} for codeowner approval label`);
+
+            const codeownersPatterns = loadCodeowners();
+            const action = await determineLabelAction(
+              github, owner, repo, pr_number, codeownersPatterns, LABEL_NAME
+            );
+
+            if (action === LabelAction.NONE) {
+              console.log('No label change needed');
+              return;
+            }
+
+            try {
+              if (action === LabelAction.ADD) {
+                await github.rest.issues.addLabels({
+                  owner, repo, issue_number: pr_number, labels: [LABEL_NAME]
+                });
+                console.log(`Added '${LABEL_NAME}' label`);
+              } else if (action === LabelAction.REMOVE) {
+                await github.rest.issues.removeLabel({
+                  owner, repo, issue_number: pr_number, name: LABEL_NAME
+                });
+                console.log(`Removed '${LABEL_NAME}' label`);
+              }
+            } catch (error) {
+              if (error.status === 403) {
+                console.log(`Warning: insufficient permissions to update label (expected for fork PRs)`);
+              } else if (error.status === 404) {
+                console.log(`Label '${LABEL_NAME}' not present, nothing to remove`);
+              } else {
+                throw error;
+              }
+            }

.github/workflows/codeowner-review-request.yml

@@ -13,6 +13,9 @@ on:
   # Needs to be pull_request_target to get write permissions
   pull_request_target:
     types: [opened, reopened, synchronize, ready_for_review]
+    branches-ignore:
+      - release
+      - beta
 
 permissions:
   pull-requests: write
@@ -24,10 +27,17 @@ jobs:
     if: ${{ github.repository == 'esphome/esphome' && !github.event.pull_request.draft }}
     runs-on: ubuntu-latest
     steps:
+      - name: Checkout base branch
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+        with:
+          ref: ${{ github.event.pull_request.base.sha }}
+
       - name: Request reviews from component codeowners
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:
           script: |
+            const { loadCodeowners, getEffectiveOwners } = require('./.github/scripts/codeowners.js');
+
             const owner = context.repo.owner;
             const repo = context.repo.repo;
             const pr_number = context.payload.pull_request.number;
@@ -38,12 +48,15 @@ jobs:
             const BOT_COMMENT_MARKER = '<!-- codeowner-review-request-bot -->';
 
             try {
-              // Get the list of changed files in this PR
-              const { data: files } = await github.rest.pulls.listFiles({
-                owner,
-                repo,
-                pull_number: pr_number
-              });
+              // Get the list of changed files in this PR (with pagination)
+              const files = await github.paginate(
+                github.rest.pulls.listFiles,
+                {
+                  owner,
+                  repo,
+                  pull_number: pr_number
+                }
+              );
 
               const changedFiles = files.map(file => file.filename);
               console.log(`Found ${changedFiles.length} changed files`);
@@ -53,32 +66,10 @@ jobs:
                 return;
               }
 
-              // Fetch CODEOWNERS file from root
-              const { data: codeownersFile } = await github.rest.repos.getContent({
-                owner,
-                repo,
-                path: 'CODEOWNERS',
-                ref: context.payload.pull_request.base.sha
-              });
-              const codeownersContent = Buffer.from(codeownersFile.content, 'base64').toString('utf8');
+              // Parse CODEOWNERS from the checked-out base branch
+              const codeownersPatterns = loadCodeowners();
 
-              // Parse CODEOWNERS file to extract all patterns and their owners
-              const codeownersLines = codeownersContent.split('\n')
-                .map(line => line.trim())
-                .filter(line => line && !line.startsWith('#'));
-
-              const codeownersPatterns = [];
-
-              // Convert CODEOWNERS pattern to regex (robust glob handling)
-              function globToRegex(pattern) {
-                // Escape regex special characters except for glob wildcards
-                let regexStr = pattern
-                  .replace(/([.+^=!:${}()|[\]\\])/g, '\\$1') // escape regex chars
-                  .replace(/\*\*/g, '.*') // globstar
-                  .replace(/\*/g, '[^/]*') // single star
-                  .replace(/\?/g, '.'); // question mark
-                return new RegExp('^' + regexStr + '$');
-              }
+              console.log(`Parsed ${codeownersPatterns.length} codeowner patterns`);
 
               // Helper function to create comment body
               function createCommentBody(reviewersList, teamsList, matchedFileCount, isSuccessful = true) {
@@ -93,50 +84,11 @@ jobs:
                 }
               }
 
-              for (const line of codeownersLines) {
-                const parts = line.split(/\s+/);
-                if (parts.length < 2) continue;
-
-                const pattern = parts[0];
-                const owners = parts.slice(1);
-
-                // Use robust glob-to-regex conversion
-                const regex = globToRegex(pattern);
-                codeownersPatterns.push({ pattern, regex, owners });
-              }
-
-              console.log(`Parsed ${codeownersPatterns.length} codeowner patterns`);
-
-              // Match changed files against CODEOWNERS patterns
-              const matchedOwners = new Set();
-              const matchedTeams = new Set();
-              const fileMatches = new Map(); // Track which files matched which patterns
-
-              for (const file of changedFiles) {
-                for (const { pattern, regex, owners } of codeownersPatterns) {
-                  if (regex.test(file)) {
-                    console.log(`File '${file}' matches pattern '${pattern}' with owners: ${owners.join(', ')}`);
-
-                    if (!fileMatches.has(file)) {
-                      fileMatches.set(file, []);
-                    }
-                    fileMatches.get(file).push({ pattern, owners });
-
-                    // Add owners to the appropriate set (remove @ prefix)
-                    for (const owner of owners) {
-                      const cleanOwner = owner.startsWith('@') ? owner.slice(1) : owner;
-                      if (cleanOwner.includes('/')) {
-                        // Team mention (org/team-name)
-                        const teamName = cleanOwner.split('/')[1];
-                        matchedTeams.add(teamName);
-                      } else {
-                        // Individual user
-                        matchedOwners.add(cleanOwner);
-                      }
-                    }
-                  }
-                }
-              }
+              // Match changed files against CODEOWNERS patterns using last-match-wins semantics
+              const effective = getEffectiveOwners(changedFiles, codeownersPatterns);
+              const matchedOwners = effective.users;
+              const matchedTeams = effective.teams;
+              const matchedFileCount = effective.matchedFileCount;
 
               if (matchedOwners.size === 0 && matchedTeams.size === 0) {
                 console.log('No codeowners found for any changed files');
@@ -170,11 +122,14 @@ jobs:
               }
 
               // Check for completed reviews to avoid re-requesting users who have already reviewed
-              const { data: reviews } = await github.rest.pulls.listReviews({
-                owner,
-                repo,
-                pull_number: pr_number
-              });
+              const reviews = await github.paginate(
+                github.rest.pulls.listReviews,
+                {
+                  owner,
+                  repo,
+                  pull_number: pr_number
+                }
+              );
 
               const reviewedUsers = new Set();
               reviews.forEach(review => {
@@ -247,7 +202,7 @@ jobs:
               }
 
               const totalReviewers = reviewersList.length + teamsList.length;
-              console.log(`Requesting reviews from ${reviewersList.length} users and ${teamsList.length} teams for ${fileMatches.size} matched files`);
+              console.log(`Requesting reviews from ${reviewersList.length} users and ${teamsList.length} teams for ${matchedFileCount} matched files`);
 
               // Request reviews
               try {
@@ -279,7 +234,7 @@ jobs:
 
                 // Only add a comment if there are new codeowners to mention (not previously pinged)
                 if (reviewersList.length > 0 || teamsList.length > 0) {
-                  const commentBody = createCommentBody(reviewersList, teamsList, fileMatches.size, true);
+                  const commentBody = createCommentBody(reviewersList, teamsList, matchedFileCount, true);
 
                   await github.rest.issues.createComment({
                     owner,
@@ -297,7 +252,7 @@ jobs:
 
                   // Only try to add a comment if there are new codeowners to mention
                   if (reviewersList.length > 0 || teamsList.length > 0) {
-                    const commentBody = createCommentBody(reviewersList, teamsList, fileMatches.size, false);
+                    const commentBody = createCommentBody(reviewersList, teamsList, matchedFileCount, false);
 
                     try {
                       await github.rest.issues.createComment({

.github/workflows/codeql.yml

@@ -58,7 +58,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@45cbd0c69e560cd9e7cd7f8c32362050c9b7ded2 # v4.32.2
+        uses: github/codeql-action/init@c10b8064de6f491fea524254123dbe5e09572f13 # v4.35.1
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
@@ -86,6 +86,6 @@ jobs:
           exit 1
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@45cbd0c69e560cd9e7cd7f8c32362050c9b7ded2 # v4.32.2
+        uses: github/codeql-action/analyze@c10b8064de6f491fea524254123dbe5e09572f13 # v4.35.1
         with:
           category: "/language:${{matrix.language}}"

.github/workflows/pr-title-check.yml

@@ -0,0 +1,96 @@
+name: PR Title Check
+
+on:
+  pull_request:
+    types: [opened, edited, synchronize, reopened]
+    branches-ignore:
+      - release
+      - beta
+
+permissions:
+  contents: read
+  pull-requests: read
+
+jobs:
+  check:
+    name: Validate PR title
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+
+      - uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          script: |
+            const {
+              detectComponents,
+              hasCoreChanges,
+              hasDashboardChanges,
+              hasGitHubActionsChanges,
+            } = require('./.github/scripts/detect-tags.js');
+
+            const title = context.payload.pull_request.title;
+            const author = context.payload.pull_request.user.login;
+
+            // Skip bot PRs (e.g. dependabot) - they have their own title format
+            if (author === 'dependabot[bot]') {
+              return;
+            }
+
+            // Block titles starting with "word:" or "word(scope):" patterns
+            const commitStylePattern = /^\w+(\(.*?\))?[!]?\s*:/;
+            if (commitStylePattern.test(title)) {
+              core.setFailed(
+                `PR title should not start with a "prefix:" style format.\n` +
+                `Please use the format: [component] Brief description\n`
+              );
+              return;
+            }
+
+            // Get changed files to detect tags
+            const files = await github.paginate(github.rest.pulls.listFiles, {
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              pull_number: context.issue.number,
+            });
+            const filenames = files.map(f => f.filename);
+
+            // Detect tags from changed files using shared logic
+            const tags = new Set();
+
+            for (const comp of detectComponents(filenames)) {
+              tags.add(comp);
+            }
+            if (hasCoreChanges(filenames)) tags.add('core');
+            if (hasDashboardChanges(filenames)) tags.add('dashboard');
+            if (hasGitHubActionsChanges(filenames)) tags.add('ci');
+
+            if (tags.size === 0) {
+              return;
+            }
+
+            // Check for angle brackets not wrapped in backticks.
+            // Astro docs MDX treats bare < as JSX component opening tags.
+            const stripped = title.replace(/`[^`]*`/g, '');
+            if (/[<>]/.test(stripped)) {
+              core.setFailed(
+                'PR title contains `<` or `>` not wrapped in backticks.\n' +
+                'Astro docs MDX interprets bare `<` as JSX components.\n' +
+                'Please wrap angle brackets with backticks, e.g.: [component] Add `<feature>` support'
+              );
+              return;
+            }
+
+            // Check title starts with [tag] prefix
+            const bracketPattern = /^\[\w+\]/;
+            if (!bracketPattern.test(title)) {
+              const suggestion = [...tags].map(c => `[${c}]`).join('');
+              // Skip if the suggested prefix would be too long for a readable title
+              if (suggestion.length > 40) {
+                return;
+              }
+              core.setFailed(
+                `PR modifies: ${[...tags].join(', ')}\n` +
+                `Title must start with a [tag] prefix.\n` +
+                `Suggested: ${suggestion} <description>`
+              );
+            }

.github/workflows/release.yml

@@ -70,7 +70,7 @@ jobs:
           pip3 install build
           python3 -m build
       - name: Publish
-        uses: pypa/gh-action-pypi-publish@ed0c53931b1dc9bd32cbe73a98c7f6766f8a527e # v1.13.0
+        uses: pypa/gh-action-pypi-publish@cef221092ed1bacb1cc03d23a2d87d1d172e277b # v1.14.0
         with:
           skip-existing: true
 
@@ -99,15 +99,15 @@ jobs:
           python-version: "3.11"
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
+        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Log in to docker hub
-        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3.7.0
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4.1.0
         with:
           username: ${{ secrets.DOCKER_USER }}
           password: ${{ secrets.DOCKER_PASSWORD }}
       - name: Log in to the GitHub container registry
-        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3.7.0
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4.1.0
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
@@ -138,7 +138,7 @@ jobs:
       #     version: ${{ needs.init.outputs.tag }}
 
       - name: Upload digests
-        uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
+        uses: actions/upload-artifact@bbbca2ddaa5d8feaa63e36b76fdaad77386f024f # v7.0.0
         with:
           name: digests-${{ matrix.platform.arch }}
           path: /tmp/digests
@@ -171,24 +171,24 @@ jobs:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
 
       - name: Download digests
-        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7.0.0
+        uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v8.0.1
         with:
           pattern: digests-*
           path: /tmp/digests
           merge-multiple: true
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
+        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4.0.0
 
       - name: Log in to docker hub
         if: matrix.registry == 'dockerhub'
-        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3.7.0
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4.1.0
         with:
           username: ${{ secrets.DOCKER_USER }}
           password: ${{ secrets.DOCKER_PASSWORD }}
       - name: Log in to the GitHub container registry
         if: matrix.registry == 'ghcr'
-        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3.7.0
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4.1.0
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
@@ -221,7 +221,7 @@ jobs:
     steps:
       - name: Generate a token
         id: generate-token
-        uses: actions/create-github-app-token@29824e69f54612133e76f7eaac726eef6c875baf # v2.2.1
+        uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859 # v3.0.0
         with:
           app-id: ${{ secrets.ESPHOME_GITHUB_APP_ID }}
           private-key: ${{ secrets.ESPHOME_GITHUB_APP_PRIVATE_KEY }}
@@ -256,7 +256,7 @@ jobs:
     steps:
       - name: Generate a token
         id: generate-token
-        uses: actions/create-github-app-token@29824e69f54612133e76f7eaac726eef6c875baf # v2.2.1
+        uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859 # v3.0.0
         with:
           app-id: ${{ secrets.ESPHOME_GITHUB_APP_ID }}
           private-key: ${{ secrets.ESPHOME_GITHUB_APP_PRIVATE_KEY }}
@@ -287,7 +287,7 @@ jobs:
     steps:
       - name: Generate a token
         id: generate-token
-        uses: actions/create-github-app-token@29824e69f54612133e76f7eaac726eef6c875baf # v2.2.1
+        uses: actions/create-github-app-token@f8d387b68d61c58ab83c6c016672934102569859 # v3.0.0
         with:
           app-id: ${{ secrets.ESPHOME_GITHUB_APP_ID }}
           private-key: ${{ secrets.ESPHOME_GITHUB_APP_PRIVATE_KEY }}

.github/workflows/stale.yml

@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Stale
-        uses: actions/stale@997185467fa4f803885201cee163a9f38240193d # v10.1.1
+        uses: actions/stale@b5d41d4e1d5dceea10e7104786b73624c18a190f # v10.2.0
         with:
           debug-only: ${{ github.ref != 'refs/heads/dev' }} # Dry-run when not run on dev branch
           remove-stale-when-updated: true

.github/workflows/status-check-labels.yml

@@ -2,30 +2,29 @@ name: Status check labels
 
 on:
   pull_request:
-    types: [labeled, unlabeled]
+    types: [opened, reopened, labeled, unlabeled, synchronize]
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
 
 jobs:
   check:
-    name: Check ${{ matrix.label }}
+    name: Check blocking labels
     runs-on: ubuntu-latest
-    strategy:
-      fail-fast: false
-      matrix:
-        label:
-          - needs-docs
-          - merge-after-release
-          - chained-pr
     steps:
-      - name: Check for ${{ matrix.label }} label
+      - name: Check for blocking labels
         uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:
           script: |
+            const blockingLabels = ['needs-docs', 'merge-after-release', 'chained-pr'];
             const { data: labels } = await github.rest.issues.listLabelsOnIssue({
               owner: context.repo.owner,
               repo: context.repo.repo,
               issue_number: context.issue.number
             });
-            const hasLabel = labels.find(label => label.name === '${{ matrix.label }}');
-            if (hasLabel) {
-              core.setFailed('Pull request cannot be merged, it is labeled as ${{ matrix.label }}');
+            const labelNames = labels.map(l => l.name);
+            const found = blockingLabels.filter(bl => labelNames.includes(bl));
+            if (found.length > 0) {
+              core.setFailed(`Pull request cannot be merged, it has blocking label(s): ${found.join(', ')}`);
             }

.github/workflows/sync-device-classes.yml

@@ -24,7 +24,7 @@ jobs:
       - name: Setup Python
         uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
-          python-version: 3.13
+          python-version: "3.14"
 
       - name: Install Home Assistant
         run: |

.pre-commit-config.yaml

@@ -11,7 +11,7 @@ ci:
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.15.0
+    rev: v0.15.10
     hooks:
       # Run the linter.
       - id: ruff
@@ -37,7 +37,7 @@ repos:
       - id: end-of-file-fixer
       - id: trailing-whitespace
   - repo: https://github.com/asottile/pyupgrade
-    rev: v3.20.0
+    rev: v3.21.2
     hooks:
       - id: pyupgrade
         args: [--py311-plus]
@@ -65,3 +65,7 @@ repos:
         files: ^(\.clang-tidy|platformio\.ini|requirements_dev\.txt)$
         pass_filenames: false
         additional_dependencies: []
+      - id: ci-custom
+        name: ci-custom
+        entry: python3 script/run-in-env.py script/ci-custom.py
+        language: system

CODEOWNERS

@@ -54,6 +54,8 @@ esphome/components/atm90e32/* @circuitsetup @descipher
 esphome/components/audio/* @kahrendt
 esphome/components/audio_adc/* @kbx81
 esphome/components/audio_dac/* @kbx81
+esphome/components/audio_file/* @kahrendt
+esphome/components/audio_file/media_source/* @kahrendt
 esphome/components/axs15231/* @clydebarrow
 esphome/components/b_parasite/* @rbaron
 esphome/components/ballu/* @bazuchan
@@ -90,6 +92,7 @@ esphome/components/bmp3xx_i2c/* @latonita
 esphome/components/bmp3xx_spi/* @latonita
 esphome/components/bmp581_base/* @danielkent-net @kahrendt
 esphome/components/bmp581_i2c/* @danielkent-net @kahrendt
+esphome/components/bmp581_spi/* @danielkent-net @kahrendt
 esphome/components/bp1658cj/* @Cossid
 esphome/components/bp5758d/* @Cossid
 esphome/components/bthome_mithermometer/* @nagyrobi
@@ -130,6 +133,7 @@ esphome/components/dashboard_import/* @esphome/core
 esphome/components/datetime/* @jesserockz @rfdarter
 esphome/components/debug/* @esphome/core
 esphome/components/delonghi/* @grob6000
+esphome/components/dew_point/* @CFlix
 esphome/components/dfplayer/* @glmnet
 esphome/components/dfrobot_sen0395/* @niklasweber
 esphome/components/dht/* @OttoWinter
@@ -138,12 +142,13 @@ esphome/components/dlms_meter/* @SimonFischer04
 esphome/components/dps310/* @kbx81
 esphome/components/ds1307/* @badbadc0ffee
 esphome/components/ds2484/* @mrk-its
-esphome/components/dsmr/* @glmnet @PolarGoose @zuidwijk
+esphome/components/dsmr/* @glmnet @PolarGoose
 esphome/components/duty_time/* @dudanov
 esphome/components/ee895/* @Stock-M
 esphome/components/ektf2232/touchscreen/* @jesserockz
 esphome/components/emc2101/* @ellull
 esphome/components/emmeti/* @E440QF
+esphome/components/emontx/* @FredM67 @glynhudson @TrystanLea
 esphome/components/ens160/* @latonita
 esphome/components/ens160_base/* @latonita @vincentscode
 esphome/components/ens160_i2c/* @latonita
@@ -213,6 +218,8 @@ esphome/components/hbridge/light/* @DotNetDann
 esphome/components/hbridge/switch/* @dwmw2
 esphome/components/hc8/* @omartijn
 esphome/components/hdc2010/* @optimusprimespace @ssieb
+esphome/components/hdc2080/* @G-Pereira @jesserockz
+esphome/components/hdc302x/* @joshuasing
 esphome/components/he60r/* @clydebarrow
 esphome/components/heatpumpir/* @rob-deutsch
 esphome/components/hitachi_ac424/* @sourabhjaiswal
@@ -240,7 +247,6 @@ esphome/components/hyt271/* @Philippe12
 esphome/components/i2c/* @esphome/core
 esphome/components/i2c_device/* @gabest11
 esphome/components/i2s_audio/* @jesserockz
-esphome/components/i2s_audio/media_player/* @jesserockz
 esphome/components/i2s_audio/microphone/* @jesserockz
 esphome/components/i2s_audio/speaker/* @jesserockz @kahrendt
 esphome/components/iaqcore/* @yozik04
@@ -315,6 +321,7 @@ esphome/components/mcp9808/* @k7hpn
 esphome/components/md5/* @esphome/core
 esphome/components/mdns/* @esphome/core
 esphome/components/media_player/* @jesserockz
+esphome/components/media_source/* @kahrendt
 esphome/components/micro_wake_word/* @jesserockz @kahrendt
 esphome/components/micronova/* @edenhaus @jorre05
 esphome/components/microphone/* @jesserockz @kahrendt
@@ -325,6 +332,7 @@ esphome/components/mipi_dsi/* @clydebarrow
 esphome/components/mipi_rgb/* @clydebarrow
 esphome/components/mipi_spi/* @clydebarrow
 esphome/components/mitsubishi/* @RubyBailey
+esphome/components/mitsubishi_cn105/* @crnjan
 esphome/components/mixer/speaker/* @kahrendt
 esphome/components/mlx90393/* @functionpointer
 esphome/components/mlx90614/* @jesserockz
@@ -406,11 +414,13 @@ esphome/components/restart/* @esphome/core
 esphome/components/rf_bridge/* @jesserockz
 esphome/components/rgbct/* @jesserockz
 esphome/components/rp2040/* @jesserockz
+esphome/components/rp2040_ble/* @bdraco
 esphome/components/rp2040_pio_led_strip/* @Papa-DMan
 esphome/components/rp2040_pwm/* @jesserockz
 esphome/components/rpi_dpi_rgb/* @clydebarrow
 esphome/components/rtl87xx/* @kuba2k2
-esphome/components/rtttl/* @glmnet
+esphome/components/rtttl/* @glmnet @ximex
+esphome/components/runtime_image/* @clydebarrow @guillempages @kahrendt
 esphome/components/runtime_stats/* @bdraco
 esphome/components/rx8130/* @beormund
 esphome/components/safe_mode/* @jsuanet @kbx81 @paulmonigatti
@@ -427,8 +437,10 @@ esphome/components/select/* @esphome/core
 esphome/components/sen0321/* @notjj
 esphome/components/sen21231/* @shreyaskarnik
 esphome/components/sen5x/* @martgras
+esphome/components/sen6x/* @martgras @mebner86 @mikelawrence @tuct
 esphome/components/sensirion_common/* @martgras
 esphome/components/sensor/* @esphome/core
+esphome/components/serial_proxy/* @kbx81
 esphome/components/sfa30/* @ghsensdev
 esphome/components/sgp40/* @SenexCrenshaw
 esphome/components/sgp4x/* @martgras @SenexCrenshaw
@@ -449,8 +461,12 @@ esphome/components/sn74hc165/* @jesserockz
 esphome/components/socket/* @esphome/core
 esphome/components/sonoff_d1/* @anatoly-savchenkov
 esphome/components/sound_level/* @kahrendt
+esphome/components/spa06_base/* @danielkent-net
+esphome/components/spa06_i2c/* @danielkent-net
+esphome/components/spa06_spi/* @danielkent-net
 esphome/components/speaker/* @jesserockz @kahrendt
 esphome/components/speaker/media_player/* @kahrendt @synesthesiam
+esphome/components/speaker_source/* @kahrendt
 esphome/components/spi/* @clydebarrow @esphome/core
 esphome/components/spi_device/* @clydebarrow
 esphome/components/spi_led_strip/* @clydebarrow
@@ -581,6 +597,7 @@ esphome/components/xl9535/* @mreditor97
 esphome/components/xpt2046/touchscreen/* @nielsnl68 @numo68
 esphome/components/xxtea/* @clydebarrow
 esphome/components/zephyr/* @tomaszduda23
+esphome/components/zephyr_mcumgr/ota/* @tomaszduda23
 esphome/components/zhlt01/* @cfeenstra1024
 esphome/components/zigbee/* @tomaszduda23
 esphome/components/zio_ultrasonic/* @kahrendt

Doxyfile

@@ -48,7 +48,7 @@ PROJECT_NAME           = ESPHome
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = 2026.2.4
+PROJECT_NUMBER         = 2026.5.0-dev
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a

README.md

@@ -1,4 +1,4 @@
-# ESPHome [![Discord Chat](https://img.shields.io/discord/429907082951524364.svg)](https://discord.gg/KhAMKrd) [![GitHub release](https://img.shields.io/github/release/esphome/esphome.svg)](https://GitHub.com/esphome/esphome/releases/)
+# ESPHome [![Discord Chat](https://img.shields.io/discord/429907082951524364.svg)](https://discord.gg/KhAMKrd) [![GitHub release](https://img.shields.io/github/release/esphome/esphome.svg)](https://GitHub.com/esphome/esphome/releases/) [![CodSpeed](https://img.shields.io/endpoint?url=https://codspeed.io/badge.json)](https://codspeed.io/esphome/esphome)
 
 <a href="https://esphome.io/">
   <picture>

esphome/__main__.py

@@ -1,6 +1,7 @@
 # PYTHON_ARGCOMPLETE_OK
 import argparse
 from collections.abc import Callable
+from contextlib import suppress
 from datetime import datetime
 import functools
 import getpass
@@ -9,6 +10,8 @@ import logging
 import os
 from pathlib import Path
 import re
+import shutil
+import subprocess
 import sys
 import time
 from typing import Protocol
@@ -23,6 +26,7 @@ import esphome.codegen as cg
 from esphome.config import iter_component_configs, read_config, strip_default_ids
 from esphome.const import (
     ALLOWED_NAME_CHARS,
+    ARGUMENT_HELP_DEVICE,
     CONF_API,
     CONF_BAUD_RATE,
     CONF_BROKER,
@@ -43,7 +47,9 @@ from esphome.const import (
     CONF_SUBSTITUTIONS,
     CONF_TOPIC,
     ENV_NOGITIGNORE,
+    KEY_CORE,
     KEY_NATIVE_IDF,
+    KEY_TARGET_PLATFORM,
     PLATFORM_ESP32,
     PLATFORM_ESP8266,
     PLATFORM_RP2040,
@@ -55,7 +61,11 @@ from esphome.helpers import get_bool_env, indent, is_ip_address
 from esphome.log import AnsiFore, color, setup_log
 from esphome.types import ConfigType
 from esphome.util import (
+    PICOTOOL_PACKAGE,
+    detect_rp2040_bootsel,
+    get_picotool_path,
     get_serial_ports,
+    is_picotool_usb_permission_error,
     list_yaml_files,
     run_external_command,
     run_external_process,
@@ -64,9 +74,26 @@ from esphome.util import (
 
 _LOGGER = logging.getLogger(__name__)
 
+ESPHOME_COMMAND = [sys.executable, "-m", "esphome"]
+
 # Maximum buffer size for serial log reading to prevent unbounded memory growth
 SERIAL_BUFFER_MAX_SIZE = 65536
 
+_RP2040_BOOTSEL_INSTRUCTIONS = (
+    "To enter BOOTSEL mode:\n"
+    "  1. Unplug the device\n"
+    "  2. Hold the BOOT/BOOTSEL button\n"
+    "  3. Plug in the USB cable while holding the button\n"
+    "  4. Release the button - the device should appear as a USB drive (RPI-RP2)\n"
+    "Then run the upload command again."
+)
+
+_RP2040_UDEV_HINT = (
+    "You may need to add a udev rule for RP2040 devices. "
+    "See: https://github.com/raspberrypi/picotool"
+    "/blob/master/udev/60-picotool.rules"
+)
+
 # Special non-component keys that appear in configs
 _NON_COMPONENT_KEYS = frozenset(
     {
@@ -162,6 +189,7 @@ class PortType(StrEnum):
     NETWORK = "NETWORK"
     MQTT = "MQTT"
     MQTTIP = "MQTTIP"
+    BOOTSEL = "BOOTSEL"
 
 
 # Magic MQTT port types that require special handling
@@ -240,6 +268,19 @@ def choose_upload_log_host(
         (f"{port.path} ({port.description})", port.path) for port in get_serial_ports()
     ]
 
+    # Add RP2040 BOOTSEL device option when uploading
+    bootsel_permission_error = False
+    if (
+        purpose == Purpose.UPLOADING
+        and CORE.data.get(KEY_CORE, {}).get(KEY_TARGET_PLATFORM) == PLATFORM_RP2040
+        and (picotool := _find_picotool()) is not None
+    ):
+        bootsel = detect_rp2040_bootsel(picotool)
+        if bootsel.device_count > 0:
+            options.append(("RP2040 BOOTSEL (via picotool)", "BOOTSEL"))
+        elif bootsel.permission_error:
+            bootsel_permission_error = True
+
     if purpose == Purpose.LOGGING:
         if has_mqtt_logging():
             mqtt_config = CORE.config[CONF_MQTT]
@@ -257,6 +298,25 @@ def choose_upload_log_host(
         if has_mqtt_ip_lookup():
             options.append(("Over The Air (MQTT IP lookup)", "MQTTIP"))
 
+    # Show helpful BOOTSEL instructions for RP2040 when no BOOTSEL device is found
+    if (
+        purpose == Purpose.UPLOADING
+        and CORE.data.get(KEY_CORE, {}).get(KEY_TARGET_PLATFORM) == PLATFORM_RP2040
+        and not any(get_port_type(opt[1]) == PortType.BOOTSEL for opt in options)
+    ):
+        if bootsel_permission_error:
+            _LOGGER.warning(
+                "An RP2040 device in BOOTSEL mode was detected but could "
+                "not be accessed due to USB permissions."
+            )
+            if sys.platform.startswith("linux"):
+                _LOGGER.warning(_RP2040_UDEV_HINT)
+        if not options:
+            raise EsphomeError(
+                f"No RP2040 device found. {_RP2040_BOOTSEL_INSTRUCTIONS}"
+            )
+        _LOGGER.info("Tip: %s", _RP2040_BOOTSEL_INSTRUCTIONS)
+
     if check_default is not None and check_default in [opt[1] for opt in options]:
         return [check_default]
     return [choose_prompt(options, purpose=purpose)]
@@ -403,10 +463,13 @@ def get_port_type(port: str) -> PortType:
 
     Returns:
         PortType.SERIAL for serial ports (/dev/ttyUSB0, COM1, etc.)
+        PortType.BOOTSEL for RP2040 BOOTSEL upload via picotool
         PortType.MQTT for MQTT logging
         PortType.MQTTIP for MQTT IP lookup
         PortType.NETWORK for IP addresses, hostnames, or mDNS names
     """
+    if port == "BOOTSEL":
+        return PortType.BOOTSEL
     if port.startswith("/") or port.startswith("COM"):
         return PortType.SERIAL
     if port == "MQTT":
@@ -431,6 +494,14 @@ def run_miniterm(config: ConfigType, port: str, args) -> int:
         return 1
     _LOGGER.info("Starting log output from %s with baud rate %s", port, baud_rate)
 
+    process_stacktrace = None
+
+    try:
+        module = importlib.import_module("esphome.components." + CORE.target_platform)
+        process_stacktrace = getattr(module, "process_stacktrace")
+    except AttributeError:
+        pass
+
     backtrace_state = False
     ser = serial.Serial()
     ser.baudrate = baud_rate
@@ -472,9 +543,14 @@ def run_miniterm(config: ConfigType, port: str, args) -> int:
                             )
                             safe_print(parser.parse_line(line, time_str))
 
-                            backtrace_state = platformio_api.process_stacktrace(
-                                config, line, backtrace_state=backtrace_state
-                            )
+                            if process_stacktrace:
+                                backtrace_state = process_stacktrace(
+                                    config, line, backtrace_state
+                                )
+                            else:
+                                backtrace_state = platformio_api.process_stacktrace(
+                                    config, line, backtrace_state=backtrace_state
+                                )
                     except serial.SerialException:
                         _LOGGER.error("Serial port closed!")
                         return 0
@@ -614,6 +690,47 @@ def _check_and_emit_build_info() -> None:
     )
 
 
+def _get_configured_xtal_freq() -> int | None:
+    """Read the configured crystal frequency from the sdkconfig file."""
+    sdkconfig_path = CORE.relative_build_path(f"sdkconfig.{CORE.name}")
+    if not sdkconfig_path.is_file():
+        return None
+    with suppress(OSError, ValueError):
+        content = sdkconfig_path.read_text()
+        for line in content.splitlines():
+            if line.startswith("CONFIG_XTAL_FREQ="):
+                return int(line.split("=", 1)[1])
+    return None
+
+
+def _make_crystal_freq_callback(
+    configured_freq: int,
+) -> Callable[[str], str | None]:
+    """Create a callback that checks esptool crystal frequency output."""
+    crystal_re = re.compile(r"Crystal frequency:\s+(\d+)\s*MHz")
+
+    def check_crystal_line(line: str) -> str | None:
+        if not (match := crystal_re.search(line)):
+            return None
+        detected = int(match.group(1))
+        if detected == configured_freq:
+            return None
+        return (
+            f"\n\033[33mWARNING: Crystal frequency mismatch! "
+            f"Device reports {detected}MHz but firmware is configured "
+            f"for {configured_freq}MHz.\n"
+            f"UART logging and other clock-dependent features will not "
+            f"work correctly.\n"
+            f"Set the correct crystal frequency with sdkconfig_options:\n"
+            f"  esp32:\n"
+            f"    framework:\n"
+            f"      sdkconfig_options:\n"
+            f"        CONFIG_XTAL_FREQ_{detected}: 'y'\033[0m\n\n"
+        )
+
+    return check_crystal_line
+
+
 def upload_using_esptool(
     config: ConfigType, port: str, file: str, speed: int
 ) -> str | int:
@@ -642,6 +759,14 @@ def upload_using_esptool(
 
         mcu = get_esp32_variant().lower()
 
+    line_callbacks: list[Callable[[str], str | None]] = []
+    if (
+        CORE.is_esp32
+        and file is None
+        and (configured_freq := _get_configured_xtal_freq()) is not None
+    ):
+        line_callbacks.append(_make_crystal_freq_callback(configured_freq))
+
     def run_esptool(baud_rate):
         cmd = [
             "esptool",
@@ -666,9 +791,13 @@ def upload_using_esptool(
         if os.environ.get("ESPHOME_USE_SUBPROCESS") is None:
             import esptool
 
-            return run_external_command(esptool.main, *cmd)  # pylint: disable=no-member
+            return run_external_command(
+                esptool.main,  # pylint: disable=no-member
+                *cmd,
+                line_callbacks=line_callbacks,
+            )
 
-        return run_external_process(*cmd)
+        return run_external_process(*cmd, line_callbacks=line_callbacks)
 
     rc = run_esptool(first_baudrate)
     if rc == 0 or first_baudrate == 115200:
@@ -681,15 +810,140 @@ def upload_using_esptool(
     return run_esptool(115200)
 
 
-def upload_using_platformio(config: ConfigType, port: str):
+def upload_using_platformio(config: ConfigType, port: str) -> int:
     from esphome import platformio_api
 
+    # RP2040 platform-raspberrypi build recipe expects firmware.bin.signed for
+    # the upload target, but 'nobuild' skips the build phase that creates it.
+    # Create it here so the upload doesn't fail.
+    if CORE.data.get(KEY_CORE, {}).get(KEY_TARGET_PLATFORM) == PLATFORM_RP2040:
+        idedata = platformio_api.get_idedata(config)
+        build_dir = Path(idedata.firmware_elf_path).parent
+        firmware_bin = build_dir / "firmware.bin"
+        signed_bin = build_dir / "firmware.bin.signed"
+        if firmware_bin.is_file() and not signed_bin.is_file():
+            shutil.copy2(firmware_bin, signed_bin)
+
     upload_args = ["-t", "upload", "-t", "nobuild"]
     if port is not None:
         upload_args += ["--upload-port", port]
     return platformio_api.run_platformio_cli_run(config, CORE.verbose, *upload_args)
 
 
+def _find_picotool() -> Path | None:
+    """Find the picotool binary from PlatformIO packages."""
+    from esphome import platformio_api
+
+    try:
+        idedata = platformio_api.get_idedata(CORE.config)
+    except Exception:  # noqa: BLE001  # pylint: disable=broad-except
+        return None
+    return get_picotool_path(idedata.cc_path)
+
+
+def upload_using_picotool(config: ConfigType) -> int:
+    """Upload firmware to RP2040 in BOOTSEL mode using picotool.
+
+    Uses picotool to load the ELF firmware directly via USB, avoiding
+    the mass storage copy approach that causes "disk not ejected properly"
+    warnings on macOS.
+    """
+    from esphome import platformio_api
+
+    idedata = platformio_api.get_idedata(config)
+    firmware_elf = Path(idedata.firmware_elf_path)
+
+    if not firmware_elf.is_file():
+        _LOGGER.error(
+            "Firmware ELF file not found at %s. "
+            "Make sure the project has been compiled first.",
+            firmware_elf,
+        )
+        return 1
+
+    picotool = get_picotool_path(idedata.cc_path)
+    if picotool is None:
+        _LOGGER.error(
+            "picotool not found. Ensure the RP2040 PlatformIO platform "
+            "is installed (%s).",
+            PICOTOOL_PACKAGE,
+        )
+        return 1
+
+    _LOGGER.info("Uploading firmware to RP2040 via picotool...")
+    try:
+        # Don't capture stdout — let picotool write directly to the terminal
+        # so progress bars display in real-time with \r updates.
+        # Capture stderr only so we can detect permission errors.
+        result = subprocess.run(
+            [str(picotool), "load", "-v", "-x", str(firmware_elf)],
+            stderr=subprocess.PIPE,
+            timeout=60,
+            check=False,
+        )
+    except subprocess.TimeoutExpired:
+        _LOGGER.error("picotool upload timed out after 60 seconds.")
+        return 1
+    except OSError as err:
+        _LOGGER.error("Failed to run picotool: %s", err)
+        return 1
+
+    if result.returncode != 0:
+        stderr = result.stderr.decode("utf-8", errors="replace").strip()
+        if stderr:
+            for line in stderr.splitlines():
+                safe_print(line)
+        if is_picotool_usb_permission_error(stderr):
+            msg = "Permission denied accessing USB device."
+            if sys.platform.startswith("linux"):
+                msg += f" {_RP2040_UDEV_HINT}"
+            _LOGGER.error(msg)
+        else:
+            _LOGGER.error("picotool upload failed (exit code %d).", result.returncode)
+        return 1
+
+    return 0
+
+
+def _wait_for_serial_port(
+    port: str | None = None,
+    timeout: float = 30.0,
+    known_ports: set[str] | None = None,
+) -> None:
+    """Wait for a serial port to appear, e.g. after a device reboot.
+
+    USB-CDC devices disappear briefly after flashing while the device
+    reboots and re-enumerates on the USB bus.
+
+    If port is given, wait for that specific path. If known_ports is
+    given, wait for a new port that wasn't in the set. Otherwise wait
+    for any serial port to appear.
+    """
+
+    def _port_found() -> bool:
+        if port is not None:
+            if os.name == "posix":
+                return os.path.exists(port)
+            return any(p.path == port for p in get_serial_ports())
+        ports = get_serial_ports()
+        if known_ports is not None:
+            return any(p.path not in known_ports for p in ports)
+        return bool(ports)
+
+    if _port_found():
+        return
+    if port is not None:
+        _LOGGER.info("Waiting for %s to come online...", port)
+    else:
+        _LOGGER.info("Waiting for device to reboot...")
+    start = time.monotonic()
+    while time.monotonic() - start < timeout:
+        time.sleep(0.05)
+        if _port_found():
+            time.sleep(0.05)
+            return
+
+
 def check_permissions(port: str):
     if os.name == "posix" and get_port_type(port) == PortType.SERIAL:
         # Check if we can open selected serial port
@@ -719,7 +973,15 @@ def upload_program(
     except AttributeError:
         pass
 
-    if get_port_type(host) == PortType.SERIAL:
+    port_type = get_port_type(host)
+
+    if port_type == PortType.BOOTSEL:
+        exit_code = upload_using_picotool(config)
+        # Return None for device - BOOTSEL can't be used for logging,
+        # so command_run will show the interactive chooser for log source
+        return exit_code, None
+
+    if port_type == PortType.SERIAL:
         check_permissions(host)
 
         exit_code = 1
@@ -773,6 +1035,7 @@ def show_logs(config: ConfigType, args: ArgsProtocol, devices: list[str]) -> int
     port_type = get_port_type(port)
 
     if port_type == PortType.SERIAL:
+        _wait_for_serial_port(port)
         check_permissions(port)
         return run_miniterm(config, port, args)
 
@@ -783,7 +1046,11 @@ def show_logs(config: ConfigType, args: ArgsProtocol, devices: list[str]) -> int
     ):
         from esphome.components.api.client import run_logs
 
-        return run_logs(config, network_devices)
+        return run_logs(
+            config,
+            network_devices,
+            subscribe_states=not getattr(args, "no_states", False),
+        )
 
     if port_type in (PortType.NETWORK, PortType.MQTT) and has_mqtt_logging():
         from esphome import mqtt
@@ -816,7 +1083,7 @@ def command_config(args: ArgsProtocol, config: ConfigType) -> int | None:
     # add the console decoration so the front-end can hide the secrets
     if not args.show_secrets:
         output = re.sub(
-            r"(password|key|psk|ssid)\: (.+)", r"\1: \\033[5m\2\\033[6m", output
+            r"(password|key|psk|ssid)\: (.+)", r"\1: \\033[8m\2\\033[28m", output
         )
     if not CORE.quiet:
         safe_print(output)
@@ -911,6 +1178,9 @@ def command_run(args: ArgsProtocol, config: ConfigType) -> int | None:
         purpose=Purpose.UPLOADING,
     )
 
+    # Snapshot current serial ports before upload so we can detect new ones
+    pre_upload_ports = {p.path for p in get_serial_ports()}
+
     exit_code, successful_device = upload_program(config, args, devices)
     if exit_code == 0:
         _LOGGER.info("Successfully uploaded program.")
@@ -921,6 +1191,19 @@ def command_run(args: ArgsProtocol, config: ConfigType) -> int | None:
     if args.no_logs:
         return 0
 
+    # After BOOTSEL upload, wait for a new serial port to appear
+    # so it shows up in the log chooser
+    if (
+        successful_device is None
+        and CORE.data.get(KEY_CORE, {}).get(KEY_TARGET_PLATFORM) == PLATFORM_RP2040
+    ):
+        _wait_for_serial_port(known_ports=pre_upload_ports)
+        # If exactly one new serial port appeared, use it directly
+        serial_ports = get_serial_ports()
+        new_ports = [p for p in serial_ports if p.path not in pre_upload_ports]
+        if len(new_ports) == 1:
+            successful_device = new_ports[0].path
+
     # For logs, prefer the device we successfully uploaded to
     devices = choose_upload_log_host(
         default=successful_device,
@@ -959,6 +1242,38 @@ def command_clean(args: ArgsProtocol, config: ConfigType) -> int | None:
     return 0
 
 
+def command_bundle(args: ArgsProtocol, config: ConfigType) -> int | None:
+    from esphome.bundle import BUNDLE_EXTENSION, ConfigBundleCreator
+
+    creator = ConfigBundleCreator(config)
+
+    if args.list_only:
+        files = creator.discover_files()
+        for bf in sorted(files, key=lambda f: f.path):
+            safe_print(f"  {bf.path}")
+        _LOGGER.info("Found %d files", len(files))
+        return 0
+
+    result = creator.create_bundle()
+
+    if args.output:
+        output_path = Path(args.output)
+    else:
+        stem = CORE.config_path.stem
+        output_path = CORE.config_dir / f"{stem}{BUNDLE_EXTENSION}"
+
+    output_path.parent.mkdir(parents=True, exist_ok=True)
+    output_path.write_bytes(result.data)
+
+    _LOGGER.info(
+        "Bundle created: %s (%d files, %.1f KB)",
+        output_path,
+        len(result.files),
+        len(result.data) / 1024,
+    )
+    return 0
+
+
 def command_dashboard(args: ArgsProtocol) -> int | None:
     from esphome.dashboard import dashboard
 
@@ -1030,9 +1345,8 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     files = list_yaml_files(args.configuration)
 
     def build_command(f):
-        if CORE.dashboard:
-            return ["esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"]
-        return ["esphome", "run", f, "--no-logs", "--device", "OTA"]
+        dashboard = ["--dashboard"] if CORE.dashboard else []
+        return [*ESPHOME_COMMAND, *dashboard, "run", f, "--no-logs", "--device", "OTA"]
 
     return run_multiple_configs(files, build_command)
 
@@ -1181,7 +1495,7 @@ def command_rename(args: ArgsProtocol, config: ConfigType) -> int | None:
 
     new_path.write_text(new_raw, encoding="utf-8")
 
-    rc = run_external_process("esphome", "config", str(new_path))
+    rc = run_external_process(*ESPHOME_COMMAND, "config", str(new_path))
     if rc != 0:
         print(color(AnsiFore.BOLD_RED, "Rename failed. Reverting changes."))
         new_path.unlink()
@@ -1199,7 +1513,7 @@ def command_rename(args: ArgsProtocol, config: ConfigType) -> int | None:
         cli_args.insert(0, "--dashboard")
 
     try:
-        rc = run_external_process("esphome", *cli_args)
+        rc = run_external_process(*ESPHOME_COMMAND, *cli_args)
     except KeyboardInterrupt:
         rc = 1
     if rc != 0:
@@ -1235,6 +1549,7 @@ POST_CONFIG_ACTIONS = {
     "rename": command_rename,
     "discover": command_discover,
     "analyze-memory": command_analyze_memory,
+    "bundle": command_bundle,
 }
 
 SIMPLE_CONFIG_ACTIONS = [
@@ -1354,7 +1669,7 @@ def parse_args(argv):
     parser_upload.add_argument(
         "--device",
         action="append",
-        help="Manually specify the serial port/address to use, for example /dev/ttyUSB0. Can be specified multiple times for fallback addresses.",
+        help=ARGUMENT_HELP_DEVICE,
     )
     parser_upload.add_argument(
         "--upload_speed",
@@ -1377,7 +1692,7 @@ def parse_args(argv):
     parser_logs.add_argument(
         "--device",
         action="append",
-        help="Manually specify the serial port/address to use, for example /dev/ttyUSB0. Can be specified multiple times for fallback addresses.",
+        help=ARGUMENT_HELP_DEVICE,
     )
     parser_logs.add_argument(
         "--reset",
@@ -1386,6 +1701,11 @@ def parse_args(argv):
         help="Reset the device before starting serial logs.",
         default=os.getenv("ESPHOME_SERIAL_LOGGING_RESET"),
     )
+    parser_logs.add_argument(
+        "--no-states",
+        action="store_true",
+        help="Do not show entity state changes in log output.",
+    )
 
     parser_discover = subparsers.add_parser(
         "discover",
@@ -1407,7 +1727,7 @@ def parse_args(argv):
     parser_run.add_argument(
         "--device",
         action="append",
-        help="Manually specify the serial port/address to use, for example /dev/ttyUSB0. Can be specified multiple times for fallback addresses.",
+        help=ARGUMENT_HELP_DEVICE,
     )
     parser_run.add_argument(
         "--upload_speed",
@@ -1531,6 +1851,24 @@ def parse_args(argv):
         "configuration", help="Your YAML configuration file(s).", nargs="+"
     )
 
+    parser_bundle = subparsers.add_parser(
+        "bundle",
+        help="Create a self-contained config bundle for remote compilation.",
+    )
+    parser_bundle.add_argument(
+        "configuration", help="Your YAML configuration file(s).", nargs="+"
+    )
+    parser_bundle.add_argument(
+        "-o",
+        "--output",
+        help="Output path for the bundle archive.",
+    )
+    parser_bundle.add_argument(
+        "--list-only",
+        help="List discovered files without creating the archive.",
+        action="store_true",
+    )
+
     # Keep backward compatibility with the old command line format of
     # esphome <config> <command>.
     #
@@ -1596,7 +1934,7 @@ def run_esphome(argv):
         # argv[0] is the program path, skip it since we prefix with "esphome"
         def build_command(f):
             return (
-                ["esphome"]
+                [*ESPHOME_COMMAND]
                 + [arg for arg in argv[1:] if arg not in args.configuration]
                 + [str(f)]
             )
@@ -1609,6 +1947,16 @@ def run_esphome(argv):
         _LOGGER.warning("Skipping secrets file %s", conf_path)
         return 0
 
+    # Bundle support: if the configuration is a .esphomebundle, extract it
+    # and rewrite conf_path to the extracted YAML config.
+    from esphome.bundle import is_bundle_path, prepare_bundle_for_compile
+
+    if is_bundle_path(conf_path):
+        _LOGGER.info("Extracting config bundle %s...", conf_path)
+        conf_path = prepare_bundle_for_compile(conf_path)
+        # Update the argument so downstream code sees the extracted path
+        args.configuration[0] = str(conf_path)
+
     CORE.config_path = conf_path
     CORE.dashboard = args.dashboard
 

esphome/analyze_memory/__init__.py

@@ -1,6 +1,6 @@
 """Memory usage analyzer for ESPHome compiled binaries."""
 
