Merge branch 'dev' into compact_string_wifi

# Conflicts:
#	esphome/components/wifi/wifi_component_esp_idf.cpp

.github/workflows/codeql.yml

@@ -58,7 +58,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@6bc82e05fd0ea64601dd4b465378bbcf57de0314 # v4.32.1
+        uses: github/codeql-action/init@b20883b0cd1f46c72ae0ba6d1090936928f9fa30 # v4.32.0
         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@6bc82e05fd0ea64601dd4b465378bbcf57de0314 # v4.32.1
+        uses: github/codeql-action/analyze@b20883b0cd1f46c72ae0ba6d1090936928f9fa30 # v4.32.0
         with:
           category: "/language:${{matrix.language}}"

esphome/components/cse7766/cse7766.cpp

@@ -152,10 +152,6 @@ void CSE7766Component::parse_data_() {
     if (this->power_sensor_ != nullptr) {
       this->power_sensor_->publish_state(power);
     }
-  } else if (this->power_sensor_ != nullptr) {
-    // No valid power measurement from chip - publish 0W to avoid stale readings
-    // This typically happens when current is below the measurable threshold (~50mA)
-    this->power_sensor_->publish_state(0.0f);
   }
 
   float current = 0.0f;

esphome/components/esp32/__init__.py

@@ -124,14 +124,10 @@ COMPILER_OPTIMIZATIONS = {
 # - "sdmmc": driver -> esp_driver_sdmmc -> sdmmc dependency chain
 DEFAULT_EXCLUDED_IDF_COMPONENTS = (
     "cmock",  # Unit testing mock framework - ESPHome doesn't use IDF's testing
-    "driver",  # Legacy driver shim - only needed by esp32_touch, esp32_can for legacy headers
     "esp_adc",  # ADC driver - only needed by adc component
-    "esp_driver_dac",  # DAC driver - only needed by esp32_dac component
     "esp_driver_i2s",  # I2S driver - only needed by i2s_audio component
-    "esp_driver_mcpwm",  # MCPWM driver - ESPHome doesn't use motor control PWM
     "esp_driver_rmt",  # RMT driver - only needed by remote_transmitter/receiver, neopixelbus
     "esp_driver_touch_sens",  # Touch sensor driver - only needed by esp32_touch
-    "esp_driver_twai",  # TWAI/CAN driver - only needed by esp32_can component
     "esp_eth",  # Ethernet driver - only needed by ethernet component
     "esp_hid",  # HID host/device support - ESPHome doesn't implement HID functionality
     "esp_http_client",  # HTTP client - only needed by http_request component
@@ -142,11 +138,9 @@ DEFAULT_EXCLUDED_IDF_COMPONENTS = (
     "espcoredump",  # Core dump support - ESPHome has its own debug component
     "fatfs",  # FAT filesystem - ESPHome doesn't use filesystem storage
     "mqtt",  # ESP-IDF MQTT library - ESPHome has its own MQTT implementation
-    "openthread",  # Thread protocol - only needed by openthread component
     "perfmon",  # Xtensa performance monitor - ESPHome has its own debug component
     "protocomm",  # Protocol communication for provisioning - unused by ESPHome
     "spiffs",  # SPIFFS filesystem - ESPHome doesn't use filesystem storage (IDF only)
-    "ulp",  # ULP coprocessor - not currently used by any ESPHome component
     "unity",  # Unit testing framework - ESPHome doesn't use IDF's testing
     "wear_levelling",  # Flash wear levelling for fatfs - unused since fatfs unused
     "wifi_provisioning",  # WiFi provisioning - ESPHome uses its own improv implementation

esphome/components/esp32/preferences.cpp

@@ -203,11 +203,10 @@ class ESP32Preferences : public ESPPreferences {
   }
 };
 
-static ESP32Preferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 void setup_preferences() {
-  s_preferences.open();
-  global_preferences = &s_preferences;
+  auto *prefs = new ESP32Preferences();  // NOLINT(cppcoreguidelines-owning-memory)
+  prefs->open();
+  global_preferences = prefs;
 }
 
 }  // namespace esp32

esphome/components/esp32_can/canbus.py

@@ -15,7 +15,6 @@ from esphome.components.esp32 import (
     VARIANT_ESP32S2,
     VARIANT_ESP32S3,
     get_esp32_variant,
-    include_builtin_idf_component,
 )
 import esphome.config_validation as cv
 from esphome.const import (
@@ -122,10 +121,6 @@ def get_default_tx_enqueue_timeout(bit_rate):
 
 
 async def to_code(config):
-    # Legacy driver component provides driver/twai.h header
-    include_builtin_idf_component("driver")
-    # Also enable esp_driver_twai for future migration to new API
-    include_builtin_idf_component("esp_driver_twai")
     var = cg.new_Pvariable(config[CONF_ID])
     await canbus.register_canbus(var, config)
 

esphome/components/esp32_dac/output.py

@@ -1,12 +1,7 @@
 from esphome import pins
 import esphome.codegen as cg
 from esphome.components import output
-from esphome.components.esp32 import (
-    VARIANT_ESP32,
-    VARIANT_ESP32S2,
-    get_esp32_variant,
-    include_builtin_idf_component,
-)
+from esphome.components.esp32 import VARIANT_ESP32, VARIANT_ESP32S2, get_esp32_variant
 import esphome.config_validation as cv
 from esphome.const import CONF_ID, CONF_NUMBER, CONF_PIN
 
@@ -43,7 +38,6 @@ CONFIG_SCHEMA = output.FLOAT_OUTPUT_SCHEMA.extend(
 
 
 async def to_code(config):
-    include_builtin_idf_component("esp_driver_dac")
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
     await output.register_output(var, config)

esphome/components/esp32_hosted/update/esp32_hosted_update.cpp

@@ -211,14 +211,11 @@ bool Esp32HostedUpdate::fetch_manifest_() {
     int read_or_error = container->read(buf, sizeof(buf));
     App.feed_wdt();
     yield();
-    auto result =
-        http_request::http_read_loop_result(read_or_error, last_data_time, read_timeout, container->is_read_complete());
+    auto result = http_request::http_read_loop_result(read_or_error, last_data_time, read_timeout);
     if (result == http_request::HttpReadLoopResult::RETRY)
       continue;
-    // Note: COMPLETE is currently unreachable since the loop condition checks bytes_read < content_length,
-    // but this is defensive code in case chunked transfer encoding support is added in the future.
     if (result != http_request::HttpReadLoopResult::DATA)
-      break;  // COMPLETE, ERROR, or TIMEOUT
+      break;  // ERROR or TIMEOUT
     json_str.append(reinterpret_cast<char *>(buf), read_or_error);
   }
   container->end();
@@ -339,14 +336,9 @@ bool Esp32HostedUpdate::stream_firmware_to_coprocessor_() {
     App.feed_wdt();
     yield();
 
