From 4cbced407ddf12252895161a9d58e3b36bc7d835 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Thu, 24 Sep 2026 13:49:40 +0100
Subject: [PATCH] [ha-addon] Announce the MCP server to Home Assistant (#19413)

---
 .../etc/s6-overlay/s6-rc.d/discovery/run      | 24 ++++++++++---------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/docker/ha-addon-rootfs/etc/s6-overlay/s6-rc.d/discovery/run b/docker/ha-addon-rootfs/etc/s6-overlay/s6-rc.d/discovery/run
index bb36cfcdb4..5b0ff67909 100755
--- a/docker/ha-addon-rootfs/etc/s6-overlay/s6-rc.d/discovery/run
+++ b/docker/ha-addon-rootfs/etc/s6-overlay/s6-rc.d/discovery/run
@@ -4,7 +4,6 @@
 # Home Assistant Add-on: ESPHome
 # Sends discovery information to Home Assistant.
 # ==============================================================================
-declare config
 declare port
 
 # We only disable it when disabled explicitly
@@ -19,14 +18,17 @@ port=$(bashio::addon.ingress_port)
 # Wait for the ESPHome Device Builder to become available
 bashio::net.wait_for "${port}" "127.0.0.1" 300
 
-config=$(\
-    bashio::var.json \
-        host "127.0.0.1" \
-        port "^${port}" \
-)
+# Send one discovery message; the config is a JSON string built with bashio::var.json.
+send_discovery() {
+    local service=$1
+    local config=$2
+    if bashio::discovery "${service}" "${config}" > /dev/null; then
+        bashio::log.info "Successfully send ${service} discovery information to Home Assistant."
+    else
+        bashio::log.error "${service} discovery message to Home Assistant failed!"
+    fi
+}
 
-if bashio::discovery "esphome" "${config}" > /dev/null; then
-    bashio::log.info "Successfully send discovery information to Home Assistant."
-else
-    bashio::log.error "Discovery message to Home Assistant failed!"
-fi
+send_discovery "esphome" "$(bashio::var.json host "127.0.0.1" port "^${port}")"
+# The Device Builder MCP server, consumed by Home Assistant's mcp integration.
+send_discovery "mcp" "$(bashio::var.json url "http://127.0.0.1:${port}/api/mcp")"