-from collections import defaultdict
+from collections import Counter, defaultdict
 from dataclasses import dataclass, field
 import logging
 from pathlib import Path
@@ -40,6 +40,15 @@ _READELF_SECTION_PATTERN = re.compile(
     r"\s*\[\s*\d+\]\s+([\.\w]+)\s+\w+\s+[\da-fA-F]+\s+[\da-fA-F]+\s+([\da-fA-F]+)"
 )
 
+# Regex for extracting call targets from objdump disassembly
+# Matches direct call instructions across architectures:
+#   Xtensa: call0/call4/call8/call12/callx0/callx4/callx8/callx12 <addr> <symbol>
+#   ARM:    bl/blx <addr> <symbol>
+# Captures the mangled symbol name inside angle brackets.
+_CALL_TARGET_PATTERN = re.compile(
+    r"\t(?:call(?:0|4|8|12)|callx(?:0|4|8|12)|blx?)\s+[\da-fA-F]+ <([^>]+)>"
+)
+
 # Component category prefixes
 _COMPONENT_PREFIX_ESPHOME = "[esphome]"
 _COMPONENT_PREFIX_EXTERNAL = "[external]"
@@ -47,6 +56,10 @@ _COMPONENT_PREFIX_LIB = "[lib]"
 _COMPONENT_CORE = f"{_COMPONENT_PREFIX_ESPHOME}core"
 _COMPONENT_API = f"{_COMPONENT_PREFIX_ESPHOME}api"
 
+# Placement new storage suffix (generated by codegen Pvariable)
+_PSTORAGE_SUFFIX = "__pstorage"
+
+
 # C++ namespace prefixes
 _NAMESPACE_ESPHOME = "esphome::"
 _NAMESPACE_STD = "std::"
@@ -192,20 +205,27 @@ class MemoryAnalyzer:
         self._cswtch_symbols: list[tuple[str, int, str, str]] = []
         # Library symbol mapping: symbol_name -> library_name
         self._lib_symbol_map: dict[str, str] = {}
+        # Source file symbol mapping: symbol_name -> component_name
+        # Used for extern "C" and other symbols without C++ namespace
+        self._source_symbol_map: dict[str, str] = {}
         # Library dir to name mapping: "lib641" -> "espsoftwareserial",
         # "espressif__mdns" -> "mdns"
         self._lib_hash_to_name: dict[str, str] = {}
         # Heuristic category to library redirect: "mdns_lib" -> "[lib]mdns"
         self._heuristic_to_lib: dict[str, str] = {}
+        # Function call counts: mangled_name -> call_count
+        self._function_call_counts: Counter[str] = Counter()
 
     def analyze(self) -> dict[str, ComponentMemory]:
         """Analyze the ELF file and return component memory usage."""
         self._parse_sections()
         self._parse_symbols()
         self._scan_libraries()
+        self._scan_source_symbols()
         self._categorize_symbols()
         self._analyze_cswtch_symbols()
         self._analyze_sdk_libraries()
+        self._analyze_function_calls()
         return dict(self.components)
 
     def _parse_sections(self) -> None:
@@ -316,6 +336,13 @@ class MemoryAnalyzer:
         # Demangle C++ names if needed
         demangled = self._demangle_symbol(symbol_name)
 
+        # Check for placement new storage symbols (generated by codegen)
+        # Format: {component}__{id}__pstorage
+        if demangled.endswith(_PSTORAGE_SUFFIX) and (
+            component := self._match_pstorage_component(demangled)
+        ):
+            return component
+
         # Check for special component classes first (before namespace pattern)
         # This handles cases like esphome::ESPHomeOTAComponent which should map to ota
         if _NAMESPACE_ESPHOME in demangled:
@@ -351,6 +378,11 @@ class MemoryAnalyzer:
         if lib_name := self._lib_symbol_map.get(symbol_name):
             return f"{_COMPONENT_PREFIX_LIB}{lib_name}"
 
+        # Check source file mapping (catches extern "C" functions in ESPHome sources)
+        # Must be before heuristic patterns since source attribution is authoritative
+        if component := self._source_symbol_map.get(symbol_name):
+            return component
+
         # Check against symbol patterns
         for component, patterns in SYMBOL_PATTERNS.items():
             if any(pattern in symbol_name for pattern in patterns):
@@ -378,14 +410,33 @@ class MemoryAnalyzer:
         # Track uncategorized symbols for analysis
         return "other"
 
+    def _match_pstorage_component(self, symbol_name: str) -> str | None:
+        """Match a __pstorage symbol to its ESPHome component.
+
+        Symbol format: {component}__{id}__pstorage
+        The component namespace is embedded by codegen before the double underscore.
+        """
+        prefix = symbol_name[: -len(_PSTORAGE_SUFFIX)]
+        # Extract component namespace before the first double underscore
+        dunder_pos = prefix.find("__")
+        if dunder_pos == -1:
+            return None
+        component_name = prefix[:dunder_pos]
+        if component_name in get_esphome_components():
+            return f"{_COMPONENT_PREFIX_ESPHOME}{component_name}"
+        if component_name in self.external_components:
+            return f"{_COMPONENT_PREFIX_EXTERNAL}{component_name}"
+        return None
+
     def _batch_demangle_symbols(self, symbols: list[str]) -> None:
         """Batch demangle C++ symbol names for efficiency."""
         if not symbols:
             return
 
         _LOGGER.info("Demangling %d symbols", len(symbols))
-        self._demangle_cache = batch_demangle(symbols, objdump_path=self.objdump_path)
-        _LOGGER.info("Successfully demangled %d symbols", len(self._demangle_cache))
+        demangled = batch_demangle(symbols, objdump_path=self.objdump_path)
+        self._demangle_cache.update(demangled)
+        _LOGGER.info("Successfully demangled %d symbols", len(demangled))
 
     def _demangle_symbol(self, symbol: str) -> str:
         """Get demangled C++ symbol name from cache."""
@@ -640,6 +691,7 @@ class MemoryAnalyzer:
             return None
 
         symbol_map: dict[str, str] = {}
+        source_symbol_map: dict[str, str] = {}
         current_symbol: str | None = None
         section_prefixes = (".text.", ".rodata.", ".data.", ".bss.", ".literal.")
 
@@ -675,9 +727,18 @@ class MemoryAnalyzer:
                     if dir_key in source_path:
                         symbol_map[current_symbol] = lib_name
                         break
+                else:
+                    # Map ESPHome source files to components for extern "C"
+                    # and other symbols without C++ namespace
+                    component = self._source_file_to_component(source_path)
+                    if component.startswith(
+                        (_COMPONENT_PREFIX_ESPHOME, _COMPONENT_PREFIX_EXTERNAL)
+                    ):
+                        source_symbol_map[current_symbol] = component
 
             current_symbol = None
 
+        self._source_symbol_map = source_symbol_map
         return symbol_map or None
 
     def _scan_libraries(self) -> None:
@@ -728,6 +789,112 @@ class MemoryAnalyzer:
             len(libraries),
         )
 
+    def _scan_source_symbols(self) -> None:
+        """Scan ESPHome source object files to map extern "C" symbols to components.
+
+        When no linker map file is available, this uses ``nm`` to scan ``.o`` files
+        under ``src/esphome/`` and build a symbol-to-component mapping. This catches
+        ``extern "C"`` functions and other symbols that lack C++ namespace prefixes.
+
+        Skips scanning if ``_source_symbol_map`` was already populated by
+        ``_parse_map_file()``.
+        """
+        if self._source_symbol_map or not self.nm_path:
+            return
+
+        obj_dir = self._find_object_files_dir()
+        if obj_dir is None:
+            return
+
+        # Find ESPHome source object files
+        esphome_src_dir = obj_dir / "src" / "esphome"
+        if not esphome_src_dir.is_dir():
+            return
+
+        obj_files = sorted(esphome_src_dir.rglob("*.o"))
+        if not obj_files:
+            return
+
+        # Run nm with --print-file-name to get file:symbol mapping
+        result = run_tool(
+            [self.nm_path, "--print-file-name", "-g", "--defined-only"]
+            + [str(f) for f in obj_files],
+        )
+        if result is None or result.returncode != 0:
+            _LOGGER.debug("nm scan of source objects failed")
+            return
+
+        self._source_symbol_map = self._parse_nm_source_output(result.stdout, obj_dir)
+        if self._source_symbol_map:
+            _LOGGER.info(
+                "Built source symbol map from nm: %d symbols",
+                len(self._source_symbol_map),
+            )
+
+    def _parse_nm_source_output(self, output: str, base_dir: Path) -> dict[str, str]:
+        """Parse nm output to map non-namespaced symbols to ESPHome components.
+
+        Extracts global defined symbols from ESPHome source object files that
+        don't use C++ namespacing (e.g. ``extern "C"`` functions).
+
+        Args:
+            output: Raw stdout from ``nm --print-file-name -g --defined-only``
+                or ``nm --print-file-name -S``.
+            base_dir: Build directory for computing relative paths.
+
+        Returns:
+            Dict mapping symbol names to component names.
+        """
+        source_map: dict[str, str] = {}
+        for line in output.splitlines():
+            # Format: /path/to/file.o: addr type name
+            #     or: /path/to/file.o: addr size type name (with -S)
+            colon_idx = line.rfind(".o:")
+            if colon_idx == -1:
+                continue
+
+            file_path = line[: colon_idx + 2]
+            fields = line[colon_idx + 3 :].split()
+            if len(fields) < 3:
+                continue
+
+            # With -S flag, format is: addr size type name
+            # Without -S flag: addr type name
+            # type is a single char; size is hex digits
+            # Detect by checking if fields[1] is a single uppercase letter (type)
+            if len(fields[1]) == 1 and fields[1].isalpha():
+                # addr type name
+                sym_type = fields[1]
+                symbol_name = fields[2]
+            elif len(fields) >= 4:
+                # addr size type name
+                sym_type = fields[2]
+                symbol_name = fields[3]
+            else:
+                continue
+
+            # Only global defined symbols (uppercase type)
+            if not sym_type.isupper() or sym_type == "U":
+                continue
+
+            # Skip symbols already in esphome:: namespace
+            if symbol_name.startswith("_ZN7esphome"):
+                continue
+
+            # Make path relative to base_dir for _source_file_to_component
+            try:
+                rel_path = str(Path(file_path).relative_to(base_dir))
+            except ValueError:
+                continue
+
+            component = self._source_file_to_component(rel_path)
+            if component.startswith(
+                (_COMPONENT_PREFIX_ESPHOME, _COMPONENT_PREFIX_EXTERNAL)
+            ):
+                source_map[symbol_name] = component
+
+        return source_map
+
     def _find_object_files_dir(self) -> Path | None:
         """Find the directory containing object files for this build.
 
@@ -1011,6 +1178,43 @@ class MemoryAnalyzer:
             total_size,
         )
 
+    def _analyze_function_calls(self) -> None:
+        """Count function call sites by parsing disassembly output.
+
+        Parses direct call instructions (call0/call8/bl/blx) from objdump -d
+        to count how many times each function is called. This helps identify
+        inlining candidates — frequently called small functions benefit most
+        from inlining.
+        """
+        result = run_tool(
+            [self.objdump_path, "-d", str(self.elf_path)],
+            timeout=60,
+        )
+        if result is None or result.returncode != 0:
+            _LOGGER.debug("Failed to disassemble ELF for function call analysis")
+            return
+
+        self._function_call_counts = Counter(
+            match.group(1)
+            for line in result.stdout.splitlines()
+            if (match := _CALL_TARGET_PATTERN.search(line))
+        )
+
+        # Demangle any call targets not already in the cache
+        missing = [
+            name
+            for name in self._function_call_counts
+            if name not in self._demangle_cache
+        ]
+        if missing:
+            self._batch_demangle_symbols(missing)
+
+        _LOGGER.debug(
+            "Function call analysis: %d unique targets, %d total calls",
+            len(self._function_call_counts),
+            sum(self._function_call_counts.values()),
+        )
+
     def get_unattributed_ram(self) -> tuple[int, int, int]:
         """Get unattributed RAM sizes (SDK/framework overhead).
 

esphome/analyze_memory/cli.py

@@ -15,6 +15,7 @@ from . import (
     _COMPONENT_PREFIX_ESPHOME,
     _COMPONENT_PREFIX_EXTERNAL,
     _COMPONENT_PREFIX_LIB,
+    _PSTORAGE_SUFFIX,
     RAM_SECTIONS,
     MemoryAnalyzer,
 )
@@ -23,6 +24,17 @@ if TYPE_CHECKING:
     from . import ComponentMemory
 
 
+def _format_pstorage_name(name: str) -> str:
+    """Format a __pstorage symbol as 'storage for {id}'."""
+    if not name.endswith(_PSTORAGE_SUFFIX):
+        return name
+    prefix = name[: -len(_PSTORAGE_SUFFIX)]
+    # Strip component namespace prefix: {component}__{id} -> {id}
+    dunder_pos = prefix.find("__")
+    var_id = prefix[dunder_pos + 2 :] if dunder_pos != -1 else prefix
+    return f"storage for {var_id}"
+
+
 class MemoryAnalyzerCLI(MemoryAnalyzer):
     """Memory analyzer with CLI-specific report generation."""
 
@@ -148,11 +160,14 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
         If section is one of the RAM sections (.data or .bss), a label like
         " [data]" or " [bss]" is appended. For non-RAM sections or when
         section is None, no section label is added.
+
+        Placement new storage symbols are formatted as "storage for {id}".
         """
+        display_name = _format_pstorage_name(demangled)
         section_label = ""
         if section in RAM_SECTIONS:
             section_label = f" [{section[1:]}]"  # .data -> [data], .bss -> [bss]
-        return f"{demangled} ({size:,} B){section_label}"
+        return f"{display_name} ({size:,} B){section_label}"
 
     def _add_top_symbols(self, lines: list[str]) -> None:
         """Add a section showing the top largest symbols in the binary."""
@@ -175,11 +190,13 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
         for i, (_, demangled, size, section, component) in enumerate(top_symbols):
             # Format section label
             section_label = f"[{section[1:]}]" if section else ""
-            # Truncate demangled name if too long
+            # Format storage symbols readably
+            display_name = _format_pstorage_name(demangled)
+            # Truncate if too long
             demangled_display = (
-                f"{demangled[:truncate_limit]}..."
-                if len(demangled) > self.COL_TOP_SYMBOL_NAME
-                else demangled
+                f"{display_name[:truncate_limit]}..."
+                if len(display_name) > self.COL_TOP_SYMBOL_NAME
+                else display_name
             )
             lines.append(
                 f"{i + 1:>2}. {size:>7,} B {section_label:<8} {demangled_display:<{self.COL_TOP_SYMBOL_NAME}} {component}"
@@ -231,6 +248,110 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
                     lines.append(f"    {size:>6,} B  {sym_name}")
             lines.append("")
 
+    # Number of top called functions to show
+    TOP_CALLS_LIMIT: int = 50
+    # Number of inlining candidates to show
+    INLINE_CANDIDATES_LIMIT: int = 25
+    # Maximum function size in bytes to consider for inlining
+    INLINE_SIZE_THRESHOLD: int = 16
+
+    def _build_symbol_sizes(self) -> dict[str, int]:
+        """Build a size lookup from all component symbols: mangled_name -> size."""
+        return {
+            symbol: size
+            for symbols in self._component_symbols.values()
+            for symbol, _, size, _ in symbols
+        }
+
+    def _format_call_row(
+        self, index: int, mangled: str, count: int, symbol_sizes: dict[str, int]
+    ) -> str:
+        """Format a single row for call frequency tables."""
+        demangled = self._demangle_cache.get(mangled, mangled)
+        if len(demangled) > 80:
+            demangled = f"{demangled[:77]}..."
+        size = symbol_sizes.get(mangled)
+        size_str = f"{size:>5,} B" if size is not None else "      ?"
+        return f"{index:>3}  {count:>5}  {size_str}  {demangled}"
+
+    def _add_call_table_header(self, lines: list[str]) -> None:
+        """Add the header row for call frequency tables."""
+        lines.append(f"{'#':>3}  {'Calls':>5}  {'Size':>7}  Function")
+        lines.append(f"{'---':>3}  {'-----':>5}  {'-------':>7}  {'-' * 60}")
+
+    def _add_function_call_analysis(self, lines: list[str]) -> None:
+        """Add function call frequency analysis section.
+
+        Shows the most frequently called functions by call site count.
+        """
+        self._add_section_header(lines, "Top Called Functions")
+
+        symbol_sizes = self._build_symbol_sizes()
+
+        # Sort by call count descending
+        sorted_calls = sorted(
+            self._function_call_counts.items(), key=lambda x: x[1], reverse=True
+        )
+
+        self._add_call_table_header(lines)
+
+        for i, (mangled, count) in enumerate(sorted_calls[: self.TOP_CALLS_LIMIT]):
+            lines.append(self._format_call_row(i + 1, mangled, count, symbol_sizes))
+
+        total_calls = sum(self._function_call_counts.values())
+        lines.append("")
+        lines.append(
+            f"Total: {len(self._function_call_counts)} unique targets, "
+            f"{total_calls:,} call sites"
+        )
+        lines.append("")
+
+    def _add_inline_candidates(self, lines: list[str]) -> None:
+        """Add inlining candidates section.
+
+        Shows frequently called functions that are small enough to benefit
+        from inlining (< 16 bytes). These are the best candidates for
+        reducing call overhead.
+        """
+        self._add_section_header(
+            lines,
+            f"Inlining Candidates (<{self.INLINE_SIZE_THRESHOLD} B, by call count)",
+        )
+
+        symbol_sizes = self._build_symbol_sizes()
+
+        # Filter to small functions with known size, sort by call count
+        candidates = sorted(
+            (
+                (mangled, count)
+                for mangled, count in self._function_call_counts.items()
+                if mangled in symbol_sizes
+                and symbol_sizes[mangled] < self.INLINE_SIZE_THRESHOLD
+            ),
+            key=lambda x: x[1],
+            reverse=True,
+        )
+
+        if not candidates:
+            lines.append("No candidates found.")
+            lines.append("")
+            return
+
+        self._add_call_table_header(lines)
+
+        for i, (mangled, count) in enumerate(
+            candidates[: self.INLINE_CANDIDATES_LIMIT]
+        ):
+            lines.append(self._format_call_row(i + 1, mangled, count, symbol_sizes))
+
+        lines.append("")
+        lines.append(
+            f"Showing top {min(len(candidates), self.INLINE_CANDIDATES_LIMIT)} "
+            f"of {len(candidates)} functions under "
+            f"{self.INLINE_SIZE_THRESHOLD} B"
+        )
+        lines.append("")
+
     def generate_report(self, detailed: bool = False) -> str:
         """Generate a formatted memory report."""
         components = sorted(
@@ -469,15 +590,16 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
                 lines.append(f"Total size: {comp_mem.flash_total:,} B")
                 lines.append("")
 
-                # Show all symbols above threshold for better visibility
+                # Show symbols above threshold, always include storage symbols
                 large_symbols = [
                     (sym, dem, size, sec)
                     for sym, dem, size, sec in sorted_symbols
                     if size > self.SYMBOL_SIZE_THRESHOLD
+                    or dem.endswith(_PSTORAGE_SUFFIX)
                 ]
 
                 lines.append(
-                    f"{comp_name} Symbols > {self.SYMBOL_SIZE_THRESHOLD} B ({len(large_symbols)} symbols):"
+                    f"{comp_name} Symbols > {self.SYMBOL_SIZE_THRESHOLD} B & storage ({len(large_symbols)} symbols):"
                 )
                 for i, (symbol, demangled, size, section) in enumerate(large_symbols):
                     lines.append(
@@ -500,7 +622,10 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
             # Sort by size descending
             sorted_ram_syms = sorted(ram_syms, key=lambda x: x[2], reverse=True)
             large_ram_syms = [
-                s for s in sorted_ram_syms if s[2] > self.RAM_SYMBOL_SIZE_THRESHOLD
+                s
+                for s in sorted_ram_syms
+                if s[2] > self.RAM_SYMBOL_SIZE_THRESHOLD
+                or s[1].endswith(_PSTORAGE_SUFFIX)
             ]
 
             lines.append(f"{name} ({mem.ram_total:,} B total RAM):")
@@ -518,13 +643,14 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
                 for symbol, demangled, size, section in large_ram_syms[:10]:
                     # Format section label consistently by stripping leading dot
                     section_label = section.lstrip(".") if section else ""
+                    display_name = _format_pstorage_name(demangled)
                     # Add ellipsis if name is truncated
-                    demangled_display = (
-                        f"{demangled[:70]}..." if len(demangled) > 70 else demangled
-                    )
-                    lines.append(
-                        f"    {size:>6,} B [{section_label}] {demangled_display}"
+                    display_name = (
+                        f"{display_name[:70]}..."
+                        if len(display_name) > 70
+                        else display_name
                     )
+                    lines.append(f"    {size:>6,} B [{section_label}] {display_name}")
                 if len(large_ram_syms) > 10:
                     lines.append(f"    ... and {len(large_ram_syms) - 10} more")
             lines.append("")
@@ -533,6 +659,11 @@ class MemoryAnalyzerCLI(MemoryAnalyzer):
         if self._cswtch_symbols:
             self._add_cswtch_analysis(lines)
 
+        # Function call frequency analysis
+        if self._function_call_counts:
+            self._add_function_call_analysis(lines)
+            self._add_inline_candidates(lines)
+
         lines.append(
             "Note: This analysis covers symbols in the ELF file. Some runtime allocations may not be included."
         )

esphome/analyze_memory/const.py

@@ -256,7 +256,7 @@ SYMBOL_PATTERNS = {
     "ipv6_stack": ["nd6_", "ip6_", "mld6_", "icmp6_", "icmp6_input"],
     # Order matters! More specific categories must come before general ones.
     # mdns must come before bluetooth to avoid "_mdns_disable_pcb" matching "ble_" pattern
-    "mdns_lib": ["mdns"],
+    "mdns_lib": ["mdns", "packet$"],
     # memory_mgmt must come before wifi_stack to catch mmu_hal_* symbols
     "memory_mgmt": [
         "mem_",
@@ -408,7 +408,6 @@ SYMBOL_PATTERNS = {
     ],
     "arduino_core": [
         "pinMode",
-        "resetPins",
         "millis",
         "micros",
         "delay(",  # More specific - Arduino delay function with parenthesis
@@ -794,7 +793,6 @@ SYMBOL_PATTERNS = {
         "s_dp",
         "s_ni",
         "s_reg_dump",
-        "packet$",
         "d_mult_table",
         "K",
         "fcstab",

esphome/automation.py

@@ -1,3 +1,6 @@
+from dataclasses import dataclass, field
+import logging
+
 import esphome.codegen as cg
 import esphome.config_validation as cv
 from esphome.const import (
@@ -57,8 +60,42 @@ def maybe_conf(conf, *validators):
     return validate
 
 
-def register_action(name: str, action_type: MockObjClass, schema: cv.Schema):
-    return ACTION_REGISTRY.register(name, action_type, schema)
+_LOGGER = logging.getLogger(__name__)
+
+
+def register_action(
+    name: str,
+    action_type: MockObjClass,
+    schema: cv.Schema,
+    *,
+    synchronous: bool | None = None,
+):
+    """Register an action type.
+
+    All callers must pass ``synchronous`` explicitly.
+
+    ``synchronous=True`` — the action never defers ``play_next_()`` to a
+    later point (callback, timer, or ``loop()``).  Trigger arguments are
+    only used during the initial call, so string args can use non-owning
+    StringRef for zero-copy access.
+
+    ``synchronous=False`` — the action defers ``play_next_()`` via a
+    callback, timer, or ``Component::loop()``.  Trigger arguments must
+    outlive the initial call, so string args use owning std::string to
+    prevent dangling references.
+    """
+    if synchronous is None:
+        _LOGGER.warning(
+            "register_action('%s', ...) is missing the synchronous= parameter. "
+            "Defaulting to synchronous=False (safe but prevents StringRef "
+            "optimization). Check the C++ class: use synchronous=False if "
+            "play_next_() is deferred to a callback, timer, or loop(); "
+            "use synchronous=True if play_next_() always runs before the "
+            "initial play/play_complex call returns",
+            name,
+        )
+        synchronous = False
+    return ACTION_REGISTRY.register(name, action_type, schema, synchronous=synchronous)
 
 
 def register_condition(name: str, condition_type: MockObjClass, schema: cv.Schema):
@@ -101,6 +138,9 @@ UpdateComponentAction = cg.esphome_ns.class_("UpdateComponentAction", Action)
 SuspendComponentAction = cg.esphome_ns.class_("SuspendComponentAction", Action)
 ResumeComponentAction = cg.esphome_ns.class_("ResumeComponentAction", Action)
 Automation = cg.esphome_ns.class_("Automation")
+TriggerForwarder = cg.esphome_ns.class_("TriggerForwarder")
+TriggerOnTrueForwarder = cg.esphome_ns.class_("TriggerOnTrueForwarder")
+TriggerOnFalseForwarder = cg.esphome_ns.class_("TriggerOnFalseForwarder")
 
 LambdaCondition = cg.esphome_ns.class_("LambdaCondition", Condition)
 StatelessLambdaCondition = cg.esphome_ns.class_("StatelessLambdaCondition", Condition)
@@ -211,7 +251,9 @@ async def and_condition_to_code(
     args: TemplateArgsType,
 ) -> MockObj:
     conditions = await build_condition_list(config, template_arg, args)
-    return cg.new_Pvariable(condition_id, template_arg, conditions)
+    return cg.new_Pvariable(
+        condition_id, cg.TemplateArguments(len(conditions), *template_arg), conditions
+    )
 
 
 @register_condition("or", OrCondition, validate_condition_list)
@@ -222,7 +264,9 @@ async def or_condition_to_code(
     args: TemplateArgsType,
 ) -> MockObj:
     conditions = await build_condition_list(config, template_arg, args)
-    return cg.new_Pvariable(condition_id, template_arg, conditions)
+    return cg.new_Pvariable(
+        condition_id, cg.TemplateArguments(len(conditions), *template_arg), conditions
+    )
 
 
 @register_condition("all", AndCondition, validate_condition_list)
@@ -233,7 +277,9 @@ async def all_condition_to_code(
     args: TemplateArgsType,
 ) -> MockObj:
     conditions = await build_condition_list(config, template_arg, args)
-    return cg.new_Pvariable(condition_id, template_arg, conditions)
+    return cg.new_Pvariable(
+        condition_id, cg.TemplateArguments(len(conditions), *template_arg), conditions
+    )
 
 
 @register_condition("any", OrCondition, validate_condition_list)
@@ -244,7 +290,9 @@ async def any_condition_to_code(
     args: TemplateArgsType,
 ) -> MockObj:
     conditions = await build_condition_list(config, template_arg, args)
-    return cg.new_Pvariable(condition_id, template_arg, conditions)
+    return cg.new_Pvariable(
+        condition_id, cg.TemplateArguments(len(conditions), *template_arg), conditions
+    )
 
 
 @register_condition("not", NotCondition, validate_potentially_and_condition)
@@ -266,7 +314,9 @@ async def xor_condition_to_code(
     args: TemplateArgsType,
 ) -> MockObj:
     conditions = await build_condition_list(config, template_arg, args)
-    return cg.new_Pvariable(condition_id, template_arg, conditions)
+    return cg.new_Pvariable(
+        condition_id, cg.TemplateArguments(len(conditions), *template_arg), conditions
+    )
 
 
 @register_condition("lambda", LambdaCondition, cv.returning_lambda)
@@ -335,7 +385,10 @@ async def component_is_idle_condition_to_code(
 
 
 @register_action(
-    "delay", DelayAction, cv.templatable(cv.positive_time_period_milliseconds)
+    "delay",
+    DelayAction,
+    cv.templatable(cv.positive_time_period_milliseconds),
+    synchronous=False,
 )
 async def delay_action_to_code(
     config: ConfigType,
@@ -366,6 +419,7 @@ async def delay_action_to_code(
         cv.has_at_least_one_key(CONF_THEN, CONF_ELSE),
         cv.has_at_least_one_key(CONF_CONDITION, CONF_ANY, CONF_ALL),
     ),
+    synchronous=True,
 )
 async def if_action_to_code(
     config: ConfigType,
@@ -373,13 +427,16 @@ async def if_action_to_code(
     template_arg: cg.TemplateArguments,
     args: TemplateArgsType,
 ) -> MockObj:
+    has_else = CONF_ELSE in config
+    # Prepend HasElse bool to template arguments: IfAction<HasElse, Ts...>
+    if_template_arg = cg.TemplateArguments(has_else, *template_arg)
     cond_conf = next(el for el in config if el in (CONF_ANY, CONF_ALL, CONF_CONDITION))
     condition = await build_condition(config[cond_conf], template_arg, args)
-    var = cg.new_Pvariable(action_id, template_arg, condition)
+    var = cg.new_Pvariable(action_id, if_template_arg, condition)
     if CONF_THEN in config:
         actions = await build_action_list(config[CONF_THEN], template_arg, args)
         cg.add(var.add_then(actions))
-    if CONF_ELSE in config:
+    if has_else:
         actions = await build_action_list(config[CONF_ELSE], template_arg, args)
         cg.add(var.add_else(actions))
     return var
@@ -394,6 +451,7 @@ async def if_action_to_code(
             cv.Required(CONF_THEN): validate_action_list,
         }
     ),
+    synchronous=True,
 )
 async def while_action_to_code(
     config: ConfigType,
@@ -417,6 +475,7 @@ async def while_action_to_code(
             cv.Required(CONF_THEN): validate_action_list,
         }
     ),
+    synchronous=True,
 )
 async def repeat_action_to_code(
     config: ConfigType,
@@ -445,7 +504,7 @@ _validate_wait_until = cv.maybe_simple_value(
 )
 
 
-@register_action("wait_until", WaitUntilAction, _validate_wait_until)
+@register_action("wait_until", WaitUntilAction, _validate_wait_until, synchronous=False)
 async def wait_until_action_to_code(
     config: ConfigType,
     action_id: ID,
@@ -461,7 +520,12 @@ async def wait_until_action_to_code(
     return var
 
 
-@register_action("lambda", LambdaAction, cv.lambda_)
+# Lambda executes user C++ inline and returns — synchronous by execution model.
+# User code could theoretically store the StringRef for deferred use, but StringRef
+# is a view type and storing views beyond their scope is always unsafe regardless
+# of this optimization.  Marking non-synchronous would disable StringRef for nearly
+# all user services since most use lambda.
+@register_action("lambda", LambdaAction, cv.lambda_, synchronous=True)
 async def lambda_action_to_code(
     config: ConfigType,
     action_id: ID,
@@ -480,6 +544,7 @@ async def lambda_action_to_code(
             cv.Required(CONF_ID): cv.use_id(cg.PollingComponent),
         }
     ),
+    synchronous=True,
 )
 async def component_update_action_to_code(
     config: ConfigType,
@@ -499,6 +564,7 @@ async def component_update_action_to_code(
             cv.Required(CONF_ID): cv.use_id(cg.PollingComponent),
         }
     ),
+    synchronous=True,
 )
 async def component_suspend_action_to_code(
     config: ConfigType,
@@ -521,6 +587,7 @@ async def component_suspend_action_to_code(
             ),
         }
     ),
+    synchronous=True,
 )
 async def component_resume_action_to_code(
     config: ConfigType,
@@ -578,6 +645,27 @@ async def build_condition_list(
     return conditions
 
 
+def has_non_synchronous_actions(actions: ConfigType) -> bool:
+    """Check if a validated action list contains any non-synchronous actions.
+
+    Non-synchronous actions (delay, wait_until, script.wait, etc.) store
+    trigger args for later execution, making non-owning types like StringRef
+    unsafe.
+    """
+    if isinstance(actions, list):
+        return any(has_non_synchronous_actions(item) for item in actions)
+    if isinstance(actions, dict):
+        for key in actions:
+            if key in ACTION_REGISTRY and not ACTION_REGISTRY[key].synchronous:
+                return True
+        return any(
+            has_non_synchronous_actions(v)
+            for v in actions.values()
+            if isinstance(v, (list, dict))
+        )
+    return False
+
+
 async def build_automation(
     trigger: MockObj, args: TemplateArgsType, config: ConfigType
 ) -> MockObj:
@@ -587,3 +675,76 @@ async def build_automation(
     actions = await build_action_list(config[CONF_THEN], templ, args)
     cg.add(obj.add_actions(actions))
     return obj
+
+
+async def build_callback_automation(
+    parent: MockObj,
+    callback_method: str,
+    args: TemplateArgsType,
+    config: ConfigType,
+    forwarder: MockObj | MockObjClass | None = None,
+) -> None:
+    """Build an Automation and register it as a callback on the parent.
+
+    Eliminates the need for a Trigger wrapper object by registering the
+    automation's trigger() directly as a callback on the parent component.
+
+    Uses template forwarder structs so the compiler deduplicates the operator()
+    body across all call sites with the same signature. The forwarder must be
+    pointer-sized (single Automation* field) to fit inline in Callback::ctx_
+    and avoid heap allocation.
+
+    :param parent: The component object (e.g., button, sensor).
+    :param callback_method: Name of the callback method (e.g., "add_on_press_callback").
+    :param args: Automation template args as list of (type, name) tuples.
+    :param config: The automation config dict.
+    :param forwarder: Optional forwarder type to use instead of the default
+        TriggerForwarder<Ts...>. Pass any struct type whose aggregate init takes
+        a single Automation pointer (e.g., TriggerOnTrueForwarder).
+    """
+    arg_types = [arg[0] for arg in args]
+    templ = cg.TemplateArguments(*arg_types)
+    obj = cg.new_Pvariable(config[CONF_AUTOMATION_ID], templ)
+    actions = await build_action_list(config[CONF_THEN], templ, args)
+    cg.add(obj.add_actions(actions))
+    # Use template forwarder structs for deduplication. The compiler generates
+    # one operator() per forwarder type; different automation pointers are just
+    # data in the struct.
+    if forwarder is None:
+        forwarder = TriggerForwarder.template(templ)
+    # RawExpression for aggregate init — both forwarder and obj are codegen
+    # MockObjs (not user input), and there's no Expression type for positional
+    # aggregate initialization (StructInitializer uses named fields).
+    cg.add(getattr(parent, callback_method)(cg.RawExpression(f"{forwarder}{{{obj}}}")))
+
+
+@dataclass(frozen=True, slots=True)
+class CallbackAutomation:
+    """A single callback automation entry for build_callback_automations."""
+
+    conf_key: str
+    callback_method: str
+    args: TemplateArgsType = field(default_factory=list)
+    forwarder: MockObj | MockObjClass | None = None
+
+
+async def build_callback_automations(
+    parent: MockObj,
+    config: ConfigType,
+    entries: tuple[CallbackAutomation, ...],
+) -> None:
+    """Build multiple callback automations from a tuple of entries.
+
+    :param parent: The component object (e.g., button, sensor).
+    :param config: The full component config dict.
+    :param entries: Tuple of CallbackAutomation entries to process.
+    """
+    for entry in entries:
+        for conf in config.get(entry.conf_key, []):
+            await build_callback_automation(
+                parent,
+                entry.callback_method,
+                entry.args,
+                conf,
+                forwarder=entry.forwarder,
+            )

esphome/build_gen/espidf.py

@@ -53,6 +53,13 @@ def get_project_cmakelists() -> str:
     variant = get_esp32_variant()
     idf_target = variant.lower().replace("-", "")
 
+    # Extract compile definitions from build flags (-DXXX -> XXX)
+    compile_defs = [flag for flag in CORE.build_flags if flag.startswith("-D")]
+    extra_compile_options = "\n".join(
+        f'idf_build_set_property(COMPILE_OPTIONS "{compile_def}" APPEND)'
+        for compile_def in compile_defs
+    )
+
     return f"""\
 # Auto-generated by ESPHome
 cmake_minimum_required(VERSION 3.16)
@@ -61,6 +68,9 @@ set(IDF_TARGET {idf_target})
 set(EXTRA_COMPONENT_DIRS ${{CMAKE_SOURCE_DIR}}/src)
 
 include($ENV{{IDF_PATH}}/tools/cmake/project.cmake)
+
+{extra_compile_options}
+
 project({CORE.name})
 """
 
@@ -70,21 +80,17 @@ def get_component_cmakelists(minimal: bool = False) -> str:
     idf_requires = [] if minimal else (get_available_components() or [])
     requires_str = " ".join(idf_requires)
 
-    # Extract compile definitions from build flags (-DXXX -> XXX)
-    compile_defs = [flag[2:] for flag in CORE.build_flags if flag.startswith("-D")]
-    compile_defs_str = "\n    ".join(compile_defs) if compile_defs else ""
-
     # Extract compile options (-W flags, excluding linker flags)
     compile_opts = [
         flag
         for flag in CORE.build_flags
         if flag.startswith("-W") and not flag.startswith("-Wl,")
     ]
-    compile_opts_str = "\n    ".join(compile_opts) if compile_opts else ""
+    compile_opts_str = "\n    ".join(sorted(compile_opts)) if compile_opts else ""
 
     # Extract linker options (-Wl, flags)
     link_opts = [flag for flag in CORE.build_flags if flag.startswith("-Wl,")]
-    link_opts_str = "\n    ".join(link_opts) if link_opts else ""
+    link_opts_str = "\n    ".join(sorted(link_opts)) if link_opts else ""
 
     return f"""\
 # Auto-generated by ESPHome
@@ -104,11 +110,6 @@ idf_component_register(
 # Apply C++ standard
 target_compile_features(${{COMPONENT_LIB}} PUBLIC cxx_std_20)
 