-    auto result =
-        http_request::http_read_loop_result(read_or_error, last_data_time, read_timeout, container->is_read_complete());
+    auto result = http_request::http_read_loop_result(read_or_error, last_data_time, read_timeout);
     if (result == http_request::HttpReadLoopResult::RETRY)
       continue;
-    // Note: COMPLETE is currently unreachable since the loop condition checks bytes_read < content_length,
-    // but this is defensive code in case chunked transfer encoding support is added in the future.
-    if (result == http_request::HttpReadLoopResult::COMPLETE)
-      break;
     if (result != http_request::HttpReadLoopResult::DATA) {
       if (result == http_request::HttpReadLoopResult::TIMEOUT) {
         ESP_LOGE(TAG, "Timeout reading firmware data");

esphome/components/esp32_touch/__init__.py

@@ -269,8 +269,6 @@ CONFIG_SCHEMA = cv.All(
 async def to_code(config):
     # Re-enable ESP-IDF's touch sensor driver (excluded by default to save compile time)
     include_builtin_idf_component("esp_driver_touch_sens")
-    # Legacy driver component provides driver/touch_sensor.h header
-    include_builtin_idf_component("driver")
 
     touch = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(touch, config)

esphome/components/esp8266/preferences.cpp

@@ -17,6 +17,10 @@ namespace esphome::esp8266 {
 
 static const char *const TAG = "esp8266.preferences";
 
+static uint32_t *s_flash_storage = nullptr;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+static bool s_prevent_write = false;         // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+static bool s_flash_dirty = false;           // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+
 static constexpr uint32_t ESP_RTC_USER_MEM_START = 0x60001200;
 static constexpr uint32_t ESP_RTC_USER_MEM_SIZE_WORDS = 128;
 static constexpr uint32_t ESP_RTC_USER_MEM_SIZE_BYTES = ESP_RTC_USER_MEM_SIZE_WORDS * 4;
@@ -39,11 +43,6 @@ static constexpr uint32_t ESP8266_FLASH_STORAGE_SIZE = 128;
 static constexpr uint32_t ESP8266_FLASH_STORAGE_SIZE = 64;
 #endif
 
-static uint32_t
-    s_flash_storage[ESP8266_FLASH_STORAGE_SIZE];  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-static bool s_prevent_write = false;              // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-static bool s_flash_dirty = false;                // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 static inline bool esp_rtc_user_mem_read(uint32_t index, uint32_t *dest) {
   if (index >= ESP_RTC_USER_MEM_SIZE_WORDS) {
     return false;
@@ -181,6 +180,7 @@ class ESP8266Preferences : public ESPPreferences {
   uint32_t current_flash_offset = 0;  // in words
 
   void setup() {
+    s_flash_storage = new uint32_t[ESP8266_FLASH_STORAGE_SIZE];  // NOLINT
     ESP_LOGVV(TAG, "Loading preferences from flash");
 
     {
@@ -283,11 +283,10 @@ class ESP8266Preferences : public ESPPreferences {
   }
 };
 
-static ESP8266Preferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 void setup_preferences() {
-  s_preferences.setup();
-  global_preferences = &s_preferences;
+  auto *pref = new ESP8266Preferences();  // NOLINT(cppcoreguidelines-owning-memory)
+  pref->setup();
+  global_preferences = pref;
 }
 void preferences_prevent_write(bool prevent) { s_prevent_write = prevent; }
 

esphome/components/host/preferences.cpp

@@ -66,11 +66,10 @@ ESPPreferenceObject HostPreferences::make_preference(size_t length, uint32_t typ
   return ESPPreferenceObject(backend);
 };
 
-static HostPreferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 void setup_preferences() {
-  host_preferences = &s_preferences;
-  global_preferences = &s_preferences;
+  auto *pref = new HostPreferences();  // NOLINT(cppcoreguidelines-owning-memory)
+  host_preferences = pref;
+  global_preferences = pref;
 }
 
 bool HostPreferenceBackend::save(const uint8_t *data, size_t len) {

esphome/components/http_request/http_request.h

@@ -26,7 +26,6 @@ struct Header {
 enum HttpStatus {
   HTTP_STATUS_OK = 200,
   HTTP_STATUS_NO_CONTENT = 204,
-  HTTP_STATUS_RESET_CONTENT = 205,
   HTTP_STATUS_PARTIAL_CONTENT = 206,
 
   /* 3xx - Redirection */
@@ -127,21 +126,19 @@ struct HttpReadResult {
 
 /// Result of processing a non-blocking read with timeout (for manual loops)
 enum class HttpReadLoopResult : uint8_t {
-  DATA,      ///< Data was read, process it
-  COMPLETE,  ///< All content has been read, caller should exit loop
-  RETRY,     ///< No data yet, already delayed, caller should continue loop
-  ERROR,     ///< Read error, caller should exit loop
-  TIMEOUT,   ///< Timeout waiting for data, caller should exit loop
+  DATA,     ///< Data was read, process it
+  RETRY,    ///< No data yet, already delayed, caller should continue loop
+  ERROR,    ///< Read error, caller should exit loop
+  TIMEOUT,  ///< Timeout waiting for data, caller should exit loop
 };
 
