[api] Skip setters that pass the default port, reboot timeout and batch delay (#19227)

esphome/components/api/__init__.py

@@ -136,6 +136,12 @@ CONF_LISTEN_BACKLOG = "listen_backlog"
 CONF_MAX_SEND_QUEUE = "max_send_queue"
 CONF_STATE_SUBSCRIPTION_ONLY = "state_subscription_only"
 
+# Schema defaults that also match the C++ initializers in api_server.h; codegen
+# skips the setter when the config equals them.
+DEFAULT_PORT = 6053
+DEFAULT_REBOOT_TIMEOUT = "15min"
+DEFAULT_BATCH_DELAY = "100ms"
+
 
 def _register_provisioning_source(config: ConfigType) -> ConfigType:
     """Register the API as a provisioning source when encryption is enabled.
@@ -292,7 +298,7 @@ CONFIG_SCHEMA = cv.All(
     cv.Schema(
         {
             cv.GenerateID(): cv.declare_id(APIServer),
-            cv.Optional(CONF_PORT, default=6053): cv.port,
+            cv.Optional(CONF_PORT, default=DEFAULT_PORT): cv.port,
             # Removed in 2026.1.0 - kept to provide helpful error message
             cv.Optional(CONF_PASSWORD): cv.invalid(
                 "The 'password' option has been removed in ESPHome 2026.1.0.\n"
@@ -305,14 +311,14 @@ CONFIG_SCHEMA = cv.All(
                 "Or visit https://esphome.io/components/api/#configuration-variables"
             ),
             cv.Optional(
-                CONF_REBOOT_TIMEOUT, default="15min"
+                CONF_REBOOT_TIMEOUT, default=DEFAULT_REBOOT_TIMEOUT
             ): cv.positive_time_period_milliseconds,
             cv.Exclusive(
                 CONF_SERVICES, group_of_exclusion=CONF_ACTIONS
             ): ACTIONS_SCHEMA,
             cv.Exclusive(CONF_ACTIONS, group_of_exclusion=CONF_ACTIONS): ACTIONS_SCHEMA,
             cv.Optional(CONF_ENCRYPTION): encryption_schema,
-            cv.Optional(CONF_BATCH_DELAY, default="100ms"): cv.All(
+            cv.Optional(CONF_BATCH_DELAY, default=DEFAULT_BATCH_DELAY): cv.All(
                 cv.positive_time_period_milliseconds,
                 cv.Range(max=cv.TimePeriod(milliseconds=65535)),
             ),
@@ -462,9 +468,15 @@ async def to_code(config: ConfigType) -> None:
     # Request a log listener slot for API log streaming
     request_log_listener()
 
-    cg.add(var.set_port(config[CONF_PORT]))
-    cg.add(var.set_reboot_timeout(config[CONF_REBOOT_TIMEOUT]))
-    cg.add(var.set_batch_delay(config[CONF_BATCH_DELAY]))
+    # Skip the setters when the config matches the C++ initializers (DEFAULT_*).
+    if (port := config[CONF_PORT]) != DEFAULT_PORT:
+        cg.add(var.set_port(port))
+    if (reboot_timeout := config[CONF_REBOOT_TIMEOUT]) != cv.time_period(
+        DEFAULT_REBOOT_TIMEOUT
+    ):
+        cg.add(var.set_reboot_timeout(reboot_timeout))
+    if (batch_delay := config[CONF_BATCH_DELAY]) != cv.time_period(DEFAULT_BATCH_DELAY):
+        cg.add(var.set_batch_delay(batch_delay))
     if CONF_LISTEN_BACKLOG in config:
         cg.add(var.set_listen_backlog(config[CONF_LISTEN_BACKLOG]))
     cg.add_define("MAX_API_CONNECTIONS", config[CONF_MAX_CONNECTIONS])

esphome/components/api/api_server.h

@@ -314,7 +314,7 @@ class APIServer final : public Component,
 #endif
 
   // 4-byte aligned types
-  uint32_t reboot_timeout_{300000};
+  uint32_t reboot_timeout_{900000};  // Keep in sync with DEFAULT_REBOOT_TIMEOUT in __init__.py
   uint32_t last_connected_{0};
 
   // Slots [0, api_connection_count_) are populated; trailing slots are always nullptr.
@@ -351,8 +351,8 @@ class APIServer final : public Component,
 #endif
 
   // Group smaller types together
-  uint16_t port_{6053};
-  uint16_t batch_delay_{100};
+  uint16_t port_{6053};        // Keep in sync with DEFAULT_PORT in __init__.py
+  uint16_t batch_delay_{100};  // Keep in sync with DEFAULT_BATCH_DELAY in __init__.py
   // Connection limits - these defaults will be overridden by config values
   // from cv.SplitDefault in __init__.py which sets platform-specific defaults.
   uint8_t listen_backlog_{4};

tests/component_tests/api/config/bare.yaml

@@ -0,0 +1,12 @@
+---
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: test
+  password: testtest
+
+api:

tests/component_tests/api/config/custom.yaml

@@ -0,0 +1,15 @@
+---
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: test
+  password: testtest
+
+api:
+  port: 6054
+  reboot_timeout: 0s
+  batch_delay: 0ms

tests/component_tests/api/config/defaults.yaml

@@ -0,0 +1,15 @@
+---
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+
+wifi:
+  ssid: test
+  password: testtest
+
+api:
+  port: 6053
+  reboot_timeout: 15min
+  batch_delay: 100ms

tests/component_tests/api/test_default_setters.py

@@ -0,0 +1,35 @@
+"""Tests that the api component only emits setters for non default values."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+
+@pytest.mark.parametrize("config_file", ["bare.yaml", "defaults.yaml"])
+def test_default_values_are_not_emitted(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+    config_file: str,
+) -> None:
+    """Port 6053, a 15 min reboot timeout and 100 ms batch delay are C++ initializers.
+
+    Both the schema defaults and the same values written explicitly take the skip path.
+    """
+    main_cpp = generate_main(component_config_path(config_file))
+
+    assert "api_apiserver_id->set_port(" not in main_cpp
+    assert "api_apiserver_id->set_reboot_timeout(" not in main_cpp
+    assert "api_apiserver_id->set_batch_delay(" not in main_cpp
+
+
+def test_custom_values_are_emitted(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Non default values still reach the C++ setters."""
+    main_cpp = generate_main(component_config_path("custom.yaml"))
+
+    assert "api_apiserver_id->set_port(6054);" in main_cpp
+    assert "api_apiserver_id->set_reboot_timeout(0);" in main_cpp
+    assert "api_apiserver_id->set_batch_delay(0);" in main_cpp