-# ESPHome compile definitions
-target_compile_definitions(${{COMPONENT_LIB}} PUBLIC
-    {compile_defs_str}
-)
-
 # ESPHome compile options
 target_compile_options(${{COMPONENT_LIB}} PUBLIC
     {compile_opts_str}

esphome/bundle.py

@@ -0,0 +1,699 @@
+"""Config bundle creator and extractor for ESPHome.
+
+A bundle is a self-contained .tar.gz archive containing a YAML config
+and every local file it depends on. Bundles can be created from a config
+and compiled directly: ``esphome compile my_device.esphomebundle.tar.gz``
+"""
+
+from __future__ import annotations
+
+from dataclasses import dataclass
+from enum import StrEnum
+import io
+import json
+import logging
+from pathlib import Path
+import re
+import shutil
+import tarfile
+from typing import Any
+
+from esphome import const, yaml_util
+from esphome.const import (
+    CONF_ESPHOME,
+    CONF_EXTERNAL_COMPONENTS,
+    CONF_INCLUDES,
+    CONF_INCLUDES_C,
+    CONF_PATH,
+    CONF_SOURCE,
+    CONF_TYPE,
+)
+from esphome.core import CORE, EsphomeError
+
+_LOGGER = logging.getLogger(__name__)
+
+BUNDLE_EXTENSION = ".esphomebundle.tar.gz"
+MANIFEST_FILENAME = "manifest.json"
+CURRENT_MANIFEST_VERSION = 1
+MAX_DECOMPRESSED_SIZE = 500 * 1024 * 1024  # 500 MB
+MAX_MANIFEST_SIZE = 1024 * 1024  # 1 MB
+
+# Directories preserved across bundle extractions (build caches)
+_PRESERVE_DIRS = (".esphome", ".pioenvs", ".pio")
+_BUNDLE_STAGING_DIR = ".bundle_staging"
+
+
+class ManifestKey(StrEnum):
+    """Keys used in bundle manifest.json."""
+
+    MANIFEST_VERSION = "manifest_version"
+    ESPHOME_VERSION = "esphome_version"
+    CONFIG_FILENAME = "config_filename"
+    FILES = "files"
+    HAS_SECRETS = "has_secrets"
+
+
+# String prefixes that are never local file paths
+_NON_PATH_PREFIXES = ("http://", "https://", "ftp://", "mdi:", "<")
+
+# File extensions recognized when resolving relative path strings.
+# A relative string with one of these extensions is resolved against the
+# config directory and included if the file exists.
+_KNOWN_FILE_EXTENSIONS = frozenset(
+    {
+        # Fonts
+        ".ttf",
+        ".otf",
+        ".woff",
+        ".woff2",
+        ".pcf",
+        ".bdf",
+        # Images
+        ".png",
+        ".jpg",
+        ".jpeg",
+        ".bmp",
+        ".gif",
+        ".svg",
+        ".ico",
+        ".webp",
+        # Certificates
+        ".pem",
+        ".crt",
+        ".key",
+        ".der",
+        ".p12",
+        ".pfx",
+        # C/C++ includes
+        ".h",
+        ".hpp",
+        ".c",
+        ".cpp",
+        ".ino",
+        # Web assets
+        ".css",
+        ".js",
+        ".html",
+    }
+)
+
+
+# Matches !secret references in YAML text.  This is intentionally a simple
+# regex scan rather than a YAML parse — it may match inside comments or
+# multi-line strings, which is the conservative direction (include more
+# secrets rather than fewer).
+_SECRET_RE = re.compile(r"!secret\s+(\S+)")
+
+
+def _find_used_secret_keys(yaml_files: list[Path]) -> set[str]:
+    """Scan YAML files for ``!secret <key>`` references."""
+    keys: set[str] = set()
+    for fpath in yaml_files:
+        try:
+            text = fpath.read_text(encoding="utf-8")
+        except (OSError, UnicodeDecodeError):
+            continue
+        for match in _SECRET_RE.finditer(text):
+            keys.add(match.group(1))
+    return keys
+
+
+@dataclass
+class BundleFile:
+    """A file to include in the bundle."""
+
+    path: str  # Relative path inside the archive
+    source: Path  # Absolute path on disk
+
+
+@dataclass
+class BundleResult:
+    """Result of creating a bundle."""
+
+    data: bytes
+    manifest: dict[str, Any]
+    files: list[BundleFile]
+
+
+@dataclass
+class BundleManifest:
+    """Parsed and validated bundle manifest."""
+
+    manifest_version: int
+    esphome_version: str
+    config_filename: str
+    files: list[str]
+    has_secrets: bool
+
+
+class ConfigBundleCreator:
+    """Creates a self-contained bundle from an ESPHome config."""
+
+    def __init__(self, config: dict[str, Any]) -> None:
+        self._config = config
+        self._config_dir = CORE.config_dir
+        self._config_path = CORE.config_path
+        self._files: list[BundleFile] = []
+        self._seen_paths: set[Path] = set()
+        self._secrets_paths: set[Path] = set()
+
+    def discover_files(self) -> list[BundleFile]:
+        """Discover all files needed for the bundle."""
+        self._files = []
+        self._seen_paths = set()
+        self._secrets_paths = set()
+
+        # The main config file
+        self._add_file(self._config_path)
+
+        # Phase 1: YAML includes (tracked during config loading)
+        self._discover_yaml_includes()
+
+        # Phase 2: Component-referenced files from validated config
+        self._discover_component_files()
+
+        return list(self._files)
+
+    def create_bundle(self) -> BundleResult:
+        """Create the bundle archive."""
+        files = self.discover_files()
+
+        # Determine which secret keys are actually referenced by the
+        # bundled YAML files so we only ship those, not the entire
+        # secrets.yaml which may contain secrets for other devices.
+        yaml_sources = [
+            bf.source for bf in files if bf.source.suffix in (".yaml", ".yml")
+        ]
+        used_secret_keys = _find_used_secret_keys(yaml_sources)
+        filtered_secrets = self._build_filtered_secrets(used_secret_keys)
+
+        has_secrets = bool(filtered_secrets)
+        if has_secrets:
+            _LOGGER.warning(
+                "Bundle contains secrets (e.g. Wi-Fi passwords). "
+                "Do not share it with untrusted parties."
+            )
+
+        manifest = self._build_manifest(files, has_secrets=has_secrets)
+
+        buf = io.BytesIO()
+        with tarfile.open(fileobj=buf, mode="w:gz") as tar:
+            # Add manifest first
+            manifest_data = json.dumps(manifest, indent=2).encode("utf-8")
+            _add_bytes_to_tar(tar, MANIFEST_FILENAME, manifest_data)
+
+            # Add filtered secrets files
+            for rel_path, data in sorted(filtered_secrets.items()):
+                _add_bytes_to_tar(tar, rel_path, data)
+
+            # Add files in sorted order for determinism, skipping secrets
+            # files which were already added above with filtered content
+            for bf in sorted(files, key=lambda f: f.path):
+                if bf.source in self._secrets_paths:
+                    continue
+                self._add_to_tar(tar, bf)
+
+        return BundleResult(data=buf.getvalue(), manifest=manifest, files=files)
+
+    def _add_file(self, abs_path: Path) -> bool:
+        """Add a file to the bundle. Returns False if already added."""
+        abs_path = abs_path.resolve()
+        if abs_path in self._seen_paths:
+            return False
+        if not abs_path.is_file():
+            _LOGGER.warning("Bundle: skipping missing file %s", abs_path)
+            return False
+
+        rel_path = self._relative_to_config_dir(abs_path)
+        if rel_path is None:
+            _LOGGER.warning(
+                "Bundle: skipping file outside config directory: %s", abs_path
+            )
+            return False
+
+        self._seen_paths.add(abs_path)
+        self._files.append(BundleFile(path=rel_path, source=abs_path))
+        return True
+
+    def _add_directory(self, abs_path: Path) -> None:
+        """Recursively add all files in a directory."""
+        abs_path = abs_path.resolve()
+        if not abs_path.is_dir():
+            _LOGGER.warning("Bundle: skipping missing directory %s", abs_path)
+            return
+        for child in sorted(abs_path.rglob("*")):
+            if child.is_file() and "__pycache__" not in child.parts:
+                self._add_file(child)
+
+    def _relative_to_config_dir(self, abs_path: Path) -> str | None:
+        """Get a path relative to the config directory. Returns None if outside.
+
+        Always uses forward slashes for consistency in tar archives.
+        """
+        try:
+            return abs_path.relative_to(self._config_dir).as_posix()
+        except ValueError:
+            return None
+
+    def _discover_yaml_includes(self) -> None:
+        """Discover YAML files loaded during config parsing.
+
+        We track files by wrapping _load_yaml_internal. The config has already
+        been loaded at this point (bundle is a POST_CONFIG_ACTION), so we
+        re-load just to discover the file list.
+
+        Secrets files are tracked separately so we can filter them to
+        only include the keys this config actually references.
+        """
+        with yaml_util.track_yaml_loads() as loaded_files:
+            try:
+                yaml_util.load_yaml(self._config_path)
+            except EsphomeError:
+                _LOGGER.debug(
+                    "Bundle: re-loading YAML for include discovery failed, "
+                    "proceeding with partial file list"
+                )
+
+        for fpath in loaded_files:
+            if fpath == self._config_path.resolve():
+                continue  # Already added as config
+            if fpath.name in const.SECRETS_FILES:
+                self._secrets_paths.add(fpath)
+            self._add_file(fpath)
+
+    def _discover_component_files(self) -> None:
+        """Walk the validated config for file references.
+
+        Uses a generic recursive walk to find file paths instead of
+        hardcoding per-component knowledge about config dict formats.
+        After validation, components typically resolve paths to absolute
+        using CORE.relative_config_path() or cv.file_(). Relative paths
+        with known file extensions are also resolved and checked.
+
+        Core ESPHome concepts that use relative paths or directories
+        are handled explicitly.
+        """
+        config = self._config
+
+        # Generic walk: find all file paths in the validated config
+        self._walk_config_for_files(config)
+
+        # --- Core ESPHome concepts needing explicit handling ---
+
+        # esphome.includes / includes_c - can be relative paths and directories
+        esphome_conf = config.get(CONF_ESPHOME, {})
+        for include_path in esphome_conf.get(CONF_INCLUDES, []):
+            resolved = _resolve_include_path(include_path)
+            if resolved is None:
+                continue
+            if resolved.is_dir():
+                self._add_directory(resolved)
+            else:
+                self._add_file(resolved)
+        for include_path in esphome_conf.get(CONF_INCLUDES_C, []):
+            resolved = _resolve_include_path(include_path)
+            if resolved is not None:
+                self._add_file(resolved)
+
+        # external_components with source: local - directories
+        for ext_conf in config.get(CONF_EXTERNAL_COMPONENTS, []):
+            source = ext_conf.get(CONF_SOURCE, {})
+            if not isinstance(source, dict):
+                continue
+            if source.get(CONF_TYPE) != "local":
+                continue
+            path = source.get(CONF_PATH)
+            if not path:
+                continue
+            p = Path(path)
+            if not p.is_absolute():
+                p = CORE.relative_config_path(p)
+            self._add_directory(p)
+
+    def _walk_config_for_files(self, obj: Any) -> None:
+        """Recursively walk the config dict looking for file path references."""
+        if isinstance(obj, dict):
+            for value in obj.values():
+                self._walk_config_for_files(value)
+        elif isinstance(obj, (list, tuple)):
+            for item in obj:
+                self._walk_config_for_files(item)
+        elif isinstance(obj, Path):
+            if obj.is_absolute() and obj.is_file():
+                self._add_file(obj)
+        elif isinstance(obj, str):
+            self._check_string_path(obj)
+
+    def _check_string_path(self, value: str) -> None:
+        """Check if a string value is a local file reference."""
+        # Fast exits for strings that cannot be file paths
+        if len(value) < 2 or "\n" in value:
+            return
+        if value.startswith(_NON_PATH_PREFIXES):
+            return
+        # File paths must contain a path separator or a dot (for extension)
+        if "/" not in value and "\\" not in value and "." not in value:
+            return
+
+        p = Path(value)
+
+        # Absolute path - check if it points to an existing file
+        if p.is_absolute():
+            if p.is_file():
+                self._add_file(p)
+            return
+
+        # Relative path with a known file extension - likely a component
+        # validator that forgot to resolve to absolute via cv.file_() or
+        # CORE.relative_config_path(). Warn and try to resolve.
+        if p.suffix.lower() in _KNOWN_FILE_EXTENSIONS:
+            _LOGGER.warning(
+                "Bundle: non-absolute path in validated config: %s "
+                "(component validator should return absolute paths)",
+                value,
+            )
+            resolved = CORE.relative_config_path(p)
+            if resolved.is_file():
+                self._add_file(resolved)
+
+    def _build_filtered_secrets(self, used_keys: set[str]) -> dict[str, bytes]:
+        """Build filtered secrets files containing only the referenced keys.
+
+        Returns a dict mapping relative archive path to YAML bytes.
+        """
+        if not used_keys or not self._secrets_paths:
+            return {}
+
+        result: dict[str, bytes] = {}
+        for secrets_path in self._secrets_paths:
+            rel_path = self._relative_to_config_dir(secrets_path)
+            if rel_path is None:
+                continue
+            try:
+                all_secrets = yaml_util.load_yaml(secrets_path, clear_secrets=False)
+            except EsphomeError:
+                _LOGGER.warning("Bundle: failed to load secrets file %s", secrets_path)
+                continue
+            if not isinstance(all_secrets, dict):
+                continue
+            filtered = {k: v for k, v in all_secrets.items() if k in used_keys}
+            if filtered:
+                data = yaml_util.dump(filtered, show_secrets=True).encode("utf-8")
+                result[rel_path] = data
+        return result
+
+    def _build_manifest(
+        self, files: list[BundleFile], *, has_secrets: bool
+    ) -> dict[str, Any]:
+        """Build the manifest.json content."""
+        return {
+            ManifestKey.MANIFEST_VERSION: CURRENT_MANIFEST_VERSION,
+            ManifestKey.ESPHOME_VERSION: const.__version__,
+            ManifestKey.CONFIG_FILENAME: self._config_path.name,
+            ManifestKey.FILES: [f.path for f in files],
+            ManifestKey.HAS_SECRETS: has_secrets,
+        }
+
+    @staticmethod
+    def _add_to_tar(tar: tarfile.TarFile, bf: BundleFile) -> None:
+        """Add a BundleFile to the tar archive with deterministic metadata."""
+        with open(bf.source, "rb") as f:
+            _add_bytes_to_tar(tar, bf.path, f.read())
+
+
+def extract_bundle(
+    bundle_path: Path,
+    target_dir: Path | None = None,
+) -> Path:
+    """Extract a bundle archive and return the path to the config YAML.
+
+    Sanity checks reject path traversal, symlinks, absolute paths, and
+    oversized archives to prevent accidental file overwrites or extraction
+    outside the target directory.  These are **not** a security boundary —
+    bundles are assumed to come from the user's own machine or a trusted
+    build pipeline.
+
+    Args:
+        bundle_path: Path to the .tar.gz bundle file.
+        target_dir: Directory to extract into. If None, extracts next to
+                     the bundle file in a directory named after it.
+
+    Returns:
+        Absolute path to the extracted config YAML file.
+
+    Raises:
+        EsphomeError: If the bundle is invalid or extraction fails.
+    """
+
+    bundle_path = bundle_path.resolve()
+    if not bundle_path.is_file():
+        raise EsphomeError(f"Bundle file not found: {bundle_path}")
+
+    if target_dir is None:
+        target_dir = _default_target_dir(bundle_path)
+
+    target_dir = target_dir.resolve()
+    target_dir.mkdir(parents=True, exist_ok=True)
+
+    # Read and validate the archive
+    try:
+        with tarfile.open(bundle_path, "r:gz") as tar:
+            manifest = _read_manifest_from_tar(tar)
+            _validate_tar_members(tar, target_dir)
+            tar.extractall(path=target_dir, filter="data")
+    except tarfile.TarError as err:
+        raise EsphomeError(f"Failed to extract bundle: {err}") from err
+
+    config_filename = manifest[ManifestKey.CONFIG_FILENAME]
+    config_path = target_dir / config_filename
+    if not config_path.is_file():
+        raise EsphomeError(
+            f"Bundle manifest references config '{config_filename}' "
+            f"but it was not found in the archive"
+        )
+
+    return config_path
+
+
+def read_bundle_manifest(bundle_path: Path) -> BundleManifest:
+    """Read and validate the manifest from a bundle without full extraction.
+
+    Args:
+        bundle_path: Path to the .tar.gz bundle file.
+
+    Returns:
+        Parsed BundleManifest.
+
+    Raises:
+        EsphomeError: If the manifest is missing, invalid, or version unsupported.
+    """
+
+    try:
+        with tarfile.open(bundle_path, "r:gz") as tar:
+            manifest = _read_manifest_from_tar(tar)
+    except tarfile.TarError as err:
+        raise EsphomeError(f"Failed to read bundle: {err}") from err
+
+    return BundleManifest(
+        manifest_version=manifest[ManifestKey.MANIFEST_VERSION],
+        esphome_version=manifest.get(ManifestKey.ESPHOME_VERSION, "unknown"),
+        config_filename=manifest[ManifestKey.CONFIG_FILENAME],
+        files=manifest.get(ManifestKey.FILES, []),
+        has_secrets=manifest.get(ManifestKey.HAS_SECRETS, False),
+    )
+
+
+def _read_manifest_from_tar(tar: tarfile.TarFile) -> dict[str, Any]:
+    """Read and validate manifest.json from an open tar archive."""
+
+    try:
+        member = tar.getmember(MANIFEST_FILENAME)
+    except KeyError:
+        raise EsphomeError("Invalid bundle: missing manifest.json") from None
+
+    f = tar.extractfile(member)
+    if f is None:
+        raise EsphomeError("Invalid bundle: manifest.json is not a regular file")
+
+    if member.size > MAX_MANIFEST_SIZE:
+        raise EsphomeError(
+            f"Invalid bundle: manifest.json too large "
+            f"({member.size} bytes, max {MAX_MANIFEST_SIZE})"
+        )
+
+    try:
+        manifest = json.loads(f.read())
+    except (json.JSONDecodeError, UnicodeDecodeError) as err:
+        raise EsphomeError(f"Invalid bundle: malformed manifest.json: {err}") from err
+
+    # Version check
+    version = manifest.get(ManifestKey.MANIFEST_VERSION)
+    if version is None:
+        raise EsphomeError("Invalid bundle: manifest.json missing 'manifest_version'")
+    if not isinstance(version, int) or version < 1:
+        raise EsphomeError(
+            f"Invalid bundle: manifest_version must be a positive integer, got {version!r}"
+        )
+    if version > CURRENT_MANIFEST_VERSION:
+        raise EsphomeError(
+            f"Bundle manifest version {version} is newer than this ESPHome "
+            f"version supports (max {CURRENT_MANIFEST_VERSION}). "
+            f"Please upgrade ESPHome to compile this bundle."
+        )
+
+    # Required fields
+    if ManifestKey.CONFIG_FILENAME not in manifest:
+        raise EsphomeError("Invalid bundle: manifest.json missing 'config_filename'")
+
+    return manifest
+
+
+def _validate_tar_members(tar: tarfile.TarFile, target_dir: Path) -> None:
+    """Sanity-check tar members to prevent mistakes and accidental overwrites.
+
+    This is not a security boundary — bundles are created locally or come
+    from a trusted build pipeline.  The checks catch malformed archives
+    and common mistakes (stray absolute paths, ``..`` components) that
+    could silently overwrite unrelated files.
+    """
+
+    total_size = 0
+    for member in tar.getmembers():
+        # Reject absolute paths (Unix and Windows)
+        if member.name.startswith(("/", "\\")):
+            raise EsphomeError(
+                f"Invalid bundle: absolute path in archive: {member.name}"
+            )
+
+        # Reject path traversal (split on both / and \ for cross-platform)
+        parts = re.split(r"[/\\]", member.name)
+        if ".." in parts:
+            raise EsphomeError(
+                f"Invalid bundle: path traversal in archive: {member.name}"
+            )
+
+        # Reject symlinks
+        if member.issym() or member.islnk():
+            raise EsphomeError(f"Invalid bundle: symlink in archive: {member.name}")
+
+        # Ensure extraction stays within target_dir
+        target_path = (target_dir / member.name).resolve()
+        if not target_path.is_relative_to(target_dir):
+            raise EsphomeError(
+                f"Invalid bundle: file would extract outside target: {member.name}"
+            )
+
+        # Track total decompressed size
+        total_size += member.size
+        if total_size > MAX_DECOMPRESSED_SIZE:
+            raise EsphomeError(
+                f"Invalid bundle: decompressed size exceeds "
+                f"{MAX_DECOMPRESSED_SIZE // (1024 * 1024)}MB limit"
+            )
+
+
+def is_bundle_path(path: Path) -> bool:
+    """Check if a path looks like a bundle file."""
+    return path.name.lower().endswith(BUNDLE_EXTENSION)
+
+
+def _add_bytes_to_tar(tar: tarfile.TarFile, name: str, data: bytes) -> None:
+    """Add in-memory bytes to a tar archive with deterministic metadata."""
+    info = tarfile.TarInfo(name=name)
+    info.size = len(data)
+    info.mtime = 0
+    info.uid = 0
+    info.gid = 0
+    info.mode = 0o644
+    tar.addfile(info, io.BytesIO(data))
+
+
+def _resolve_include_path(include_path: Any) -> Path | None:
+    """Resolve an include path to absolute, skipping system includes."""
+    if isinstance(include_path, str) and include_path.startswith("<"):
+        return None  # System include, not a local file
+    p = Path(include_path)
+    if not p.is_absolute():
+        p = CORE.relative_config_path(p)
+    return p
+
+
+def _default_target_dir(bundle_path: Path) -> Path:
+    """Compute the default extraction directory for a bundle."""
+    name = bundle_path.name
+    if name.lower().endswith(BUNDLE_EXTENSION):
+        name = name[: -len(BUNDLE_EXTENSION)]
+    return bundle_path.parent / name
+
+
+def _restore_preserved_dirs(preserved: dict[str, Path], target_dir: Path) -> None:
+    """Move preserved build cache directories back into target_dir.
+
+    If the bundle contained entries under a preserved directory name,
+    the extracted copy is removed so the original cache always wins.
+    """
+    for dirname, src in preserved.items():
+        dst = target_dir / dirname
+        if dst.exists():
+            shutil.rmtree(dst)
+        shutil.move(str(src), str(dst))
+
+
+def prepare_bundle_for_compile(
+    bundle_path: Path,
+    target_dir: Path | None = None,
+) -> Path:
+    """Extract a bundle for compilation, preserving build caches.
+
+    Unlike extract_bundle(), this preserves .esphome/ and .pioenvs/
+    directories in the target if they already exist (for incremental builds).
+
+    Args:
+        bundle_path: Path to the .tar.gz bundle file.
+        target_dir: Directory to extract into. Must be specified for
+                     build server use.
+
+    Returns:
+        Absolute path to the extracted config YAML file.
+    """
+
+    bundle_path = bundle_path.resolve()
+    if not bundle_path.is_file():
+        raise EsphomeError(f"Bundle file not found: {bundle_path}")
+
+    if target_dir is None:
+        target_dir = _default_target_dir(bundle_path)
+
+    target_dir = target_dir.resolve()
+    target_dir.mkdir(parents=True, exist_ok=True)
+
+    preserved: dict[str, Path] = {}
+
+    # Temporarily move preserved dirs out of the way
+    staging = target_dir / _BUNDLE_STAGING_DIR
+    for dirname in _PRESERVE_DIRS:
+        src = target_dir / dirname
+        if src.is_dir():
+            dst = staging / dirname
+            dst.parent.mkdir(parents=True, exist_ok=True)
+            shutil.move(str(src), str(dst))
+            preserved[dirname] = dst
+
+    try:
+        # Clean non-preserved content and extract fresh
+        for item in target_dir.iterdir():
+            if item.name == _BUNDLE_STAGING_DIR:
+                continue
+            if item.is_dir():
+                shutil.rmtree(item)
+            else:
+                item.unlink()
+
+        config_path = extract_bundle(bundle_path, target_dir)
+    finally:
+        # Restore preserved dirs (idempotent) and clean staging
+        _restore_preserved_dirs(preserved, target_dir)
+        if staging.is_dir():
+            shutil.rmtree(staging)
+
+    return config_path

esphome/codegen.py

@@ -11,6 +11,7 @@
 from esphome.cpp_generator import (  # noqa: F401
     ArrayInitializer,
     Expression,
+    FlashStringLiteral,
     LineComment,
     LogStringLiteral,
     MockObj,
@@ -78,6 +79,7 @@ from esphome.cpp_types import (  # noqa: F401
     float_,
     global_ns,
     gpio_Flags,
+    int8,
     int16,
     int32,
     int64,

esphome/components/absolute_humidity/absolute_humidity.cpp

@@ -1,22 +1,29 @@
 #include "esphome/core/log.h"
 #include "absolute_humidity.h"
 
-namespace esphome {
-namespace absolute_humidity {
+namespace esphome::absolute_humidity {
 
-static const char *const TAG = "absolute_humidity.sensor";
+static const char *const TAG{"absolute_humidity.sensor"};
 
 void AbsoluteHumidityComponent::setup() {
+  this->temperature_sensor_->add_on_state_callback([this](float state) {
+    this->temperature_ = state;
+    this->enable_loop();
+  });
   ESP_LOGD(TAG, "  Added callback for temperature '%s'", this->temperature_sensor_->get_name().c_str());
-  this->temperature_sensor_->add_on_state_callback([this](float state) { this->temperature_callback_(state); });
+  // Get initial value
   if (this->temperature_sensor_->has_state()) {
-    this->temperature_callback_(this->temperature_sensor_->get_state());
+    this->temperature_ = this->temperature_sensor_->get_state();
   }
 
+  this->humidity_sensor_->add_on_state_callback([this](float state) {
+    this->humidity_ = state;
+    this->enable_loop();
+  });
   ESP_LOGD(TAG, "  Added callback for relative humidity '%s'", this->humidity_sensor_->get_name().c_str());
-  this->humidity_sensor_->add_on_state_callback([this](float state) { this->humidity_callback_(state); });
+  // Get initial value
   if (this->humidity_sensor_->has_state()) {
-    this->humidity_callback_(this->humidity_sensor_->get_state());
+    this->humidity_ = this->humidity_sensor_->get_state();
   }
 }
 
@@ -46,14 +53,12 @@ void AbsoluteHumidityComponent::dump_config() {
 }
 
 void AbsoluteHumidityComponent::loop() {
-  if (!this->next_update_) {
-    return;
-  }
-  this->next_update_ = false;
+  // Only run once
+  this->disable_loop();
 
   // Ensure we have source data
-  const bool no_temperature = std::isnan(this->temperature_);
-  const bool no_humidity = std::isnan(this->humidity_);
+  const bool no_temperature{std::isnan(this->temperature_)};
+  const bool no_humidity{std::isnan(this->humidity_)};
   if (no_temperature || no_humidity) {
     if (no_temperature) {
       ESP_LOGW(TAG, "No valid state from temperature sensor!");
@@ -67,9 +72,9 @@ void AbsoluteHumidityComponent::loop() {
   }
 
   // Convert to desired units
-  const float temperature_c = this->temperature_;
-  const float temperature_k = temperature_c + 273.15;
-  const float hr = this->humidity_ / 100;
+  const float temperature_c{this->temperature_};
+  const float temperature_k{temperature_c + 273.15f};
+  const float hr{this->humidity_ / 100.0f};
 
   // Calculate saturation vapor pressure
   float es;
@@ -90,12 +95,9 @@ void AbsoluteHumidityComponent::loop() {
   }
 
   // Calculate absolute humidity
-  const float absolute_humidity = vapor_density(es, hr, temperature_k);
+  const float absolute_humidity{vapor_density(es, hr, temperature_k)};
 
-  ESP_LOGD(TAG,
-           "Saturation vapor pressure %f kPa\n"
-           "Publishing absolute humidity %f g/m³",
-           es, absolute_humidity);
+  ESP_LOGD(TAG, "Saturation vapor pressure %f kPa, absolute humidity %f g/m³", es, absolute_humidity);
 
   // Publish absolute humidity
   this->status_clear_warning();
@@ -106,16 +108,16 @@ void AbsoluteHumidityComponent::loop() {
 // More accurate than Tetens in normal meteorologic conditions
 float AbsoluteHumidityComponent::es_buck(float temperature_c) {
   float a, b, c, d;
-  if (temperature_c >= 0) {
-    a = 0.61121;
-    b = 18.678;
-    c = 234.5;
-    d = 257.14;
+  if (temperature_c >= 0.0f) {
+    a = 0.61121f;
+    b = 18.678f;
+    c = 234.5f;
+    d = 257.14f;
   } else {
-    a = 0.61115;
-    b = 18.678;
-    c = 233.7;
-    d = 279.82;
+    a = 0.61115f;
+    b = 18.678f;
+    c = 233.7f;
+    d = 279.82f;
   }
   return a * expf((b - (temperature_c / c)) * (temperature_c / (d + temperature_c)));
 }
@@ -123,14 +125,14 @@ float AbsoluteHumidityComponent::es_buck(float temperature_c) {
 // Tetens equation (https://en.wikipedia.org/wiki/Tetens_equation)
 float AbsoluteHumidityComponent::es_tetens(float temperature_c) {
   float a, b;
-  if (temperature_c >= 0) {
-    a = 17.27;
-    b = 237.3;
+  if (temperature_c >= 0.0f) {
+    a = 17.27f;
+    b = 237.3f;
   } else {
-    a = 21.875;
-    b = 265.5;
+    a = 21.875f;
+    b = 265.5f;
   }
-  return 0.61078 * expf((a * temperature_c) / (temperature_c + b));
+  return 0.61078f * expf((a * temperature_c) / (temperature_c + b));
 }
 
 // Wobus equation
@@ -149,18 +151,18 @@ float AbsoluteHumidityComponent::es_wobus(float t) {
   //
   //     Baker, Schlatter  17-MAY-1982     Original version.
 
-  const float c0 = +0.99999683e00;
-  const float c1 = -0.90826951e-02;
-  const float c2 = +0.78736169e-04;
-  const float c3 = -0.61117958e-06;
-  const float c4 = +0.43884187e-08;
-  const float c5 = -0.29883885e-10;
-  const float c6 = +0.21874425e-12;
-  const float c7 = -0.17892321e-14;
-  const float c8 = +0.11112018e-16;
-  const float c9 = -0.30994571e-19;
-  const float p = c0 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * (c5 + t * (c6 + t * (c7 + t * (c8 + t * (c9)))))))));
-  return 0.61078 / pow(p, 8);
+  constexpr float c0{+0.99999683e+00f};
+  constexpr float c1{-0.90826951e-02f};
+  constexpr float c2{+0.78736169e-04f};
+  constexpr float c3{-0.61117958e-06f};
+  constexpr float c4{+0.43884187e-08f};
+  constexpr float c5{-0.29883885e-10f};
+  constexpr float c6{+0.21874425e-12f};
+  constexpr float c7{-0.17892321e-14f};
+  constexpr float c8{+0.11112018e-16f};
+  constexpr float c9{-0.30994571e-19f};
+  const float p{c0 + t * (c1 + t * (c2 + t * (c3 + t * (c4 + t * (c5 + t * (c6 + t * (c7 + t * (c8 + t * (c9)))))))))};
+  return 0.61078f / powf(p, 8.0f);
 }
 
 // From https://www.environmentalbiophysics.org/chalk-talk-how-to-calculate-absolute-humidity/
@@ -171,11 +173,10 @@ float AbsoluteHumidityComponent::vapor_density(float es, float hr, float ta) {
   // hr = relative humidity [0-1]
   // ta = absolute temperature (K)
 
-  const float ea = hr * es * 1000;   // vapor pressure of the air (Pa)
-  const float mw = 18.01528;         // molar mass of water (g⋅mol⁻¹)
-  const float r = 8.31446261815324;  // molar gas constant (J⋅K⁻¹)
+  const float ea{hr * es * 1000.0f};  // vapor pressure of the air (Pa)
+  const float mw{18.01528f};          // molar mass of water (g⋅mol⁻¹)
+  const float r{8.31446261815324f};   // molar gas constant (J⋅K⁻¹)
   return (ea * mw) / (r * ta);
 }
 
-}  // namespace absolute_humidity
-}  // namespace esphome
+}  // namespace esphome::absolute_humidity

esphome/components/absolute_humidity/absolute_humidity.h

@@ -3,8 +3,7 @@
 #include "esphome/core/component.h"
 #include "esphome/components/sensor/sensor.h"
 
-namespace esphome {
-namespace absolute_humidity {
+namespace esphome::absolute_humidity {
 
 /// Enum listing all implemented saturation vapor pressure equations.
 enum SaturationVaporPressureEquation {
@@ -16,8 +15,6 @@ enum SaturationVaporPressureEquation {
 /// This class implements calculation of absolute humidity from temperature and relative humidity.
 class AbsoluteHumidityComponent : public sensor::Sensor, public Component {
  public:
-  AbsoluteHumidityComponent() = default;
-
   void set_temperature_sensor(sensor::Sensor *temperature_sensor) { this->temperature_sensor_ = temperature_sensor; }
   void set_humidity_sensor(sensor::Sensor *humidity_sensor) { this->humidity_sensor_ = humidity_sensor; }
   void set_equation(SaturationVaporPressureEquation equation) { this->equation_ = equation; }
@@ -27,15 +24,6 @@ class AbsoluteHumidityComponent : public sensor::Sensor, public Component {
   void loop() override;
 
  protected:
-  void temperature_callback_(float state) {
-    this->next_update_ = true;
-    this->temperature_ = state;
-  }
-  void humidity_callback_(float state) {
-    this->next_update_ = true;
-    this->humidity_ = state;
-  }
-
   /** Buck equation for saturation vapor pressure in kPa.
    *
    * @param temperature_c Air temperature in °C.
@@ -57,19 +45,15 @@ class AbsoluteHumidityComponent : public sensor::Sensor, public Component {
    * @param es Saturation vapor pressure in kPa.
    * @param hr Relative humidity 0 to 1.
    * @param ta Absolute temperature in K.
-   * @param heater_duration The duration in ms that the heater should turn on for when measuring.
    */
   static float vapor_density(float es, float hr, float ta);
 
   sensor::Sensor *temperature_sensor_{nullptr};
   sensor::Sensor *humidity_sensor_{nullptr};
 
-  bool next_update_{false};
-
   float temperature_{NAN};
   float humidity_{NAN};
   SaturationVaporPressureEquation equation_;
 };
 
-}  // namespace absolute_humidity
-}  // namespace esphome
+}  // namespace esphome::absolute_humidity

esphome/components/ac_dimmer/ac_dimmer.cpp

@@ -199,12 +199,19 @@ void AcDimmer::setup() {
   setTimer1Callback(&timer_interrupt);
 #endif
 #ifdef USE_ESP32
-  dimmer_timer = timer_begin(TIMER_FREQUENCY_HZ);
-  timer_attach_interrupt(dimmer_timer, &AcDimmerDataStore::s_timer_intr);
-  // For ESP32, we can't use dynamic interval calculation because the timerX functions
-  // are not callable from ISR (placed in flash storage).
-  // Here we just use an interrupt firing every 50 µs.
-  timer_alarm(dimmer_timer, TIMER_INTERVAL_US, true, 0);
+  if (dimmer_timer == nullptr) {
+    dimmer_timer = timer_begin(TIMER_FREQUENCY_HZ);
+    if (dimmer_timer == nullptr) {
+      ESP_LOGE(TAG, "Failed to create GPTimer for AC dimmer");
+      this->mark_failed();
+      return;
+    }
+    timer_attach_interrupt(dimmer_timer, &AcDimmerDataStore::s_timer_intr);
+    // For ESP32, we can't use dynamic interval calculation because the timerX functions
+    // are not callable from ISR (placed in flash storage).
+    // Here we just use an interrupt firing every 50 µs.
+    timer_alarm(dimmer_timer, TIMER_INTERVAL_US, true, 0);
+  }
 #endif
 }
 

esphome/components/adc/adc_sensor.h

@@ -22,7 +22,8 @@ namespace adc {
 
 #ifdef USE_ESP32
 // clang-format off
-#if (ESP_IDF_VERSION_MAJOR == 5 && \
+#if ESP_IDF_VERSION_MAJOR >= 6 || \
+    (ESP_IDF_VERSION_MAJOR == 5 && \
      ((ESP_IDF_VERSION_MINOR == 0 && ESP_IDF_VERSION_PATCH >= 5) || \
       (ESP_IDF_VERSION_MINOR == 1 && ESP_IDF_VERSION_PATCH >= 3) || \
       (ESP_IDF_VERSION_MINOR >= 2)) \

esphome/components/adc/adc_sensor_esp32.cpp

@@ -2,6 +2,7 @@
 
 #include "adc_sensor.h"
 #include "esphome/core/log.h"
+#include <cinttypes>
 
 namespace esphome {
 namespace adc {
@@ -346,7 +347,8 @@ float ADCSensor::sample_autorange_() {
   ESP_LOGVV(TAG, "Autorange summary:");
   ESP_LOGVV(TAG, "  Raw readings: 12db=%d, 6db=%d, 2.5db=%d, 0db=%d", raw12, raw6, raw2, raw0);
   ESP_LOGVV(TAG, "  Voltages: 12db=%.6f, 6db=%.6f, 2.5db=%.6f, 0db=%.6f", mv12, mv6, mv2, mv0);
-  ESP_LOGVV(TAG, "  Coefficients: c12=%u, c6=%u, c2=%u, c0=%u, sum=%u", c12, c6, c2, c0, csum);
+  ESP_LOGVV(TAG, "  Coefficients: c12=%" PRIu32 ", c6=%" PRIu32 ", c2=%" PRIu32 ", c0=%" PRIu32 ", sum=%" PRIu32, c12,
+            c6, c2, c0, csum);
 
   if (csum == 0) {
     ESP_LOGE(TAG, "Invalid weight sum in autorange calculation");
@@ -354,8 +356,10 @@ float ADCSensor::sample_autorange_() {
   }
 
   const float final_result = (mv12 * c12 + mv6 * c6 + mv2 * c2 + mv0 * c0) / csum;
-  ESP_LOGV(TAG, "Autorange final: (%.6f*%u + %.6f*%u + %.6f*%u + %.6f*%u)/%u = %.6fV", mv12, c12, mv6, c6, mv2, c2, mv0,
-           c0, csum, final_result);
+  ESP_LOGV(TAG,
+           "Autorange final: (%.6f*%" PRIu32 " + %.6f*%" PRIu32 " + %.6f*%" PRIu32 " + %.6f*%" PRIu32 ")/%" PRIu32
+           " = %.6fV",
+           mv12, c12, mv6, c6, mv2, c2, mv0, c0, csum, final_result);
 
   return final_result;
 }

esphome/components/adc/adc_sensor_rp2040.cpp

@@ -8,6 +8,13 @@
 #endif  // CYW43_USES_VSYS_PIN
 #include <hardware/adc.h>
 
+// PICO_VSYS_PIN is defined in pico-sdk board headers (e.g. boards/pico2.h),
+// but the Arduino framework's config_autogen.h includes a generic board header
+// that doesn't define it. Provide the standard value (pin 29) as a fallback.
+#ifndef PICO_VSYS_PIN
+#define PICO_VSYS_PIN 29  // NOLINT(cppcoreguidelines-macro-usage)
+#endif
+
 namespace esphome {
 namespace adc {
 

esphome/components/addressable_light/addressable_light_display.cpp

@@ -58,7 +58,10 @@ void HOT AddressableLightDisplay::draw_absolute_pixel_internal(int x, int y, Col
 
   if (this->pixel_mapper_f_.has_value()) {
     // Params are passed by reference, so they may be modified in call.
-    this->addressable_light_buffer_[(*this->pixel_mapper_f_)(x, y)] = color;
+    int index = (*this->pixel_mapper_f_)(x, y);
+    if (index < 0 || static_cast<size_t>(index) >= this->addressable_light_buffer_.size())
+      return;
+    this->addressable_light_buffer_[index] = color;
   } else {
     this->addressable_light_buffer_[y * this->get_width_internal() + x] = color;
   }

esphome/components/addressable_light/addressable_light_display.h

@@ -33,7 +33,7 @@ class AddressableLightDisplay : public display::DisplayBuffer {
         // - Save the current effect index.
         this->last_effect_index_ = light_state_->get_current_effect_index();
         // - Disable any current effect.
-        light_state_->make_call().set_effect(0).perform();
+        light_state_->make_call().set_effect(uint32_t{0}).perform();
       }
     }
     enabled_ = enabled;

esphome/components/ade7880/ade7880.cpp

@@ -121,7 +121,7 @@ void ADE7880::update() {
     this->update_sensor_from_s32_register16_(chan->forward_active_energy, AFWATTHR, [&chan](float val) {
       return chan->forward_active_energy_total += val / 14400.0f;
     });
-    this->update_sensor_from_s32_register16_(chan->reverse_active_energy, AFWATTHR, [&chan](float val) {
+    this->update_sensor_from_s32_register16_(chan->reverse_active_energy, ARWATTHR, [&chan](float val) {
       return chan->reverse_active_energy_total += val / 14400.0f;
     });
   }
@@ -137,7 +137,7 @@ void ADE7880::update() {
     this->update_sensor_from_s32_register16_(chan->forward_active_energy, BFWATTHR, [&chan](float val) {
       return chan->forward_active_energy_total += val / 14400.0f;
     });
-    this->update_sensor_from_s32_register16_(chan->reverse_active_energy, BFWATTHR, [&chan](float val) {
+    this->update_sensor_from_s32_register16_(chan->reverse_active_energy, BRWATTHR, [&chan](float val) {
       return chan->reverse_active_energy_total += val / 14400.0f;
     });
   }
@@ -153,7 +153,7 @@ void ADE7880::update() {
     this->update_sensor_from_s32_register16_(chan->forward_active_energy, CFWATTHR, [&chan](float val) {
       return chan->forward_active_energy_total += val / 14400.0f;
     });
-    this->update_sensor_from_s32_register16_(chan->reverse_active_energy, CFWATTHR, [&chan](float val) {
+    this->update_sensor_from_s32_register16_(chan->reverse_active_energy, CRWATTHR, [&chan](float val) {
       return chan->reverse_active_energy_total += val / 14400.0f;
     });
   }

esphome/components/ade7880/ade7880_registers.h

@@ -85,6 +85,9 @@ constexpr uint16_t CWATTHR = 0xE402;
 constexpr uint16_t AFWATTHR = 0xE403;
 constexpr uint16_t BFWATTHR = 0xE404;
 constexpr uint16_t CFWATTHR = 0xE405;
+constexpr uint16_t ARWATTHR = 0xE406;
+constexpr uint16_t BRWATTHR = 0xE407;
+constexpr uint16_t CRWATTHR = 0xE408;
 constexpr uint16_t AFVARHR = 0xE409;
 constexpr uint16_t BFVARHR = 0xE40A;
 constexpr uint16_t CFVARHR = 0xE40B;

esphome/components/ade7953_base/ade7953_base.cpp

@@ -8,6 +8,9 @@ namespace ade7953_base {
 
 static const char *const TAG = "ade7953";
 
+constexpr uint16_t CONFIG_DEFAULT = 0x8004u;
+constexpr uint16_t CONFIG_LOCK_BIT = 0x8000u;
+
 static const float ADE_POWER_FACTOR = 154.0f;
 static const float ADE_WATTSEC_POWER_FACTOR = ADE_POWER_FACTOR * ADE_POWER_FACTOR / 3600;
 
@@ -18,7 +21,12 @@ void ADE7953::setup() {
 
   // The chip might take up to 100ms to initialise
   this->set_timeout(100, [this]() {
-    // this->ade_write_8(0x0010, 0x04);
+    // Lock communication interface (SPI or I2C)
+    uint16_t config_v = CONFIG_DEFAULT;
+    this->ade_read_16(CONFIG_16, &config_v);
+    config_v &= static_cast<uint16_t>(~CONFIG_LOCK_BIT);  // Clear the lock bit
+    this->ade_write_16(CONFIG_16, config_v);
+    // Configure optimum settings according to datasheet
     this->ade_write_8(0x00FE, 0xAD);
     this->ade_write_16(0x0120, 0x0030);
     // Set gains

esphome/components/ade7953_base/ade7953_base.h

@@ -9,31 +9,35 @@
 namespace esphome {
 namespace ade7953_base {
 
-static const uint8_t PGA_V_8 =
+static constexpr uint8_t PGA_V_8 =
     0x007;  // PGA_V,  (R/W) Default: 0x00, Unsigned, Voltage channel gain configuration (Bits[2:0])
-static const uint8_t PGA_IA_8 =
+static constexpr uint8_t PGA_IA_8 =
     0x008;  // PGA_IA, (R/W) Default: 0x00, Unsigned, Current Channel A gain configuration (Bits[2:0])
-static const uint8_t PGA_IB_8 =
+static constexpr uint8_t PGA_IB_8 =
     0x009;  // PGA_IB, (R/W) Default: 0x00, Unsigned, Current Channel B gain configuration (Bits[2:0])
 
-static const uint32_t AIGAIN_32 =
+static constexpr uint16_t CONFIG_16 = 0x102;  // CONFIG, (R/W) Default: 0x8004, Unsigned, Configuration register
+
+static constexpr uint16_t AIGAIN_32 =
     0x380;  // AIGAIN, (R/W)   Default: 0x400000, Unsigned,Current channel gain (Current Channel A)(32 bit)
-static const uint32_t AVGAIN_32 = 0x381;  // AVGAIN, (R/W)   Default: 0x400000, Unsigned,Voltage channel gain(32 bit)
-static const uint32_t AWGAIN_32 =
+static constexpr uint16_t AVGAIN_32 =
+    0x381;  // AVGAIN, (R/W)   Default: 0x400000, Unsigned,Voltage channel gain(32 bit)
+static constexpr uint16_t AWGAIN_32 =
     0x382;  // AWGAIN, (R/W)   Default: 0x400000, Unsigned,Active power gain (Current Channel A)(32 bit)
-static const uint32_t AVARGAIN_32 =
+static constexpr uint16_t AVARGAIN_32 =
     0x383;  // AVARGAIN, (R/W) Default: 0x400000, Unsigned, Reactive power gain (Current Channel A)(32 bit)
-static const uint32_t AVAGAIN_32 =
+static constexpr uint16_t AVAGAIN_32 =
     0x384;  // AVAGAIN, (R/W)  Default: 0x400000, Unsigned,Apparent power gain (Current Channel A)(32 bit)
 