 /// Process a read result with timeout tracking and delay handling
 /// @param bytes_read_or_error Return value from read() - positive for bytes read, negative for error
 /// @param last_data_time Time of last successful read, updated when data received
 /// @param timeout_ms Maximum time to wait for data
-/// @param is_read_complete Whether all expected content has been read (from HttpContainer::is_read_complete())
-/// @return How the caller should proceed - see HttpReadLoopResult enum
-inline HttpReadLoopResult http_read_loop_result(int bytes_read_or_error, uint32_t &last_data_time, uint32_t timeout_ms,
-                                                bool is_read_complete) {
+/// @return DATA if data received, RETRY if should continue loop, ERROR/TIMEOUT if should exit
+inline HttpReadLoopResult http_read_loop_result(int bytes_read_or_error, uint32_t &last_data_time,
+                                                uint32_t timeout_ms) {
   if (bytes_read_or_error > 0) {
     last_data_time = millis();
     return HttpReadLoopResult::DATA;
@@ -149,10 +146,7 @@ inline HttpReadLoopResult http_read_loop_result(int bytes_read_or_error, uint32_
   if (bytes_read_or_error < 0) {
     return HttpReadLoopResult::ERROR;
   }
-  // bytes_read_or_error == 0: either "no data yet" or "all content read"
-  if (is_read_complete) {
-    return HttpReadLoopResult::COMPLETE;
-  }
+  // bytes_read_or_error == 0: no data available yet
   if (millis() - last_data_time >= timeout_ms) {
     return HttpReadLoopResult::TIMEOUT;
   }
@@ -165,9 +159,9 @@ class HttpRequestComponent;
 class HttpContainer : public Parented<HttpRequestComponent> {
  public:
   virtual ~HttpContainer() = default;
-  size_t content_length{0};
-  int status_code{-1};  ///< -1 indicates no response received yet
-  uint32_t duration_ms{0};
+  size_t content_length;
+  int status_code;
+  uint32_t duration_ms;
 
   /**
    * @brief Read data from the HTTP response body.
@@ -200,24 +194,9 @@ class HttpContainer : public Parented<HttpRequestComponent> {
   virtual void end() = 0;
 
   void set_secure(bool secure) { this->secure_ = secure; }
-  void set_chunked(bool chunked) { this->is_chunked_ = chunked; }
 
   size_t get_bytes_read() const { return this->bytes_read_; }
 
-  /// Check if all expected content has been read
-  /// For chunked responses, returns false (completion detected via read() returning error/EOF)
-  bool is_read_complete() const {
-    // Per RFC 9112, these responses have no body:
-    // - 1xx (Informational), 204 No Content, 205 Reset Content, 304 Not Modified
-    if ((this->status_code >= 100 && this->status_code < 200) || this->status_code == HTTP_STATUS_NO_CONTENT ||
-        this->status_code == HTTP_STATUS_RESET_CONTENT || this->status_code == HTTP_STATUS_NOT_MODIFIED) {
-      return true;
-    }
-    // For non-chunked responses, complete when bytes_read >= content_length
-    // This handles both Content-Length: 0 and Content-Length: N cases
-    return !this->is_chunked_ && this->bytes_read_ >= this->content_length;
-  }
-
   /**
    * @brief Get response headers.
    *
@@ -230,7 +209,6 @@ class HttpContainer : public Parented<HttpRequestComponent> {
  protected:
   size_t bytes_read_{0};
   bool secure_{false};
-  bool is_chunked_{false};  ///< True if response uses chunked transfer encoding
   std::map<std::string, std::list<std::string>> response_headers_{};
 };
 
@@ -241,7 +219,7 @@ class HttpContainer : public Parented<HttpRequestComponent> {
 /// @param total_size Total bytes to read
 /// @param chunk_size Maximum bytes per read call
 /// @param timeout_ms Read timeout in milliseconds
-/// @return HttpReadResult with status and error_code on failure; use container->get_bytes_read() for total bytes read
+/// @return HttpReadResult with status and error_code on failure
 inline HttpReadResult http_read_fully(HttpContainer *container, uint8_t *buffer, size_t total_size, size_t chunk_size,
                                       uint32_t timeout_ms) {
   size_t read_index = 0;
@@ -253,11 +231,9 @@ inline HttpReadResult http_read_fully(HttpContainer *container, uint8_t *buffer,
     App.feed_wdt();
     yield();
 
-    auto result = http_read_loop_result(read_bytes_or_error, last_data_time, timeout_ms, container->is_read_complete());
+    auto result = http_read_loop_result(read_bytes_or_error, last_data_time, timeout_ms);
     if (result == HttpReadLoopResult::RETRY)
       continue;
-    if (result == HttpReadLoopResult::COMPLETE)
-      break;  // Server sent less data than requested, but transfer is complete
     if (result == HttpReadLoopResult::ERROR)
       return {HttpReadStatus::ERROR, read_bytes_or_error};
     if (result == HttpReadLoopResult::TIMEOUT)
@@ -417,12 +393,11 @@ template<typename... Ts> class HttpRequestSendAction : public Action<Ts...> {
           int read_or_error = container->read(buf + read_index, std::min<size_t>(max_length - read_index, 512));
           App.feed_wdt();
           yield();
-          auto result =
-              http_read_loop_result(read_or_error, last_data_time, read_timeout, container->is_read_complete());
+          auto result = http_read_loop_result(read_or_error, last_data_time, read_timeout);
           if (result == HttpReadLoopResult::RETRY)
             continue;
           if (result != HttpReadLoopResult::DATA)
-            break;  // COMPLETE, ERROR, or TIMEOUT
+            break;  // ERROR or TIMEOUT
           read_index += read_or_error;
         }
         response_body.reserve(read_index);

esphome/components/http_request/http_request_arduino.cpp

@@ -135,23 +135,9 @@ std::shared_ptr<HttpContainer> HttpRequestArduino::perform(const std::string &ur
   // When cast to size_t, -1 becomes SIZE_MAX (4294967295 on 32-bit).
   // The read() method handles this: bytes_read_ can never reach SIZE_MAX, so the
   // early return check (bytes_read_ >= content_length) will never trigger.
-  //
-  // TODO: Chunked transfer encoding is NOT properly supported on Arduino.
-  // The implementation in #7884 was incomplete - it only works correctly on ESP-IDF where
-  // esp_http_client_read() decodes chunks internally. On Arduino, using getStreamPtr()
-  // returns raw TCP data with chunk framing (e.g., "12a\r\n{json}\r\n0\r\n\r\n") instead
-  // of decoded content. This wasn't noticed because requests would complete and payloads
-  // were only examined on IDF. The long transfer times were also masked by the misleading
-  // "HTTP on Arduino version >= 3.1 is **very** slow" warning above. This causes two issues:
-  // 1. Response body is corrupted - contains chunk size headers mixed with data
-  // 2. Cannot detect end of transfer - connection stays open (keep-alive), causing timeout
-  // The proper fix would be to use getString() for chunked responses, which decodes chunks
-  // internally, but this buffers the entire response in memory.
   int content_length = container->client_.getSize();
   ESP_LOGD(TAG, "Content-Length: %d", content_length);
   container->content_length = (size_t) content_length;
-  // -1 (SIZE_MAX when cast to size_t) means chunked transfer encoding
-  container->set_chunked(content_length == -1);
   container->duration_ms = millis() - start;
 