-static const uint32_t BIGAIN_32 =
+static constexpr uint16_t BIGAIN_32 =
     0x38C;  // BIGAIN, (R/W)   Default: 0x400000, Unsigned,Current channel gain (Current Channel B)(32 bit)
-static const uint32_t BVGAIN_32 = 0x38D;  // BVGAIN, (R/W)   Default: 0x400000, Unsigned,Voltage channel gain(32 bit)
-static const uint32_t BWGAIN_32 =
+static constexpr uint16_t BVGAIN_32 =
+    0x38D;  // BVGAIN, (R/W)   Default: 0x400000, Unsigned,Voltage channel gain(32 bit)
+static constexpr uint16_t BWGAIN_32 =
     0x38E;  // BWGAIN, (R/W)   Default: 0x400000, Unsigned,Active power gain (Current Channel B)(32 bit)
-static const uint32_t BVARGAIN_32 =
+static constexpr uint16_t BVARGAIN_32 =
     0x38F;  // BVARGAIN, (R/W) Default: 0x400000, Unsigned, Reactive power gain (Current Channel B)(32 bit)
-static const uint32_t BVAGAIN_32 =
+static constexpr uint16_t BVAGAIN_32 =
     0x390;  // BVAGAIN, (R/W)  Default: 0x400000, Unsigned,Apparent power gain (Current Channel B)(32 bit)
 
 class ADE7953 : public PollingComponent, public sensor::Sensor {

esphome/components/ade7953_spi/ade7953_spi.cpp

@@ -7,6 +7,9 @@ namespace ade7953_spi {
 
 static const char *const TAG = "ade7953";
 
+// Datasheet requires at least 1.2µs after clearing CONFIG LOCK_BIT before raising CS
+constexpr uint8_t CONFIG_LOCK_SETTLE_US = 2;
+
 void AdE7953Spi::setup() {
   this->spi_setup();
   ade7953_base::ADE7953::setup();
@@ -32,6 +35,9 @@ bool AdE7953Spi::ade_write_16(uint16_t reg, uint16_t value) {
   this->write_byte16(reg);
   this->transfer_byte(0);
   this->write_byte16(value);
+  if (reg == ade7953_base::CONFIG_16) {
+    delayMicroseconds(CONFIG_LOCK_SETTLE_US);
+  }
   this->disable();
   return false;
 }

esphome/components/ade7953_spi/ade7953_spi.h

@@ -12,7 +12,7 @@ namespace esphome {
 namespace ade7953_spi {
 
 class AdE7953Spi : public ade7953_base::ADE7953,
-                   public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_HIGH, spi::CLOCK_PHASE_LEADING,
+                   public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_HIGH, spi::CLOCK_PHASE_TRAILING,
                                          spi::DATA_RATE_1MHZ> {
  public:
   void setup() override;

esphome/components/ads1115/ads1115.cpp

@@ -173,19 +173,8 @@ float ADS1115Component::request_measurement(ADS1115Multiplexer multiplexer, ADS1
   }
 
   if (resolution == ADS1015_12_BITS) {
-    bool negative = (raw_conversion >> 15) == 1;
-
-    // shift raw_conversion as it's only 12-bits, left justified
-    raw_conversion = raw_conversion >> (16 - ADS1015_12_BITS);
-
-    // check if number was negative in order to keep the sign
-    if (negative) {
-      // the number was negative
-      // 1) set the negative bit back
-      raw_conversion |= 0x8000;
-      // 2) reset the former (shifted) negative bit
-      raw_conversion &= 0xF7FF;
-    }
+    // ADS1015 returns 12-bit value left-justified in 16 bits; shift right and sign-extend
+    raw_conversion = static_cast<uint16_t>(static_cast<int16_t>(raw_conversion) >> (16 - ADS1015_12_BITS));
   }
 
   auto signed_conversion = static_cast<int16_t>(raw_conversion);

esphome/components/ads1118/__init__.py

@@ -12,11 +12,15 @@ CONF_ADS1118_ID = "ads1118_id"
 ads1118_ns = cg.esphome_ns.namespace("ads1118")
 ADS1118 = ads1118_ns.class_("ADS1118", cg.Component, spi.SPIDevice)
 
-CONFIG_SCHEMA = cv.Schema(
-    {
-        cv.GenerateID(): cv.declare_id(ADS1118),
-    }
-).extend(spi.spi_device_schema(cs_pin_required=True))
+CONFIG_SCHEMA = (
+    cv.Schema(
+        {
+            cv.GenerateID(): cv.declare_id(ADS1118),
+        }
+    )
+    .extend(spi.spi_device_schema(cs_pin_required=True))
+    .extend(cv.COMPONENT_SCHEMA)
+)
 
 
 async def to_code(config):

esphome/components/ags10/sensor.py

@@ -35,7 +35,7 @@ CONFIG_SCHEMA = (
     cv.Schema(
         {
             cv.GenerateID(): cv.declare_id(AGS10Component),
-            cv.Optional(CONF_TVOC): sensor.sensor_schema(
+            cv.Required(CONF_TVOC): sensor.sensor_schema(
                 unit_of_measurement=UNIT_PARTS_PER_BILLION,
                 icon=ICON_RADIATOR,
                 accuracy_decimals=0,
@@ -92,11 +92,12 @@ AGS10_NEW_I2C_ADDRESS_SCHEMA = cv.maybe_simple_value(
     "ags10.new_i2c_address",
     AGS10NewI2cAddressAction,
     AGS10_NEW_I2C_ADDRESS_SCHEMA,
+    synchronous=True,
 )
 async def ags10newi2caddress_to_code(config, action_id, template_arg, args):
     var = cg.new_Pvariable(action_id, template_arg)
     await cg.register_parented(var, config[CONF_ID])
-    address = await cg.templatable(config[CONF_ADDRESS], args, int)
+    address = await cg.templatable(config[CONF_ADDRESS], args, cg.uint8)
     cg.add(var.set_new_address(address))
     return var
 
@@ -111,7 +112,9 @@ AGS10_SET_ZERO_POINT_ACTION_MODE = {
 AGS10_SET_ZERO_POINT_SCHEMA = cv.Schema(
     {
         cv.GenerateID(): cv.use_id(AGS10Component),
-        cv.Required(CONF_MODE): cv.enum(AGS10_SET_ZERO_POINT_ACTION_MODE, upper=True),
+        cv.Required(CONF_MODE): cv.templatable(
+            cv.enum(AGS10_SET_ZERO_POINT_ACTION_MODE, upper=True)
+        ),
         cv.Optional(CONF_VALUE, default=0xFFFF): cv.templatable(cv.uint16_t),
     },
 )
@@ -121,12 +124,15 @@ AGS10_SET_ZERO_POINT_SCHEMA = cv.Schema(
     "ags10.set_zero_point",
     AGS10SetZeroPointAction,
     AGS10_SET_ZERO_POINT_SCHEMA,
+    synchronous=True,
 )
 async def ags10setzeropoint_to_code(config, action_id, template_arg, args):
     var = cg.new_Pvariable(action_id, template_arg)
     await cg.register_parented(var, config[CONF_ID])
-    mode = await cg.templatable(config.get(CONF_MODE), args, enumerate)
+    mode = await cg.templatable(
+        config.get(CONF_MODE), args, AGS10SetZeroPointActionMode
+    )
     cg.add(var.set_mode(mode))
-    value = await cg.templatable(config[CONF_VALUE], args, int)
+    value = await cg.templatable(config[CONF_VALUE], args, cg.uint16)
     cg.add(var.set_value(value))
     return var

esphome/components/aic3204/audio_dac.py

@@ -34,13 +34,16 @@ SET_AUTO_MUTE_ACTION_SCHEMA = cv.maybe_simple_value(
 
 
 @automation.register_action(
-    "aic3204.set_auto_mute_mode", SetAutoMuteAction, SET_AUTO_MUTE_ACTION_SCHEMA
+    "aic3204.set_auto_mute_mode",
+    SetAutoMuteAction,
+    SET_AUTO_MUTE_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def aic3204_set_volume_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, paren)
 
-    template_ = await cg.templatable(config.get(CONF_MODE), args, int)
+    template_ = await cg.templatable(config.get(CONF_MODE), args, cg.uint8)
     cg.add(var.set_auto_mute_mode(template_))
 
     return var

esphome/components/alarm_control_panel/__init__.py

@@ -10,7 +10,6 @@ from esphome.const import (
     CONF_ID,
     CONF_MQTT_ID,
     CONF_ON_STATE,
-    CONF_TRIGGER_ID,
     CONF_WEB_SERVER,
 )
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
@@ -34,39 +33,9 @@ CONF_ON_READY = "on_ready"
 alarm_control_panel_ns = cg.esphome_ns.namespace("alarm_control_panel")
 AlarmControlPanel = alarm_control_panel_ns.class_("AlarmControlPanel", cg.EntityBase)
 
-StateTrigger = alarm_control_panel_ns.class_(
-    "StateTrigger", automation.Trigger.template()
-)
-TriggeredTrigger = alarm_control_panel_ns.class_(
-    "TriggeredTrigger", automation.Trigger.template()
-)
-ClearedTrigger = alarm_control_panel_ns.class_(
-    "ClearedTrigger", automation.Trigger.template()
-)
-ArmingTrigger = alarm_control_panel_ns.class_(
-    "ArmingTrigger", automation.Trigger.template()
-)
-PendingTrigger = alarm_control_panel_ns.class_(
-    "PendingTrigger", automation.Trigger.template()
-)
-ArmedHomeTrigger = alarm_control_panel_ns.class_(
-    "ArmedHomeTrigger", automation.Trigger.template()
-)
-ArmedNightTrigger = alarm_control_panel_ns.class_(
-    "ArmedNightTrigger", automation.Trigger.template()
-)
-ArmedAwayTrigger = alarm_control_panel_ns.class_(
-    "ArmedAwayTrigger", automation.Trigger.template()
-)
-DisarmedTrigger = alarm_control_panel_ns.class_(
-    "DisarmedTrigger", automation.Trigger.template()
-)
-ChimeTrigger = alarm_control_panel_ns.class_(
-    "ChimeTrigger", automation.Trigger.template()
-)
-ReadyTrigger = alarm_control_panel_ns.class_(
-    "ReadyTrigger", automation.Trigger.template()
-)
+StateAnyForwarder = alarm_control_panel_ns.class_("StateAnyForwarder")
+StateEnterForwarder = alarm_control_panel_ns.class_("StateEnterForwarder")
+AlarmControlPanelState = alarm_control_panel_ns.enum("AlarmControlPanelState")
 
 ArmAwayAction = alarm_control_panel_ns.class_("ArmAwayAction", automation.Action)
 ArmHomeAction = alarm_control_panel_ns.class_("ArmHomeAction", automation.Action)
@@ -89,61 +58,17 @@ _ALARM_CONTROL_PANEL_SCHEMA = (
             cv.OnlyWith(CONF_MQTT_ID, "mqtt"): cv.declare_id(
                 mqtt.MQTTAlarmControlPanelComponent
             ),
-            cv.Optional(CONF_ON_STATE): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(StateTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_TRIGGERED): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(TriggeredTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_ARMING): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ArmingTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_PENDING): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(PendingTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_ARMED_HOME): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ArmedHomeTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_ARMED_NIGHT): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ArmedNightTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_ARMED_AWAY): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ArmedAwayTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_DISARMED): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(DisarmedTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_CLEARED): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ClearedTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_CHIME): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ChimeTrigger),
-                }
-            ),
-            cv.Optional(CONF_ON_READY): automation.validate_automation(
-                {
-                    cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ReadyTrigger),
-                }
-            ),
+            cv.Optional(CONF_ON_STATE): automation.validate_automation({}),
+            cv.Optional(CONF_ON_TRIGGERED): automation.validate_automation({}),
+            cv.Optional(CONF_ON_ARMING): automation.validate_automation({}),
+            cv.Optional(CONF_ON_PENDING): automation.validate_automation({}),
+            cv.Optional(CONF_ON_ARMED_HOME): automation.validate_automation({}),
+            cv.Optional(CONF_ON_ARMED_NIGHT): automation.validate_automation({}),
+            cv.Optional(CONF_ON_ARMED_AWAY): automation.validate_automation({}),
+            cv.Optional(CONF_ON_DISARMED): automation.validate_automation({}),
+            cv.Optional(CONF_ON_CLEARED): automation.validate_automation({}),
+            cv.Optional(CONF_ON_CHIME): automation.validate_automation({}),
+            cv.Optional(CONF_ON_READY): automation.validate_automation({}),
         }
     )
 )
@@ -186,41 +111,66 @@ ALARM_CONTROL_PANEL_CONDITION_SCHEMA = maybe_simple_id(
 )
 
 
+_CALLBACK_AUTOMATIONS = (
+    automation.CallbackAutomation(
+        CONF_ON_STATE, "add_on_state_callback", forwarder=StateAnyForwarder
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_TRIGGERED,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(
+            AlarmControlPanelState.ACP_STATE_TRIGGERED
+        ),
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_ARMING,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(AlarmControlPanelState.ACP_STATE_ARMING),
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_PENDING,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(
+            AlarmControlPanelState.ACP_STATE_PENDING
+        ),
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_ARMED_HOME,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(
+            AlarmControlPanelState.ACP_STATE_ARMED_HOME
+        ),
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_ARMED_NIGHT,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(
+            AlarmControlPanelState.ACP_STATE_ARMED_NIGHT
+        ),
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_ARMED_AWAY,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(
+            AlarmControlPanelState.ACP_STATE_ARMED_AWAY
+        ),
+    ),
+    automation.CallbackAutomation(
+        CONF_ON_DISARMED,
+        "add_on_state_callback",
+        forwarder=StateEnterForwarder.template(
+            AlarmControlPanelState.ACP_STATE_DISARMED
+        ),
+    ),
+    automation.CallbackAutomation(CONF_ON_CLEARED, "add_on_cleared_callback"),
+    automation.CallbackAutomation(CONF_ON_CHIME, "add_on_chime_callback"),
+    automation.CallbackAutomation(CONF_ON_READY, "add_on_ready_callback"),
+)
+
+
+@setup_entity("alarm_control_panel")
 async def setup_alarm_control_panel_core_(var, config):
-    await setup_entity(var, config, "alarm_control_panel")
-    for conf in config.get(CONF_ON_STATE, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_TRIGGERED, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_ARMING, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_PENDING, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_ARMED_HOME, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_ARMED_NIGHT, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_ARMED_AWAY, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_DISARMED, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_CLEARED, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_CHIME, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
-    for conf in config.get(CONF_ON_READY, []):
-        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [], conf)
+    await automation.build_callback_automations(var, config, _CALLBACK_AUTOMATIONS)
     if web_server_config := config.get(CONF_WEB_SERVER):
         await web_server.add_entity_config(var, web_server_config)
     if mqtt_id := config.get(CONF_MQTT_ID):
@@ -243,7 +193,10 @@ async def new_alarm_control_panel(config, *args):
 
 
 @automation.register_action(
-    "alarm_control_panel.arm_away", ArmAwayAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.arm_away",
+    ArmAwayAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_arm_away_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -255,7 +208,10 @@ async def alarm_action_arm_away_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.arm_home", ArmHomeAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.arm_home",
+    ArmHomeAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_arm_home_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -267,7 +223,10 @@ async def alarm_action_arm_home_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.arm_night", ArmNightAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.arm_night",
+    ArmNightAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_arm_night_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -279,7 +238,10 @@ async def alarm_action_arm_night_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.disarm", DisarmAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.disarm",
+    DisarmAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_disarm_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -291,7 +253,10 @@ async def alarm_action_disarm_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.pending", PendingAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.pending",
+    PendingAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_pending_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -299,7 +264,10 @@ async def alarm_action_pending_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.triggered", TriggeredAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.triggered",
+    TriggeredAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_trigger_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -307,7 +275,10 @@ async def alarm_action_trigger_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.chime", ChimeAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.chime",
+    ChimeAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def alarm_action_chime_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
@@ -315,7 +286,10 @@ async def alarm_action_chime_to_code(config, action_id, template_arg, args):
 
 
 @automation.register_action(
-    "alarm_control_panel.ready", ReadyAction, ALARM_CONTROL_PANEL_ACTION_SCHEMA
+    "alarm_control_panel.ready",
+    ReadyAction,
+    ALARM_CONTROL_PANEL_ACTION_SCHEMA,
+    synchronous=True,
 )
 @automation.register_condition(
     "alarm_control_panel.ready",

esphome/components/alarm_control_panel/alarm_control_panel.cpp

@@ -31,12 +31,12 @@ void AlarmControlPanel::publish_state(AlarmControlPanelState state) {
   this->last_update_ = millis();
   if (state != this->current_state_) {
     auto prev_state = this->current_state_;
-    ESP_LOGD(TAG, "'%s' >> %s (was %s)", this->get_name().c_str(),
+    ESP_LOGV(TAG, "'%s' >> %s (was %s)", this->get_name().c_str(),
              LOG_STR_ARG(alarm_control_panel_state_to_string(state)),
              LOG_STR_ARG(alarm_control_panel_state_to_string(prev_state)));
     this->current_state_ = state;
-    // Single state callback - triggers check get_state() for specific states
-    this->state_callback_.call();
+    // Single state callback - listeners receive the new state as an argument
+    this->state_callback_.call(state);
 #if defined(USE_ALARM_CONTROL_PANEL) && defined(USE_CONTROLLER_REGISTRY)
     ControllerRegistry::notify_alarm_control_panel_update(this);
 #endif
@@ -51,22 +51,6 @@ void AlarmControlPanel::publish_state(AlarmControlPanelState state) {
   }
 }
 
-void AlarmControlPanel::add_on_state_callback(std::function<void()> &&callback) {
-  this->state_callback_.add(std::move(callback));
-}
-
-void AlarmControlPanel::add_on_cleared_callback(std::function<void()> &&callback) {
-  this->cleared_callback_.add(std::move(callback));
-}
-
-void AlarmControlPanel::add_on_chime_callback(std::function<void()> &&callback) {
-  this->chime_callback_.add(std::move(callback));
-}
-
-void AlarmControlPanel::add_on_ready_callback(std::function<void()> &&callback) {
-  this->ready_callback_.add(std::move(callback));
-}
-
 void AlarmControlPanel::arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(),
                                        const char *code) {
   auto call = this->make_call();

esphome/components/alarm_control_panel/alarm_control_panel.h

@@ -37,25 +37,24 @@ class AlarmControlPanel : public EntityBase {
    *
    * @param callback The callback function
    */
-  void add_on_state_callback(std::function<void()> &&callback);
+  template<typename F> void add_on_state_callback(F &&callback) {
+    this->state_callback_.add(std::forward<F>(callback));
+  }
 
-  /** Add a callback for when the state of the alarm_control_panel clears from triggered
-   *
-   * @param callback The callback function
-   */
-  void add_on_cleared_callback(std::function<void()> &&callback);
+  /** Add a callback for when the state of the alarm_control_panel clears from triggered. */
+  template<typename F> void add_on_cleared_callback(F &&callback) {
+    this->cleared_callback_.add(std::forward<F>(callback));
+  }
 
-  /** Add a callback for when a chime zone goes from closed to open
-   *
-   * @param callback The callback function
-   */
-  void add_on_chime_callback(std::function<void()> &&callback);
+  /** Add a callback for when a chime zone goes from closed to open. */
+  template<typename F> void add_on_chime_callback(F &&callback) {
+    this->chime_callback_.add(std::forward<F>(callback));
+  }
 
-  /** Add a callback for when a ready state changes
-   *
-   * @param callback The callback function
-   */
-  void add_on_ready_callback(std::function<void()> &&callback);
+  /** Add a callback for when a ready state changes. */
+  template<typename F> void add_on_ready_callback(F &&callback) {
+    this->ready_callback_.add(std::forward<F>(callback));
+  }
 
   /** A numeric representation of the supported features as per HomeAssistant
    *
@@ -146,8 +145,8 @@ class AlarmControlPanel : public EntityBase {
   uint32_t last_update_;
   // the call control function
   virtual void control(const AlarmControlPanelCall &call) = 0;
-  // state callback - triggers check get_state() for specific state
-  LazyCallbackManager<void()> state_callback_{};
+  // state callback - passes the new state to listeners
+  LazyCallbackManager<void(AlarmControlPanelState)> state_callback_{};
   // clear callback - fires when leaving TRIGGERED state
   LazyCallbackManager<void()> cleared_callback_{};
   // chime callback

esphome/components/alarm_control_panel/alarm_control_panel_call.cpp

@@ -12,7 +12,14 @@ AlarmControlPanelCall::AlarmControlPanelCall(AlarmControlPanel *parent) : parent
 
 AlarmControlPanelCall &AlarmControlPanelCall::set_code(const char *code) {
   if (code != nullptr) {
-    this->code_ = std::string(code);
+    return this->set_code(code, strlen(code));
+  }
+  return *this;
+}
+
+AlarmControlPanelCall &AlarmControlPanelCall::set_code(const char *code, size_t len) {
+  if (code != nullptr) {
+    this->code_ = std::string(code, len);
   }
   return *this;
 }

esphome/components/alarm_control_panel/alarm_control_panel_call.h

@@ -15,7 +15,8 @@ class AlarmControlPanelCall {
   AlarmControlPanelCall(AlarmControlPanel *parent);
 
   AlarmControlPanelCall &set_code(const char *code);
-  AlarmControlPanelCall &set_code(const std::string &code) { return this->set_code(code.c_str()); }
+  AlarmControlPanelCall &set_code(const char *code, size_t len);
+  AlarmControlPanelCall &set_code(const std::string &code) { return this->set_code(code.c_str(), code.size()); }
   AlarmControlPanelCall &arm_away();
   AlarmControlPanelCall &arm_home();
   AlarmControlPanelCall &arm_night();

esphome/components/alarm_control_panel/automation.h

@@ -5,60 +5,27 @@
 
 namespace esphome::alarm_control_panel {
 
-/// Trigger on any state change
-class StateTrigger : public Trigger<> {
- public:
-  explicit StateTrigger(AlarmControlPanel *alarm_control_panel) {
-    alarm_control_panel->add_on_state_callback([this]() { this->trigger(); });
+/// Callback forwarder that triggers an Automation<> on any state change.
+/// Pointer-sized (single Automation* field) to fit inline in Callback::ctx_.
+struct StateAnyForwarder {
+  Automation<> *automation;
+  void operator()(AlarmControlPanelState /*state*/) const { this->automation->trigger(); }
+};
+
+/// Callback forwarder that triggers an Automation<> only when the alarm enters a specific state.
+/// Pointer-sized (single Automation* field) to fit inline in Callback::ctx_.
+template<AlarmControlPanelState State> struct StateEnterForwarder {
+  Automation<> *automation;
+  void operator()(AlarmControlPanelState state) const {
+    if (state == State)
+      this->automation->trigger();
   }
 };
 
-/// Template trigger that fires when entering a specific state
-template<AlarmControlPanelState State> class StateEnterTrigger : public Trigger<> {
- public:
-  explicit StateEnterTrigger(AlarmControlPanel *alarm_control_panel) : alarm_control_panel_(alarm_control_panel) {
-    alarm_control_panel->add_on_state_callback([this]() {
-      if (this->alarm_control_panel_->get_state() == State)
-        this->trigger();
-    });
-  }
-
- protected:
-  AlarmControlPanel *alarm_control_panel_;
-};
-
-// Type aliases for state-specific triggers
-using TriggeredTrigger = StateEnterTrigger<ACP_STATE_TRIGGERED>;
-using ArmingTrigger = StateEnterTrigger<ACP_STATE_ARMING>;
-using PendingTrigger = StateEnterTrigger<ACP_STATE_PENDING>;
-using ArmedHomeTrigger = StateEnterTrigger<ACP_STATE_ARMED_HOME>;
-using ArmedNightTrigger = StateEnterTrigger<ACP_STATE_ARMED_NIGHT>;
-using ArmedAwayTrigger = StateEnterTrigger<ACP_STATE_ARMED_AWAY>;
-using DisarmedTrigger = StateEnterTrigger<ACP_STATE_DISARMED>;
-
-/// Trigger when leaving TRIGGERED state (alarm cleared)
-class ClearedTrigger : public Trigger<> {
- public:
-  explicit ClearedTrigger(AlarmControlPanel *alarm_control_panel) {
-    alarm_control_panel->add_on_cleared_callback([this]() { this->trigger(); });
-  }
-};
-
-/// Trigger on chime event (zone opened while disarmed)
-class ChimeTrigger : public Trigger<> {
- public:
-  explicit ChimeTrigger(AlarmControlPanel *alarm_control_panel) {
-    alarm_control_panel->add_on_chime_callback([this]() { this->trigger(); });
-  }
-};
-
-/// Trigger on ready state change
-class ReadyTrigger : public Trigger<> {
- public:
-  explicit ReadyTrigger(AlarmControlPanel *alarm_control_panel) {
-    alarm_control_panel->add_on_ready_callback([this]() { this->trigger(); });
-  }
-};
+static_assert(sizeof(StateAnyForwarder) <= sizeof(void *));
+static_assert(std::is_trivially_copyable_v<StateAnyForwarder>);
+static_assert(sizeof(StateEnterForwarder<ACP_STATE_TRIGGERED>) <= sizeof(void *));
+static_assert(std::is_trivially_copyable_v<StateEnterForwarder<ACP_STATE_TRIGGERED>>);
 
 template<typename... Ts> class ArmAwayAction : public Action<Ts...> {
  public:

esphome/components/alpha3/alpha3.cpp

@@ -125,7 +125,7 @@ void Alpha3::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc
         this->current_sensor_->publish_state(NAN);
       if (this->speed_sensor_ != nullptr)
         this->speed_sensor_->publish_state(NAN);
-      if (this->speed_sensor_ != nullptr)
+      if (this->voltage_sensor_ != nullptr)
         this->voltage_sensor_->publish_state(NAN);
       break;
     }

esphome/components/alpha3/sensor.py

@@ -9,6 +9,10 @@ from esphome.const import (
     CONF_POWER,
     CONF_SPEED,
     CONF_VOLTAGE,
+    DEVICE_CLASS_CURRENT,
+    DEVICE_CLASS_POWER,
+    DEVICE_CLASS_VOLTAGE,
+    STATE_CLASS_MEASUREMENT,
     UNIT_AMPERE,
     UNIT_CUBIC_METER_PER_HOUR,
     UNIT_METER,
@@ -27,26 +31,35 @@ CONFIG_SCHEMA = (
             cv.Optional(CONF_FLOW): sensor.sensor_schema(
                 unit_of_measurement=UNIT_CUBIC_METER_PER_HOUR,
                 accuracy_decimals=2,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
             cv.Optional(CONF_HEAD): sensor.sensor_schema(
                 unit_of_measurement=UNIT_METER,
                 accuracy_decimals=2,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
             cv.Optional(CONF_POWER): sensor.sensor_schema(
                 unit_of_measurement=UNIT_WATT,
                 accuracy_decimals=2,
+                device_class=DEVICE_CLASS_POWER,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
             cv.Optional(CONF_CURRENT): sensor.sensor_schema(
                 unit_of_measurement=UNIT_AMPERE,
                 accuracy_decimals=2,
+                device_class=DEVICE_CLASS_CURRENT,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
             cv.Optional(CONF_SPEED): sensor.sensor_schema(
                 unit_of_measurement=UNIT_REVOLUTIONS_PER_MINUTE,
                 accuracy_decimals=2,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
             cv.Optional(CONF_VOLTAGE): sensor.sensor_schema(
                 unit_of_measurement=UNIT_VOLT,
                 accuracy_decimals=2,
+                device_class=DEVICE_CLASS_VOLTAGE,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
         }
     )

esphome/components/am43/cover/am43_cover.cpp

@@ -63,8 +63,9 @@ void Am43Component::control(const CoverCall &call) {
       ESP_LOGW(TAG, "[%s] Error writing stop command to device, error = %d", this->get_name().c_str(), status);
     }
   }
-  if (call.get_position().has_value()) {
-    auto pos = *call.get_position();
+  auto opt_pos = call.get_position();
+  if (opt_pos.has_value()) {
+    auto pos = *opt_pos;
 
     if (this->invert_position_)
       pos = 1 - pos;

esphome/components/am43/sensor/__init__.py

@@ -8,6 +8,7 @@ from esphome.const import (
     DEVICE_CLASS_BATTERY,
     ENTITY_CATEGORY_DIAGNOSTIC,
     ICON_BRIGHTNESS_5,
+    STATE_CLASS_MEASUREMENT,
     UNIT_PERCENT,
 )
 
@@ -26,11 +27,13 @@ CONFIG_SCHEMA = (
                 device_class=DEVICE_CLASS_BATTERY,
                 accuracy_decimals=0,
                 entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
             cv.Optional(CONF_ILLUMINANCE): sensor.sensor_schema(
                 unit_of_measurement=UNIT_PERCENT,
                 icon=ICON_BRIGHTNESS_5,
                 accuracy_decimals=0,
+                state_class=STATE_CLASS_MEASUREMENT,
             ),
         }
     )

esphome/components/am43/sensor/am43_sensor.h

@@ -35,7 +35,7 @@ class Am43 : public esphome::ble_client::BLEClientNode, public PollingComponent
   uint8_t current_sensor_;
   // The AM43 often gets into a state where it spams loads of battery update
   // notifications. Here we will limit to no more than every 10s.
-  uint8_t last_battery_update_;
+  uint32_t last_battery_update_;
 };
 
 }  // namespace am43

esphome/components/analog_threshold/analog_threshold_binary_sensor.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/components/binary_sensor/binary_sensor.h"
 #include "esphome/components/sensor/sensor.h"
@@ -18,8 +19,8 @@ class AnalogThresholdBinarySensor : public Component, public binary_sensor::Bina
 
  protected:
   sensor::Sensor *sensor_{nullptr};
-  TemplatableValue<float> upper_threshold_{};
-  TemplatableValue<float> lower_threshold_{};
+  TemplatableFn<float> upper_threshold_{};
+  TemplatableFn<float> lower_threshold_{};
   bool raw_state_{false};  // Pre-filter state for hysteresis logic
 };
 

esphome/components/analog_threshold/binary_sensor.py

@@ -40,10 +40,10 @@ async def to_code(config):
     cg.add(var.set_sensor(sens))
 
     if isinstance(config[CONF_THRESHOLD], dict):
-        lower = await cg.templatable(config[CONF_THRESHOLD][CONF_LOWER], [], float)
-        upper = await cg.templatable(config[CONF_THRESHOLD][CONF_UPPER], [], float)
+        lower = await cg.templatable(config[CONF_THRESHOLD][CONF_LOWER], [], cg.float_)
+        upper = await cg.templatable(config[CONF_THRESHOLD][CONF_UPPER], [], cg.float_)
     else:
-        lower = await cg.templatable(config[CONF_THRESHOLD], [], float)
+        lower = await cg.templatable(config[CONF_THRESHOLD], [], cg.float_)
         upper = lower
     cg.add(var.set_upper_threshold(upper))
     cg.add(var.set_lower_threshold(lower))

esphome/components/animation/__init__.py

@@ -69,9 +69,15 @@ SET_FRAME_SCHEMA = cv.Schema(
 )
 
 
-@automation.register_action("animation.next_frame", NextFrameAction, NEXT_FRAME_SCHEMA)
-@automation.register_action("animation.prev_frame", PrevFrameAction, PREV_FRAME_SCHEMA)
-@automation.register_action("animation.set_frame", SetFrameAction, SET_FRAME_SCHEMA)
+@automation.register_action(
+    "animation.next_frame", NextFrameAction, NEXT_FRAME_SCHEMA, synchronous=True
+)
+@automation.register_action(
+    "animation.prev_frame", PrevFrameAction, PREV_FRAME_SCHEMA, synchronous=True
+)
+@automation.register_action(
+    "animation.set_frame", SetFrameAction, SET_FRAME_SCHEMA, synchronous=True
+)
 async def animation_action_to_code(config, action_id, template_arg, args):
     paren = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, paren)

esphome/components/anova/anova.cpp

@@ -24,8 +24,9 @@ void Anova::loop() {
 }
 
 void Anova::control(const ClimateCall &call) {
-  if (call.get_mode().has_value()) {
-    ClimateMode mode = *call.get_mode();
+  auto mode_val = call.get_mode();
+  if (mode_val.has_value()) {
+    ClimateMode mode = *mode_val;
     AnovaPacket *pkt;
     switch (mode) {
       case climate::CLIMATE_MODE_OFF:
@@ -45,8 +46,9 @@ void Anova::control(const ClimateCall &call) {
       ESP_LOGW(TAG, "[%s] esp_ble_gattc_write_char failed, status=%d", this->parent_->address_str(), status);
     }
   }
-  if (call.get_target_temperature().has_value()) {
-    auto *pkt = this->codec_->get_set_target_temp_request(*call.get_target_temperature());
+  auto target_temp = call.get_target_temperature();
+  if (target_temp.has_value()) {
+    auto *pkt = this->codec_->get_set_target_temp_request(*target_temp);
     auto status =
         esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
                                  pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);
@@ -67,10 +69,8 @@ void Anova::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_
     case ESP_GATTC_SEARCH_CMPL_EVT: {
       auto *chr = this->parent_->get_characteristic(ANOVA_SERVICE_UUID, ANOVA_CHARACTERISTIC_UUID);
       if (chr == nullptr) {
-        ESP_LOGW(TAG,
-                 "[%s] No control service found at device, not an Anova..?\n"
-                 "[%s] Note, this component does not currently support Anova Nano.",
-                 this->get_name().c_str(), this->get_name().c_str());
+        ESP_LOGW(TAG, "[%s] No control service found at device, not an Anova..?", this->get_name().c_str());
+        ESP_LOGW(TAG, "[%s] Note, this component does not currently support Anova Nano.", this->get_name().c_str());
         break;
       }
       this->char_handle_ = chr->handle;
@@ -144,9 +144,12 @@ void Anova::update() {
     return;
 
   if (this->current_request_ < 2) {
-    auto *pkt = this->codec_->get_read_device_status_request();
-    if (this->current_request_ == 0)
-      this->codec_->get_set_unit_request(this->fahrenheit_ ? 'f' : 'c');
+    AnovaPacket *pkt;
+    if (this->current_request_ == 0) {
+      pkt = this->codec_->get_set_unit_request(this->fahrenheit_ ? 'f' : 'c');
+    } else {
+      pkt = this->codec_->get_read_device_status_request();
+    }
     auto status =
         esp_ble_gattc_write_char(this->parent_->get_gattc_if(), this->parent_->get_conn_id(), this->char_handle_,
                                  pkt->length, pkt->data, ESP_GATT_WRITE_TYPE_NO_RSP, ESP_GATT_AUTH_REQ_NONE);

esphome/components/apds9960/apds9960.cpp

@@ -251,11 +251,11 @@ void APDS9960::read_gesture_data_() {
 
   uint8_t buf[128];
   for (uint8_t pos = 0; pos < fifo_level * 4; pos += 32) {
-    // The ESP's i2c driver has a limited buffer size.
-    // This way of retrieving the data should be wrong according to the datasheet
-    // but it seems to work.
+    // Read in 32-byte chunks due to ESP8266 I2C buffer limit.
+    // Always read from 0xFC — the FIFO auto-increments through 0xFC-0xFF
+    // and advances its internal pointer after every 4th byte.
     uint8_t read = std::min(32, fifo_level * 4 - pos);
-    APDS9960_WARNING_CHECK(this->read_bytes(0xFC + pos, buf + pos, read), "Reading FIFO buffer failed.");
+    APDS9960_WARNING_CHECK(this->read_bytes(0xFC, buf + pos, read), "Reading FIFO buffer failed.");
   }
 
   if (millis() - this->gesture_start_ > 500) {

esphome/components/api/__init__.py

@@ -76,7 +76,7 @@ SERVICE_ARG_NATIVE_TYPES: dict[str, MockObj] = {
     "bool": cg.bool_,
     "int": cg.int32,
     "float": cg.float_,
-    "string": cg.std_string,
+    "string": cg.StringRef,
     "bool[]": cg.FixedVector.template(cg.bool_).operator("const").operator("ref"),
     "int[]": cg.FixedVector.template(cg.int32).operator("const").operator("ref"),
     "float[]": cg.FixedVector.template(cg.float_).operator("const").operator("ref"),
@@ -233,8 +233,8 @@ def _consume_api_sockets(config: ConfigType) -> ConfigType:
 
     # API needs 1 listening socket + typically 3 concurrent client connections
     # (not max_connections, which is the upper limit rarely reached)
-    sockets_needed = 1 + 3
-    socket.consume_sockets(sockets_needed, "api")(config)
+    socket.consume_sockets(3, "api")(config)
+    socket.consume_sockets(1, "api", socket.SocketType.TCP_LISTEN)(config)
     return config
 
 
@@ -301,11 +301,12 @@ CONFIG_SCHEMA = cv.All(
             # Maximum queued send buffers per connection before dropping connection
             # Each buffer uses ~8-12 bytes overhead plus actual message size
             # Platform defaults based on available RAM and typical message rates:
+            # CONF_MAX_SEND_QUEUE defaults are power of 2 for efficient modulo
             cv.SplitDefault(
                 CONF_MAX_SEND_QUEUE,
-                esp8266=5,  # Limited RAM, need to fail fast
+                esp8266=4,  # Limited RAM, need to fail fast
                 esp32=8,  # More RAM, can buffer more
-                rp2040=5,  # Limited RAM
+                rp2040=8,  # Moderate RAM
                 bk72xx=8,  # Moderate RAM
                 nrf52=8,  # Moderate RAM
                 rtl87xx=8,  # Moderate RAM
@@ -380,9 +381,18 @@ async def to_code(config: ConfigType) -> None:
                 if is_optional:
                     func_args.append((cg.bool_, "return_response"))
 
+            # Check if action chain has non-synchronous actions that would make
+            # non-owning StringRef dangle (rx_buf_ reused after delay)
+            has_non_synchronous = automation.has_non_synchronous_actions(
+                conf.get(CONF_THEN, [])
+            )
+
             service_arg_names: list[str] = []
             for name, var_ in conf[CONF_VARIABLES].items():
                 native = SERVICE_ARG_NATIVE_TYPES[var_]
+                # Fall back to std::string for string args if non-synchronous actions exist
+                if has_non_synchronous and native is cg.StringRef:
+                    native = cg.std_string
                 service_template_args.append(native)
                 func_args.append((native, name))
                 service_arg_names.append(name)
@@ -444,7 +454,10 @@ async def to_code(config: ConfigType) -> None:
             # and plaintext disabled. Only a factory reset can remove it.
             cg.add_define("USE_API_PLAINTEXT")
         cg.add_define("USE_API_NOISE")
-        cg.add_library("esphome/noise-c", "0.1.10")
+        cg.add_library("esphome/noise-c", "0.1.11")
+        # Enable optimized memzero/memcmp in libsodium instead of volatile byte loops
+        cg.add_build_flag("-DHAVE_WEAK_SYMBOLS=1")
+        cg.add_build_flag("-DHAVE_INLINE_ASM=1")
     else:
         cg.add_define("USE_API_PLAINTEXT")
 
@@ -509,11 +522,13 @@ HOMEASSISTANT_ACTION_ACTION_SCHEMA = cv.All(
     "homeassistant.action",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_ACTION_ACTION_SCHEMA,
+    synchronous=True,
 )
 @automation.register_action(
     "homeassistant.service",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_ACTION_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def homeassistant_service_to_code(
     config: ConfigType,
@@ -524,24 +539,31 @@ async def homeassistant_service_to_code(
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
     serv = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, serv, False)
-    templ = await cg.templatable(config[CONF_ACTION], args, None)
+    templ = await cg.templatable(config[CONF_ACTION], args, cg.std_string)
     cg.add(var.set_service(templ))
 
     # Initialize FixedVectors with exact sizes from config
     cg.add(var.init_data(len(config[CONF_DATA])))
     for key, value in config[CONF_DATA].items():
+        # output_type=None because lambdas can return non-string types (int,
+        # float, char*) that TemplatableStringValue converts via to_string.
+        # Static strings are manually wrapped for PROGMEM on ESP8266.
         templ = await cg.templatable(value, args, None)
-        cg.add(var.add_data(key, templ))
+        if isinstance(templ, str):
+            templ = cg.FlashStringLiteral(templ)
+        cg.add(var.add_data(cg.FlashStringLiteral(key), templ))
 
     cg.add(var.init_data_template(len(config[CONF_DATA_TEMPLATE])))
     for key, value in config[CONF_DATA_TEMPLATE].items():
         templ = await cg.templatable(value, args, None)
-        cg.add(var.add_data_template(key, templ))
+        if isinstance(templ, str):
+            templ = cg.FlashStringLiteral(templ)
+        cg.add(var.add_data_template(cg.FlashStringLiteral(key), templ))
 
     cg.add(var.init_variables(len(config[CONF_VARIABLES])))
     for key, value in config[CONF_VARIABLES].items():
         templ = await cg.templatable(value, args, None)
-        cg.add(var.add_variable(key, templ))
+        cg.add(var.add_variable(cg.FlashStringLiteral(key), templ))
 
     if on_error := config.get(CONF_ON_ERROR):
         cg.add_define("USE_API_HOMEASSISTANT_ACTION_RESPONSES")
@@ -604,29 +626,37 @@ HOMEASSISTANT_EVENT_ACTION_SCHEMA = cv.Schema(
     "homeassistant.event",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_EVENT_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def homeassistant_event_to_code(config, action_id, template_arg, args):
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
     serv = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, serv, True)
-    templ = await cg.templatable(config[CONF_EVENT], args, None)
+    templ = await cg.templatable(config[CONF_EVENT], args, cg.std_string)
     cg.add(var.set_service(templ))
 
     # Initialize FixedVectors with exact sizes from config
     cg.add(var.init_data(len(config[CONF_DATA])))
     for key, value in config[CONF_DATA].items():
+        # output_type=None because lambdas can return non-string types (int,
+        # float, char*) that TemplatableStringValue converts via to_string.
+        # Static strings are manually wrapped for PROGMEM on ESP8266.
         templ = await cg.templatable(value, args, None)
-        cg.add(var.add_data(key, templ))
+        if isinstance(templ, str):
+            templ = cg.FlashStringLiteral(templ)
+        cg.add(var.add_data(cg.FlashStringLiteral(key), templ))
 
     cg.add(var.init_data_template(len(config[CONF_DATA_TEMPLATE])))
     for key, value in config[CONF_DATA_TEMPLATE].items():
         templ = await cg.templatable(value, args, None)
-        cg.add(var.add_data_template(key, templ))
+        if isinstance(templ, str):
+            templ = cg.FlashStringLiteral(templ)
+        cg.add(var.add_data_template(cg.FlashStringLiteral(key), templ))
 
     cg.add(var.init_variables(len(config[CONF_VARIABLES])))
     for key, value in config[CONF_VARIABLES].items():
         templ = await cg.templatable(value, args, None)
-        cg.add(var.add_variable(key, templ))
+        cg.add(var.add_variable(cg.FlashStringLiteral(key), templ))
 
     return var
 
@@ -644,16 +674,17 @@ HOMEASSISTANT_TAG_SCANNED_ACTION_SCHEMA = cv.maybe_simple_value(
     "homeassistant.tag_scanned",
     HomeAssistantServiceCallAction,
     HOMEASSISTANT_TAG_SCANNED_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def homeassistant_tag_scanned_to_code(config, action_id, template_arg, args):
     cg.add_define("USE_API_HOMEASSISTANT_SERVICES")
     serv = await cg.get_variable(config[CONF_ID])
     var = cg.new_Pvariable(action_id, template_arg, serv, True)
-    cg.add(var.set_service("esphome.tag_scanned"))
+    cg.add(var.set_service(cg.FlashStringLiteral("esphome.tag_scanned")))
     # Initialize FixedVector with exact size (1 data field)
     cg.add(var.init_data(1))
     templ = await cg.templatable(config[CONF_TAG], args, cg.std_string)
-    cg.add(var.add_data("tag_id", templ))
+    cg.add(var.add_data(cg.FlashStringLiteral("tag_id"), templ))
     return var
 
 
@@ -685,6 +716,7 @@ API_RESPOND_ACTION_SCHEMA = cv.All(
     "api.respond",
     APIRespondAction,
     API_RESPOND_ACTION_SCHEMA,
+    synchronous=True,
 )
 async def api_respond_to_code(
     config: ConfigType,

esphome/components/api/api_buffer.cpp

@@ -0,0 +1,13 @@
+#include "api_buffer.h"
+
+namespace esphome::api {
+
+void APIBuffer::grow_(size_t n) {
+  auto new_data = make_buffer(n);
+  if (this->size_)
+    std::memcpy(new_data.get(), this->data_.get(), this->size_);
+  this->data_ = std::move(new_data);
+  this->capacity_ = n;
+}
+
+}  // namespace esphome::api

esphome/components/api/api_buffer.h

@@ -0,0 +1,73 @@
+#pragma once
+
+#include <cstdint>
+#include <cstring>
+#include <memory>
+
+#include "esphome/core/defines.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome::api {
+
+/// Helper to use make_unique_for_overwrite where available (skips zero-fill),
+/// falling back to make_unique on older GCC (ESP8266, LibreTiny).
+inline std::unique_ptr<uint8_t[]> make_buffer(size_t n) {
+#if defined(USE_ESP8266) || defined(USE_LIBRETINY)
+  return std::make_unique<uint8_t[]>(n);
+#else
+  return std::make_unique_for_overwrite<uint8_t[]>(n);
+#endif
+}
+
+/// Byte buffer that skips zero-initialization on resize().
+///
+/// std::vector<uint8_t>::resize() zero-fills new bytes via memset. For the
+/// shared protobuf write buffer, every byte is overwritten by the encoder,
+/// making the zero-fill pure waste. For the receive buffer, bytes are
+/// overwritten by socket reads.
+///
+/// Designed for bulk clear/resize/overwrite patterns. grow_() allocates
+/// exactly the requested size (no growth factor) since callers resize to
+/// known sizes rather than appending incrementally.
+///
+/// Safe because: callers always write exactly the number of bytes they
+/// resize for. In the protobuf write path, debug_check_bounds_ validates
+/// writes in debug builds.
+class APIBuffer {
+ public:
+  void clear() { this->size_ = 0; }
+  inline void reserve(size_t n) ESPHOME_ALWAYS_INLINE {
+    if (n > this->capacity_)
+      this->grow_(n);
+  }
+  inline void resize(size_t n) ESPHOME_ALWAYS_INLINE {
+    this->reserve(n);
+    this->size_ = n;  // no zero-fill
+  }
+  /// Reserve capacity for max(reserve_size, new_size) bytes, then set size to new_size.
+  /// Single grow_ check regardless of argument order.
+  inline void reserve_and_resize(size_t reserve_size, size_t new_size) ESPHOME_ALWAYS_INLINE {
+    this->reserve(std::max(reserve_size, new_size));
+    this->size_ = new_size;
+  }
+  uint8_t *data() { return this->data_.get(); }
+  const uint8_t *data() const { return this->data_.get(); }
+  size_t size() const { return this->size_; }
+  bool empty() const { return this->size_ == 0; }
+  uint8_t &operator[](size_t i) { return this->data_[i]; }
+  const uint8_t &operator[](size_t i) const { return this->data_[i]; }
+  /// Release all memory (equivalent to std::vector swap trick).
+  void release() {
+    this->data_.reset();
+    this->size_ = 0;
+    this->capacity_ = 0;
+  }
+
+ protected:
+  void grow_(size_t n);
+  std::unique_ptr<uint8_t[]> data_;
+  size_t size_{0};
+  size_t capacity_{0};
+};
+
+}  // namespace esphome::api

esphome/components/api/api_connection.h

@@ -3,11 +3,26 @@
 #include "esphome/core/defines.h"
 #ifdef USE_API
 #include "api_frame_helper.h"
+#ifdef USE_API_NOISE
+#include "api_frame_helper_noise.h"
+#endif
+#ifdef USE_API_PLAINTEXT
+#include "api_frame_helper_plaintext.h"
+#endif
 #include "api_pb2.h"
 #include "api_pb2_service.h"
 #include "api_server.h"
 #include "esphome/core/application.h"
 #include "esphome/core/component.h"
+#ifdef USE_ESP32_CRASH_HANDLER
+#include "esphome/components/esp32/crash_handler.h"
+#endif
+#ifdef USE_RP2040_CRASH_HANDLER
+#include "esphome/components/rp2040/crash_handler.h"
+#endif
+#ifdef USE_ESP8266_CRASH_HANDLER
+#include "esphome/components/esp8266/crash_handler.h"
+#endif
 #include "esphome/core/entity_base.h"
 #include "esphome/core/string_ref.h"
 
@@ -32,16 +47,46 @@ static constexpr size_t MAX_INITIAL_PER_BATCH = 34;         // For clients >= AP
 static_assert(MAX_MESSAGES_PER_BATCH >= MAX_INITIAL_PER_BATCH,
               "MAX_MESSAGES_PER_BATCH must be >= MAX_INITIAL_PER_BATCH");
 
+#ifdef USE_BENCHMARK
+class APIConnection;
+void bench_enable_immediate_send(APIConnection *conn);
+void bench_clear_batch(APIConnection *conn);
+void bench_process_batch(APIConnection *conn);
+#endif
+
 class APIConnection final : public APIServerConnectionBase {
  public:
   friend class APIServer;
   friend class ListEntitiesIterator;
+#ifdef USE_BENCHMARK
+  friend void bench_enable_immediate_send(APIConnection *conn);
+  friend void bench_clear_batch(APIConnection *conn);
+  friend void bench_process_batch(APIConnection *conn);
+#endif
   APIConnection(std::unique_ptr<socket::Socket> socket, APIServer *parent);
-  virtual ~APIConnection();
+  ~APIConnection();
 
   void start();
   void loop();
 
+ protected:
+  // read_message_ is defined here (instead of in APIServerConnectionBase) so the
+  // compiler can devirtualize and inline on_* handler calls within this final class.
+  void read_message_(uint32_t msg_size, uint32_t msg_type, const uint8_t *msg_data);
+
+  // Auth helpers defined here (not in ProtoService) so the compiler can
+  // devirtualize is_connection_setup()/on_no_setup_connection() calls
+  // within this final class.
+  inline bool check_connection_setup_() {
+    if (!this->is_connection_setup()) {
+      this->on_no_setup_connection();
+      return false;
+    }
+    return true;
+  }
+  inline bool check_authenticated_() { return this->check_connection_setup_(); }
+
+ public:
   bool send_list_info_done() {
     return this->schedule_message_(nullptr, ListEntitiesDoneResponse::MESSAGE_TYPE,
                                    ListEntitiesDoneResponse::ESTIMATED_SIZE);
@@ -51,163 +96,173 @@ class APIConnection final : public APIServerConnectionBase {
 #endif
 #ifdef USE_COVER
   bool send_cover_state(cover::Cover *cover);
-  void on_cover_command_request(const CoverCommandRequest &msg) override;
+  void on_cover_command_request(const CoverCommandRequest &msg);
 #endif
 #ifdef USE_FAN
   bool send_fan_state(fan::Fan *fan);
-  void on_fan_command_request(const FanCommandRequest &msg) override;
+  void on_fan_command_request(const FanCommandRequest &msg);
 #endif
 #ifdef USE_LIGHT
   bool send_light_state(light::LightState *light);
-  void on_light_command_request(const LightCommandRequest &msg) override;
+  void on_light_command_request(const LightCommandRequest &msg);
 #endif
 #ifdef USE_SENSOR
   bool send_sensor_state(sensor::Sensor *sensor);
 #endif
 #ifdef USE_SWITCH
   bool send_switch_state(switch_::Switch *a_switch);
-  void on_switch_command_request(const SwitchCommandRequest &msg) override;
+  void on_switch_command_request(const SwitchCommandRequest &msg);
 #endif
 #ifdef USE_TEXT_SENSOR
   bool send_text_sensor_state(text_sensor::TextSensor *text_sensor);
 #endif
 #ifdef USE_CAMERA
   void set_camera_state(std::shared_ptr<camera::CameraImage> image);
-  void on_camera_image_request(const CameraImageRequest &msg) override;
+  void on_camera_image_request(const CameraImageRequest &msg);
 #endif
 #ifdef USE_CLIMATE
   bool send_climate_state(climate::Climate *climate);
-  void on_climate_command_request(const ClimateCommandRequest &msg) override;
+  void on_climate_command_request(const ClimateCommandRequest &msg);
 #endif
 #ifdef USE_NUMBER
   bool send_number_state(number::Number *number);
-  void on_number_command_request(const NumberCommandRequest &msg) override;
+  void on_number_command_request(const NumberCommandRequest &msg);
 #endif
 #ifdef USE_DATETIME_DATE
   bool send_date_state(datetime::DateEntity *date);
-  void on_date_command_request(const DateCommandRequest &msg) override;
+  void on_date_command_request(const DateCommandRequest &msg);
 #endif
 #ifdef USE_DATETIME_TIME
   bool send_time_state(datetime::TimeEntity *time);
-  void on_time_command_request(const TimeCommandRequest &msg) override;
+  void on_time_command_request(const TimeCommandRequest &msg);
 #endif
 #ifdef USE_DATETIME_DATETIME
   bool send_datetime_state(datetime::DateTimeEntity *datetime);
-  void on_date_time_command_request(const DateTimeCommandRequest &msg) override;
+  void on_date_time_command_request(const DateTimeCommandRequest &msg);
 #endif
 #ifdef USE_TEXT
   bool send_text_state(text::Text *text);
-  void on_text_command_request(const TextCommandRequest &msg) override;
+  void on_text_command_request(const TextCommandRequest &msg);
 #endif
 #ifdef USE_SELECT
   bool send_select_state(select::Select *select);
-  void on_select_command_request(const SelectCommandRequest &msg) override;
+  void on_select_command_request(const SelectCommandRequest &msg);
 #endif
 #ifdef USE_BUTTON
-  void on_button_command_request(const ButtonCommandRequest &msg) override;
+  void on_button_command_request(const ButtonCommandRequest &msg);
 #endif
 #ifdef USE_LOCK
   bool send_lock_state(lock::Lock *a_lock);
-  void on_lock_command_request(const LockCommandRequest &msg) override;
+  void on_lock_command_request(const LockCommandRequest &msg);
 #endif
 #ifdef USE_VALVE
   bool send_valve_state(valve::Valve *valve);
-  void on_valve_command_request(const ValveCommandRequest &msg) override;
+  void on_valve_command_request(const ValveCommandRequest &msg);
 #endif
 #ifdef USE_MEDIA_PLAYER
   bool send_media_player_state(media_player::MediaPlayer *media_player);
-  void on_media_player_command_request(const MediaPlayerCommandRequest &msg) override;
+  void on_media_player_command_request(const MediaPlayerCommandRequest &msg);
 #endif
   bool try_send_log_message(int level, const char *tag, const char *line, size_t message_len);
 #ifdef USE_API_HOMEASSISTANT_SERVICES
   void send_homeassistant_action(const HomeassistantActionRequest &call) {
     if (!this->flags_.service_call_subscription)
       return;
-    this->send_message(call, HomeassistantActionRequest::MESSAGE_TYPE);
+    this->send_message(call);
   }
 #ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
-  void on_homeassistant_action_response(const HomeassistantActionResponse &msg) override;
+  void on_homeassistant_action_response(const HomeassistantActionResponse &msg);
 #endif  // USE_API_HOMEASSISTANT_ACTION_RESPONSES
 #endif  // USE_API_HOMEASSISTANT_SERVICES
 #ifdef USE_BLUETOOTH_PROXY
-  void on_subscribe_bluetooth_le_advertisements_request(const SubscribeBluetoothLEAdvertisementsRequest &msg) override;
-  void on_unsubscribe_bluetooth_le_advertisements_request() override;
+  void on_subscribe_bluetooth_le_advertisements_request(const SubscribeBluetoothLEAdvertisementsRequest &msg);
+  void on_unsubscribe_bluetooth_le_advertisements_request();
 
-  void on_bluetooth_device_request(const BluetoothDeviceRequest &msg) override;
-  void on_bluetooth_gatt_read_request(const BluetoothGATTReadRequest &msg) override;
-  void on_bluetooth_gatt_write_request(const BluetoothGATTWriteRequest &msg) override;
-  void on_bluetooth_gatt_read_descriptor_request(const BluetoothGATTReadDescriptorRequest &msg) override;
-  void on_bluetooth_gatt_write_descriptor_request(const BluetoothGATTWriteDescriptorRequest &msg) override;
-  void on_bluetooth_gatt_get_services_request(const BluetoothGATTGetServicesRequest &msg) override;
-  void on_bluetooth_gatt_notify_request(const BluetoothGATTNotifyRequest &msg) override;
-  void on_subscribe_bluetooth_connections_free_request() override;
-  void on_bluetooth_scanner_set_mode_request(const BluetoothScannerSetModeRequest &msg) override;
+  void on_bluetooth_device_request(const BluetoothDeviceRequest &msg);
+  void on_bluetooth_gatt_read_request(const BluetoothGATTReadRequest &msg);
+  void on_bluetooth_gatt_write_request(const BluetoothGATTWriteRequest &msg);
+  void on_bluetooth_gatt_read_descriptor_request(const BluetoothGATTReadDescriptorRequest &msg);
+  void on_bluetooth_gatt_write_descriptor_request(const BluetoothGATTWriteDescriptorRequest &msg);
+  void on_bluetooth_gatt_get_services_request(const BluetoothGATTGetServicesRequest &msg);
+  void on_bluetooth_gatt_notify_request(const BluetoothGATTNotifyRequest &msg);
+  void on_subscribe_bluetooth_connections_free_request();
+  void on_bluetooth_scanner_set_mode_request(const BluetoothScannerSetModeRequest &msg);
+  void on_bluetooth_set_connection_params_request(const BluetoothSetConnectionParamsRequest &msg);
 
 #endif
 #ifdef USE_HOMEASSISTANT_TIME
   void send_time_request() {
     GetTimeRequest req;
-    this->send_message(req, GetTimeRequest::MESSAGE_TYPE);
+    this->send_message(req);
   }
 #endif
 
 #ifdef USE_VOICE_ASSISTANT
-  void on_subscribe_voice_assistant_request(const SubscribeVoiceAssistantRequest &msg) override;
-  void on_voice_assistant_response(const VoiceAssistantResponse &msg) override;
-  void on_voice_assistant_event_response(const VoiceAssistantEventResponse &msg) override;
-  void on_voice_assistant_audio(const VoiceAssistantAudio &msg) override;
-  void on_voice_assistant_timer_event_response(const VoiceAssistantTimerEventResponse &msg) override;
-  void on_voice_assistant_announce_request(const VoiceAssistantAnnounceRequest &msg) override;
-  void on_voice_assistant_configuration_request(const VoiceAssistantConfigurationRequest &msg) override;
-  void on_voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &msg) override;
+  void on_subscribe_voice_assistant_request(const SubscribeVoiceAssistantRequest &msg);
+  void on_voice_assistant_response(const VoiceAssistantResponse &msg);
+  void on_voice_assistant_event_response(const VoiceAssistantEventResponse &msg);
+  void on_voice_assistant_audio(const VoiceAssistantAudio &msg);
+  void on_voice_assistant_timer_event_response(const VoiceAssistantTimerEventResponse &msg);
+  void on_voice_assistant_announce_request(const VoiceAssistantAnnounceRequest &msg);
+  void on_voice_assistant_configuration_request(const VoiceAssistantConfigurationRequest &msg);
+  void on_voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &msg);
 #endif
 
 #ifdef USE_ZWAVE_PROXY
-  void on_z_wave_proxy_frame(const ZWaveProxyFrame &msg) override;
-  void on_z_wave_proxy_request(const ZWaveProxyRequest &msg) override;
+  void on_z_wave_proxy_frame(const ZWaveProxyFrame &msg);
+  void on_z_wave_proxy_request(const ZWaveProxyRequest &msg);
 #endif
 
 #ifdef USE_ALARM_CONTROL_PANEL
   bool send_alarm_control_panel_state(alarm_control_panel::AlarmControlPanel *a_alarm_control_panel);
-  void on_alarm_control_panel_command_request(const AlarmControlPanelCommandRequest &msg) override;
+  void on_alarm_control_panel_command_request(const AlarmControlPanelCommandRequest &msg);
 #endif
 
 #ifdef USE_WATER_HEATER
   bool send_water_heater_state(water_heater::WaterHeater *water_heater);
-  void on_water_heater_command_request(const WaterHeaterCommandRequest &msg) override;
+  void on_water_heater_command_request(const WaterHeaterCommandRequest &msg);
 #endif
 
 #ifdef USE_IR_RF
-  void on_infrared_rf_transmit_raw_timings_request(const InfraredRFTransmitRawTimingsRequest &msg) override;
+  void on_infrared_rf_transmit_raw_timings_request(const InfraredRFTransmitRawTimingsRequest &msg);
   void send_infrared_rf_receive_event(const InfraredRFReceiveEvent &msg);
 #endif
 
+#ifdef USE_SERIAL_PROXY
+  void on_serial_proxy_configure_request(const SerialProxyConfigureRequest &msg);
+  void on_serial_proxy_write_request(const SerialProxyWriteRequest &msg);
+  void on_serial_proxy_set_modem_pins_request(const SerialProxySetModemPinsRequest &msg);
+  void on_serial_proxy_get_modem_pins_request(const SerialProxyGetModemPinsRequest &msg);
+  void on_serial_proxy_request(const SerialProxyRequest &msg);
+  void send_serial_proxy_data(const SerialProxyDataReceived &msg);
+#endif
+
 #ifdef USE_EVENT
   void send_event(event::Event *event);
 #endif
 
 #ifdef USE_UPDATE
   bool send_update_state(update::UpdateEntity *update);
-  void on_update_command_request(const UpdateCommandRequest &msg) override;
+  void on_update_command_request(const UpdateCommandRequest &msg);
 #endif
 
-  void on_disconnect_response() override;
-  void on_ping_response() override {
+  void on_disconnect_response();
+  void on_ping_response() {
     // we initiated ping
     this->flags_.sent_ping = false;
   }
 #ifdef USE_API_HOMEASSISTANT_STATES
-  void on_home_assistant_state_response(const HomeAssistantStateResponse &msg) override;
+  void on_home_assistant_state_response(const HomeAssistantStateResponse &msg);
 #endif
 #ifdef USE_HOMEASSISTANT_TIME
-  void on_get_time_response(const GetTimeResponse &value) override;
+  void on_get_time_response(const GetTimeResponse &value);
 #endif
-  void on_hello_request(const HelloRequest &msg) override;
-  void on_disconnect_request() override;
-  void on_ping_request() override;
-  void on_device_info_request() override;
-  void on_list_entities_request() override { this->begin_iterator_(ActiveIterator::LIST_ENTITIES); }
-  void on_subscribe_states_request() override {
+  void on_hello_request(const HelloRequest &msg);
+  void on_disconnect_request();
+  void on_ping_request();
+  void on_device_info_request();
+  void on_list_entities_request() { this->begin_iterator_(ActiveIterator::LIST_ENTITIES); }
+  void on_subscribe_states_request() {
     this->flags_.state_subscription = true;
     // Start initial state iterator only if no iterator is active
     // If list_entities is running, we'll start initial_state when it completes
@@ -215,19 +270,29 @@ class APIConnection final : public APIServerConnectionBase {
       this->begin_iterator_(ActiveIterator::INITIAL_STATE);
     }
   }
-  void on_subscribe_logs_request(const SubscribeLogsRequest &msg) override {
+  void on_subscribe_logs_request(const SubscribeLogsRequest &msg) {
     this->flags_.log_subscription = msg.level;
     if (msg.dump_config)
       App.schedule_dump_config();
+#ifdef USE_ESP32_CRASH_HANDLER
+    esp32::crash_handler_log();
+    esp32::crash_handler_clear();
+#endif
+#ifdef USE_RP2040_CRASH_HANDLER
+    rp2040::crash_handler_log();
+#endif
+#ifdef USE_ESP8266_CRASH_HANDLER
+    esp8266::crash_handler_log();
+#endif
   }
 #ifdef USE_API_HOMEASSISTANT_SERVICES
-  void on_subscribe_homeassistant_services_request() override { this->flags_.service_call_subscription = true; }
+  void on_subscribe_homeassistant_services_request() { this->flags_.service_call_subscription = true; }
 #endif
 #ifdef USE_API_HOMEASSISTANT_STATES
-  void on_subscribe_home_assistant_states_request() override;
+  void on_subscribe_home_assistant_states_request();
 #endif
 #ifdef USE_API_USER_DEFINED_ACTIONS
-  void on_execute_service_request(const ExecuteServiceRequest &msg) override;
+  void on_execute_service_request(const ExecuteServiceRequest &msg);
 #ifdef USE_API_USER_DEFINED_ACTION_RESPONSES
   void send_execute_service_response(uint32_t call_id, bool success, StringRef error_message);
 #ifdef USE_API_USER_DEFINED_ACTION_RESPONSES_JSON
@@ -237,16 +302,17 @@ class APIConnection final : public APIServerConnectionBase {
 #endif  // USE_API_USER_DEFINED_ACTION_RESPONSES
 #endif
 #ifdef USE_API_NOISE
-  void on_noise_encryption_set_key_request(const NoiseEncryptionSetKeyRequest &msg) override;
+  void on_noise_encryption_set_key_request(const NoiseEncryptionSetKeyRequest &msg);
 #endif
 
-  bool is_authenticated() override {
+  bool is_authenticated() {
     return static_cast<ConnectionState>(this->flags_.connection_state) == ConnectionState::AUTHENTICATED;
   }
-  bool is_connection_setup() override {
+  bool is_connection_setup() {
     return static_cast<ConnectionState>(this->flags_.connection_state) == ConnectionState::CONNECTED ||
            this->is_authenticated();
   }
+  bool is_marked_for_removal() const { return this->flags_.remove; }
   uint8_t get_log_subscription_level() const { return this->flags_.log_subscription; }
 
   // Get client API version for feature detection
@@ -255,29 +321,47 @@ class APIConnection final : public APIServerConnectionBase {
            (this->client_api_version_major_ == major && this->client_api_version_minor_ >= minor);
   }
 
-  void on_fatal_error() override;
-  void on_no_setup_connection() override;
-  bool send_message_impl(const ProtoMessage &msg, uint8_t message_type) override;
+  void on_fatal_error();
+  void on_no_setup_connection();
 
-  void prepare_first_message_buffer(std::vector<uint8_t> &shared_buf, size_t header_padding, size_t total_size) {
+  // Function pointer type for type-erased message encoding
+  using MessageEncodeFn = uint8_t *(*) (const void *, ProtoWriteBuffer &PROTO_ENCODE_DEBUG_PARAM);
+  // Function pointer type for type-erased size calculation
+  using CalculateSizeFn = uint32_t (*)(const void *);
+
+  template<typename T> bool send_message(const T &msg) {
+    if constexpr (T::ESTIMATED_SIZE == 0) {
+      return this->send_message_(0, T::MESSAGE_TYPE, &encode_msg_noop, &msg);
+    } else {
+      return this->send_message_(msg.calculate_size(), T::MESSAGE_TYPE, &proto_encode_msg<T>, &msg);
+    }
+  }
+
+  void prepare_first_message_buffer(APIBuffer &shared_buf, size_t header_padding, size_t total_size) {
     shared_buf.clear();
     // Reserve space for header padding + message + footer
     // - Header padding: space for protocol headers (7 bytes for Noise, 6 for Plaintext)
     // - Footer: space for MAC (16 bytes for Noise, 0 for Plaintext)
-    shared_buf.reserve(total_size);
-    // Resize to add header padding so message encoding starts at the correct position
-    shared_buf.resize(header_padding);
+    // Reserve full size but only set initial size to header padding
+    // so message encoding starts at the correct position
+    shared_buf.reserve_and_resize(total_size, header_padding);
   }
 
   // Convenience overload - computes frame overhead internally
-  void prepare_first_message_buffer(std::vector<uint8_t> &shared_buf, size_t payload_size) {
+  void prepare_first_message_buffer(APIBuffer &shared_buf, size_t payload_size) {
     const uint8_t header_padding = this->helper_->frame_header_padding();
     const uint8_t footer_size = this->helper_->frame_footer_size();
     this->prepare_first_message_buffer(shared_buf, header_padding, payload_size + header_padding + footer_size);
   }
 
-  bool try_to_clear_buffer(bool log_out_of_space);
-  bool send_buffer(ProtoWriteBuffer buffer, uint8_t message_type) override;
+  bool try_to_clear_buffer(bool log_out_of_space) {
+    if (this->flags_.remove)
+      return false;
+    if (this->helper_->can_write_without_blocking())
+      return true;
+    return this->try_to_clear_buffer_slow_(log_out_of_space);
+  }
+  bool send_buffer(ProtoWriteBuffer buffer, uint8_t message_type);
 
   const char *get_name() const { return this->helper_->get_client_name(); }
   /// Get peer name (IP address) into caller-provided buffer, returns buf for convenience
@@ -286,6 +370,8 @@ class APIConnection final : public APIServerConnectionBase {
   }
 
  protected:
+  bool try_to_clear_buffer_slow_(bool log_out_of_space);
+
   // Helper function to handle authentication completion
   void complete_authentication_();
 
@@ -312,50 +398,112 @@ class APIConnection final : public APIServerConnectionBase {
   void process_state_subscriptions_();
 #endif
 
-  // Non-template helper to encode any ProtoMessage
-  static uint16_t encode_message_to_buffer(ProtoMessage &msg, uint8_t message_type, APIConnection *conn,
-                                           uint32_t remaining_size);
-
-  // Helper to fill entity state base and encode message
-  static uint16_t fill_and_encode_entity_state(EntityBase *entity, StateResponseProtoMessage &msg, uint8_t message_type,
-                                               APIConnection *conn, uint32_t remaining_size) {
-    msg.key = entity->get_object_id_hash();
-#ifdef USE_DEVICES
-    msg.device_id = entity->get_device_id();
-#endif
-    return encode_message_to_buffer(msg, message_type, conn, remaining_size);
+  // Size thunk — converts void* back to concrete type for direct calculate_size() call
+  template<typename T> static uint32_t calc_size(const void *msg) {
+    return static_cast<const T *>(msg)->calculate_size();
   }
 
-  // Helper to fill entity info base and encode message
-  static uint16_t fill_and_encode_entity_info(EntityBase *entity, InfoResponseProtoMessage &msg, uint8_t message_type,
-                                              APIConnection *conn, uint32_t remaining_size) {
-    // Set common fields that are shared by all entity types
-    msg.key = entity->get_object_id_hash();
+  // Shared no-op encode thunk for empty messages (ESTIMATED_SIZE == 0)
+  static uint8_t *encode_msg_noop(const void *, ProtoWriteBuffer &buf PROTO_ENCODE_DEBUG_PARAM) {
+    return buf.get_pos();
+  }
 
-    // API 1.14+ clients compute object_id client-side from the entity name
-    // For older clients, we must send object_id for backward compatibility
-    // See: https://github.com/esphome/backlog/issues/76
-    // TODO: Remove this backward compat code before 2026.7.0 - all clients should support API 1.14 by then
-    // Buffer must remain in scope until encode_message_to_buffer is called
-    char object_id_buf[OBJECT_ID_MAX_LEN];
-    if (!conn->client_supports_api_version(1, 14)) {
-      msg.object_id = entity->get_object_id_to(object_id_buf);
+  // Non-template buffer management for send_message
+  bool send_message_(uint32_t payload_size, uint8_t message_type, MessageEncodeFn encode_fn, const void *msg);
+
+  // Core batch encoding logic. Computes header size, checks fit, resizes buffer, encodes.
+  // ALWAYS_INLINE so the compiler can devirtualize encode_fn at hot call sites.
+  static inline uint16_t ESPHOME_ALWAYS_INLINE encode_to_buffer(uint32_t calculated_size, MessageEncodeFn encode_fn,
+                                                                const void *msg, APIConnection *conn,
+                                                                uint32_t remaining_size) {
+#ifdef HAS_PROTO_MESSAGE_DUMP
+    if (conn->flags_.log_only_mode) {
+      auto *proto_msg = static_cast<const ProtoMessage *>(msg);
+      DumpBuffer dump_buf;
+      conn->log_send_message_(proto_msg->message_name(), proto_msg->dump_to(dump_buf));
+      return 1;
+    }
+#endif
+    const uint8_t footer_size = conn->helper_->frame_footer_size();
+
+    // First message uses max padding (already in buffer), subsequent use exact header size
+    size_t to_add;
+    if (conn->flags_.batch_first_message) {
+      conn->flags_.batch_first_message = false;
+      conn->batch_header_size_ = conn->helper_->frame_header_padding();
+      to_add = calculated_size;
+    } else {
+      conn->batch_header_size_ = conn->helper_->frame_header_size(calculated_size, conn->batch_message_type_);
+      to_add = calculated_size + conn->batch_header_size_ + footer_size;
     }
 
-    if (entity->has_own_name()) {
-      msg.name = entity->get_name();
-    }
+    // Check if it fits (using actual header size, not max padding)
+    uint16_t total_calculated_size = calculated_size + conn->batch_header_size_ + footer_size;
+    if (total_calculated_size > remaining_size)
+      return 0;
 
-    // Set common EntityBase properties
-#ifdef USE_ENTITY_ICON
-    msg.icon = entity->get_icon_ref();
-#endif
-    msg.disabled_by_default = entity->is_disabled_by_default();
-    msg.entity_category = static_cast<enums::EntityCategory>(entity->get_entity_category());
-#ifdef USE_DEVICES
-    msg.device_id = entity->get_device_id();
-#endif
-    return encode_message_to_buffer(msg, message_type, conn, remaining_size);
+    auto &shared_buf = conn->parent_->get_shared_buffer_ref();
+    shared_buf.resize(shared_buf.size() + to_add);
+    ProtoWriteBuffer buffer{&shared_buf, shared_buf.size() - calculated_size};
+    encode_fn(msg, buffer PROTO_ENCODE_DEBUG_INIT(&shared_buf));
+
+    return total_calculated_size;
+  }
+
+  // Noinline version of encode_to_buffer for cold paths (entity info, zero-payload messages).
+  // All cold callers share this single copy instead of each getting an ALWAYS_INLINE expansion.
+  static uint16_t encode_to_buffer_slow(uint32_t calculated_size, MessageEncodeFn encode_fn, const void *msg,
+                                        APIConnection *conn, uint32_t remaining_size);
+
+  // Thin template wrapper — uses noinline encode_to_buffer_slow since
+  // encode_message_to_buffer callers are cold paths (zero-payload control messages).
+  // Hot paths (state/info) go through fill_and_encode_entity_state/info instead.
+  // batch_message_type_ is already set by dispatch_message_ before reaching here.
+  template<typename T> static uint16_t encode_message_to_buffer(T &msg, APIConnection *conn, uint32_t remaining_size) {
+    if constexpr (T::ESTIMATED_SIZE == 0) {
+      return encode_to_buffer_slow(0, &encode_msg_noop, &msg, conn, remaining_size);
+    } else {
+      return encode_to_buffer_slow(msg.calculate_size(), &proto_encode_msg<T>, &msg, conn, remaining_size);
+    }
+  }
+
+  // Non-template core — fills state fields and encodes
+  static uint16_t fill_and_encode_entity_state(EntityBase *entity, StateResponseProtoMessage &msg,
+                                               CalculateSizeFn size_fn, MessageEncodeFn encode_fn, APIConnection *conn,
+                                               uint32_t remaining_size);
+
+  // Thin template wrapper
+  template<typename T>
+  static uint16_t fill_and_encode_entity_state(EntityBase *entity, T &msg, APIConnection *conn,
+                                               uint32_t remaining_size) {
+    return fill_and_encode_entity_state(entity, msg, &calc_size<T>, &proto_encode_msg<T>, conn, remaining_size);
+  }
+
+  // Non-template core — fills info fields, allocates buffers, and encodes
+  static uint16_t fill_and_encode_entity_info(EntityBase *entity, InfoResponseProtoMessage &msg,
+                                              CalculateSizeFn size_fn, MessageEncodeFn encode_fn, APIConnection *conn,
+                                              uint32_t remaining_size);
+
+  // Thin template wrapper
+  template<typename T>
+  static uint16_t fill_and_encode_entity_info(EntityBase *entity, T &msg, APIConnection *conn,
+                                              uint32_t remaining_size) {
+    return fill_and_encode_entity_info(entity, msg, &calc_size<T>, &proto_encode_msg<T>, conn, remaining_size);
+  }
+
+  // Non-template core — fills device_class, then delegates to fill_and_encode_entity_info
+  static uint16_t fill_and_encode_entity_info_with_device_class(EntityBase *entity, InfoResponseProtoMessage &msg,
+                                                                StringRef &device_class_field, CalculateSizeFn size_fn,
+                                                                MessageEncodeFn encode_fn, APIConnection *conn,
+                                                                uint32_t remaining_size);
+
+  // Thin template wrapper
+  template<typename T>
+  static uint16_t fill_and_encode_entity_info_with_device_class(EntityBase *entity, T &msg,
+                                                                StringRef &device_class_field, APIConnection *conn,
+                                                                uint32_t remaining_size) {
+    return fill_and_encode_entity_info_with_device_class(entity, msg, device_class_field, &calc_size<T>,
+                                                         &proto_encode_msg<T>, conn, remaining_size);
   }
 
 #ifdef USE_VOICE_ASSISTANT
@@ -370,6 +518,10 @@ class APIConnection final : public APIServerConnectionBase {
     return this->client_supports_api_version(1, 14) ? MAX_INITIAL_PER_BATCH : MAX_INITIAL_PER_BATCH_LEGACY;
   }
 
+  // Send keepalive ping or disconnect unresponsive client.
+  // Cold path — extracted from loop() to reduce instruction cache pressure.
+  void __attribute__((noinline)) check_keepalive_(uint32_t now);
+
   // Process active iterator (list_entities/initial_state) during connection setup.
   // Extracted from loop() — only runs during initial handshake, NONE in steady state.
   void __attribute__((noinline)) process_active_iterator_();
@@ -485,7 +637,13 @@ class APIConnection final : public APIServerConnectionBase {
   // === Optimal member ordering for 32-bit systems ===
 
   // Group 1: Pointers (4 bytes each on 32-bit)
+#if defined(USE_API_NOISE) && defined(USE_API_PLAINTEXT)
   std::unique_ptr<APIFrameHelper> helper_;
+#elif defined(USE_API_NOISE)
+  std::unique_ptr<APINoiseFrameHelper> helper_;
+#elif defined(USE_API_PLAINTEXT)
+  std::unique_ptr<APIPlaintextFrameHelper> helper_;
+#endif
   APIServer *parent_;
 
   // Group 2: Iterator union (saves ~16 bytes vs separate iterators)
@@ -504,6 +662,7 @@ class APIConnection final : public APIServerConnectionBase {
   // Helper methods for iterator lifecycle management
   void destroy_active_iterator_();
   void begin_iterator_(ActiveIterator type);
+  void finalize_iterator_sync_();
 #ifdef USE_CAMERA
   std::unique_ptr<camera::CameraImageReader> image_reader_;
 #endif
@@ -538,9 +697,28 @@ class APIConnection final : public APIServerConnectionBase {
 
     // Add item to the batch (with deduplication)
     void add_item(EntityBase *entity, uint8_t message_type, uint8_t estimated_size,
-                  uint8_t aux_data_index = AUX_DATA_UNUSED);
+                  uint8_t aux_data_index = AUX_DATA_UNUSED) {
+      // Dedup: O(n) scan but optimized for RAM over performance
+      // Skip deduplication for events - they are edge-triggered, every occurrence matters
+#ifdef USE_EVENT
+      if (message_type != EventResponse::MESSAGE_TYPE)
+#endif
+      {
+        for (const auto &item : this->items) {
+          if (item.entity == entity && item.message_type == message_type)
+            return;  // Already queued
+        }
+      }
+      this->items.push_back({entity, message_type, estimated_size, aux_data_index});
+    }
     // Add item to the front of the batch (for high priority messages like ping)
-    void add_item_front(EntityBase *entity, uint8_t message_type, uint8_t estimated_size);
+    void add_item_front(EntityBase *entity, uint8_t message_type, uint8_t estimated_size) {
+      // Swap to front avoids expensive vector::insert which shifts all elements
+      this->items.push_back({entity, message_type, estimated_size, AUX_DATA_UNUSED});
+      if (this->items.size() > 1) {
+        std::swap(this->items.front(), this->items.back());
+      }
+    }
 
     // Clear all items
     void clear() {
@@ -593,6 +771,7 @@ class APIConnection final : public APIServerConnectionBase {
     uint8_t batch_scheduled : 1;
     uint8_t batch_first_message : 1;          // For batch buffer allocation
     uint8_t should_try_send_immediately : 1;  // True after initial states are sent
+    uint8_t may_have_remaining_data : 1;      // Read loop hit limit, retry without ready check
 #ifdef HAS_PROTO_MESSAGE_DUMP
     uint8_t log_only_mode : 1;
 #endif
@@ -601,11 +780,16 @@ class APIConnection final : public APIServerConnectionBase {
   // 2-byte types immediately after flags_ (no padding between them)
   uint16_t client_api_version_major_{0};
   uint16_t client_api_version_minor_{0};
-  // 1-byte type to fill padding
+  // 1-byte types to fill remaining space before next 4-byte boundary
   ActiveIterator active_iterator_{ActiveIterator::NONE};
-  // Total: 2 (flags) + 2 + 2 + 1 = 7 bytes, then 1 byte padding to next 4-byte boundary
+  uint8_t batch_message_type_{0};  // Current message type during batch encoding
+  // Total: 2 (flags) + 2 + 2 + 1 + 1 = 8 bytes, aligned to 4-byte boundary
 
-  uint32_t get_batch_delay_ms_() const;
+  // Actual header size used by encode_to_buffer for the current message.
+  // Read by process_batch_multi_ to pass into MessageInfo.
+  uint8_t batch_header_size_{0};
+
+  uint32_t get_batch_delay_ms_() const { return this->parent_->get_batch_delay(); }
   // Message will use 8 more bytes than the minimum size, and typical
   // MTU is 1500. Sometimes users will see as low as 1460 MTU.
   // If its IPv6 the header is 40 bytes, and if its IPv4
@@ -621,8 +805,8 @@ class APIConnection final : public APIServerConnectionBase {
 
   bool schedule_batch_();
   void process_batch_();
-  void process_batch_multi_(std::vector<uint8_t> &shared_buf, size_t num_items, uint8_t header_padding,
-                            uint8_t footer_size) __attribute__((noinline));
+  void process_batch_multi_(APIBuffer &shared_buf, size_t num_items, uint8_t header_padding, uint8_t footer_size)
+      __attribute__((noinline));
   void clear_batch_() {
     this->deferred_batch_.clear();
     this->flags_.batch_scheduled = false;
@@ -672,10 +856,8 @@ class APIConnection final : public APIServerConnectionBase {
   }
 
   // Helper function to schedule a high priority message at the front of the batch
-  bool schedule_message_front_(EntityBase *entity, uint8_t message_type, uint8_t estimated_size) {
-    this->deferred_batch_.add_item_front(entity, message_type, estimated_size);
-    return this->schedule_batch_();
-  }
+  // Out-of-line: callers (on_shutdown, check_keepalive_) are cold paths
+  bool schedule_message_front_(EntityBase *entity, uint8_t message_type, uint8_t estimated_size);
 
   // Helper function to log client messages with name and peername
   void log_client_(int level, const LogString *message);

esphome/components/api/api_frame_helper.cpp

@@ -100,149 +100,81 @@ const LogString *api_error_to_logstr(APIError err) {
   return LOG_STR("UNKNOWN");
 }
 
-// Default implementation for loop - handles sending buffered data
-APIError APIFrameHelper::loop() {
-  if (this->tx_buf_count_ > 0) {
-    APIError err = try_send_tx_buf_();
-    if (err != APIError::OK && err != APIError::WOULD_BLOCK) {
-      return err;
-    }
-  }
-  return APIError::OK;  // Convert WOULD_BLOCK to OK to avoid connection termination
-}
-
-// Common socket write error handling
-APIError APIFrameHelper::handle_socket_write_error_() {
-  if (errno == EWOULDBLOCK || errno == EAGAIN) {
-    return APIError::WOULD_BLOCK;
-  }
-  HELPER_LOG("Socket write failed with errno %d", errno);
-  this->state_ = State::FAILED;
-  return APIError::SOCKET_WRITE_FAILED;
-}
-
-// Helper method to buffer data from IOVs
-void APIFrameHelper::buffer_data_from_iov_(const struct iovec *iov, int iovcnt, uint16_t total_write_len,
-                                           uint16_t offset) {
-  // Check if queue is full
-  if (this->tx_buf_count_ >= API_MAX_SEND_QUEUE) {
-    HELPER_LOG("Send queue full (%u buffers), dropping connection", this->tx_buf_count_);
-    this->state_ = State::FAILED;
-    return;
-  }
-
-  uint16_t buffer_size = total_write_len - offset;
-  auto &buffer = this->tx_buf_[this->tx_buf_tail_];
-  buffer = std::make_unique<SendBuffer>(SendBuffer{
-      .data = std::make_unique<uint8_t[]>(buffer_size),
-      .size = buffer_size,
-      .offset = 0,
-  });
-
-  uint16_t to_skip = offset;
-  uint16_t write_pos = 0;
-
-  for (int i = 0; i < iovcnt; i++) {
-    if (to_skip >= iov[i].iov_len) {
-      // Skip this entire segment
-      to_skip -= static_cast<uint16_t>(iov[i].iov_len);
-    } else {
-      // Include this segment (partially or fully)
-      const uint8_t *src = reinterpret_cast<uint8_t *>(iov[i].iov_base) + to_skip;
-      uint16_t len = static_cast<uint16_t>(iov[i].iov_len) - to_skip;
-      std::memcpy(buffer->data.get() + write_pos, src, len);
-      write_pos += len;
-      to_skip = 0;
-    }
-  }
-
-  // Update circular buffer tracking
-  this->tx_buf_tail_ = (this->tx_buf_tail_ + 1) % API_MAX_SEND_QUEUE;
-  this->tx_buf_count_++;
-}
-
-// This method writes data to socket or buffers it
-APIError APIFrameHelper::write_raw_(const struct iovec *iov, int iovcnt, uint16_t total_write_len) {
-  // Returns APIError::OK if successful (or would block, but data has been buffered)
-  // Returns APIError::SOCKET_WRITE_FAILED if socket write failed, and sets state to FAILED
-
-  if (iovcnt == 0)
-    return APIError::OK;  // Nothing to do, success
-
 #ifdef HELPER_LOG_PACKETS
-  for (int i = 0; i < iovcnt; i++) {
-    LOG_PACKET_SENDING(reinterpret_cast<uint8_t *>(iov[i].iov_base), iov[i].iov_len);
-  }
+void APIFrameHelper::log_packet_sending_(const void *data, uint16_t len) {
+  LOG_PACKET_SENDING(reinterpret_cast<const uint8_t *>(data), len);
+}
 #endif
 
-  // Try to send any existing buffered data first if there is any
-  if (this->tx_buf_count_ > 0) {
-    APIError send_result = try_send_tx_buf_();
-    // If real error occurred (not just WOULD_BLOCK), return it
-    if (send_result != APIError::OK && send_result != APIError::WOULD_BLOCK) {
-      return send_result;
-    }
-
-    // If there is still data in the buffer, we can't send, buffer
-    // the new data and return
-    if (this->tx_buf_count_ > 0) {
-      this->buffer_data_from_iov_(iov, iovcnt, total_write_len, 0);
-      return APIError::OK;  // Success, data buffered
+APIError APIFrameHelper::drain_overflow_and_handle_errors_() {
+  if (this->overflow_buf_.try_drain(this->socket_.get()) == -1) {
+    int err = errno;
+    if (err != EWOULDBLOCK && err != EAGAIN) {
+      this->state_ = State::FAILED;
+      HELPER_LOG("Socket write failed with errno %d", err);
+      return APIError::SOCKET_WRITE_FAILED;
     }
   }
-
-  // Try to send directly if no buffered data
-  // Optimize for single iovec case (common for plaintext API)
-  ssize_t sent =
-      (iovcnt == 1) ? this->socket_->write(iov[0].iov_base, iov[0].iov_len) : this->socket_->writev(iov, iovcnt);
-
-  if (sent == -1) {
-    APIError err = this->handle_socket_write_error_();
-    if (err == APIError::WOULD_BLOCK) {
-      // Socket would block, buffer the data
-      this->buffer_data_from_iov_(iov, iovcnt, total_write_len, 0);
-      return APIError::OK;  // Success, data buffered
-    }
-    return err;  // Socket write failed
-  } else if (static_cast<uint16_t>(sent) < total_write_len) {
-    // Partially sent, buffer the remaining data
-    this->buffer_data_from_iov_(iov, iovcnt, total_write_len, static_cast<uint16_t>(sent));
-  }
-
-  return APIError::OK;  // Success, all data sent or buffered
+  return APIError::OK;
 }
 