   return container;
@@ -192,9 +178,9 @@ int HttpContainerArduino::read(uint8_t *buf, size_t max_len) {
 
   if (bufsize == 0) {
     this->duration_ms += (millis() - start);
-    // Check if we've read all expected content (non-chunked only)
-    // For chunked encoding (content_length == SIZE_MAX), is_read_complete() returns false
-    if (this->is_read_complete()) {
+    // Check if we've read all expected content (only valid when content_length is known and not SIZE_MAX)
+    // For chunked encoding (content_length == SIZE_MAX), we can't use this check
+    if (this->content_length > 0 && this->bytes_read_ >= this->content_length) {
       return 0;  // All content read successfully
     }
     // No data available - check if connection is still open

esphome/components/http_request/http_request_idf.cpp

@@ -160,7 +160,6 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const std::string &url, c
   // esp_http_client_fetch_headers() returns 0 for chunked transfer encoding (no Content-Length header).
   // The read() method handles content_length == 0 specially to support chunked responses.
   container->content_length = esp_http_client_fetch_headers(client);
-  container->set_chunked(esp_http_client_is_chunked_response(client));
   container->feed_wdt();
   container->status_code = esp_http_client_get_status_code(client);
   container->feed_wdt();
@@ -196,7 +195,6 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const std::string &url, c
 
       container->feed_wdt();
       container->content_length = esp_http_client_fetch_headers(client);
-      container->set_chunked(esp_http_client_is_chunked_response(client));
       container->feed_wdt();
       container->status_code = esp_http_client_get_status_code(client);
       container->feed_wdt();
@@ -241,9 +239,10 @@ int HttpContainerIDF::read(uint8_t *buf, size_t max_len) {
   const uint32_t start = millis();
   watchdog::WatchdogManager wdm(this->parent_->get_watchdog_timeout());
 
-  // Check if we've already read all expected content (non-chunked only)
-  // For chunked responses (content_length == 0), esp_http_client_read() handles EOF
-  if (this->is_read_complete()) {
+  // Check if we've already read all expected content
+  // Skip this check when content_length is 0 (chunked transfer encoding or unknown length)
+  // For chunked responses, esp_http_client_read() will return 0 when all data is received
+  if (this->content_length > 0 && this->bytes_read_ >= this->content_length) {
     return 0;  // All content read successfully
   }
 

esphome/components/http_request/ota/ota_http_request.cpp

@@ -130,13 +130,9 @@ uint8_t OtaHttpRequestComponent::do_ota_() {
     App.feed_wdt();
     yield();
 
-    auto result = http_read_loop_result(bufsize_or_error, last_data_time, read_timeout, container->is_read_complete());
+    auto result = http_read_loop_result(bufsize_or_error, last_data_time, read_timeout);
     if (result == HttpReadLoopResult::RETRY)
       continue;
-    // Note: COMPLETE is currently unreachable since the loop condition checks bytes_read < content_length,
-    // but this is defensive code in case chunked transfer encoding support is added for OTA in the future.
-    if (result == HttpReadLoopResult::COMPLETE)
-      break;
     if (result != HttpReadLoopResult::DATA) {
       if (result == HttpReadLoopResult::TIMEOUT) {
         ESP_LOGE(TAG, "Timeout reading data");

esphome/components/improv_serial/improv_serial_component.cpp

@@ -267,16 +267,26 @@ bool ImprovSerialComponent::parse_improv_payload_(improv::ImprovCommand &command
       for (auto &scan : results) {
         if (scan.get_is_hidden())
           continue;
-        const std::string &ssid = scan.get_ssid();
-        if (std::find(networks.begin(), networks.end(), ssid) != networks.end())
+        const char *ssid_cstr = scan.get_ssid().c_str();
+        // Check if we've already sent this SSID
+        bool duplicate = false;
+        for (const auto &seen : networks) {
+          if (strcmp(seen.c_str(), ssid_cstr) == 0) {
+            duplicate = true;
+            break;
+          }
+        }
+        if (duplicate)
           continue;
+        // Only allocate std::string after confirming it's not a duplicate
+        std::string ssid(ssid_cstr);
         // Send each ssid separately to avoid overflowing the buffer
         char rssi_buf[5];  // int8_t: -128 to 127, max 4 chars + null
         *int8_to_str(rssi_buf, scan.get_rssi()) = '\0';
         std::vector<uint8_t> data =
             improv::build_rpc_response(improv::GET_WIFI_NETWORKS, {ssid, rssi_buf, YESNO(scan.get_with_auth())}, false);
         this->send_response_(data);
-        networks.push_back(ssid);
+        networks.push_back(std::move(ssid));
       }
       // Send empty response to signify the end of the list.
       std::vector<uint8_t> data =

esphome/components/libretiny/preferences.cpp

@@ -189,11 +189,10 @@ class LibreTinyPreferences : public ESPPreferences {
   }
 };
 
-static LibreTinyPreferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 void setup_preferences() {
-  s_preferences.open();
-  global_preferences = &s_preferences;
+  auto *prefs = new LibreTinyPreferences();  // NOLINT(cppcoreguidelines-owning-memory)
+  prefs->open();
+  global_preferences = prefs;
 }
 
 }  // namespace libretiny

esphome/components/lock/lock.cpp

@@ -2,7 +2,6 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/controller_registry.h"
 #include "esphome/core/log.h"
-#include "esphome/core/progmem.h"
 
 namespace esphome::lock {
 
@@ -85,21 +84,21 @@ LockCall &LockCall::set_state(optional<LockState> state) {
   this->state_ = state;
   return *this;
 }
-LockCall &LockCall::set_state(const char *state) {
-  if (ESPHOME_strcasecmp_P(state, ESPHOME_PSTR("LOCKED")) == 0) {
+LockCall &LockCall::set_state(const std::string &state) {
+  if (str_equals_case_insensitive(state, "LOCKED")) {
     this->set_state(LOCK_STATE_LOCKED);
-  } else if (ESPHOME_strcasecmp_P(state, ESPHOME_PSTR("UNLOCKED")) == 0) {
+  } else if (str_equals_case_insensitive(state, "UNLOCKED")) {
     this->set_state(LOCK_STATE_UNLOCKED);
-  } else if (ESPHOME_strcasecmp_P(state, ESPHOME_PSTR("JAMMED")) == 0) {
+  } else if (str_equals_case_insensitive(state, "JAMMED")) {
     this->set_state(LOCK_STATE_JAMMED);
-  } else if (ESPHOME_strcasecmp_P(state, ESPHOME_PSTR("LOCKING")) == 0) {
+  } else if (str_equals_case_insensitive(state, "LOCKING")) {
     this->set_state(LOCK_STATE_LOCKING);
-  } else if (ESPHOME_strcasecmp_P(state, ESPHOME_PSTR("UNLOCKING")) == 0) {
+  } else if (str_equals_case_insensitive(state, "UNLOCKING")) {
     this->set_state(LOCK_STATE_UNLOCKING);
-  } else if (ESPHOME_strcasecmp_P(state, ESPHOME_PSTR("NONE")) == 0) {
+  } else if (str_equals_case_insensitive(state, "NONE")) {
     this->set_state(LOCK_STATE_NONE);
   } else {
-    ESP_LOGW(TAG, "'%s' - Unrecognized state %s", this->parent_->get_name().c_str(), state);
+    ESP_LOGW(TAG, "'%s' - Unrecognized state %s", this->parent_->get_name().c_str(), state.c_str());
   }
   return *this;
 }

esphome/components/lock/lock.h

@@ -83,8 +83,7 @@ class LockCall {
   /// Set the state of the lock device.
   LockCall &set_state(optional<LockState> state);
   /// Set the state of the lock device based on a string.
-  LockCall &set_state(const char *state);
-  LockCall &set_state(const std::string &state) { return this->set_state(state.c_str()); }
+  LockCall &set_state(const std::string &state);
 
   void perform();
 

esphome/components/logger/logger.cpp

@@ -128,7 +128,22 @@ void HOT Logger::log_vprintf_(uint8_t level, const char *tag, int line, const ch
 // Note: USE_STORE_LOG_STR_IN_FLASH is only defined for ESP8266.
 //
 // This function handles format strings stored in flash memory (PROGMEM) to save RAM.
-// Uses vsnprintf_P to read the format string directly from flash without copying to RAM.
+// The buffer is used in a special way to avoid allocating extra memory:
+//
+// Memory layout during execution:
+// Step 1: Copy format string from flash to buffer
+//         tx_buffer_: [format_string][null][.....................]
+//         tx_buffer_at_: ------------------^
+//         msg_start: saved here -----------^
+//
+// Step 2: format_log_to_buffer_with_terminator_ reads format string from beginning
+//         and writes formatted output starting at msg_start position
+//         tx_buffer_: [format_string][null][formatted_message][null]
+//         tx_buffer_at_: -------------------------------------^
+//
+// Step 3: Output the formatted message (starting at msg_start)
+//         write_msg_ and callbacks receive: this->tx_buffer_ + msg_start
+//         which points to: [formatted_message][null]
 //
 void Logger::log_vprintf_(uint8_t level, const char *tag, int line, const __FlashStringHelper *format,
                           va_list args) {  // NOLINT
@@ -138,25 +153,35 @@ void Logger::log_vprintf_(uint8_t level, const char *tag, int line, const __Flas
   RecursionGuard guard(global_recursion_guard_);
   this->tx_buffer_at_ = 0;
 
-  // Write header, format body directly from flash, and write footer
-  this->write_header_to_buffer_(level, tag, line, nullptr, this->tx_buffer_, &this->tx_buffer_at_,
-                                this->tx_buffer_size_);
-  this->format_body_to_buffer_P_(this->tx_buffer_, &this->tx_buffer_at_, this->tx_buffer_size_,
-                                 reinterpret_cast<PGM_P>(format), args);
-  this->write_footer_to_buffer_(this->tx_buffer_, &this->tx_buffer_at_, this->tx_buffer_size_);
+  // Copy format string from progmem
+  auto *format_pgm_p = reinterpret_cast<const uint8_t *>(format);
+  char ch = '.';
+  while (this->tx_buffer_at_ < this->tx_buffer_size_ && ch != '\0') {
+    this->tx_buffer_[this->tx_buffer_at_++] = ch = (char) progmem_read_byte(format_pgm_p++);
+  }
 
-  // Ensure null termination
-  uint16_t null_pos = this->tx_buffer_at_ >= this->tx_buffer_size_ ? this->tx_buffer_size_ - 1 : this->tx_buffer_at_;
-  this->tx_buffer_[null_pos] = '\0';
+  // Buffer full from copying format - RAII guard handles cleanup on return
+  if (this->tx_buffer_at_ >= this->tx_buffer_size_) {
+    return;
+  }
+
+  // Save the offset before calling format_log_to_buffer_with_terminator_
+  // since it will increment tx_buffer_at_ to the end of the formatted string
+  uint16_t msg_start = this->tx_buffer_at_;
+  this->format_log_to_buffer_with_terminator_(level, tag, line, this->tx_buffer_, args, this->tx_buffer_,
+                                              &this->tx_buffer_at_, this->tx_buffer_size_);
+
+  uint16_t msg_length =
+      this->tx_buffer_at_ - msg_start;  // Don't subtract 1 - tx_buffer_at_ is already at the null terminator position
 
   // Listeners get message first (before console write)
 #ifdef USE_LOG_LISTENERS
   for (auto *listener : this->log_listeners_)
-    listener->on_log(level, tag, this->tx_buffer_, this->tx_buffer_at_);
+    listener->on_log(level, tag, this->tx_buffer_ + msg_start, msg_length);
 #endif
 
-  // Write to console
-  this->write_tx_buffer_to_console_();
+  // Write to console starting at the msg_start
+  this->write_tx_buffer_to_console_(msg_start, &msg_length);
 }
 #endif  // USE_STORE_LOG_STR_IN_FLASH
 

esphome/components/logger/logger.h

@@ -597,39 +597,30 @@ class Logger : public Component {
     *buffer_at = pos;
   }
 