-// Common implementation for trying to send buffered data
-// IMPORTANT: Caller MUST ensure tx_buf_count_ > 0 before calling this method
-APIError APIFrameHelper::try_send_tx_buf_() {
-  // Try to send from tx_buf - we assume it's not empty as it's the caller's responsibility to check
-  while (this->tx_buf_count_ > 0) {
-    // Get the first buffer in the queue
-    SendBuffer *front_buffer = this->tx_buf_[this->tx_buf_head_].get();
+// Single-buffer write path: wraps in iovec and delegates.
+APIError APIFrameHelper::write_raw_buf_(const void *data, uint16_t len, ssize_t sent) {
+  struct iovec iov = {const_cast<void *>(data), len};
+  APIError err = this->write_raw_iov_(&iov, 1, len, sent);
+#ifdef HELPER_LOG_PACKETS
+  // Log after write/enqueue so re-entrant log sends can't corrupt data before it's sent
+  if (err == APIError::OK)
+    LOG_PACKET_SENDING(reinterpret_cast<const uint8_t *>(data), len);
+#endif
+  return err;
+}
 
-    // Try to send the remaining data in this buffer
-    ssize_t sent = this->socket_->write(front_buffer->current_data(), front_buffer->remaining());
-
-    if (sent == -1) {
-      return this->handle_socket_write_error_();
-    } else if (sent == 0) {
-      // Nothing sent but not an error
-      return APIError::WOULD_BLOCK;
-    } else if (static_cast<uint16_t>(sent) < front_buffer->remaining()) {
-      // Partially sent, update offset
-      // Cast to ensure no overflow issues with uint16_t
-      front_buffer->offset += static_cast<uint16_t>(sent);
-      return APIError::WOULD_BLOCK;  // Stop processing more buffers if we couldn't send a complete buffer
-    } else {
-      // Buffer completely sent, remove it from the queue
-      this->tx_buf_[this->tx_buf_head_].reset();
-      this->tx_buf_head_ = (this->tx_buf_head_ + 1) % API_MAX_SEND_QUEUE;
-      this->tx_buf_count_--;
-      // Continue loop to try sending the next buffer
+// Handles partial writes, errors, and overflow buffering.
+// Called when the inline fast path couldn't complete the write,
+// or directly from cold paths (handshake, error handling).
+APIError APIFrameHelper::write_raw_iov_(const struct iovec *iov, int iovcnt, uint16_t total_write_len, ssize_t sent) {
+  if (sent <= 0) {
+    if (sent == WRITE_NOT_ATTEMPTED) {
+      // Cold path: no write attempted yet, drain overflow and try
+      if (!this->overflow_buf_.empty()) {
+        APIError err = this->drain_overflow_and_handle_errors_();
+        if (err != APIError::OK)
+          return err;
+      }
+      if (this->overflow_buf_.empty()) {
+        sent = this->write_iov_to_socket_(iov, iovcnt);
+        if (sent == static_cast<ssize_t>(total_write_len))
+          return APIError::OK;
+        // Partial write or -1: fall through to error check / enqueue below
+      } else {
+        // Overflow backlog remains after drain; skip socket write, enqueue everything
+        sent = 0;
+      }
+    }
+    // WRITE_FAILED (-1): fast path or retry write returned -1, check errno
+    if (sent == WRITE_FAILED) {
+      int err = errno;
+      if (err != EWOULDBLOCK && err != EAGAIN) {
+        this->state_ = State::FAILED;
+        HELPER_LOG("Socket write failed with errno %d", err);
+        return APIError::SOCKET_WRITE_FAILED;
+      }
+      sent = 0;  // Treat WOULD_BLOCK as zero bytes sent
     }
   }
 
-  return APIError::OK;  // All buffers sent successfully
+  // Full write completed (possible when called directly, not via write_raw_fast_buf_)
+  if (sent == static_cast<ssize_t>(total_write_len))
+    return APIError::OK;
+
+  // Queue unsent data into overflow buffer
+  if (!this->overflow_buf_.enqueue_iov(iov, iovcnt, total_write_len, static_cast<uint16_t>(sent))) {
+    HELPER_LOG("Overflow buffer full, dropping connection");
+    this->state_ = State::FAILED;
+    return APIError::SOCKET_WRITE_FAILED;
+  }
+  return APIError::OK;
 }
 
 const char *APIFrameHelper::get_peername_to(std::span<char, socket::SOCKADDR_STR_LEN> buf) const {
@@ -278,11 +210,12 @@ APIError APIFrameHelper::init_common_() {
 
 APIError APIFrameHelper::handle_socket_read_result_(ssize_t received) {
   if (received == -1) {
-    if (errno == EWOULDBLOCK || errno == EAGAIN) {
+    const int err = errno;
+    if (err == EWOULDBLOCK || err == EAGAIN) {
       return APIError::WOULD_BLOCK;
     }
     state_ = State::FAILED;
-    HELPER_LOG("Socket read failed with errno %d", errno);
+    HELPER_LOG("Socket read failed with errno %d", err);
     return APIError::SOCKET_READ_FAILED;
   } else if (received == 0) {
     state_ = State::FAILED;

esphome/components/api/api_frame_helper.h

@@ -5,13 +5,15 @@
 #include <memory>
 #include <span>
 #include <utility>
-#include <vector>
 
 #include "esphome/core/defines.h"
 #ifdef USE_API
+#include "esphome/components/api/api_buffer.h"
+#include "esphome/components/api/api_overflow_buffer.h"
 #include "esphome/components/socket/socket.h"
 #include "esphome/core/application.h"
 #include "esphome/core/log.h"
+#include "proto.h"
 
 namespace esphome::api {
 
@@ -29,12 +31,14 @@ static constexpr uint16_t MAX_MESSAGE_SIZE = 8192;  // 8 KiB for ESP8266
 static constexpr uint16_t MAX_MESSAGE_SIZE = 32768;  // 32 KiB for ESP32 and other platforms
 #endif
 
+// Extra byte reserved in rx_buf_ beyond the message size so protobuf
+// StringRef fields can be null-terminated in-place after decode.
+static constexpr uint16_t RX_BUF_NULL_TERMINATOR = 1;
+
 // Maximum number of messages to batch in a single write operation
 // Must be >= MAX_INITIAL_PER_BATCH in api_connection.h (enforced by static_assert there)
 static constexpr size_t MAX_MESSAGES_PER_BATCH = 34;
 
-class ProtoWriteBuffer;
-
 // Max client name length (e.g., "Home Assistant 2026.1.0.dev0" = 28 chars)
 static constexpr size_t CLIENT_INFO_NAME_MAX_LEN = 32;
 
@@ -45,12 +49,17 @@ struct ReadPacketBuffer {
 };
 
 // Packed message info structure to minimize memory usage
+// Note: message_type is uint8_t — all current protobuf message types fit in 8 bits.
+// The noise wire format encodes types as 16-bit, but the high byte is always 0.
+// If message types ever exceed 255, this and encrypt_noise_message_ must be updated.
 struct MessageInfo {
   uint16_t offset;        // Offset in buffer where message starts
   uint16_t payload_size;  // Size of the message payload
   uint8_t message_type;   // Message type (0-255)
+  uint8_t header_size;    // Actual header size used (avoids recomputation in write path)
 
-  MessageInfo(uint8_t type, uint16_t off, uint16_t size) : offset(off), payload_size(size), message_type(type) {}
+  MessageInfo(uint8_t type, uint16_t off, uint16_t size, uint8_t hdr)
+      : offset(off), payload_size(size), message_type(type), header_size(hdr) {}
 };
 
 enum class APIError : uint16_t {
@@ -101,9 +110,9 @@ class APIFrameHelper {
   }
   virtual ~APIFrameHelper() = default;
   virtual APIError init() = 0;
-  virtual APIError loop();
+  virtual APIError loop() = 0;
   virtual APIError read_packet(ReadPacketBuffer *buffer) = 0;
-  bool can_write_without_blocking() { return this->state_ == State::DATA && this->tx_buf_count_ == 0; }
+  bool can_write_without_blocking() { return this->state_ == State::DATA && this->overflow_buf_.empty(); }
   int getpeername(struct sockaddr *addr, socklen_t *addrlen) { return socket_->getpeername(addr, addrlen); }
   APIError close() {
     if (state_ == State::CLOSED)
@@ -130,43 +139,66 @@ class APIFrameHelper {
   //
   // For log messages: Use Nagle to coalesce multiple small log packets into
   // fewer larger packets, reducing WiFi overhead. However, we limit batching
-  // to 3 messages to avoid excessive LWIP buffer pressure on memory-constrained
-  // devices like ESP8266. LWIP's TCP_OVERSIZE option coalesces the data into
-  // shared pbufs, but holding data too long waiting for Nagle's timer causes
-  // buffer exhaustion and dropped messages.
+  // to avoid excessive LWIP buffer pressure on memory-constrained devices.
+  // LWIP's TCP_OVERSIZE option coalesces the data into shared pbufs, but
+  // holding data too long waiting for Nagle's timer causes buffer exhaustion
+  // and dropped messages.
   //
-  // Flow: Log 1 (Nagle on) -> Log 2 (Nagle on) -> Log 3 (NODELAY, flush all)
+  // ESP32 (TCP_SND_BUF=4×MSS+) / RP2040 (8×MSS) / LibreTiny (4×MSS): 4 logs per cycle
+  // ESP8266 (2×MSS): 3 logs per cycle (tightest buffers)
+  //
+  // Flow (ESP32/RP2040/LT): Log 1 (Nagle on) -> Log 2 -> Log 3 -> Log 4 (NODELAY, flush)
+  // Flow (ESP8266):         Log 1 (Nagle on) -> Log 2 -> Log 3 (NODELAY, flush all)
   //
   void set_nodelay_for_message(bool is_log_message) {
     if (!is_log_message) {
-      if (this->nodelay_state_ != NODELAY_ON) {
+      if (this->nodelay_counter_) {
         this->set_nodelay_raw_(true);
-        this->nodelay_state_ = NODELAY_ON;
+        this->nodelay_counter_ = 0;
       }
       return;
     }
-
-    // Log messages 1-3: state transitions -1 -> 1 -> 2 -> -1 (flush on 3rd)
-    if (this->nodelay_state_ == NODELAY_ON) {
+    // Log message: enable Nagle on first, flush after LOG_NAGLE_COUNT
+    if (!this->nodelay_counter_)
       this->set_nodelay_raw_(false);
-      this->nodelay_state_ = 1;
-    } else if (this->nodelay_state_ >= LOG_NAGLE_COUNT) {
+    if (++this->nodelay_counter_ > LOG_NAGLE_COUNT) {
       this->set_nodelay_raw_(true);
-      this->nodelay_state_ = NODELAY_ON;
-    } else {
-      this->nodelay_state_++;
+      this->nodelay_counter_ = 0;
     }
   }
+  // Write a single protobuf message - the hot path (87-100% of all writes).
+  // Caller must ensure state is DATA before calling.
   virtual APIError write_protobuf_packet(uint8_t type, ProtoWriteBuffer buffer) = 0;
-  // Write multiple protobuf messages in a single operation
-  // messages contains (message_type, offset, length) for each message in the buffer
-  // The buffer contains all messages with appropriate padding before each
+  // Write multiple protobuf messages in a single batched operation.
+  // Caller must ensure state is DATA and messages is not empty.
+  // messages contains (message_type, offset, length) for each message in the buffer.
+  // The buffer contains all messages with appropriate padding before each.
   virtual APIError write_protobuf_messages(ProtoWriteBuffer buffer, std::span<const MessageInfo> messages) = 0;
-  // Get the frame header padding required by this protocol
+  // Get the maximum frame header padding required by this protocol (worst case)
   uint8_t frame_header_padding() const { return frame_header_padding_; }
+  // Get the actual frame header size for a specific message.
+  // For noise: always returns frame_header_padding_ (fixed 7-byte header).
+  // For plaintext: computes actual size from varint lengths (3-6 bytes).
+  // Distinguishes protocols via frame_footer_size_ (noise always has a non-zero MAC
+  // footer, plaintext has footer=0). If a protocol with a plaintext footer is ever
+  // added, this should become a virtual method.
+  uint8_t frame_header_size(uint16_t payload_size, uint8_t message_type) const {
+#if defined(USE_API_NOISE) && defined(USE_API_PLAINTEXT)
+    return this->frame_footer_size_
+               ? this->frame_header_padding_
+               : static_cast<uint8_t>(1 + ProtoSize::varint16(payload_size) + ProtoSize::varint8(message_type));
+#elif defined(USE_API_NOISE)
+    return this->frame_header_padding_;
+#else  // USE_API_PLAINTEXT only
+    return static_cast<uint8_t>(1 + ProtoSize::varint16(payload_size) + ProtoSize::varint8(message_type));
+#endif
+  }
   // Get the frame footer size required by this protocol
   uint8_t frame_footer_size() const { return frame_footer_size_; }
-  // Check if socket has data ready to read
+  // Check if socket has buffered data ready to read.
+  // Contract: callers must read until it would block (EAGAIN/EWOULDBLOCK)
+  // or track that they stopped early and retry without this check.
+  // See Socket::ready() for details.
   bool is_socket_ready() const { return socket_ != nullptr && socket_->ready(); }
   // Release excess memory from internal buffers after initial sync
   void release_buffers() {
@@ -174,37 +206,51 @@ class APIFrameHelper {
     // rx_buf_len_ tracks bytes read so far; if non-zero, we're mid-frame
     // and clearing would lose partially received data.
     if (this->rx_buf_len_ == 0) {
-      // Use swap trick since shrink_to_fit() is non-binding and may be ignored
-      std::vector<uint8_t>().swap(this->rx_buf_);
+      this->rx_buf_.release();
     }
   }
 
  protected:
-  // Buffer containing data to be sent
-  struct SendBuffer {
-    std::unique_ptr<uint8_t[]> data;
-    uint16_t size{0};    // Total size of the buffer
-    uint16_t offset{0};  // Current offset within the buffer
+  // Drain backlogged overflow data to the socket and handle errors.
+  // Called when overflow_buf_.empty() is false. Out-of-line to keep the
+  // fast path (empty check) inline at call sites.
+  // Returns OK for transient errors (WOULD_BLOCK), SOCKET_WRITE_FAILED for hard errors.
+  APIError drain_overflow_and_handle_errors_();
 
-    // Using uint16_t reduces memory usage since ESPHome API messages are limited to UINT16_MAX (65535) bytes
-    uint16_t remaining() const { return size - offset; }
-    const uint8_t *current_data() const { return data.get() + offset; }
-  };
+  // Sentinel values for the sent parameter in write_raw_ methods
+  static constexpr ssize_t WRITE_FAILED = -1;         // Fast path: write()/writev() returned -1
+  static constexpr ssize_t WRITE_NOT_ATTEMPTED = -2;  // Cold path: no write attempted yet
 
-  // Common implementation for writing raw data to socket
-  APIError write_raw_(const struct iovec *iov, int iovcnt, uint16_t total_write_len);
+  // Dispatch to write() or writev() based on iovec count
+  inline ssize_t ESPHOME_ALWAYS_INLINE write_iov_to_socket_(const struct iovec *iov, int iovcnt) {
+    return (iovcnt == 1) ? this->socket_->write(iov[0].iov_base, iov[0].iov_len) : this->socket_->writev(iov, iovcnt);
+  }
 
-  // Try to send data from the tx buffer
-  APIError try_send_tx_buf_();
-
-  // Helper method to buffer data from IOVs
-  void buffer_data_from_iov_(const struct iovec *iov, int iovcnt, uint16_t total_write_len, uint16_t offset);
-
-  // Common socket write error handling
-  APIError handle_socket_write_error_();
-  template<typename StateEnum>
-  APIError write_raw_(const struct iovec *iov, int iovcnt, socket::Socket *socket, std::vector<uint8_t> &tx_buf,
-                      const std::string &info, StateEnum &state, StateEnum failed_state);
+  // Inlined write methods — used by hot paths (write_protobuf_packet, write_protobuf_messages)
+  // These inline the fast path (overflow empty + full write) and tail-call the out-of-line
+  // slow path only on failure/partial write.
+  inline APIError ESPHOME_ALWAYS_INLINE write_raw_fast_buf_(const void *data, uint16_t len) {
+    if (this->overflow_buf_.empty()) [[likely]] {
+      ssize_t sent = this->socket_->write(data, len);
+      if (sent == static_cast<ssize_t>(len)) [[likely]] {
+#ifdef HELPER_LOG_PACKETS
+        this->log_packet_sending_(data, len);
+#endif
+        return APIError::OK;
+      }
+      // sent is -1 (WRITE_FAILED) or partial write count
+      return this->write_raw_buf_(data, len, sent);
+    }
+    return this->write_raw_buf_(data, len, WRITE_NOT_ATTEMPTED);
+  }
+  // Out-of-line write paths: handle partial writes, errors, overflow buffering
+  // sent: WRITE_NOT_ATTEMPTED (cold path), WRITE_FAILED (fast path write returned -1), or bytes sent (partial write)
+  APIError write_raw_buf_(const void *data, uint16_t len, ssize_t sent = WRITE_NOT_ATTEMPTED);
+  APIError write_raw_iov_(const struct iovec *iov, int iovcnt, uint16_t total_write_len,
+                          ssize_t sent = WRITE_NOT_ATTEMPTED);
+#ifdef HELPER_LOG_PACKETS
+  void log_packet_sending_(const void *data, uint16_t len);
+#endif
 
   // Socket ownership (4 bytes on 32-bit, 8 bytes on 64-bit)
   std::unique_ptr<socket::Socket> socket_;
@@ -228,9 +274,20 @@ class APIFrameHelper {
     EXPLICIT_REJECT = 8,  // Noise only
   };
 
-  // Containers (size varies, but typically 12+ bytes on 32-bit)
-  std::array<std::unique_ptr<SendBuffer>, API_MAX_SEND_QUEUE> tx_buf_;
-  std::vector<uint8_t> rx_buf_;
+  // Fast inline state check for read_packet/write_protobuf_messages hot path.
+  // Returns OK only in DATA state; maps CLOSED/FAILED to BAD_STATE and any
+  // other intermediate state to WOULD_BLOCK.
+  inline APIError ESPHOME_ALWAYS_INLINE check_data_state_() const {
+    if (this->state_ == State::DATA)
+      return APIError::OK;
+    if (this->state_ == State::CLOSED || this->state_ == State::FAILED)
+      return APIError::BAD_STATE;
+    return APIError::WOULD_BLOCK;
+  }
+
+  // Backlog for unsent data when TCP send buffer is full (rarely used in production)
+  APIOverflowBuffer overflow_buf_;
+  APIBuffer rx_buf_;
 
   // Client name buffer - stores name from Hello message or initial peername
   char client_name_[CLIENT_INFO_NAME_MAX_LEN]{};
@@ -240,15 +297,17 @@ class APIFrameHelper {
   State state_{State::INITIALIZE};
   uint8_t frame_header_padding_{0};
   uint8_t frame_footer_size_{0};
-  uint8_t tx_buf_head_{0};
-  uint8_t tx_buf_tail_{0};
-  uint8_t tx_buf_count_{0};
-  // Nagle batching state for log messages. NODELAY_ON (-1) means NODELAY is enabled
-  // (immediate send). Values 1-2 count log messages in the current Nagle batch.
-  // After LOG_NAGLE_COUNT logs, we switch to NODELAY to flush and reset.
-  static constexpr int8_t NODELAY_ON = -1;
-  static constexpr int8_t LOG_NAGLE_COUNT = 2;
-  int8_t nodelay_state_{NODELAY_ON};
+  // Nagle batching counter for log messages. 0 means NODELAY is enabled (immediate send).
+  // Values 1..LOG_NAGLE_COUNT count log messages in the current Nagle batch.
+  // After LOG_NAGLE_COUNT logs, we flush by re-enabling NODELAY and resetting to 0.
+  // ESP8266 has the tightest TCP send buffer (2×MSS) and needs conservative batching.
+  // ESP32 (4×MSS+), RP2040 (8×MSS), and LibreTiny (4×MSS) can coalesce more.
+#ifdef USE_ESP8266
+  static constexpr uint8_t LOG_NAGLE_COUNT = 2;
+#else
+  static constexpr uint8_t LOG_NAGLE_COUNT = 3;
+#endif
+  uint8_t nodelay_counter_{0};
 
   // Internal helper to set TCP_NODELAY socket option
   void set_nodelay_raw_(bool enable) {

esphome/components/api/api_frame_helper_noise.cpp

@@ -19,7 +19,7 @@ namespace esphome::api {
 
 static const char *const TAG = "api.noise";
 #ifdef USE_ESP8266
-static const char PROLOGUE_INIT[] PROGMEM = "NoiseAPIInit";
+static constexpr char PROLOGUE_INIT[] PROGMEM = "NoiseAPIInit";
 #else
 static const char *const PROLOGUE_INIT = "NoiseAPIInit";
 #endif
@@ -47,15 +47,8 @@ static constexpr size_t API_MAX_LOG_BYTES = 168;
               format_hex_pretty_to(hex_buf_, (buffer).data(), \
                                    (buffer).size() < API_MAX_LOG_BYTES ? (buffer).size() : API_MAX_LOG_BYTES)); \
   } while (0)
-#define LOG_PACKET_SENDING(data, len) \
-  do { \
-    char hex_buf_[format_hex_pretty_size(API_MAX_LOG_BYTES)]; \
-    ESP_LOGVV(TAG, "Sending raw: %s", \
-              format_hex_pretty_to(hex_buf_, data, (len) < API_MAX_LOG_BYTES ? (len) : API_MAX_LOG_BYTES)); \
-  } while (0)
 #else
 #define LOG_PACKET_RECEIVED(buffer) ((void) 0)
-#define LOG_PACKET_SENDING(data, len) ((void) 0)
 #endif
 
 /// Convert a noise error code to a readable error
@@ -153,8 +146,10 @@ APIError APINoiseFrameHelper::loop() {
     }
   }
 
-  // Use base class implementation for buffer sending
-  return APIFrameHelper::loop();
+  if (!this->overflow_buf_.empty()) [[unlikely]] {
+    return this->drain_overflow_and_handle_errors_();
+  }
+  return APIError::OK;
 }
 
 /** Read a packet into the rx_buf_.
@@ -194,17 +189,20 @@ APIError APINoiseFrameHelper::try_read_frame_() {
   uint16_t msg_size = (((uint16_t) rx_header_buf_[1]) << 8) | rx_header_buf_[2];
 
   // Check against size limits to prevent OOM: MAX_HANDSHAKE_SIZE for handshake, MAX_MESSAGE_SIZE for data
-  uint16_t limit = (state_ == State::DATA) ? MAX_MESSAGE_SIZE : MAX_HANDSHAKE_SIZE;
+  bool is_data = (state_ == State::DATA);
+  uint16_t limit = is_data ? MAX_MESSAGE_SIZE : MAX_HANDSHAKE_SIZE;
   if (msg_size > limit) {
     state_ = State::FAILED;
     HELPER_LOG("Bad packet: message size %u exceeds maximum %u", msg_size, limit);
-    return (state_ == State::DATA) ? APIError::BAD_DATA_PACKET : APIError::BAD_HANDSHAKE_PACKET_LEN;
+    return is_data ? APIError::BAD_DATA_PACKET : APIError::BAD_HANDSHAKE_PACKET_LEN;
   }
 
-  // Reserve space for body
-  if (this->rx_buf_.size() != msg_size) {
-    this->rx_buf_.resize(msg_size);
-  }
+  // Reserve space for body (+ null terminator in DATA state so protobuf
+  // StringRef fields can be safely null-terminated in-place after decode.
+  // During handshake, rx_buf_.size() is used in prologue construction, so
+  // the buffer must be exactly msg_size to avoid prologue mismatch.)
+  uint16_t alloc_size = msg_size + (is_data ? RX_BUF_NULL_TERMINATOR : 0);
+  this->rx_buf_.resize(alloc_size);
 
   if (rx_buf_len_ < msg_size) {
     // more data to read
@@ -239,129 +237,144 @@ APIError APINoiseFrameHelper::try_read_frame_() {
  * If an error occurred, returns that error. Only returns OK if the transport is ready for data
  * traffic.
  */
+// Split into per-state methods so the compiler doesn't allocate stack space
+// for all branches simultaneously. On RP2040 the core0 stack lives in a 4KB
+// scratch RAM bank; the Noise crypto path (curve25519) needs ~2KB+ of stack,
+// so every byte saved in the caller matters.
 APIError APINoiseFrameHelper::state_action_() {
-  int err;
-  APIError aerr;
-  if (state_ == State::INITIALIZE) {
-    HELPER_LOG("Bad state for method: %d", (int) state_);
-    return APIError::BAD_STATE;
+  switch (this->state_) {
+    case State::INITIALIZE:
+      HELPER_LOG("Bad state for method: %d", (int) this->state_);
+      return APIError::BAD_STATE;
+    case State::CLIENT_HELLO:
+      return this->state_action_client_hello_();
+    case State::SERVER_HELLO:
+      return this->state_action_server_hello_();
+    case State::HANDSHAKE:
+      return this->state_action_handshake_();
+    case State::CLOSED:
+    case State::FAILED:
+      return APIError::BAD_STATE;
+    default:
+      return APIError::OK;
   }
-  if (state_ == State::CLIENT_HELLO) {
-    // waiting for client hello
-    aerr = this->try_read_frame_();
-    if (aerr != APIError::OK) {
-      return handle_handshake_frame_error_(aerr);
-    }
-    // ignore contents, may be used in future for flags
-    // Resize for: existing prologue + 2 size bytes + frame data
-    size_t old_size = this->prologue_.size();
-    this->prologue_.resize(old_size + 2 + this->rx_buf_.size());
-    this->prologue_[old_size] = (uint8_t) (this->rx_buf_.size() >> 8);
-    this->prologue_[old_size + 1] = (uint8_t) this->rx_buf_.size();
-    std::memcpy(this->prologue_.data() + old_size + 2, this->rx_buf_.data(), this->rx_buf_.size());
-
-    state_ = State::SERVER_HELLO;
+}
+APIError APINoiseFrameHelper::state_action_client_hello_() {
+  // waiting for client hello
+  APIError aerr = this->try_read_frame_();
+  if (aerr != APIError::OK) {
+    return handle_handshake_frame_error_(aerr);
   }
-  if (state_ == State::SERVER_HELLO) {
-    // send server hello
-    const std::string &name = App.get_name();
-    char mac[MAC_ADDRESS_BUFFER_SIZE];
-    get_mac_address_into_buffer(mac);
-
-    // Calculate positions and sizes
-    size_t name_len = name.size() + 1;  // including null terminator
-    size_t name_offset = 1;
-    size_t mac_offset = name_offset + name_len;
-    size_t total_size = 1 + name_len + MAC_ADDRESS_BUFFER_SIZE;
-
-    // 1 (proto) + name (max ESPHOME_DEVICE_NAME_MAX_LEN) + 1 (name null)
-    // + mac (MAC_ADDRESS_BUFFER_SIZE - 1) + 1 (mac null)
-    constexpr size_t max_msg_size = 1 + ESPHOME_DEVICE_NAME_MAX_LEN + 1 + MAC_ADDRESS_BUFFER_SIZE;
-    uint8_t msg[max_msg_size];
-
-    // chosen proto
-    msg[0] = 0x01;
-
-    // node name, terminated by null byte
-    std::memcpy(msg + name_offset, name.c_str(), name_len);
-    // node mac, terminated by null byte
-    std::memcpy(msg + mac_offset, mac, MAC_ADDRESS_BUFFER_SIZE);
-
-    aerr = write_frame_(msg, total_size);
-    if (aerr != APIError::OK)
-      return aerr;
-
-    // start handshake
-    aerr = init_handshake_();
-    if (aerr != APIError::OK)
-      return aerr;
-
-    state_ = State::HANDSHAKE;
+  // ignore contents, may be used in future for flags
+  // Resize for: existing prologue + 2 size bytes + frame data
+  size_t old_size = this->prologue_.size();
+  size_t rx_size = this->rx_buf_.size();
+  this->prologue_.resize(old_size + 2 + rx_size);
+  this->prologue_[old_size] = (uint8_t) (rx_size >> 8);
+  this->prologue_[old_size + 1] = (uint8_t) rx_size;
+  if (rx_size > 0) {
+    std::memcpy(this->prologue_.data() + old_size + 2, this->rx_buf_.data(), rx_size);
   }
-  if (state_ == State::HANDSHAKE) {
-    int action = noise_handshakestate_get_action(handshake_);
-    if (action == NOISE_ACTION_READ_MESSAGE) {
-      // waiting for handshake msg
-      aerr = this->try_read_frame_();
-      if (aerr != APIError::OK) {
-        return handle_handshake_frame_error_(aerr);
-      }
 
-      if (this->rx_buf_.empty()) {
-        send_explicit_handshake_reject_(LOG_STR("Empty handshake message"));
-        return APIError::BAD_HANDSHAKE_ERROR_BYTE;
-      } else if (this->rx_buf_[0] != 0x00) {
-        HELPER_LOG("Bad handshake error byte: %u", this->rx_buf_[0]);
-        send_explicit_handshake_reject_(LOG_STR("Bad handshake error byte"));
-        return APIError::BAD_HANDSHAKE_ERROR_BYTE;
-      }
-
-      NoiseBuffer mbuf;
-      noise_buffer_init(mbuf);
-      noise_buffer_set_input(mbuf, this->rx_buf_.data() + 1, this->rx_buf_.size() - 1);
-      err = noise_handshakestate_read_message(handshake_, &mbuf, nullptr);
-      if (err != 0) {
-        // Special handling for MAC failure
-        send_explicit_handshake_reject_(err == NOISE_ERROR_MAC_FAILURE ? LOG_STR("Handshake MAC failure")
-                                                                       : LOG_STR("Handshake error"));
-        return handle_noise_error_(err, LOG_STR("noise_handshakestate_read_message"),
-                                   APIError::HANDSHAKESTATE_READ_FAILED);
-      }
-
-      aerr = check_handshake_finished_();
-      if (aerr != APIError::OK)
-        return aerr;
-    } else if (action == NOISE_ACTION_WRITE_MESSAGE) {
-      uint8_t buffer[65];
-      NoiseBuffer mbuf;
-      noise_buffer_init(mbuf);
-      noise_buffer_set_output(mbuf, buffer + 1, sizeof(buffer) - 1);
-
-      err = noise_handshakestate_write_message(handshake_, &mbuf, nullptr);
-      APIError aerr_write = handle_noise_error_(err, LOG_STR("noise_handshakestate_write_message"),
-                                                APIError::HANDSHAKESTATE_WRITE_FAILED);
-      if (aerr_write != APIError::OK)
-        return aerr_write;
-      buffer[0] = 0x00;  // success
-
-      aerr = write_frame_(buffer, mbuf.size + 1);
-      if (aerr != APIError::OK)
-        return aerr;
-      aerr = check_handshake_finished_();
-      if (aerr != APIError::OK)
-        return aerr;
-    } else {
-      // bad state for action
-      state_ = State::FAILED;
-      HELPER_LOG("Bad action for handshake: %d", action);
-      return APIError::HANDSHAKESTATE_BAD_STATE;
-    }
-  }
-  if (state_ == State::CLOSED || state_ == State::FAILED) {
-    return APIError::BAD_STATE;
-  }
+  state_ = State::SERVER_HELLO;
   return APIError::OK;
 }
+APIError APINoiseFrameHelper::state_action_server_hello_() {
+  // send server hello
+  const auto &name = App.get_name();
+  char mac[MAC_ADDRESS_BUFFER_SIZE];
+  get_mac_address_into_buffer(mac);
+
+  // Calculate positions and sizes
+  size_t name_len = name.size() + 1;  // including null terminator
+  size_t name_offset = 1;
+  size_t mac_offset = name_offset + name_len;
+  size_t total_size = 1 + name_len + MAC_ADDRESS_BUFFER_SIZE;
+
+  // 1 (proto) + name (max ESPHOME_DEVICE_NAME_MAX_LEN) + 1 (name null)
+  // + mac (MAC_ADDRESS_BUFFER_SIZE - 1) + 1 (mac null)
+  constexpr size_t max_msg_size = 1 + ESPHOME_DEVICE_NAME_MAX_LEN + 1 + MAC_ADDRESS_BUFFER_SIZE;
+  uint8_t msg[max_msg_size];
+
+  // chosen proto
+  msg[0] = 0x01;
+
+  // node name, terminated by null byte
+  std::memcpy(msg + name_offset, name.c_str(), name_len);
+  // node mac, terminated by null byte
+  std::memcpy(msg + mac_offset, mac, MAC_ADDRESS_BUFFER_SIZE);
+
+  APIError aerr = write_frame_(msg, total_size);
+  if (aerr != APIError::OK)
+    return aerr;
+
+  // start handshake
+  aerr = init_handshake_();
+  if (aerr != APIError::OK)
+    return aerr;
+
+  state_ = State::HANDSHAKE;
+  return APIError::OK;
+}
+APIError APINoiseFrameHelper::state_action_handshake_() {
+  int action = noise_handshakestate_get_action(this->handshake_);
+  if (action == NOISE_ACTION_READ_MESSAGE) {
+    return this->state_action_handshake_read_();
+  } else if (action == NOISE_ACTION_WRITE_MESSAGE) {
+    return this->state_action_handshake_write_();
+  }
+  // bad state for action
+  this->state_ = State::FAILED;
+  HELPER_LOG("Bad action for handshake: %d", action);
+  return APIError::HANDSHAKESTATE_BAD_STATE;
+}
+APIError APINoiseFrameHelper::state_action_handshake_read_() {
+  APIError aerr = this->try_read_frame_();
+  if (aerr != APIError::OK) {
+    return this->handle_handshake_frame_error_(aerr);
+  }
+
+  if (this->rx_buf_.empty()) {
+    this->send_explicit_handshake_reject_(LOG_STR("Empty handshake message"));
+    return APIError::BAD_HANDSHAKE_ERROR_BYTE;
+  } else if (this->rx_buf_[0] != 0x00) {
+    HELPER_LOG("Bad handshake error byte: %u", this->rx_buf_[0]);
+    this->send_explicit_handshake_reject_(LOG_STR("Bad handshake error byte"));
+    return APIError::BAD_HANDSHAKE_ERROR_BYTE;
+  }
+
+  NoiseBuffer mbuf;
+  noise_buffer_init(mbuf);
+  noise_buffer_set_input(mbuf, this->rx_buf_.data() + 1, this->rx_buf_.size() - 1);
+  int err = noise_handshakestate_read_message(this->handshake_, &mbuf, nullptr);
+  if (err != 0) {
+    // Special handling for MAC failure
+    this->send_explicit_handshake_reject_(err == NOISE_ERROR_MAC_FAILURE ? LOG_STR("Handshake MAC failure")
+                                                                         : LOG_STR("Handshake error"));
+    return this->handle_noise_error_(err, LOG_STR("noise_handshakestate_read_message"),
+                                     APIError::HANDSHAKESTATE_READ_FAILED);
+  }
+
+  return this->check_handshake_finished_();
+}
+APIError APINoiseFrameHelper::state_action_handshake_write_() {
+  uint8_t buffer[65];
+  NoiseBuffer mbuf;
+  noise_buffer_init(mbuf);
+  noise_buffer_set_output(mbuf, buffer + 1, sizeof(buffer) - 1);
+
+  int err = noise_handshakestate_write_message(this->handshake_, &mbuf, nullptr);
+  APIError aerr = this->handle_noise_error_(err, LOG_STR("noise_handshakestate_write_message"),
+                                            APIError::HANDSHAKESTATE_WRITE_FAILED);
+  if (aerr != APIError::OK)
+    return aerr;
+  buffer[0] = 0x00;  // success
+
+  aerr = this->write_frame_(buffer, mbuf.size + 1);
+  if (aerr != APIError::OK)
+    return aerr;
+  return this->check_handshake_finished_();
+}
 void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reason) {
   // Max reject message: "Bad handshake packet len" (24) + 1 (failure byte) = 25 bytes
   uint8_t data[32];
@@ -370,6 +383,7 @@ void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reaso
 #ifdef USE_STORE_LOG_STR_IN_FLASH
   // On ESP8266 with flash strings, we need to use PROGMEM-aware functions
   size_t reason_len = strlen_P(reinterpret_cast<PGM_P>(reason));
+  reason_len = std::min(reason_len, sizeof(data) - 1);
   if (reason_len > 0) {
     memcpy_P(data + 1, reinterpret_cast<PGM_P>(reason), reason_len);
   }
@@ -377,6 +391,7 @@ void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reaso
   // Normal memory access
   const char *reason_str = LOG_STR_ARG(reason);
   size_t reason_len = strlen(reason_str);
+  reason_len = std::min(reason_len, sizeof(data) - 1);
   if (reason_len > 0) {
     // NOLINTNEXTLINE(bugprone-not-null-terminated-result) - binary protocol, not a C string
     std::memcpy(data + 1, reason_str, reason_len);
@@ -392,14 +407,9 @@ void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reaso
   state_ = orig_state;
 }
 APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {
-  APIError aerr = this->state_action_();
-  if (aerr != APIError::OK) {
+  APIError aerr = this->check_data_state_();
+  if (aerr != APIError::OK)
     return aerr;
-  }
-
-  if (this->state_ != State::DATA) {
-    return APIError::WOULD_BLOCK;
-  }
 
   aerr = this->try_read_frame_();
   if (aerr != APIError::OK)
@@ -407,7 +417,18 @@ APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {
 
   NoiseBuffer mbuf;
   noise_buffer_init(mbuf);
-  noise_buffer_set_inout(mbuf, this->rx_buf_.data(), this->rx_buf_.size(), this->rx_buf_.size());
+  // read_packet() must only be called in DATA state; the extra
+  // RX_BUF_NULL_TERMINATOR byte is only allocated in DATA state
+  // (see try_read_frame_), so calling this during handshake would
+  // underflow the size calculation below.
+#ifdef ESPHOME_DEBUG_API
+  assert(this->state_ == State::DATA);
+#endif
+  // rx_buf_ has RX_BUF_NULL_TERMINATOR extra byte for null termination
+  // (only added in DATA state — see try_read_frame_), so subtract it
+  // to get the actual encrypted data size for decryption.
+  size_t encrypted_size = this->rx_buf_.size() - RX_BUF_NULL_TERMINATOR;
+  noise_buffer_set_inout(mbuf, this->rx_buf_.data(), encrypted_size, encrypted_size);
   int err = noise_cipherstate_decrypt(this->recv_cipher_, &mbuf);
   APIError decrypt_err =
       handle_noise_error_(err, LOG_STR("noise_cipherstate_decrypt"), APIError::CIPHERSTATE_DECRYPT_FAILED);
@@ -436,78 +457,83 @@ APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {
   buffer->type = type;
   return APIError::OK;
 }
+// Encrypt a single noise message in place and return the encrypted frame length.
+// Returns APIError::OK on success.
+APIError APINoiseFrameHelper::encrypt_noise_message_(uint8_t *buf_start, uint16_t payload_size, uint8_t message_type,
+                                                     uint16_t &encrypted_len_out) {
+  // Write noise header
+  buf_start[0] = 0x01;  // indicator
+  // buf_start[1], buf_start[2] to be set after encryption
+
+  // Write message header (to be encrypted)
+  constexpr uint8_t msg_offset = 3;
+  buf_start[msg_offset] = static_cast<uint8_t>(message_type >> 8);      // type high byte
+  buf_start[msg_offset + 1] = static_cast<uint8_t>(message_type);       // type low byte
+  buf_start[msg_offset + 2] = static_cast<uint8_t>(payload_size >> 8);  // data_len high byte
+  buf_start[msg_offset + 3] = static_cast<uint8_t>(payload_size);       // data_len low byte
+  // payload data is already in the buffer starting at offset + 7
+
+  // Encrypt the message in place
+  NoiseBuffer mbuf;
+  noise_buffer_init(mbuf);
+  noise_buffer_set_inout(mbuf, buf_start + msg_offset, 4 + payload_size, 4 + payload_size + this->frame_footer_size_);
+
+  int err = noise_cipherstate_encrypt(this->send_cipher_, &mbuf);
+  APIError aerr =
+      this->handle_noise_error_(err, LOG_STR("noise_cipherstate_encrypt"), APIError::CIPHERSTATE_ENCRYPT_FAILED);
+  if (aerr != APIError::OK)
+    return aerr;
+
+  // Fill in the encrypted size
+  buf_start[1] = static_cast<uint8_t>(mbuf.size >> 8);
+  buf_start[2] = static_cast<uint8_t>(mbuf.size);
+
+  encrypted_len_out = static_cast<uint16_t>(3 + mbuf.size);  // indicator + size + encrypted data
+  return APIError::OK;
+}
+
 APIError APINoiseFrameHelper::write_protobuf_packet(uint8_t type, ProtoWriteBuffer buffer) {
-  // Resize to include MAC space (required for Noise encryption)
-  buffer.get_buffer()->resize(buffer.get_buffer()->size() + frame_footer_size_);
-  MessageInfo msg{type, 0,
-                  static_cast<uint16_t>(buffer.get_buffer()->size() - frame_header_padding_ - frame_footer_size_)};
-  return write_protobuf_messages(buffer, std::span<const MessageInfo>(&msg, 1));
+#ifdef ESPHOME_DEBUG_API
+  assert(this->state_ == State::DATA);
+#endif
+
+  // Resize buffer to include footer space for Noise MAC
+  if (this->frame_footer_size_)
+    buffer.get_buffer()->resize(buffer.get_buffer()->size() + this->frame_footer_size_);
+
+  uint16_t payload_size =
+      static_cast<uint16_t>(buffer.get_buffer()->size() - HEADER_PADDING - this->frame_footer_size_);
+  uint8_t *buf_start = buffer.get_buffer()->data();
+  uint16_t encrypted_len;
+  APIError aerr = this->encrypt_noise_message_(buf_start, payload_size, type, encrypted_len);
+  if (aerr != APIError::OK)
+    return aerr;
+  return this->write_raw_fast_buf_(buf_start, encrypted_len);
 }
 
 APIError APINoiseFrameHelper::write_protobuf_messages(ProtoWriteBuffer buffer, std::span<const MessageInfo> messages) {
-  APIError aerr = state_action_();
-  if (aerr != APIError::OK) {
-    return aerr;
-  }
-
-  if (state_ != State::DATA) {
-    return APIError::WOULD_BLOCK;
-  }
-
-  if (messages.empty()) {
-    return APIError::OK;
-  }
+#ifdef ESPHOME_DEBUG_API
+  assert(this->state_ == State::DATA);
+  assert(!messages.empty());
+#endif
 
+  // Noise messages are already contiguous in the buffer:
+  // HEADER_PADDING (7) exactly matches the fixed header size, and
+  // footer space (16) is consumed by the encryption MAC.
   uint8_t *buffer_data = buffer.get_buffer()->data();
-
-  // Stack-allocated iovec array - no heap allocation
-  StaticVector<struct iovec, MAX_MESSAGES_PER_BATCH> iovs;
+  uint8_t *write_start = buffer_data + messages[0].offset;
   uint16_t total_write_len = 0;
 