-  // Helper to process vsnprintf return value and strip trailing newlines.
-  // Updates buffer_at with the formatted length, handling truncation:
-  // - When vsnprintf truncates (ret >= remaining), it writes (remaining - 1) chars + null terminator
-  // - When it doesn't truncate (ret < remaining), it writes ret chars + null terminator
-  __attribute__((always_inline)) static inline void process_vsnprintf_result(const char *buffer, uint16_t *buffer_at,
-                                                                             uint16_t remaining, int ret) {
-    if (ret < 0)
-      return;  // Encoding error, do not increment buffer_at
-    *buffer_at += (ret >= remaining) ? (remaining - 1) : static_cast<uint16_t>(ret);
-    // Remove all trailing newlines right after formatting
-    while (*buffer_at > 0 && buffer[*buffer_at - 1] == '\n')
-      (*buffer_at)--;
-  }
-
   inline void HOT format_body_to_buffer_(char *buffer, uint16_t *buffer_at, uint16_t buffer_size, const char *format,
                                          va_list args) {
-    // Check remaining capacity in the buffer
+    // Get remaining capacity in the buffer
     if (*buffer_at >= buffer_size)
       return;
     const uint16_t remaining = buffer_size - *buffer_at;
-    process_vsnprintf_result(buffer, buffer_at, remaining, vsnprintf(buffer + *buffer_at, remaining, format, args));
-  }
 
-#ifdef USE_STORE_LOG_STR_IN_FLASH
-  // ESP8266 variant that reads format string directly from flash using vsnprintf_P
-  inline void HOT format_body_to_buffer_P_(char *buffer, uint16_t *buffer_at, uint16_t buffer_size, PGM_P format,
-                                           va_list args) {
-    if (*buffer_at >= buffer_size)
-      return;
-    const uint16_t remaining = buffer_size - *buffer_at;
-    process_vsnprintf_result(buffer, buffer_at, remaining, vsnprintf_P(buffer + *buffer_at, remaining, format, args));
+    const int ret = vsnprintf(buffer + *buffer_at, remaining, format, args);
+
+    if (ret < 0) {
+      return;  // Encoding error, do not increment buffer_at
+    }
+
+    // Update buffer_at with the formatted length (handle truncation)
+    // When vsnprintf truncates (ret >= remaining), it writes (remaining - 1) chars + null terminator
+    // When it doesn't truncate (ret < remaining), it writes ret chars + null terminator
+    uint16_t formatted_len = (ret >= remaining) ? (remaining - 1) : ret;
+    *buffer_at += formatted_len;
+
+    // Remove all trailing newlines right after formatting
+    while (*buffer_at > 0 && buffer[*buffer_at - 1] == '\n') {
+      (*buffer_at)--;
+    }
   }
-#endif
 
   inline void HOT write_footer_to_buffer_(char *buffer, uint16_t *buffer_at, uint16_t buffer_size) {
     static constexpr uint16_t RESET_COLOR_LEN = sizeof(ESPHOME_LOG_RESET_COLOR) - 1;

esphome/components/media_player/media_player.cpp

@@ -2,7 +2,6 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/controller_registry.h"
 #include "esphome/core/log.h"
-#include "esphome/core/progmem.h"
 
 namespace esphome {
 namespace media_player {
@@ -108,25 +107,25 @@ MediaPlayerCall &MediaPlayerCall::set_command(optional<MediaPlayerCommand> comma
   this->command_ = command;
   return *this;
 }
-MediaPlayerCall &MediaPlayerCall::set_command(const char *command) {
-  if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("PLAY")) == 0) {
+MediaPlayerCall &MediaPlayerCall::set_command(const std::string &command) {
+  if (str_equals_case_insensitive(command, "PLAY")) {
     this->set_command(MEDIA_PLAYER_COMMAND_PLAY);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("PAUSE")) == 0) {
+  } else if (str_equals_case_insensitive(command, "PAUSE")) {
     this->set_command(MEDIA_PLAYER_COMMAND_PAUSE);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("STOP")) == 0) {
+  } else if (str_equals_case_insensitive(command, "STOP")) {
     this->set_command(MEDIA_PLAYER_COMMAND_STOP);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("MUTE")) == 0) {
+  } else if (str_equals_case_insensitive(command, "MUTE")) {
     this->set_command(MEDIA_PLAYER_COMMAND_MUTE);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("UNMUTE")) == 0) {
+  } else if (str_equals_case_insensitive(command, "UNMUTE")) {
     this->set_command(MEDIA_PLAYER_COMMAND_UNMUTE);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("TOGGLE")) == 0) {
+  } else if (str_equals_case_insensitive(command, "TOGGLE")) {
     this->set_command(MEDIA_PLAYER_COMMAND_TOGGLE);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("TURN_ON")) == 0) {
+  } else if (str_equals_case_insensitive(command, "TURN_ON")) {
     this->set_command(MEDIA_PLAYER_COMMAND_TURN_ON);
-  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("TURN_OFF")) == 0) {
+  } else if (str_equals_case_insensitive(command, "TURN_OFF")) {
     this->set_command(MEDIA_PLAYER_COMMAND_TURN_OFF);
   } else {
-    ESP_LOGW(TAG, "'%s' - Unrecognized command %s", this->parent_->get_name().c_str(), command);
+    ESP_LOGW(TAG, "'%s' - Unrecognized command %s", this->parent_->get_name().c_str(), command.c_str());
   }
   return *this;
 }

esphome/components/media_player/media_player.h

@@ -114,8 +114,7 @@ class MediaPlayerCall {
 
   MediaPlayerCall &set_command(MediaPlayerCommand command);
   MediaPlayerCall &set_command(optional<MediaPlayerCommand> command);
-  MediaPlayerCall &set_command(const char *command);
-  MediaPlayerCall &set_command(const std::string &command) { return this->set_command(command.c_str()); }
+  MediaPlayerCall &set_command(const std::string &command);
 
   MediaPlayerCall &set_media_url(const std::string &url);
 

esphome/components/mipi_dsi/models/waveshare.py

@@ -94,29 +94,3 @@ DriverChip(
         (0x29, 0x00),
     ],
 )
-
-DriverChip(
-    "WAVESHARE-ESP32-P4-WIFI6-TOUCH-LCD-7B",
-    height=600,
-    width=1024,
-    hsync_back_porch=160,
-    hsync_pulse_width=10,
-    hsync_front_porch=160,
-    vsync_back_porch=23,
-    vsync_pulse_width=1,
-    vsync_front_porch=12,
-    pclk_frequency="52MHz",
-    lane_bit_rate="900Mbps",
-    no_transform=True,
-    color_order="RGB",
-    initsequence=[
-        (0x80, 0x8B),
-        (0x81, 0x78),
-        (0x82, 0x84),
-        (0x83, 0x88),
-        (0x84, 0xA8),
-        (0x85, 0xE3),
-        (0x86, 0x88),
-        (0xB2, 0x10),
-    ],
-)

esphome/components/opentherm/__init__.py

@@ -4,10 +4,8 @@ from typing import Any
 from esphome import automation, pins
 import esphome.codegen as cg
 from esphome.components import sensor
-from esphome.components.esp32 import include_builtin_idf_component
 import esphome.config_validation as cv
 from esphome.const import CONF_ID, CONF_TRIGGER_ID, PLATFORM_ESP32, PLATFORM_ESP8266
-from esphome.core import CORE
 
 from . import const, generate, schema, validate
 
@@ -85,12 +83,6 @@ CONFIG_SCHEMA = cv.All(
 
 
 async def to_code(config: dict[str, Any]) -> None:
-    if CORE.is_esp32:
-        # Re-enable ESP-IDF's legacy driver component (excluded by default to save compile time)
-        # Provides driver/timer.h header for hardware timer API
-        # TODO: Remove this once opentherm migrates to GPTimer API (driver/gptimer.h)
-        include_builtin_idf_component("driver")
-
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
 

esphome/components/opentherm/opentherm.cpp

@@ -8,8 +8,6 @@
 #include "opentherm.h"
 #include "esphome/core/helpers.h"
 #include <cinttypes>
-// TODO: Migrate from legacy timer API (driver/timer.h) to GPTimer API (driver/gptimer.h)
-// The legacy timer API is deprecated in ESP-IDF 5.x. See opentherm.h for details.
 #ifdef USE_ESP32
 #include "driver/timer.h"
 #include "esp_err.h"

esphome/components/opentherm/opentherm.h

@@ -12,10 +12,6 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
-// TODO: Migrate from legacy timer API (driver/timer.h) to GPTimer API (driver/gptimer.h)
-// The legacy timer API is deprecated in ESP-IDF 5.x. Migration would allow removing the
-// "driver" IDF component dependency. See:
-// https://docs.espressif.com/projects/esp-idf/en/latest/esp32/migration-guides/release-5.x/5.0/peripherals.html#id4
 #ifdef USE_ESP32
 #include "driver/timer.h"
 #endif

esphome/components/openthread/__init__.py

@@ -4,7 +4,6 @@ from esphome.components.esp32 import (
     VARIANT_ESP32C6,
     VARIANT_ESP32H2,
     add_idf_sdkconfig_option,
-    include_builtin_idf_component,
     only_on_variant,
     require_vfs_select,
 )
@@ -173,9 +172,6 @@ FINAL_VALIDATE_SCHEMA = _final_validate
 
 
 async def to_code(config):
-    # Re-enable openthread IDF component (excluded by default)
-    include_builtin_idf_component("openthread")
-
     cg.add_define("USE_OPENTHREAD")
 
     # OpenThread SRP needs access to mDNS services after setup

esphome/components/rp2040/preferences.cpp

@@ -18,12 +18,11 @@ namespace rp2040 {
 
 static const char *const TAG = "rp2040.preferences";
 
-static constexpr uint32_t RP2040_FLASH_STORAGE_SIZE = 512;
+static bool s_prevent_write = false;        // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+static uint8_t *s_flash_storage = nullptr;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+static bool s_flash_dirty = false;          // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
 
-static bool s_prevent_write = false;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-static uint8_t
-    s_flash_storage[RP2040_FLASH_STORAGE_SIZE];  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-static bool s_flash_dirty = false;               // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+static const uint32_t RP2040_FLASH_STORAGE_SIZE = 512;
 
 // Stack buffer size for preferences - covers virtually all real-world preferences without heap allocation
 static constexpr size_t PREF_BUFFER_SIZE = 64;
@@ -92,6 +91,7 @@ class RP2040Preferences : public ESPPreferences {
 
   RP2040Preferences() : eeprom_sector_(&_EEPROM_start) {}
   void setup() {
+    s_flash_storage = new uint8_t[RP2040_FLASH_STORAGE_SIZE];  // NOLINT
     ESP_LOGVV(TAG, "Loading preferences from flash");
     memcpy(s_flash_storage, this->eeprom_sector_, RP2040_FLASH_STORAGE_SIZE);
   }
@@ -149,11 +149,10 @@ class RP2040Preferences : public ESPPreferences {
   uint8_t *eeprom_sector_;
 };
 
-static RP2040Preferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 void setup_preferences() {
-  s_preferences.setup();
-  global_preferences = &s_preferences;
+  auto *prefs = new RP2040Preferences();  // NOLINT(cppcoreguidelines-owning-memory)
+  prefs->setup();
+  global_preferences = prefs;
 }
 void preferences_prevent_write(bool prevent) { s_prevent_write = prevent; }
 

esphome/components/speaker/media_player/__init__.py

@@ -157,14 +157,8 @@ def _read_audio_file_and_type(file_config):
 
     import puremagic
 
-    try:
-        file_type: str = puremagic.from_string(data)
-        file_type = file_type.removeprefix(".")
-    except puremagic.PureError as e:
-        raise cv.Invalid(
-            f"Unable to determine audio file type of '{path}'. "
-            f"Try re-encoding the file into a supported format. Details: {e}"
-        )
+    file_type: str = puremagic.from_string(data)
+    file_type = file_type.removeprefix(".")
 
     media_file_type = audio.AUDIO_FILE_TYPE_ENUM["NONE"]
     if file_type in ("wav"):

esphome/components/water_heater/water_heater.cpp

@@ -2,7 +2,6 @@
 #include "esphome/core/log.h"
 #include "esphome/core/application.h"
 #include "esphome/core/controller_registry.h"
-#include "esphome/core/progmem.h"
 
 #include <cmath>
 
@@ -23,23 +22,23 @@ WaterHeaterCall &WaterHeaterCall::set_mode(WaterHeaterMode mode) {
   return *this;
 }
 