-  // We need to encrypt each message in place
   for (const auto &msg : messages) {
-    // The buffer already has padding at offset
     uint8_t *buf_start = buffer_data + msg.offset;
-
-    // Write noise header
-    buf_start[0] = 0x01;  // indicator
-    // buf_start[1], buf_start[2] to be set after encryption
-
-    // Write message header (to be encrypted)
-    const uint8_t msg_offset = 3;
-    buf_start[msg_offset] = static_cast<uint8_t>(msg.message_type >> 8);      // type high byte
-    buf_start[msg_offset + 1] = static_cast<uint8_t>(msg.message_type);       // type low byte
-    buf_start[msg_offset + 2] = static_cast<uint8_t>(msg.payload_size >> 8);  // data_len high byte
-    buf_start[msg_offset + 3] = static_cast<uint8_t>(msg.payload_size);       // data_len low byte
-    // payload data is already in the buffer starting at offset + 7
-
-    // Make sure we have space for MAC
-    // The buffer should already have been sized appropriately
-
-    // Encrypt the message in place
-    NoiseBuffer mbuf;
-    noise_buffer_init(mbuf);
-    noise_buffer_set_inout(mbuf, buf_start + msg_offset, 4 + msg.payload_size,
-                           4 + msg.payload_size + frame_footer_size_);
-
-    int err = noise_cipherstate_encrypt(send_cipher_, &mbuf);
-    APIError aerr =
-        handle_noise_error_(err, LOG_STR("noise_cipherstate_encrypt"), APIError::CIPHERSTATE_ENCRYPT_FAILED);
+    uint16_t encrypted_len;
+    APIError aerr = this->encrypt_noise_message_(buf_start, msg.payload_size, msg.message_type, encrypted_len);
     if (aerr != APIError::OK)
       return aerr;
-
-    // Fill in the encrypted size
-    buf_start[1] = static_cast<uint8_t>(mbuf.size >> 8);
-    buf_start[2] = static_cast<uint8_t>(mbuf.size);
-
-    // Add iovec for this encrypted message
-    size_t msg_len = static_cast<size_t>(3 + mbuf.size);  // indicator + size + encrypted data
-    iovs.push_back({buf_start, msg_len});
-    total_write_len += msg_len;
+    total_write_len += encrypted_len;
   }
 
-  // Send all encrypted messages in one writev call
-  return this->write_raw_(iovs.data(), iovs.size(), total_write_len);
+  return this->write_raw_fast_buf_(write_start, total_write_len);
 }
 
 APIError APINoiseFrameHelper::write_frame_(const uint8_t *data, uint16_t len) {
@@ -516,16 +542,16 @@ APIError APINoiseFrameHelper::write_frame_(const uint8_t *data, uint16_t len) {
   header[1] = (uint8_t) (len >> 8);
   header[2] = (uint8_t) len;
 
+  if (len == 0) {
+    return this->write_raw_buf_(header, 3);
+  }
   struct iovec iov[2];
   iov[0].iov_base = header;
   iov[0].iov_len = 3;
-  if (len == 0) {
-    return this->write_raw_(iov, 1, 3);  // Just header
-  }
   iov[1].iov_base = const_cast<uint8_t *>(data);
   iov[1].iov_len = len;
 
-  return this->write_raw_(iov, 2, 3 + len);  // Header + data
+  return this->write_raw_iov_(iov, 2, 3 + len);
 }
 
 /** Initiate the data structures for the handshake.
@@ -563,8 +589,7 @@ APIError APINoiseFrameHelper::init_handshake_() {
   if (aerr != APIError::OK)
     return aerr;
   // set_prologue copies it into handshakestate, so we can get rid of it now
-  // Use swap idiom to actually release memory (= {} only clears size, not capacity)
-  std::vector<uint8_t>().swap(prologue_);
+  prologue_.release();
 
   err = noise_handshakestate_start(handshake_);
   aerr = handle_noise_error_(err, LOG_STR("noise_handshakestate_start"), APIError::HANDSHAKESTATE_SETUP_FAILED);
@@ -574,7 +599,9 @@ APIError APINoiseFrameHelper::init_handshake_() {
 }
 
 APIError APINoiseFrameHelper::check_handshake_finished_() {
+#ifdef ESPHOME_DEBUG_API
   assert(state_ == State::HANDSHAKE);
+#endif
 
   int action = noise_handshakestate_get_action(handshake_);
   if (action == NOISE_ACTION_READ_MESSAGE || action == NOISE_ACTION_WRITE_MESSAGE)
@@ -590,7 +617,7 @@ APIError APINoiseFrameHelper::check_handshake_finished_() {
   if (aerr != APIError::OK)
     return aerr;
 
-  frame_footer_size_ = noise_cipherstate_get_mac_length(send_cipher_);
+  this->frame_footer_size_ = noise_cipherstate_get_mac_length(send_cipher_);
 
   HELPER_LOG("Handshake complete!");
   noise_handshakestate_free(handshake_);

esphome/components/api/api_frame_helper_noise.h

@@ -9,14 +9,16 @@ namespace esphome::api {
 
 class APINoiseFrameHelper final : public APIFrameHelper {
  public:
+  // Noise header structure:
+  // Pos 0: indicator (0x01)
+  // Pos 1-2: encrypted payload size (16-bit big-endian)
+  // Pos 3-6: encrypted type (16-bit) + data_len (16-bit)
+  // Pos 7+: actual payload data
+  static constexpr uint8_t HEADER_PADDING = 1 + 2 + 2 + 2;  // indicator + size + type + data_len
+
   APINoiseFrameHelper(std::unique_ptr<socket::Socket> socket, APINoiseContext &ctx)
       : APIFrameHelper(std::move(socket)), ctx_(ctx) {
-    // Noise header structure:
-    // Pos 0: indicator (0x01)
-    // Pos 1-2: encrypted payload size (16-bit big-endian)
-    // Pos 3-6: encrypted type (16-bit) + data_len (16-bit)
-    // Pos 7+: actual payload data
-    frame_header_padding_ = 7;
+    frame_header_padding_ = HEADER_PADDING;
   }
   ~APINoiseFrameHelper() override;
   APIError init() override;
@@ -27,8 +29,15 @@ class APINoiseFrameHelper final : public APIFrameHelper {
 
  protected:
   APIError state_action_();
+  APIError state_action_client_hello_();
+  APIError state_action_server_hello_();
+  APIError state_action_handshake_();
+  APIError state_action_handshake_read_();
+  APIError state_action_handshake_write_();
   APIError try_read_frame_();
   APIError write_frame_(const uint8_t *data, uint16_t len);
+  APIError encrypt_noise_message_(uint8_t *buf_start, uint16_t payload_size, uint8_t message_type,
+                                  uint16_t &encrypted_len_out);
   APIError init_handshake_();
   APIError check_handshake_finished_();
   void send_explicit_handshake_reject_(const LogString *reason);
@@ -43,8 +52,8 @@ class APINoiseFrameHelper final : public APIFrameHelper {
   // Reference to noise context (4 bytes on 32-bit)
   APINoiseContext &ctx_;
 
-  // Vector (12 bytes on 32-bit)
-  std::vector<uint8_t> prologue_;
+  // Buffer for noise handshake prologue (released after handshake)
+  APIBuffer prologue_;
 
   // NoiseProtocolId (size depends on implementation)
   NoiseProtocolId nid_;

esphome/components/api/api_frame_helper_plaintext.cpp

@@ -39,15 +39,8 @@ static constexpr size_t API_MAX_LOG_BYTES = 168;
               format_hex_pretty_to(hex_buf_, (buffer).data(), \
                                    (buffer).size() < API_MAX_LOG_BYTES ? (buffer).size() : API_MAX_LOG_BYTES)); \
   } while (0)
-#define LOG_PACKET_SENDING(data, len) \
-  do { \
-    char hex_buf_[format_hex_pretty_size(API_MAX_LOG_BYTES)]; \
-    ESP_LOGVV(TAG, "Sending raw: %s", \
-              format_hex_pretty_to(hex_buf_, data, (len) < API_MAX_LOG_BYTES ? (len) : API_MAX_LOG_BYTES)); \
-  } while (0)
 #else
 #define LOG_PACKET_RECEIVED(buffer) ((void) 0)
-#define LOG_PACKET_SENDING(data, len) ((void) 0)
 #endif
 
 /// Initialize the frame helper, returns OK if successful.
@@ -64,8 +57,10 @@ APIError APIPlaintextFrameHelper::loop() {
   if (state_ != State::DATA) {
     return APIError::BAD_STATE;
   }
-  // Use base class implementation for buffer sending
-  return APIFrameHelper::loop();
+  if (!this->overflow_buf_.empty()) [[unlikely]] {
+    return this->drain_overflow_and_handle_errors_();
+  }
+  return APIError::OK;
 }
 
 /** Read a packet into the rx_buf_.
@@ -128,45 +123,44 @@ APIError APIPlaintextFrameHelper::try_read_frame_() {
 
     // Skip indicator byte at position 0
     uint8_t varint_pos = 1;
-    uint32_t consumed = 0;
 
-    auto msg_size_varint = ProtoVarInt::parse(&rx_header_buf_[varint_pos], rx_header_buf_pos_ - varint_pos, &consumed);
+    // rx_header_buf_pos_ >= 3 and varint_pos == 1, so len >= 2
+    auto msg_size_varint = ProtoVarInt::parse_non_empty(&rx_header_buf_[varint_pos], rx_header_buf_pos_ - varint_pos);
     if (!msg_size_varint.has_value()) {
       // not enough data there yet
       continue;
     }
 
-    if (msg_size_varint->as_uint32() > MAX_MESSAGE_SIZE) {
+    if (msg_size_varint.value > MAX_MESSAGE_SIZE) {
       state_ = State::FAILED;
-      HELPER_LOG("Bad packet: message size %" PRIu32 " exceeds maximum %u", msg_size_varint->as_uint32(),
-                 MAX_MESSAGE_SIZE);
+      HELPER_LOG("Bad packet: message size %" PRIu32 " exceeds maximum %u",
+                 static_cast<uint32_t>(msg_size_varint.value), MAX_MESSAGE_SIZE);
       return APIError::BAD_DATA_PACKET;
     }
-    rx_header_parsed_len_ = msg_size_varint->as_uint16();
+    rx_header_parsed_len_ = static_cast<uint16_t>(msg_size_varint.value);
 
     // Move to next varint position
-    varint_pos += consumed;
+    varint_pos += msg_size_varint.consumed;
 
-    auto msg_type_varint = ProtoVarInt::parse(&rx_header_buf_[varint_pos], rx_header_buf_pos_ - varint_pos, &consumed);
+    auto msg_type_varint = ProtoVarInt::parse(&rx_header_buf_[varint_pos], rx_header_buf_pos_ - varint_pos);
     if (!msg_type_varint.has_value()) {
       // not enough data there yet
       continue;
     }
-    if (msg_type_varint->as_uint32() > std::numeric_limits<uint16_t>::max()) {
+    if (msg_type_varint.value > std::numeric_limits<uint16_t>::max()) {
       state_ = State::FAILED;
-      HELPER_LOG("Bad packet: message type %" PRIu32 " exceeds maximum %u", msg_type_varint->as_uint32(),
-                 std::numeric_limits<uint16_t>::max());
+      HELPER_LOG("Bad packet: message type %" PRIu32 " exceeds maximum %u",
+                 static_cast<uint32_t>(msg_type_varint.value), std::numeric_limits<uint16_t>::max());
       return APIError::BAD_DATA_PACKET;
     }
-    rx_header_parsed_type_ = msg_type_varint->as_uint16();
+    rx_header_parsed_type_ = static_cast<uint16_t>(msg_type_varint.value);
     rx_header_parsed_ = true;
   }
   // header reading done
 
-  // Reserve space for body
-  if (this->rx_buf_.size() != this->rx_header_parsed_len_) {
-    this->rx_buf_.resize(this->rx_header_parsed_len_);
-  }
+  // Reserve space for body (+ null terminator so protobuf StringRef fields
+  // can be safely null-terminated in-place after decode)
+  this->rx_buf_.resize(this->rx_header_parsed_len_ + RX_BUF_NULL_TERMINATOR);
 
   if (rx_buf_len_ < rx_header_parsed_len_) {
     // more data to read
@@ -194,17 +188,16 @@ APIError APIPlaintextFrameHelper::try_read_frame_() {
 }
 
 APIError APIPlaintextFrameHelper::read_packet(ReadPacketBuffer *buffer) {
-  if (this->state_ != State::DATA) {
-    return APIError::WOULD_BLOCK;
-  }
+  APIError aerr = this->check_data_state_();
+  if (aerr != APIError::OK)
+    return aerr;
 
-  APIError aerr = this->try_read_frame_();
+  aerr = this->try_read_frame_();
   if (aerr != APIError::OK) {
     if (aerr == APIError::BAD_INDICATOR) {
       // Make sure to tell the remote that we don't
       // understand the indicator byte so it knows
       // we do not support it.
-      struct iovec iov[1];
       // The \x00 first byte is the marker for plaintext.
       //
       // The remote will know how to handle the indicator byte,
@@ -219,14 +212,12 @@ APIError APIPlaintextFrameHelper::read_packet(ReadPacketBuffer *buffer) {
                                                 "Bad indicator byte";
       char msg[INDICATOR_MSG_SIZE];
       memcpy_P(msg, MSG_PROGMEM, INDICATOR_MSG_SIZE);
-      iov[0].iov_base = (void *) msg;
+      this->write_raw_buf_(msg, INDICATOR_MSG_SIZE);
 #else
       static const char MSG[] = "\x00"
                                 "Bad indicator byte";
-      iov[0].iov_base = (void *) MSG;
+      this->write_raw_buf_(MSG, INDICATOR_MSG_SIZE);
 #endif
-      iov[0].iov_len = INDICATOR_MSG_SIZE;
-      this->write_raw_(iov, 1, INDICATOR_MSG_SIZE);
     }
     return aerr;
   }
@@ -236,76 +227,101 @@ APIError APIPlaintextFrameHelper::read_packet(ReadPacketBuffer *buffer) {
   buffer->type = this->rx_header_parsed_type_;
   return APIError::OK;
 }
+
+// Encode a 16-bit varint (1-3 bytes) using pre-computed length.
+ESPHOME_ALWAYS_INLINE static inline void encode_varint_16(uint16_t value, uint8_t varint_len, uint8_t *p) {
+  if (varint_len >= 2) {
+    *p++ = static_cast<uint8_t>(value | 0x80);
+    value >>= 7;
+    if (varint_len == 3) {
+      *p++ = static_cast<uint8_t>(value | 0x80);
+      value >>= 7;
+    }
+  }
+  *p = static_cast<uint8_t>(value);
+}
+
+// Encode an 8-bit varint (1-2 bytes) using pre-computed length.
+ESPHOME_ALWAYS_INLINE static inline void encode_varint_8(uint8_t value, uint8_t varint_len, uint8_t *p) {
+  if (varint_len == 2) {
+    *p++ = static_cast<uint8_t>(value | 0x80);
+    *p = static_cast<uint8_t>(value >> 7);
+  } else {
+    *p = value;
+  }
+}
+
+// Write plaintext header into pre-allocated padding before payload.
+// padding_size: bytes reserved before payload (HEADER_PADDING for first/single msg,
+//               actual header size for contiguous batch messages).
+// Returns the total header length (indicator + varints).
+ESPHOME_ALWAYS_INLINE static inline uint8_t write_plaintext_header(uint8_t *buf_start, uint16_t payload_size,
+                                                                   uint8_t message_type, uint8_t padding_size) {
+  uint8_t size_varint_len = ProtoSize::varint16(payload_size);
+  uint8_t type_varint_len = ProtoSize::varint8(message_type);
+  uint8_t total_header_len = 1 + size_varint_len + type_varint_len;
+
+  // The header is right-justified within the padding so it sits immediately before payload.
+  //
+  // Single/first message (padding_size = HEADER_PADDING = 6):
+  //   Example (small, header=3): [0-2] unused | [3] 0x00 | [4] size | [5] type | [6...] payload
+  //   Example (medium, header=4): [0-1] unused | [2] 0x00 | [3-4] size | [5] type | [6...] payload
+  //   Example (large, header=6):  [0] 0x00 | [1-3] size | [4-5] type | [6...] payload
+  //
+  // Batch messages 2+ (padding_size = actual header size, no unused bytes):
+  //   Example (small, header=3): [0] 0x00 | [1] size | [2] type | [3...] payload
+  //   Example (medium, header=4): [0] 0x00 | [1-2] size | [3] type | [4...] payload
+#ifdef ESPHOME_DEBUG_API
+  assert(padding_size >= total_header_len);
+#endif
+  uint32_t header_offset = padding_size - total_header_len;
+
+  // Write the plaintext header
+  buf_start[header_offset] = 0x00;  // indicator
+
+  // Encode varints directly into buffer using pre-computed lengths
+  encode_varint_16(payload_size, size_varint_len, buf_start + header_offset + 1);
+  encode_varint_8(message_type, type_varint_len, buf_start + header_offset + 1 + size_varint_len);
+
+  return total_header_len;
+}
+
 APIError APIPlaintextFrameHelper::write_protobuf_packet(uint8_t type, ProtoWriteBuffer buffer) {
-  MessageInfo msg{type, 0, static_cast<uint16_t>(buffer.get_buffer()->size() - frame_header_padding_)};
-  return write_protobuf_messages(buffer, std::span<const MessageInfo>(&msg, 1));
+#ifdef ESPHOME_DEBUG_API
+  assert(this->state_ == State::DATA);
+#endif
+
+  uint16_t payload_size = static_cast<uint16_t>(buffer.get_buffer()->size() - HEADER_PADDING);
+  uint8_t *buffer_data = buffer.get_buffer()->data();
+  uint8_t header_len = write_plaintext_header(buffer_data, payload_size, type, HEADER_PADDING);
+  return this->write_raw_fast_buf_(buffer_data + HEADER_PADDING - header_len,
+                                   static_cast<uint16_t>(header_len + payload_size));
 }
 
 APIError APIPlaintextFrameHelper::write_protobuf_messages(ProtoWriteBuffer buffer,
                                                           std::span<const MessageInfo> messages) {
-  if (state_ != State::DATA) {
-    return APIError::BAD_STATE;
-  }
-
-  if (messages.empty()) {
-    return APIError::OK;
-  }
-
+#ifdef ESPHOME_DEBUG_API
+  assert(this->state_ == State::DATA);
+  assert(!messages.empty());
+#endif
   uint8_t *buffer_data = buffer.get_buffer()->data();
 
-  // Stack-allocated iovec array - no heap allocation
-  StaticVector<struct iovec, MAX_MESSAGES_PER_BATCH> iovs;
-  uint16_t total_write_len = 0;
+  // First message has max padding (header_size = HEADER_PADDING), may have unused leading bytes.
+  // Subsequent messages were encoded with exact header sizes (header_size = actual header len).
+  // write_plaintext_header right-justifies the header within header_size bytes of padding.
+  const auto &first = messages[0];
+  uint8_t *first_start = buffer_data + first.offset;
+  uint8_t header_len = write_plaintext_header(first_start, first.payload_size, first.message_type, HEADER_PADDING);
+  uint8_t *write_start = first_start + HEADER_PADDING - header_len;
+  uint16_t total_len = header_len + first.payload_size;
 
-  for (const auto &msg : messages) {
-    // Calculate varint sizes for header layout
-    uint8_t size_varint_len = api::ProtoSize::varint(static_cast<uint32_t>(msg.payload_size));
-    uint8_t type_varint_len = api::ProtoSize::varint(static_cast<uint32_t>(msg.message_type));
-    uint8_t total_header_len = 1 + size_varint_len + type_varint_len;
-
-    // Calculate where to start writing the header
-    // The header starts at the latest possible position to minimize unused padding
-    //
-    // Example 1 (small values): total_header_len = 3, header_offset = 6 - 3 = 3
-    // [0-2]  - Unused padding
-    // [3]    - 0x00 indicator byte
-    // [4]    - Payload size varint (1 byte, for sizes 0-127)
-    // [5]    - Message type varint (1 byte, for types 0-127)
-    // [6...] - Actual payload data
-    //
-    // Example 2 (medium values): total_header_len = 4, header_offset = 6 - 4 = 2
-    // [0-1]  - Unused padding
-    // [2]    - 0x00 indicator byte
-    // [3-4]  - Payload size varint (2 bytes, for sizes 128-16383)
-    // [5]    - Message type varint (1 byte, for types 0-127)
-    // [6...] - Actual payload data
-    //
-    // Example 3 (large values): total_header_len = 6, header_offset = 6 - 6 = 0
-    // [0]    - 0x00 indicator byte
-    // [1-3]  - Payload size varint (3 bytes, for sizes 16384-2097151)
-    // [4-5]  - Message type varint (2 bytes, for types 128-32767)
-    // [6...] - Actual payload data
-    //
-    // The message starts at offset + frame_header_padding_
-    // So we write the header starting at offset + frame_header_padding_ - total_header_len
-    uint8_t *buf_start = buffer_data + msg.offset;
-    uint32_t header_offset = frame_header_padding_ - total_header_len;
-
-    // Write the plaintext header
-    buf_start[header_offset] = 0x00;  // indicator
-
-    // Encode varints directly into buffer
-    encode_varint_to_buffer(msg.payload_size, buf_start + header_offset + 1);
-    encode_varint_to_buffer(msg.message_type, buf_start + header_offset + 1 + size_varint_len);
-
-    // Add iovec for this message (header + payload)
-    size_t msg_len = static_cast<size_t>(total_header_len + msg.payload_size);
-    iovs.push_back({buf_start + header_offset, msg_len});
-    total_write_len += msg_len;
+  for (size_t i = 1; i < messages.size(); i++) {
+    const auto &msg = messages[i];
+    header_len = write_plaintext_header(buffer_data + msg.offset, msg.payload_size, msg.message_type, msg.header_size);
+    total_len += header_len + msg.payload_size;
   }
 
-  // Send all messages in one writev call
-  return write_raw_(iovs.data(), iovs.size(), total_write_len);
+  return this->write_raw_fast_buf_(write_start, total_len);
 }
 
 }  // namespace esphome::api

esphome/components/api/api_frame_helper_plaintext.h

@@ -7,13 +7,15 @@ namespace esphome::api {
 
 class APIPlaintextFrameHelper final : public APIFrameHelper {
  public:
+  // Plaintext header structure (worst case):
+  // Pos 0: indicator (0x00)
+  // Pos 1-3: payload size varint (up to 3 bytes)
+  // Pos 4-5: message type varint (up to 2 bytes)
+  // Pos 6+: actual payload data
+  static constexpr uint8_t HEADER_PADDING = 1 + 3 + 2;  // indicator + size varint + type varint
+
   explicit APIPlaintextFrameHelper(std::unique_ptr<socket::Socket> socket) : APIFrameHelper(std::move(socket)) {
-    // Plaintext header structure (worst case):
-    // Pos 0: indicator (0x00)
-    // Pos 1-3: payload size varint (up to 3 bytes)
-    // Pos 4-5: message type varint (up to 2 bytes)
-    // Pos 6+: actual payload data
-    frame_header_padding_ = 6;
+    frame_header_padding_ = HEADER_PADDING;
   }
   ~APIPlaintextFrameHelper() override = default;
   APIError init() override;

esphome/components/api/api_options.proto

@@ -22,6 +22,7 @@ extend google.protobuf.MessageOptions {
     optional bool log = 1039 [default=true];
     optional bool no_delay = 1040 [default=false];
     optional string base_class = 1041;
+    optional bool inline_encode = 1042 [default=false];
 }
 
 extend google.protobuf.FieldOptions {
@@ -90,4 +91,22 @@ extend google.protobuf.FieldOptions {
     //   - uint16_t <field>_length_{0};
     //   - uint16_t <field>_count_{0};
     optional bool packed_buffer = 50015 [default=false];
+
+    // force: Always encode this field, even when its value equals the proto3 default.
+    // Skips the zero/empty check in calculate_size() and encode(), using the _force
+    // variant of the calc_ method. Use on fields that are almost always non-default
+    // to eliminate dead branches on hot paths.
+    optional bool force = 50016 [default=false];
+
+    // max_value: Maximum value a field can have.
+    // When max_value < 128, the code generator emits constant-size calculations
+    // and direct byte writes instead of varint branching, since the encoded varint
+    // is guaranteed to be 1 byte.
+    optional uint32 max_value = 50017;
+
+    // max_data_length: Maximum length of a string or bytes field.
+    // When max_data_length < 128, the code generator emits constant-size
+    // length varint calculations and direct byte writes, since the length
+    // varint is guaranteed to be 1 byte.
+    optional uint32 max_data_length = 50018;
 }

esphome/components/api/api_overflow_buffer.cpp

@@ -0,0 +1,73 @@
+#include "api_overflow_buffer.h"
+#ifdef USE_API
+#include <cstring>
+
+namespace esphome::api {
+
+APIOverflowBuffer::~APIOverflowBuffer() {
+  for (auto *entry : this->queue_) {
+    if (entry != nullptr)
+      Entry::destroy(entry);
+  }
+}
+
+ssize_t APIOverflowBuffer::try_drain(socket::Socket *socket) {
+  while (this->count_ > 0) {
+    Entry *front = this->queue_[this->head_];
+
+    ssize_t sent = socket->write(front->current_data(), front->remaining());
+
+    if (sent <= 0) {
+      // -1 = error (caller checks errno for EWOULDBLOCK vs hard error)
+      // 0 = nothing sent (treat as no progress)
+      return sent;
+    }
+
+    if (static_cast<uint16_t>(sent) < front->remaining()) {
+      // Partially sent, update offset and stop
+      front->offset += static_cast<uint16_t>(sent);
+      return sent;
+    }
+
+    // Entry fully sent — free it and advance
+    Entry::destroy(front);
+    this->queue_[this->head_] = nullptr;
+    this->head_ = (this->head_ + 1) % API_MAX_SEND_QUEUE;
+    this->count_--;
+  }
+
+  return 0;  // All drained
+}
+
+bool APIOverflowBuffer::enqueue_iov(const struct iovec *iov, int iovcnt, uint16_t total_len, uint16_t skip) {
+  if (this->count_ >= API_MAX_SEND_QUEUE)
+    return false;
+
+  uint16_t buffer_size = total_len - skip;
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory)
+  auto *entry = new Entry{new uint8_t[buffer_size], buffer_size, 0};
+  this->queue_[this->tail_] = entry;
+
+  uint16_t to_skip = skip;
+  uint16_t write_pos = 0;
+
+  for (int i = 0; i < iovcnt; i++) {
+    if (to_skip >= iov[i].iov_len) {
+      to_skip -= static_cast<uint16_t>(iov[i].iov_len);
+    } else {
+      const uint8_t *src = reinterpret_cast<uint8_t *>(iov[i].iov_base) + to_skip;
+      uint16_t len = static_cast<uint16_t>(iov[i].iov_len) - to_skip;
+      std::memcpy(entry->data + write_pos, src, len);
+      write_pos += len;
+      to_skip = 0;
+    }
+  }
+
+  this->tail_ = (this->tail_ + 1) % API_MAX_SEND_QUEUE;
+  this->count_++;
+  return true;
+}
+
+}  // namespace esphome::api
+
+#endif  // USE_API

esphome/components/api/api_overflow_buffer.h

@@ -0,0 +1,76 @@
+#pragma once
+#include <array>
+#include <cstdint>
+#include <sys/types.h>
+
+#include "esphome/core/defines.h"
+#ifdef USE_API
+
+#include "esphome/components/socket/headers.h"
+#include "esphome/components/socket/socket.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome::api {
+
+/// Circular queue of heap-allocated byte buffers used as a TCP send backlog.
+///
+/// Under normal operation this buffer is **never used** — data goes straight
+/// from the frame helper to the socket.  It only fills when the LWIP TCP
+/// send buffer is full (slow client, congested network, heavy logging).
+/// The queue drains automatically on subsequent write/loop calls once the
+/// socket becomes writable again.
+///
+/// Capacity is compile-time-fixed via API_MAX_SEND_QUEUE (set from Python
+/// config).  If the queue fills completely the connection is marked failed.
+class APIOverflowBuffer {
+ public:
+  /// A single heap-allocated send-backlog entry.
+  /// Lifetime is manually managed — see destroy().
+  struct Entry {
+    uint8_t *data;
+    uint16_t size;    // Total size of the buffer
+    uint16_t offset;  // Current send offset within the buffer
+
+    uint16_t remaining() const { return this->size - this->offset; }
+    const uint8_t *current_data() const { return this->data + this->offset; }
+
+    /// Free this entry and its data buffer.
+    static ESPHOME_ALWAYS_INLINE void destroy(Entry *entry) {
+      delete[] entry->data;
+      delete entry;  // NOLINT(cppcoreguidelines-owning-memory)
+    }
+  };
+
+  ~APIOverflowBuffer();
+
+  /// True when no backlogged data is waiting.
+  bool empty() const { return this->count_ == 0; }
+
+  /// True when the queue has no room for another entry.
+  bool full() const { return this->count_ >= API_MAX_SEND_QUEUE; }
+
+  /// Number of entries currently queued.
+  uint8_t count() const { return this->count_; }
+
+  /// Try to drain queued data to the socket.
+  /// Returns bytes-written > 0 on success/partial, 0 if all drained or no progress,
+  /// -1 on error (caller must check errno to distinguish EWOULDBLOCK from hard errors).
+  /// Callers only need to act on -1; 0 and positive values both mean "no error".
+  /// Frees entries as they are fully sent.
+  ssize_t try_drain(socket::Socket *socket);
+
+  /// Enqueue unsent IOV data into the backlog.
+  /// Copies iov data starting at byte offset `skip` into a new entry.
+  /// Returns false if the queue is full (caller should fail the connection).
+  bool enqueue_iov(const struct iovec *iov, int iovcnt, uint16_t total_len, uint16_t skip);
+
+ protected:
+  std::array<Entry *, API_MAX_SEND_QUEUE> queue_{};
+  uint8_t head_{0};
+  uint8_t tail_{0};
+  uint8_t count_{0};
+};
+
+}  // namespace esphome::api
+
+#endif  // USE_API

esphome/components/api/api_pb2_defines.h

@@ -0,0 +1,12 @@
+// This file was automatically generated with a tool.
+// See script/api_protobuf/api_protobuf.py
+#pragma once
+
+#include "esphome/core/defines.h"
+#ifdef USE_BLUETOOTH_PROXY
+#ifndef USE_API_VARINT64
+#define USE_API_VARINT64
+#endif
+#endif
+
+namespace esphome::api {}  // namespace esphome::api

esphome/components/api/api_pb2_service.cpp

@@ -1,6 +1,7 @@
 // This file was automatically generated with a tool.
 // See script/api_protobuf/api_protobuf.py
 #include "api_pb2_service.h"
+#include "api_connection.h"
 #include "esphome/core/log.h"
 
 namespace esphome::api {
@@ -8,8 +9,8 @@ namespace esphome::api {
 static const char *const TAG = "api.service";
 
 #ifdef HAS_PROTO_MESSAGE_DUMP
-void APIServerConnectionBase::log_send_message_(const char *name, const char *dump) {
-  ESP_LOGVV(TAG, "send_message %s: %s", name, dump);
+void APIServerConnectionBase::log_send_message_(const LogString *name, const char *dump) {
+  ESP_LOGVV(TAG, "send_message %s: %s", LOG_STR_ARG(name), dump);
 }
 void APIServerConnectionBase::log_receive_message_(const LogString *name, const ProtoMessage &msg) {
   DumpBuffer dump_buf;
@@ -20,7 +21,7 @@ void APIServerConnectionBase::log_receive_message_(const LogString *name) {
 }
 #endif
 
-void APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type, const uint8_t *msg_data) {
+void APIConnection::read_message_(uint32_t msg_size, uint32_t msg_type, const uint8_t *msg_data) {
   // Check authentication/connection requirements
   switch (msg_type) {
     case HelloRequest::MESSAGE_TYPE:       // No setup required
@@ -634,6 +635,72 @@ void APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type,
       this->on_infrared_rf_transmit_raw_timings_request(msg);
       break;
     }
+#endif
+#ifdef USE_SERIAL_PROXY
+    case SerialProxyConfigureRequest::MESSAGE_TYPE: {
+      SerialProxyConfigureRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      this->log_receive_message_(LOG_STR("on_serial_proxy_configure_request"), msg);
+#endif
+      this->on_serial_proxy_configure_request(msg);
+      break;
+    }
+#endif
+#ifdef USE_SERIAL_PROXY
+    case SerialProxyWriteRequest::MESSAGE_TYPE: {
+      SerialProxyWriteRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      this->log_receive_message_(LOG_STR("on_serial_proxy_write_request"), msg);
+#endif
+      this->on_serial_proxy_write_request(msg);
+      break;
+    }
+#endif
+#ifdef USE_SERIAL_PROXY
+    case SerialProxySetModemPinsRequest::MESSAGE_TYPE: {
+      SerialProxySetModemPinsRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      this->log_receive_message_(LOG_STR("on_serial_proxy_set_modem_pins_request"), msg);
+#endif
+      this->on_serial_proxy_set_modem_pins_request(msg);
+      break;
+    }
+#endif
+#ifdef USE_SERIAL_PROXY
+    case SerialProxyGetModemPinsRequest::MESSAGE_TYPE: {
+      SerialProxyGetModemPinsRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      this->log_receive_message_(LOG_STR("on_serial_proxy_get_modem_pins_request"), msg);
+#endif
+      this->on_serial_proxy_get_modem_pins_request(msg);
+      break;
+    }
+#endif
+#ifdef USE_SERIAL_PROXY
+    case SerialProxyRequest::MESSAGE_TYPE: {
+      SerialProxyRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      this->log_receive_message_(LOG_STR("on_serial_proxy_request"), msg);
+#endif
+      this->on_serial_proxy_request(msg);
+      break;
+    }
+#endif
+#ifdef USE_BLUETOOTH_PROXY
+    case BluetoothSetConnectionParamsRequest::MESSAGE_TYPE: {
+      BluetoothSetConnectionParamsRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      this->log_receive_message_(LOG_STR("on_bluetooth_set_connection_params_request"), msg);
+#endif
+      this->on_bluetooth_set_connection_params_request(msg);
+      break;
+    }
 #endif
     default:
       break;

esphome/components/api/api_pb2_service.h

@@ -8,224 +8,234 @@
 
 namespace esphome::api {
 
-class APIServerConnectionBase : public ProtoService {
+class APIServerConnectionBase {
  public:
 #ifdef HAS_PROTO_MESSAGE_DUMP
  protected:
-  void log_send_message_(const char *name, const char *dump);
+  void log_send_message_(const LogString *name, const char *dump);
   void log_receive_message_(const LogString *name, const ProtoMessage &msg);
   void log_receive_message_(const LogString *name);
 
  public:
 #endif
 
-  bool send_message(const ProtoMessage &msg, uint8_t message_type) {
-#ifdef HAS_PROTO_MESSAGE_DUMP
-    DumpBuffer dump_buf;
-    this->log_send_message_(msg.message_name(), msg.dump_to(dump_buf));
-#endif
-    return this->send_message_impl(msg, message_type);
-  }
+  void on_hello_request(const HelloRequest &value){};
 
-  virtual void on_hello_request(const HelloRequest &value){};
+  void on_disconnect_request(){};
+  void on_disconnect_response(){};
+  void on_ping_request(){};
+  void on_ping_response(){};
+  void on_device_info_request(){};
 
-  virtual void on_disconnect_request(){};
-  virtual void on_disconnect_response(){};
-  virtual void on_ping_request(){};
-  virtual void on_ping_response(){};
-  virtual void on_device_info_request(){};
+  void on_list_entities_request(){};
 
-  virtual void on_list_entities_request(){};
-
-  virtual void on_subscribe_states_request(){};
+  void on_subscribe_states_request(){};
 
 #ifdef USE_COVER
-  virtual void on_cover_command_request(const CoverCommandRequest &value){};
+  void on_cover_command_request(const CoverCommandRequest &value){};
 #endif
 
 #ifdef USE_FAN
-  virtual void on_fan_command_request(const FanCommandRequest &value){};
+  void on_fan_command_request(const FanCommandRequest &value){};
 #endif
 
 #ifdef USE_LIGHT
-  virtual void on_light_command_request(const LightCommandRequest &value){};
+  void on_light_command_request(const LightCommandRequest &value){};
 #endif
 
 #ifdef USE_SWITCH
-  virtual void on_switch_command_request(const SwitchCommandRequest &value){};
+  void on_switch_command_request(const SwitchCommandRequest &value){};
 #endif
 
-  virtual void on_subscribe_logs_request(const SubscribeLogsRequest &value){};
+  void on_subscribe_logs_request(const SubscribeLogsRequest &value){};
 
 #ifdef USE_API_NOISE
-  virtual void on_noise_encryption_set_key_request(const NoiseEncryptionSetKeyRequest &value){};
+  void on_noise_encryption_set_key_request(const NoiseEncryptionSetKeyRequest &value){};
 #endif
 
 #ifdef USE_API_HOMEASSISTANT_SERVICES
-  virtual void on_subscribe_homeassistant_services_request(){};
+  void on_subscribe_homeassistant_services_request(){};
 #endif
 
 #ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
-  virtual void on_homeassistant_action_response(const HomeassistantActionResponse &value){};
+  void on_homeassistant_action_response(const HomeassistantActionResponse &value){};
 #endif
 #ifdef USE_API_HOMEASSISTANT_STATES
-  virtual void on_subscribe_home_assistant_states_request(){};
+  void on_subscribe_home_assistant_states_request(){};
 #endif
 
 #ifdef USE_API_HOMEASSISTANT_STATES
-  virtual void on_home_assistant_state_response(const HomeAssistantStateResponse &value){};
+  void on_home_assistant_state_response(const HomeAssistantStateResponse &value){};
 #endif
 
-  virtual void on_get_time_response(const GetTimeResponse &value){};
+  void on_get_time_response(const GetTimeResponse &value){};
 
 #ifdef USE_API_USER_DEFINED_ACTIONS
-  virtual void on_execute_service_request(const ExecuteServiceRequest &value){};
+  void on_execute_service_request(const ExecuteServiceRequest &value){};
 #endif
 
 #ifdef USE_CAMERA
-  virtual void on_camera_image_request(const CameraImageRequest &value){};
+  void on_camera_image_request(const CameraImageRequest &value){};
 #endif
 
 #ifdef USE_CLIMATE
-  virtual void on_climate_command_request(const ClimateCommandRequest &value){};
+  void on_climate_command_request(const ClimateCommandRequest &value){};
 #endif
 
 #ifdef USE_WATER_HEATER
-  virtual void on_water_heater_command_request(const WaterHeaterCommandRequest &value){};
+  void on_water_heater_command_request(const WaterHeaterCommandRequest &value){};
 #endif
 
 #ifdef USE_NUMBER
-  virtual void on_number_command_request(const NumberCommandRequest &value){};
+  void on_number_command_request(const NumberCommandRequest &value){};
 #endif
 
 #ifdef USE_SELECT
-  virtual void on_select_command_request(const SelectCommandRequest &value){};
+  void on_select_command_request(const SelectCommandRequest &value){};
 #endif
 
 #ifdef USE_SIREN
-  virtual void on_siren_command_request(const SirenCommandRequest &value){};
+  void on_siren_command_request(const SirenCommandRequest &value){};
 #endif
 
 #ifdef USE_LOCK
-  virtual void on_lock_command_request(const LockCommandRequest &value){};
+  void on_lock_command_request(const LockCommandRequest &value){};
 #endif
 
 #ifdef USE_BUTTON
-  virtual void on_button_command_request(const ButtonCommandRequest &value){};
+  void on_button_command_request(const ButtonCommandRequest &value){};
 #endif
 
 #ifdef USE_MEDIA_PLAYER
-  virtual void on_media_player_command_request(const MediaPlayerCommandRequest &value){};
+  void on_media_player_command_request(const MediaPlayerCommandRequest &value){};
 #endif
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_subscribe_bluetooth_le_advertisements_request(
-      const SubscribeBluetoothLEAdvertisementsRequest &value){};
+  void on_subscribe_bluetooth_le_advertisements_request(const SubscribeBluetoothLEAdvertisementsRequest &value){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_device_request(const BluetoothDeviceRequest &value){};
+  void on_bluetooth_device_request(const BluetoothDeviceRequest &value){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_gatt_get_services_request(const BluetoothGATTGetServicesRequest &value){};
+  void on_bluetooth_gatt_get_services_request(const BluetoothGATTGetServicesRequest &value){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_gatt_read_request(const BluetoothGATTReadRequest &value){};
+  void on_bluetooth_gatt_read_request(const BluetoothGATTReadRequest &value){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_gatt_write_request(const BluetoothGATTWriteRequest &value){};
+  void on_bluetooth_gatt_write_request(const BluetoothGATTWriteRequest &value){};
 #endif
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_gatt_read_descriptor_request(const BluetoothGATTReadDescriptorRequest &value){};
+  void on_bluetooth_gatt_read_descriptor_request(const BluetoothGATTReadDescriptorRequest &value){};
 #endif
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_gatt_write_descriptor_request(const BluetoothGATTWriteDescriptorRequest &value){};
+  void on_bluetooth_gatt_write_descriptor_request(const BluetoothGATTWriteDescriptorRequest &value){};
 #endif
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_gatt_notify_request(const BluetoothGATTNotifyRequest &value){};
+  void on_bluetooth_gatt_notify_request(const BluetoothGATTNotifyRequest &value){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_subscribe_bluetooth_connections_free_request(){};
+  void on_subscribe_bluetooth_connections_free_request(){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_unsubscribe_bluetooth_le_advertisements_request(){};
+  void on_unsubscribe_bluetooth_le_advertisements_request(){};
 #endif
 
 #ifdef USE_BLUETOOTH_PROXY
-  virtual void on_bluetooth_scanner_set_mode_request(const BluetoothScannerSetModeRequest &value){};
+  void on_bluetooth_scanner_set_mode_request(const BluetoothScannerSetModeRequest &value){};
 #endif
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_subscribe_voice_assistant_request(const SubscribeVoiceAssistantRequest &value){};
+  void on_subscribe_voice_assistant_request(const SubscribeVoiceAssistantRequest &value){};
 #endif
 
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_response(const VoiceAssistantResponse &value){};
+  void on_voice_assistant_response(const VoiceAssistantResponse &value){};
 #endif
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_event_response(const VoiceAssistantEventResponse &value){};
+  void on_voice_assistant_event_response(const VoiceAssistantEventResponse &value){};
 #endif
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_audio(const VoiceAssistantAudio &value){};
+  void on_voice_assistant_audio(const VoiceAssistantAudio &value){};
 #endif
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_timer_event_response(const VoiceAssistantTimerEventResponse &value){};
+  void on_voice_assistant_timer_event_response(const VoiceAssistantTimerEventResponse &value){};
 #endif
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_announce_request(const VoiceAssistantAnnounceRequest &value){};
+  void on_voice_assistant_announce_request(const VoiceAssistantAnnounceRequest &value){};
 #endif
 
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_configuration_request(const VoiceAssistantConfigurationRequest &value){};
+  void on_voice_assistant_configuration_request(const VoiceAssistantConfigurationRequest &value){};
 #endif
 
 #ifdef USE_VOICE_ASSISTANT
-  virtual void on_voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &value){};
+  void on_voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &value){};
 #endif
 
 #ifdef USE_ALARM_CONTROL_PANEL
-  virtual void on_alarm_control_panel_command_request(const AlarmControlPanelCommandRequest &value){};
+  void on_alarm_control_panel_command_request(const AlarmControlPanelCommandRequest &value){};
 #endif
 
 #ifdef USE_TEXT
-  virtual void on_text_command_request(const TextCommandRequest &value){};
+  void on_text_command_request(const TextCommandRequest &value){};
 #endif
 
 #ifdef USE_DATETIME_DATE
-  virtual void on_date_command_request(const DateCommandRequest &value){};
+  void on_date_command_request(const DateCommandRequest &value){};
 #endif
 
 #ifdef USE_DATETIME_TIME
-  virtual void on_time_command_request(const TimeCommandRequest &value){};
+  void on_time_command_request(const TimeCommandRequest &value){};
 #endif
 
 #ifdef USE_VALVE
-  virtual void on_valve_command_request(const ValveCommandRequest &value){};
+  void on_valve_command_request(const ValveCommandRequest &value){};
 #endif
 
 #ifdef USE_DATETIME_DATETIME
-  virtual void on_date_time_command_request(const DateTimeCommandRequest &value){};
+  void on_date_time_command_request(const DateTimeCommandRequest &value){};
 #endif
 
 #ifdef USE_UPDATE
-  virtual void on_update_command_request(const UpdateCommandRequest &value){};
+  void on_update_command_request(const UpdateCommandRequest &value){};
 #endif
 #ifdef USE_ZWAVE_PROXY
-  virtual void on_z_wave_proxy_frame(const ZWaveProxyFrame &value){};
+  void on_z_wave_proxy_frame(const ZWaveProxyFrame &value){};
 #endif
 #ifdef USE_ZWAVE_PROXY
-  virtual void on_z_wave_proxy_request(const ZWaveProxyRequest &value){};
+  void on_z_wave_proxy_request(const ZWaveProxyRequest &value){};
 #endif
 
 #ifdef USE_IR_RF
-  virtual void on_infrared_rf_transmit_raw_timings_request(const InfraredRFTransmitRawTimingsRequest &value){};
+  void on_infrared_rf_transmit_raw_timings_request(const InfraredRFTransmitRawTimingsRequest &value){};
 #endif
 
- protected:
-  void read_message(uint32_t msg_size, uint32_t msg_type, const uint8_t *msg_data) override;
+#ifdef USE_SERIAL_PROXY
+  void on_serial_proxy_configure_request(const SerialProxyConfigureRequest &value){};
+#endif
+
+#ifdef USE_SERIAL_PROXY
+  void on_serial_proxy_write_request(const SerialProxyWriteRequest &value){};
+#endif
+#ifdef USE_SERIAL_PROXY
+  void on_serial_proxy_set_modem_pins_request(const SerialProxySetModemPinsRequest &value){};
+#endif
+#ifdef USE_SERIAL_PROXY
+  void on_serial_proxy_get_modem_pins_request(const SerialProxyGetModemPinsRequest &value){};
+#endif
+
+#ifdef USE_SERIAL_PROXY
+  void on_serial_proxy_request(const SerialProxyRequest &value){};
+#endif
+
+#ifdef USE_BLUETOOTH_PROXY
+  void on_bluetooth_set_connection_params_request(const BluetoothSetConnectionParamsRequest &value){};
+#endif
 };
 
 }  // namespace esphome::api

esphome/components/api/api_server.cpp

@@ -28,10 +28,12 @@ static const char *const TAG = "api";
 // APIServer
 APIServer *global_api_server = nullptr;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
-APIServer::APIServer() {
-  global_api_server = this;
-  // Pre-allocate shared write buffer
-  shared_write_buffer_.reserve(64);
+APIServer::APIServer() { global_api_server = this; }
+
+void APIServer::socket_failed_(const LogString *msg) {
+  ESP_LOGW(TAG, "Socket %s: errno %d", LOG_STR_ARG(msg), errno);
+  this->destroy_socket_();
+  this->mark_failed();
 }
 
 void APIServer::setup() {
@@ -44,30 +46,26 @@ void APIServer::setup() {
 
 #ifndef USE_API_NOISE_PSK_FROM_YAML
   // Only load saved PSK if not set from YAML
-  SavedNoisePsk noise_pref_saved{};
-  if (this->noise_pref_.load(&noise_pref_saved)) {
+  if (this->load_and_apply_noise_psk_()) {
     ESP_LOGD(TAG, "Loaded saved Noise PSK");
-    this->set_noise_psk(noise_pref_saved.psk);
   }
 #endif
 #endif
 
-  this->socket_ = socket::socket_ip_loop_monitored(SOCK_STREAM, 0);  // monitored for incoming connections
+  this->socket_ = socket::socket_ip_loop_monitored(SOCK_STREAM, 0).release();  // monitored for incoming connections
   if (this->socket_ == nullptr) {
-    ESP_LOGW(TAG, "Could not create socket");
-    this->mark_failed();
+    this->socket_failed_(LOG_STR("creation"));
     return;
   }
   int enable = 1;
   int err = this->socket_->setsockopt(SOL_SOCKET, SO_REUSEADDR, &enable, sizeof(int));
   if (err != 0) {
-    ESP_LOGW(TAG, "Socket unable to set reuseaddr: errno %d", err);
+    ESP_LOGW(TAG, "Socket reuseaddr: errno %d", errno);
     // we can still continue
   }
   err = this->socket_->setblocking(false);
   if (err != 0) {
-    ESP_LOGW(TAG, "Socket unable to set nonblocking mode: errno %d", err);
-    this->mark_failed();
+    this->socket_failed_(LOG_STR("nonblocking"));
     return;
   }
 
@@ -75,28 +73,28 @@ void APIServer::setup() {
 
   socklen_t sl = socket::set_sockaddr_any((struct sockaddr *) &server, sizeof(server), this->port_);
   if (sl == 0) {
-    ESP_LOGW(TAG, "Socket unable to set sockaddr: errno %d", errno);
-    this->mark_failed();
+    this->socket_failed_(LOG_STR("set sockaddr"));
     return;
   }
 
   err = this->socket_->bind((struct sockaddr *) &server, sl);
   if (err != 0) {
-    ESP_LOGW(TAG, "Socket unable to bind: errno %d", errno);
-    this->mark_failed();
+    this->socket_failed_(LOG_STR("bind"));
     return;
   }
 
   err = this->socket_->listen(this->listen_backlog_);
   if (err != 0) {
-    ESP_LOGW(TAG, "Socket unable to listen: errno %d", errno);
-    this->mark_failed();
+    this->socket_failed_(LOG_STR("listen"));
     return;
   }
 
 #ifdef USE_LOGGER
   if (logger::global_logger != nullptr) {
-    logger::global_logger->add_log_listener(this);
+    logger::global_logger->add_log_callback(
+        this, [](void *self, uint8_t level, const char *tag, const char *message, size_t message_len) {
+          static_cast<APIServer *>(self)->on_log(level, tag, message, message_len);
+        });
   }
 #endif
 
@@ -110,7 +108,7 @@ void APIServer::setup() {
   this->last_connected_ = App.get_loop_component_start_time();
   // Set warning status if reboot timeout is enabled
   if (this->reboot_timeout_ != 0) {
-    this->status_set_warning();
+    this->status_set_warning(LOG_STR("waiting for client connection"));
   }
 }
 
@@ -189,7 +187,7 @@ void APIServer::remove_client_(size_t client_index) {
 
   // Last client disconnected - set warning and start tracking for reboot timeout
   if (this->clients_.empty() && this->reboot_timeout_ != 0) {
-    this->status_set_warning();
+    this->status_set_warning(LOG_STR("waiting for client connection"));
     this->last_connected_ = App.get_loop_component_start_time();
   }
 
@@ -199,7 +197,7 @@ void APIServer::remove_client_(size_t client_index) {
 #endif
 }
 
-void APIServer::accept_new_connections_() {
+void __attribute__((flatten)) APIServer::accept_new_connections_() {
   while (true) {
     struct sockaddr_storage source_addr;
     socklen_t addr_len = sizeof(source_addr);
@@ -359,11 +357,11 @@ void APIServer::on_update(update::UpdateEntity *obj) {
 #endif
 
 #ifdef USE_ZWAVE_PROXY
-void APIServer::on_zwave_proxy_request(const esphome::api::ProtoMessage &msg) {
+void APIServer::on_zwave_proxy_request(const ZWaveProxyRequest &msg) {
   // We could add code to manage a second subscription type, but, since this message type is
   //  very infrequent and small, we simply send it to all clients
   for (auto &c : this->clients_)
-    c->send_message(msg, api::ZWaveProxyRequest::MESSAGE_TYPE);
+    c->send_message(msg);
 }
 #endif
 
@@ -433,8 +431,8 @@ void APIServer::handle_action_response(uint32_t call_id, bool success, StringRef
 
 #ifdef USE_API_HOMEASSISTANT_STATES
 // Helper to add subscription (reduces duplication)
-void APIServer::add_state_subscription_(const char *entity_id, const char *attribute, std::function<void(StringRef)> f,
-                                        bool once) {
+void APIServer::add_state_subscription_(const char *entity_id, const char *attribute,
+                                        std::function<void(StringRef)> &&f, bool once) {
   this->state_subs_.push_back(HomeAssistantStateSubscription{
       .entity_id = entity_id, .attribute = attribute, .callback = std::move(f), .once = once,
       // entity_id_dynamic_storage and attribute_dynamic_storage remain nullptr (no heap allocation)
@@ -443,7 +441,7 @@ void APIServer::add_state_subscription_(const char *entity_id, const char *attri
 
 // Helper to add subscription with heap-allocated strings (reduces duplication)
 void APIServer::add_state_subscription_(std::string entity_id, optional<std::string> attribute,
-                                        std::function<void(StringRef)> f, bool once) {
+                                        std::function<void(StringRef)> &&f, bool once) {
   HomeAssistantStateSubscription sub;
   // Allocate heap storage for the strings
   sub.entity_id_dynamic_storage = std::make_unique<std::string>(std::move(entity_id));
@@ -463,29 +461,29 @@ void APIServer::add_state_subscription_(std::string entity_id, optional<std::str
 
 // New const char* overload (for internal components - zero allocation)
 void APIServer::subscribe_home_assistant_state(const char *entity_id, const char *attribute,
-                                               std::function<void(StringRef)> f) {
+                                               std::function<void(StringRef)> &&f) {
   this->add_state_subscription_(entity_id, attribute, std::move(f), false);
 }
 
 void APIServer::get_home_assistant_state(const char *entity_id, const char *attribute,
-                                         std::function<void(StringRef)> f) {
+                                         std::function<void(StringRef)> &&f) {
   this->add_state_subscription_(entity_id, attribute, std::move(f), true);
 }
 
 // std::string overload with StringRef callback (zero-allocation callback)
 void APIServer::subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                               std::function<void(StringRef)> f) {
+                                               std::function<void(StringRef)> &&f) {
   this->add_state_subscription_(std::move(entity_id), std::move(attribute), std::move(f), false);
 }
 
 void APIServer::get_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                         std::function<void(StringRef)> f) {
+                                         std::function<void(StringRef)> &&f) {
   this->add_state_subscription_(std::move(entity_id), std::move(attribute), std::move(f), true);
 }
 
 // Legacy helper: wraps std::string callback and delegates to StringRef version
 void APIServer::add_state_subscription_(std::string entity_id, optional<std::string> attribute,
-                                        std::function<void(const std::string &)> f, bool once) {
+                                        std::function<void(const std::string &)> &&f, bool once) {
   // Wrap callback to convert StringRef -> std::string, then delegate
   this->add_state_subscription_(std::move(entity_id), std::move(attribute),
                                 std::function<void(StringRef)>([f = std::move(f)](StringRef state) { f(state.str()); }),
@@ -494,12 +492,12 @@ void APIServer::add_state_subscription_(std::string entity_id, optional<std::str
 
 // Legacy std::string overload (for custom_api_device.h - converts StringRef to std::string)
 void APIServer::subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                               std::function<void(const std::string &)> f) {
+                                               std::function<void(const std::string &)> &&f) {
   this->add_state_subscription_(std::move(entity_id), std::move(attribute), std::move(f), false);
 }
 
 void APIServer::get_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                         std::function<void(const std::string &)> f) {
+                                         std::function<void(const std::string &)> &&f) {
   this->add_state_subscription_(std::move(entity_id), std::move(attribute), std::move(f), true);
 }
 
@@ -514,7 +512,7 @@ void APIServer::set_reboot_timeout(uint32_t reboot_timeout) { this->reboot_timeo
 
 #ifdef USE_API_NOISE
 bool APIServer::update_noise_psk_(const SavedNoisePsk &new_psk, const LogString *save_log_msg,
-                                  const LogString *fail_log_msg, const psk_t &active_psk, bool make_active) {
+                                  const LogString *fail_log_msg, bool make_active) {
   if (!this->noise_pref_.save(&new_psk)) {
     ESP_LOGW(TAG, "%s", LOG_STR_ARG(fail_log_msg));
     return false;
@@ -526,18 +524,31 @@ bool APIServer::update_noise_psk_(const SavedNoisePsk &new_psk, const LogString
   }
   ESP_LOGD(TAG, "%s", LOG_STR_ARG(save_log_msg));
   if (make_active) {
-    this->set_timeout(100, [this, active_psk]() {
+    this->set_timeout(100, [this]() {
+      // Re-read the PSK from preferences rather than capturing the 32-byte array
+      // in the lambda (which would exceed std::function SBO and heap-allocate).
+      if (!this->load_and_apply_noise_psk_()) {
+        ESP_LOGW(TAG, "Failed to load saved PSK for activation");
+        return;
+      }
       ESP_LOGW(TAG, "Disconnecting all clients to reset PSK");
-      this->set_noise_psk(active_psk);
       for (auto &c : this->clients_) {
         DisconnectRequest req;
-        c->send_message(req, DisconnectRequest::MESSAGE_TYPE);
+        c->send_message(req);
       }
     });
   }
   return true;
 }
 
+bool APIServer::load_and_apply_noise_psk_() {
+  SavedNoisePsk saved{};
+  if (!this->noise_pref_.load(&saved))
+    return false;
+  this->set_noise_psk(saved.psk);
+  return true;
+}
+
 bool APIServer::save_noise_psk(psk_t psk, bool make_active) {
 #ifdef USE_API_NOISE_PSK_FROM_YAML
   // When PSK is set from YAML, this function should never be called
@@ -552,7 +563,7 @@ bool APIServer::save_noise_psk(psk_t psk, bool make_active) {
   }
 
   SavedNoisePsk new_saved_psk{psk};
-  return this->update_noise_psk_(new_saved_psk, LOG_STR("Noise PSK saved"), LOG_STR("Failed to save Noise PSK"), psk,
+  return this->update_noise_psk_(new_saved_psk, LOG_STR("Noise PSK saved"), LOG_STR("Failed to save Noise PSK"),
                                  make_active);
 #endif
 }
@@ -564,8 +575,7 @@ bool APIServer::clear_noise_psk(bool make_active) {
   return false;
 #else
   SavedNoisePsk empty_psk{};
-  psk_t empty{};
-  return this->update_noise_psk_(empty_psk, LOG_STR("Noise PSK cleared"), LOG_STR("Failed to clear Noise PSK"), empty,
+  return this->update_noise_psk_(empty_psk, LOG_STR("Noise PSK cleared"), LOG_STR("Failed to clear Noise PSK"),
                                  make_active);
 #endif
 }
@@ -582,11 +592,7 @@ void APIServer::request_time() {
 }
 #endif
 
-bool APIServer::is_connected(bool state_subscription_only) const {
-  if (!state_subscription_only) {
-    return !this->clients_.empty();
-  }
-
+bool APIServer::is_connected_with_state_subscription() const {
   for (const auto &client : this->clients_) {
     if (client->flags_.state_subscription) {
       return true;
@@ -623,10 +629,7 @@ void APIServer::on_shutdown() {
   this->shutting_down_ = true;
 
   // Close the listening socket to prevent new connections
-  if (this->socket_) {
-    this->socket_->close();
-    this->socket_ = nullptr;
-  }
+  this->destroy_socket_();
 
   // Change batch delay to 5ms for quick flushing during shutdown
   this->batch_delay_ = 5;
@@ -634,7 +637,7 @@ void APIServer::on_shutdown() {
   // Send disconnect requests to all connected clients
   for (auto &c : this->clients_) {
     DisconnectRequest req;
-    if (!c->send_message(req, DisconnectRequest::MESSAGE_TYPE)) {
+    if (!c->send_message(req)) {
       // If we can't send the disconnect request directly (tx_buffer full),
       // schedule it at the front of the batch so it will be sent with priority
       c->schedule_message_front_(nullptr, DisconnectRequest::MESSAGE_TYPE, DisconnectRequest::ESTIMATED_SIZE);

esphome/components/api/api_server.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/defines.h"
 #ifdef USE_API
+#include "api_buffer.h"
 #include "api_noise_context.h"
 #include "api_pb2.h"
 #include "api_pb2_service.h"
@@ -35,15 +36,11 @@ struct SavedNoisePsk {
 } PACKED;  // NOLINT
 #endif
 
-class APIServer : public Component,
-                  public Controller
-#ifdef USE_LOGGER
-    ,
-                  public logger::LogListener
-#endif
+class APIServer final : public Component,
+                        public Controller
 #ifdef USE_CAMERA
     ,
-                  public camera::CameraListener
+                        public camera::CameraListener
 #endif
 {
  public:
@@ -56,7 +53,7 @@ class APIServer : public Component,
   void on_shutdown() override;
   bool teardown() override;
 #ifdef USE_LOGGER
-  void on_log(uint8_t level, const char *tag, const char *message, size_t message_len) override;
+  void on_log(uint8_t level, const char *tag, const char *message, size_t message_len);
 #endif
 #ifdef USE_CAMERA
   void on_camera_image(const std::shared_ptr<camera::CameraImage> &image) override;
@@ -69,7 +66,7 @@ class APIServer : public Component,
   void set_max_connections(uint8_t max_connections) { this->max_connections_ = max_connections; }
 
   // Get reference to shared buffer for API connections
-  std::vector<uint8_t> &get_shared_buffer_ref() { return shared_write_buffer_; }
+  APIBuffer &get_shared_buffer_ref() { return shared_write_buffer_; }
 
 #ifdef USE_API_NOISE
   bool save_noise_psk(psk_t psk, bool make_active = true);
@@ -183,13 +180,14 @@ class APIServer : public Component,
   void on_update(update::UpdateEntity *obj) override;
 #endif
 #ifdef USE_ZWAVE_PROXY
-  void on_zwave_proxy_request(const esphome::api::ProtoMessage &msg);
+  void on_zwave_proxy_request(const ZWaveProxyRequest &msg);
 #endif
 #ifdef USE_IR_RF
   void send_infrared_rf_receive_event(uint32_t device_id, uint32_t key, const std::vector<int32_t> *timings);
 #endif
 
-  bool is_connected(bool state_subscription_only = false) const;
+  bool is_connected() const { return !this->clients_.empty(); }
+  bool is_connected_with_state_subscription() const;
 
 #ifdef USE_API_HOMEASSISTANT_STATES
   struct HomeAssistantStateSubscription {
@@ -205,20 +203,20 @@ class APIServer : public Component,
   };
 
   // New const char* overload (for internal components - zero allocation)
-  void subscribe_home_assistant_state(const char *entity_id, const char *attribute, std::function<void(StringRef)> f);
-  void get_home_assistant_state(const char *entity_id, const char *attribute, std::function<void(StringRef)> f);
+  void subscribe_home_assistant_state(const char *entity_id, const char *attribute, std::function<void(StringRef)> &&f);
+  void get_home_assistant_state(const char *entity_id, const char *attribute, std::function<void(StringRef)> &&f);
 
   // std::string overload with StringRef callback (for custom_api_device.h with zero-allocation callback)
   void subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                      std::function<void(StringRef)> f);
+                                      std::function<void(StringRef)> &&f);
   void get_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                std::function<void(StringRef)> f);
+                                std::function<void(StringRef)> &&f);
 
   // Legacy std::string overload (for custom_api_device.h - converts StringRef to std::string for callback)
   void subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                      std::function<void(const std::string &)> f);
+                                      std::function<void(const std::string &)> &&f);
   void get_home_assistant_state(std::string entity_id, optional<std::string> attribute,
-                                std::function<void(const std::string &)> f);
+                                std::function<void(const std::string &)> &&f);
 
   const std::vector<HomeAssistantStateSubscription> &get_state_subs() const;
 #endif
@@ -241,20 +239,29 @@ class APIServer : public Component,
 
 #ifdef USE_API_NOISE
   bool update_noise_psk_(const SavedNoisePsk &new_psk, const LogString *save_log_msg, const LogString *fail_log_msg,
-                         const psk_t &active_psk, bool make_active);
+                         bool make_active);
+  // Load saved PSK from preferences and apply it. Returns true on success.
+  bool load_and_apply_noise_psk_();
 #endif  // USE_API_NOISE
 #ifdef USE_API_HOMEASSISTANT_STATES
   // Helper methods to reduce code duplication
-  void add_state_subscription_(const char *entity_id, const char *attribute, std::function<void(StringRef)> f,
-                               bool once);
-  void add_state_subscription_(std::string entity_id, optional<std::string> attribute, std::function<void(StringRef)> f,
+  void add_state_subscription_(const char *entity_id, const char *attribute, std::function<void(StringRef)> &&f,
                                bool once);
+  void add_state_subscription_(std::string entity_id, optional<std::string> attribute,
+                               std::function<void(StringRef)> &&f, bool once);
   // Legacy helper: wraps std::string callback and delegates to StringRef version
   void add_state_subscription_(std::string entity_id, optional<std::string> attribute,
-                               std::function<void(const std::string &)> f, bool once);
+                               std::function<void(const std::string &)> &&f, bool once);
 #endif  // USE_API_HOMEASSISTANT_STATES
+  // No explicit close() needed — listen sockets have no active connections on
+  // failure/shutdown. Destructor handles fd cleanup (close or abort per platform).
+  inline void destroy_socket_() {
+    delete this->socket_;
+    this->socket_ = nullptr;
+  }
+  void socket_failed_(const LogString *msg);
   // Pointers and pointer-like types first (4 bytes each)
-  std::unique_ptr<socket::Socket> socket_ = nullptr;
+  socket::ListenSocket *socket_{nullptr};
 #ifdef USE_API_CLIENT_CONNECTED_TRIGGER
   Trigger<std::string, std::string> client_connected_trigger_;
 #endif
@@ -268,7 +275,11 @@ class APIServer : public Component,
 
   // Vectors and strings (12 bytes each on 32-bit)
   std::vector<std::unique_ptr<APIConnection>> clients_;
-  std::vector<uint8_t> shared_write_buffer_;  // Shared proto write buffer for all connections
+  // Shared proto write buffer for all connections.
+  // Not pre-allocated: all send paths call prepare_first_message_buffer() which
+  // reserves the exact needed size. Pre-allocating here would cause heap fragmentation
+  // since the buffer would almost always reallocate on first use.
+  APIBuffer shared_write_buffer_;
 #ifdef USE_API_HOMEASSISTANT_STATES
   std::vector<HomeAssistantStateSubscription> state_subs_;
 #endif
@@ -316,7 +327,10 @@ template<typename... Ts> class APIConnectedCondition : public Condition<Ts...> {
   TEMPLATABLE_VALUE(bool, state_subscription_only)
  public:
   bool check(const Ts &...x) override {
-    return global_api_server->is_connected(this->state_subscription_only_.value(x...));
+    if (this->state_subscription_only_.value(x...)) {
+      return global_api_server->is_connected_with_state_subscription();
+    }
+    return global_api_server->is_connected();
   }
 };
 

esphome/components/api/client.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import asyncio
 from datetime import datetime
+import importlib
 import logging
 from typing import TYPE_CHECKING, Any
 import warnings
@@ -18,6 +19,7 @@ import contextlib
 
 from esphome.const import CONF_KEY, CONF_PORT, __version__
 from esphome.core import CORE
+from esphome.platformio_api import process_stacktrace
 
 from . import CONF_ENCRYPTION
 
@@ -30,7 +32,11 @@ if TYPE_CHECKING:
 _LOGGER = logging.getLogger(__name__)
 
 
-async def async_run_logs(config: dict[str, Any], addresses: list[str]) -> None:
+async def async_run_logs(
+    config: dict[str, Any],
+    addresses: list[str],
+    subscribe_states: bool = True,
+) -> None:
     """Run the logs command in the event loop."""
     conf = config["api"]
     name = config["esphome"]["name"]
@@ -55,9 +61,19 @@ async def async_run_logs(config: dict[str, Any], addresses: list[str]) -> None:
         addresses=addresses,  # Pass all addresses for automatic retry
     )
     dashboard = CORE.dashboard
+    backtrace_state = False
+
+    # Try platform-specific stacktrace handler first, fall back to generic
+    platform_process_stacktrace = None
+    try:
+        module = importlib.import_module("esphome.components." + CORE.target_platform)
+        platform_process_stacktrace = getattr(module, "process_stacktrace")
+    except (AttributeError, ImportError):
+        pass
 
     def on_log(msg: SubscribeLogsResponse) -> None:
         """Handle a new log message."""
+        nonlocal backtrace_state
         time_ = datetime.now()
         message: bytes = msg.message
         text = message.decode("utf8", "backslashreplace")
@@ -67,15 +83,30 @@ async def async_run_logs(config: dict[str, Any], addresses: list[str]) -> None:
         )
         for parsed_msg in parse_log_message(text, timestamp):
             print(parsed_msg.replace("\033", "\\033") if dashboard else parsed_msg)
+        for raw_line in text.splitlines():
+            if platform_process_stacktrace:
+                backtrace_state = platform_process_stacktrace(
+                    config, raw_line, backtrace_state
+                )
+            else:
+                backtrace_state = process_stacktrace(
+                    config, raw_line, backtrace_state=backtrace_state
+                )
 
-    stop = await async_run(cli, on_log, name=name)
+    stop = await async_run(cli, on_log, name=name, subscribe_states=subscribe_states)
     try:
         await asyncio.Event().wait()
     finally:
         await stop()
 
 
-def run_logs(config: dict[str, Any], addresses: list[str]) -> None:
+def run_logs(
+    config: dict[str, Any],
+    addresses: list[str],
+    subscribe_states: bool = True,
+) -> None:
     """Run the logs command."""
     with contextlib.suppress(KeyboardInterrupt):
-        asyncio.run(async_run_logs(config, addresses))
+        asyncio.run(
+            async_run_logs(config, addresses, subscribe_states=subscribe_states)
+        )

esphome/components/api/custom_api_device.h

@@ -136,8 +136,9 @@ class CustomAPIDevice {
   template<typename T>
   void subscribe_homeassistant_state(void (T::*callback)(StringRef), const std::string &entity_id,
                                      const std::string &attribute = "") {
-    auto f = std::bind(callback, (T *) this, std::placeholders::_1);
-    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute), std::move(f));
+    auto *obj = static_cast<T *>(this);
+    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute),
+                                                      [obj, callback](StringRef state) { (obj->*callback)(state); });
   }
 
   /** Subscribe to the state (or attribute state) of an entity from Home Assistant (legacy std::string version).
@@ -148,10 +149,12 @@ class CustomAPIDevice {
   ESPDEPRECATED("Use void callback(StringRef) instead. Will be removed in 2027.1.0.", "2026.1.0")
   void subscribe_homeassistant_state(void (T::*callback)(std::string), const std::string &entity_id,
                                      const std::string &attribute = "") {
-    auto f = std::bind(callback, (T *) this, std::placeholders::_1);
+    auto *obj = static_cast<T *>(this);
     // Explicit type to disambiguate overload resolution
-    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute),
-                                                      std::function<void(const std::string &)>(f));
+    global_api_server->subscribe_home_assistant_state(
+        entity_id, optional<std::string>(attribute),
+        std::function<void(const std::string &)>(
+            [obj, callback](const std::string &state) { (obj->*callback)(state); }));
   }
 
   /** Subscribe to the state (or attribute state) of an entity from Home Assistant.
@@ -176,8 +179,10 @@ class CustomAPIDevice {
   template<typename T>
   void subscribe_homeassistant_state(void (T::*callback)(const std::string &, StringRef), const std::string &entity_id,
                                      const std::string &attribute = "") {
-    auto f = std::bind(callback, (T *) this, entity_id, std::placeholders::_1);
-    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute), std::move(f));
+    auto *obj = static_cast<T *>(this);
+    global_api_server->subscribe_home_assistant_state(
+        entity_id, optional<std::string>(attribute),
+        [obj, callback, entity_id](StringRef state) { (obj->*callback)(entity_id, state); });
   }
 
   /** Subscribe to the state (or attribute state) of an entity from Home Assistant (legacy std::string version).
@@ -188,10 +193,12 @@ class CustomAPIDevice {
   ESPDEPRECATED("Use void callback(const std::string &, StringRef) instead. Will be removed in 2027.1.0.", "2026.1.0")
   void subscribe_homeassistant_state(void (T::*callback)(std::string, std::string), const std::string &entity_id,
                                      const std::string &attribute = "") {
-    auto f = std::bind(callback, (T *) this, entity_id, std::placeholders::_1);
+    auto *obj = static_cast<T *>(this);
     // Explicit type to disambiguate overload resolution
-    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute),
-                                                      std::function<void(const std::string &)>(f));
+    global_api_server->subscribe_home_assistant_state(
+        entity_id, optional<std::string>(attribute),
+        std::function<void(const std::string &)>(
+            [obj, callback, entity_id](const std::string &state) { (obj->*callback)(entity_id, state); }));
   }
 #else
   template<typename T>

esphome/components/api/homeassistant_service.h

@@ -130,6 +130,20 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
     this->add_kv_(this->variables_, key, std::forward<V>(value));
   }
 
+#ifdef USE_ESP8266
+  // On ESP8266, ESPHOME_F() returns __FlashStringHelper* (PROGMEM pointer).
+  // Store as const char* — populate_service_map copies from PROGMEM at play() time.
+  template<typename V> void add_data(const __FlashStringHelper *key, V &&value) {
+    this->add_kv_(this->data_, reinterpret_cast<const char *>(key), std::forward<V>(value));
+  }
+  template<typename V> void add_data_template(const __FlashStringHelper *key, V &&value) {
+    this->add_kv_(this->data_template_, reinterpret_cast<const char *>(key), std::forward<V>(value));
+  }
+  template<typename V> void add_variable(const __FlashStringHelper *key, V &&value) {
+    this->add_kv_(this->variables_, reinterpret_cast<const char *>(key), std::forward<V>(value));
+  }
+#endif
+
 #ifdef USE_API_HOMEASSISTANT_ACTION_RESPONSES
   template<typename T> void set_response_template(T response_template) {
     this->response_template_ = response_template;
@@ -221,7 +235,32 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
                                    Ts... x) {
     dest.init(source.size());
 
-    // Count non-static strings to allocate exact storage needed
+#ifdef USE_ESP8266
+    // On ESP8266, all static strings from codegen are FLASH_STRING (PROGMEM),
+    // so is_static_string() is always false — the zero-copy STATIC_STRING fast
+    // path from the non-ESP8266 branch cannot trigger. We copy all keys and
+    // values unconditionally: keys via _P functions (may be in PROGMEM), values
+    // via value() which handles FLASH_STRING internally.
+    value_storage.init(source.size() * 2);
+
+    for (auto &it : source) {
+      auto &kv = dest.emplace_back();
+
+      // Key: copy from possible PROGMEM
+      {
+        size_t key_len = strlen_P(it.key);
+        value_storage.push_back(std::string(key_len, '\0'));
+        memcpy_P(value_storage.back().data(), it.key, key_len);
+        kv.key = StringRef(value_storage.back());
+      }
+
+      // Value: value() handles FLASH_STRING via _P functions internally
+      value_storage.push_back(it.value.value(x...));
+      kv.value = StringRef(value_storage.back());
+    }
+#else
+    // On non-ESP8266, strings are directly readable from flash-mapped memory.
+    // Count non-static strings to allocate exact storage needed.
     size_t lambda_count = 0;
     for (const auto &it : source) {
       if (!it.value.is_static_string()) {
@@ -235,14 +274,15 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
       kv.key = StringRef(it.key);
 
       if (it.value.is_static_string()) {
-        // Static string from YAML - zero allocation
+        // Static string — pointer directly readable, zero allocation
         kv.value = StringRef(it.value.get_static_string());
       } else {
-        // Lambda evaluation - store result, reference it
+        // Lambda — evaluate and store result
         value_storage.push_back(it.value.value(x...));
         kv.value = StringRef(value_storage.back());
       }
     }
+#endif
   }
 
   APIServer *parent_;

esphome/components/api/list_entities.cpp

@@ -94,7 +94,7 @@ ListEntitiesIterator::ListEntitiesIterator(APIConnection *client) : client_(clie
 #ifdef USE_API_USER_DEFINED_ACTIONS
 bool ListEntitiesIterator::on_service(UserServiceDescriptor *service) {
   auto resp = service->encode_list_service_response();
-  return this->client_->send_message(resp, ListEntitiesServicesResponse::MESSAGE_TYPE);
+  return this->client_->send_message(resp);
 }
 #endif
 

esphome/components/api/list_entities.h

@@ -15,7 +15,7 @@ class APIConnection;
     return this->client_->schedule_message_(entity, ResponseType::MESSAGE_TYPE, ResponseType::ESTIMATED_SIZE); \
   }
 
-class ListEntitiesIterator : public ComponentIterator {
+class ListEntitiesIterator final : public ComponentIterator {
  public:
   ListEntitiesIterator(APIConnection *client);
 #ifdef USE_BINARY_SENSOR

esphome/components/api/proto.cpp

@@ -1,5 +1,6 @@
 #include "proto.h"
 #include <cinttypes>
+#include <cstring>
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
@@ -7,24 +8,71 @@ namespace esphome::api {
 
 static const char *const TAG = "api.proto";
 
+uint32_t ProtoSize::varint_slow(uint32_t value) { return varint_wide(value); }
+
+void ProtoWriteBuffer::encode_varint_raw_slow_(uint32_t value) {
+  do {
+    this->debug_check_bounds_(1);
+    *this->pos_++ = static_cast<uint8_t>(value | 0x80);
+    value >>= 7;
+  } while (value > 0x7F);
+  this->debug_check_bounds_(1);
+  *this->pos_++ = static_cast<uint8_t>(value);
+}
+
+ProtoVarIntResult ProtoVarInt::parse_slow(const uint8_t *buffer, uint32_t len) {
+  // Multi-byte varint: first byte already checked to have high bit set
+  uint32_t result32 = buffer[0] & 0x7F;
+#ifdef USE_API_VARINT64
+  uint32_t limit = std::min(len, uint32_t(4));
+#else
+  uint32_t limit = std::min(len, uint32_t(5));
+#endif
+  for (uint32_t i = 1; i < limit; i++) {
+    uint8_t val = buffer[i];
+    result32 |= uint32_t(val & 0x7F) << (i * 7);
+    if ((val & 0x80) == 0) {
+      return {result32, i + 1};
+    }
+  }
+#ifdef USE_API_VARINT64
+  return parse_wide(buffer, len, result32);
+#else
+  return {0, PROTO_VARINT_PARSE_FAILED};
+#endif
+}
+
+#ifdef USE_API_VARINT64
+ProtoVarIntResult ProtoVarInt::parse_wide(const uint8_t *buffer, uint32_t len, uint32_t result32) {
+  uint64_t result64 = result32;
+  uint32_t limit = std::min(len, uint32_t(10));
+  for (uint32_t i = 4; i < limit; i++) {
+    uint8_t val = buffer[i];
+    result64 |= uint64_t(val & 0x7F) << (i * 7);
+    if ((val & 0x80) == 0) {
+      return {result64, i + 1};
+    }
+  }
+  return {0, PROTO_VARINT_PARSE_FAILED};
+}
+#endif
+
 uint32_t ProtoDecodableMessage::count_repeated_field(const uint8_t *buffer, size_t length, uint32_t target_field_id) {
   uint32_t count = 0;
   const uint8_t *ptr = buffer;
   const uint8_t *end = buffer + length;
 
   while (ptr < end) {
-    uint32_t consumed;
-
-    // Parse field header (tag)
-    auto res = ProtoVarInt::parse(ptr, end - ptr, &consumed);
+    // Parse field header (tag) - ptr < end guarantees len >= 1
+    auto res = ProtoVarInt::parse_non_empty(ptr, end - ptr);
     if (!res.has_value()) {
       break;  // Invalid data, stop counting
     }
 
-    uint32_t tag = res->as_uint32();
+    uint32_t tag = static_cast<uint32_t>(res.value);
     uint32_t field_type = tag & WIRE_TYPE_MASK;
     uint32_t field_id = tag >> 3;
-    ptr += consumed;
+    ptr += res.consumed;
 
     // Count if this is the target field
     if (field_id == target_field_id) {
@@ -34,20 +82,20 @@ uint32_t ProtoDecodableMessage::count_repeated_field(const uint8_t *buffer, size
     // Skip field data based on wire type
     switch (field_type) {
       case WIRE_TYPE_VARINT: {  // VarInt - parse and skip
-        res = ProtoVarInt::parse(ptr, end - ptr, &consumed);
+        res = ProtoVarInt::parse(ptr, end - ptr);
         if (!res.has_value()) {
           return count;  // Invalid data, return what we have
         }
-        ptr += consumed;
+        ptr += res.consumed;
         break;
       }
       case WIRE_TYPE_LENGTH_DELIMITED: {  // Length-delimited - parse length and skip data
-        res = ProtoVarInt::parse(ptr, end - ptr, &consumed);
+        res = ProtoVarInt::parse(ptr, end - ptr);
         if (!res.has_value()) {
           return count;
         }
-        uint32_t field_length = res->as_uint32();
-        ptr += consumed;
+        uint32_t field_length = static_cast<uint32_t>(res.value);
+        ptr += res.consumed;
         if (field_length > static_cast<size_t>(end - ptr)) {
           return count;  // Out of bounds
         }
@@ -70,46 +118,137 @@ uint32_t ProtoDecodableMessage::count_repeated_field(const uint8_t *buffer, size
   return count;
 }
 
+// Single-pass encode for repeated submessage elements (non-template core).
+// Writes field tag, reserves 1 byte for length varint, encodes the submessage body,
+// then backpatches the actual length. For the common case (body < 128 bytes), this is
+// just a single byte write with no memmove — all current repeated submessage types
+// (BLE advertisements at ~47B, GATT descriptors at ~24B, service args, etc.) take
+// this fast path.
+//
+// The memmove fallback for body >= 128 bytes exists only for correctness (e.g., a GATT
+// characteristic with many descriptors). It is safe because calculate_size() already
+// reserved space for the full multi-byte varint — the shift fills that reserved space:
+//
+//   calculate_size() allocates per element: tag + varint_size(body) + body_size
+//
+//   After encode, before memmove (1 byte reserved, body written):
+//   [tag][__][body ..... body][??]
+//         ^                   ^-- unused byte (v2 space from calculate_size)
+//         len_pos
+//
+//   After memmove(body_start+1, body_start, body_size):
+//   [tag][__][__][body ..... body]
+//         ^       ^-- body shifted forward, fills v2 space exactly
+//         len_pos
+//
+//   After writing 2-byte varint at len_pos:
+//   [tag][v1][v2][body ..... body]
+//                                ^-- pos_ = element end, within buffer
+void ProtoWriteBuffer::encode_sub_message(uint32_t field_id, const void *value,
+                                          uint8_t *(*encode_fn)(const void *,
+                                                                ProtoWriteBuffer &PROTO_ENCODE_DEBUG_PARAM)) {
+  this->encode_field_raw(field_id, 2);
+  // Reserve 1 byte for length varint (optimistic: submessage < 128 bytes)
+  uint8_t *len_pos = this->pos_;
+  this->debug_check_bounds_(1);
+  this->pos_++;
+  uint8_t *body_start = this->pos_;
+  this->pos_ = encode_fn(value, *this PROTO_ENCODE_DEBUG_INIT(this->buffer_));
+  uint32_t body_size = static_cast<uint32_t>(this->pos_ - body_start);
+  if (body_size < 128) [[likely]] {
+    // Common case: 1-byte varint, just backpatch
+    *len_pos = static_cast<uint8_t>(body_size);
+    return;
+  }
+  // Compute extra bytes needed for varint beyond the 1 already reserved
+  uint8_t extra = ProtoSize::varint(body_size) - 1;
+  // Shift body forward to make room for the extra varint bytes
+  this->debug_check_bounds_(extra);
+  std::memmove(body_start + extra, body_start, body_size);
+  uint8_t *end = this->pos_ + extra;
+  // Write the full varint at len_pos
+  this->pos_ = len_pos;
+  this->encode_varint_raw(body_size);
+  this->pos_ = end;
+}
+
+// Non-template core for encode_optional_sub_message.
+void ProtoWriteBuffer::encode_optional_sub_message(uint32_t field_id, uint32_t nested_size, const void *value,
+                                                   uint8_t *(*encode_fn)(const void *,
+                                                                         ProtoWriteBuffer &PROTO_ENCODE_DEBUG_PARAM)) {
+  if (nested_size == 0)
+    return;
+  this->encode_field_raw(field_id, 2);
+  this->encode_varint_raw(nested_size);
+#ifdef ESPHOME_DEBUG_API
+  uint8_t *start = this->pos_;
+  this->pos_ = encode_fn(value, *this PROTO_ENCODE_DEBUG_INIT(this->buffer_));
+  if (static_cast<uint32_t>(this->pos_ - start) != nested_size)
+    this->debug_check_encode_size_(field_id, nested_size, this->pos_ - start);
+#else
+  this->pos_ = encode_fn(value, *this PROTO_ENCODE_DEBUG_INIT(this->buffer_));
+#endif
+}
+
+#ifdef ESPHOME_DEBUG_API
+void proto_check_bounds_failed(const uint8_t *pos, size_t bytes, const uint8_t *end, const char *caller) {
+  ESP_LOGE(TAG, "Proto encode bounds check failed in %s: need %zu bytes, %td available", caller, bytes, end - pos);
+  abort();
+}
+void ProtoWriteBuffer::debug_check_bounds_(size_t bytes, const char *caller) {
+  if (this->pos_ + bytes > this->buffer_->data() + this->buffer_->size()) {
+    ESP_LOGE(TAG, "ProtoWriteBuffer bounds check failed in %s: bytes=%zu offset=%td buf_size=%zu", caller, bytes,
+             this->pos_ - this->buffer_->data(), this->buffer_->size());
+    abort();
+  }
+}
+void ProtoWriteBuffer::debug_check_encode_size_(uint32_t field_id, uint32_t expected, ptrdiff_t actual) {
+  ESP_LOGE(TAG, "encode_message: size mismatch for field %" PRIu32 ": calculated=%" PRIu32 " actual=%td", field_id,
+           expected, actual);
+  abort();
+}
+
+#endif
+
 void ProtoDecodableMessage::decode(const uint8_t *buffer, size_t length) {
   const uint8_t *ptr = buffer;
   const uint8_t *end = buffer + length;
 
   while (ptr < end) {
-    uint32_t consumed;
-
-    // Parse field header
-    auto res = ProtoVarInt::parse(ptr, end - ptr, &consumed);
+    // Parse field header - ptr < end guarantees len >= 1
+    auto res = ProtoVarInt::parse_non_empty(ptr, end - ptr);
     if (!res.has_value()) {
       ESP_LOGV(TAG, "Invalid field start at offset %ld", (long) (ptr - buffer));
       return;
     }
 
-    uint32_t tag = res->as_uint32();
+    uint32_t tag = static_cast<uint32_t>(res.value);
     uint32_t field_type = tag & WIRE_TYPE_MASK;
     uint32_t field_id = tag >> 3;
-    ptr += consumed;
+    ptr += res.consumed;
 
     switch (field_type) {
       case WIRE_TYPE_VARINT: {  // VarInt
-        res = ProtoVarInt::parse(ptr, end - ptr, &consumed);
+        res = ProtoVarInt::parse(ptr, end - ptr);
         if (!res.has_value()) {
           ESP_LOGV(TAG, "Invalid VarInt at offset %ld", (long) (ptr - buffer));
           return;
         }
-        if (!this->decode_varint(field_id, *res)) {
-          ESP_LOGV(TAG, "Cannot decode VarInt field %" PRIu32 " with value %" PRIu32 "!", field_id, res->as_uint32());
+        if (!this->decode_varint(field_id, res.value)) {
+          ESP_LOGV(TAG, "Cannot decode VarInt field %" PRIu32 " with value %" PRIu64 "!", field_id,
+                   static_cast<uint64_t>(res.value));
         }
-        ptr += consumed;
+        ptr += res.consumed;
         break;
       }
       case WIRE_TYPE_LENGTH_DELIMITED: {  // Length-delimited
-        res = ProtoVarInt::parse(ptr, end - ptr, &consumed);
+        res = ProtoVarInt::parse(ptr, end - ptr);
         if (!res.has_value()) {
           ESP_LOGV(TAG, "Invalid Length Delimited at offset %ld", (long) (ptr - buffer));
           return;
         }
-        uint32_t field_length = res->as_uint32();
-        ptr += consumed;
+        uint32_t field_length = static_cast<uint32_t>(res.value);
+        ptr += res.consumed;
         if (field_length > static_cast<size_t>(end - ptr)) {
           ESP_LOGV(TAG, "Out-of-bounds Length Delimited at offset %ld", (long) (ptr - buffer));
           return;
@@ -125,7 +264,13 @@ void ProtoDecodableMessage::decode(const uint8_t *buffer, size_t length) {
           ESP_LOGV(TAG, "Out-of-bounds Fixed32-bit at offset %ld", (long) (ptr - buffer));
           return;
         }
-        uint32_t val = encode_uint32(ptr[3], ptr[2], ptr[1], ptr[0]);
+        uint32_t val;
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+        // Protobuf fixed32 is little-endian — direct load on LE platforms
+        memcpy(&val, ptr, 4);
+#else
+        val = encode_uint32(ptr[3], ptr[2], ptr[1], ptr[0]);
+#endif
         if (!this->decode_32bit(field_id, Proto32Bit(val))) {
           ESP_LOGV(TAG, "Cannot decode 32-bit field %" PRIu32 " with value %" PRIu32 "!", field_id, val);
         }