-WaterHeaterCall &WaterHeaterCall::set_mode(const char *mode) {
-  if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("OFF")) == 0) {
+WaterHeaterCall &WaterHeaterCall::set_mode(const std::string &mode) {
+  if (str_equals_case_insensitive(mode, "OFF")) {
     this->set_mode(WATER_HEATER_MODE_OFF);
-  } else if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("ECO")) == 0) {
+  } else if (str_equals_case_insensitive(mode, "ECO")) {
     this->set_mode(WATER_HEATER_MODE_ECO);
-  } else if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("ELECTRIC")) == 0) {
+  } else if (str_equals_case_insensitive(mode, "ELECTRIC")) {
     this->set_mode(WATER_HEATER_MODE_ELECTRIC);
-  } else if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("PERFORMANCE")) == 0) {
+  } else if (str_equals_case_insensitive(mode, "PERFORMANCE")) {
     this->set_mode(WATER_HEATER_MODE_PERFORMANCE);
-  } else if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("HIGH_DEMAND")) == 0) {
+  } else if (str_equals_case_insensitive(mode, "HIGH_DEMAND")) {
     this->set_mode(WATER_HEATER_MODE_HIGH_DEMAND);
-  } else if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("HEAT_PUMP")) == 0) {
+  } else if (str_equals_case_insensitive(mode, "HEAT_PUMP")) {
     this->set_mode(WATER_HEATER_MODE_HEAT_PUMP);
-  } else if (ESPHOME_strcasecmp_P(mode, ESPHOME_PSTR("GAS")) == 0) {
+  } else if (str_equals_case_insensitive(mode, "GAS")) {
     this->set_mode(WATER_HEATER_MODE_GAS);
   } else {
-    ESP_LOGW(TAG, "'%s' - Unrecognized mode %s", this->parent_->get_name().c_str(), mode);
+    ESP_LOGW(TAG, "'%s' - Unrecognized mode %s", this->parent_->get_name().c_str(), mode.c_str());
   }
   return *this;
 }

esphome/components/water_heater/water_heater.h

@@ -75,8 +75,7 @@ class WaterHeaterCall {
   WaterHeaterCall(WaterHeater *parent);
 
   WaterHeaterCall &set_mode(WaterHeaterMode mode);
-  WaterHeaterCall &set_mode(const char *mode);
-  WaterHeaterCall &set_mode(const std::string &mode) { return this->set_mode(mode.c_str()); }
+  WaterHeaterCall &set_mode(const std::string &mode);
   WaterHeaterCall &set_target_temperature(float temperature);
   WaterHeaterCall &set_target_temperature_low(float temperature);
   WaterHeaterCall &set_target_temperature_high(float temperature);

esphome/components/wifi/__init__.py

@@ -585,13 +585,11 @@ async def to_code(config):
     await cg.past_safe_mode()
 
     if on_connect_config := config.get(CONF_ON_CONNECT):
-        cg.add_define("USE_WIFI_CONNECT_TRIGGER")
         await automation.build_automation(
             var.get_connect_trigger(), [], on_connect_config
         )
 
     if on_disconnect_config := config.get(CONF_ON_DISCONNECT):
-        cg.add_define("USE_WIFI_DISCONNECT_TRIGGER")
         await automation.build_automation(
             var.get_disconnect_trigger(), [], on_disconnect_config
         )

esphome/components/wifi/automation.h

@@ -48,7 +48,7 @@ template<typename... Ts> class WiFiConfigureAction : public Action<Ts...>, publi
     char ssid_buf[SSID_BUFFER_SIZE];
     if (strcmp(global_wifi_component->wifi_ssid_to(ssid_buf), ssid.c_str()) == 0) {
       // Callback to notify the user that the connection was successful
-      this->connect_trigger_.trigger();
+      this->connect_trigger_->trigger();
       return;
     }
     // Create a new WiFiAP object with the new SSID and password
@@ -79,13 +79,13 @@ template<typename... Ts> class WiFiConfigureAction : public Action<Ts...>, publi
       // Start a timeout for the fallback if the connection to the old AP fails
       this->set_timeout("wifi-fallback-timeout", this->connection_timeout_.value(x...), [this]() {
         this->connecting_ = false;
-        this->error_trigger_.trigger();
+        this->error_trigger_->trigger();
       });
     });
   }
 
-  Trigger<> *get_connect_trigger() { return &this->connect_trigger_; }
-  Trigger<> *get_error_trigger() { return &this->error_trigger_; }
+  Trigger<> *get_connect_trigger() const { return this->connect_trigger_; }
+  Trigger<> *get_error_trigger() const { return this->error_trigger_; }
 
   void loop() override {
     if (!this->connecting_)
@@ -98,10 +98,10 @@ template<typename... Ts> class WiFiConfigureAction : public Action<Ts...>, publi
       char ssid_buf[SSID_BUFFER_SIZE];
       if (strcmp(global_wifi_component->wifi_ssid_to(ssid_buf), this->new_sta_.get_ssid().c_str()) == 0) {
         // Callback to notify the user that the connection was successful
-        this->connect_trigger_.trigger();
+        this->connect_trigger_->trigger();
       } else {
         // Callback to notify the user that the connection failed
-        this->error_trigger_.trigger();
+        this->error_trigger_->trigger();
       }
     }
   }
@@ -110,8 +110,8 @@ template<typename... Ts> class WiFiConfigureAction : public Action<Ts...>, publi
   bool connecting_{false};
   WiFiAP new_sta_;
   WiFiAP old_sta_;
-  Trigger<> connect_trigger_;
-  Trigger<> error_trigger_;
+  Trigger<> *connect_trigger_{new Trigger<>()};
+  Trigger<> *error_trigger_{new Trigger<>()};
 };
 
 }  // namespace esphome::wifi

esphome/components/wifi/wifi_component.cpp

@@ -351,7 +351,7 @@ bool WiFiComponent::needs_scan_results_() const {
   return this->scan_result_.empty() || !this->scan_result_[0].get_matches();
 }
 
-bool WiFiComponent::ssid_was_seen_in_scan_(const std::string &ssid) const {
+bool WiFiComponent::ssid_was_seen_in_scan_(const CompactString &ssid) const {
   // Check if this SSID is configured as hidden
   // If explicitly marked hidden, we should always try hidden mode regardless of scan results
   for (const auto &conf : this->sta_) {
@@ -651,21 +651,14 @@ void WiFiComponent::loop() {
   const uint32_t now = App.get_loop_component_start_time();
 
   if (this->has_sta()) {
-#if defined(USE_WIFI_CONNECT_TRIGGER) || defined(USE_WIFI_DISCONNECT_TRIGGER)
     if (this->is_connected() != this->handled_connected_state_) {
-#ifdef USE_WIFI_DISCONNECT_TRIGGER
       if (this->handled_connected_state_) {
-        this->disconnect_trigger_.trigger();
+        this->disconnect_trigger_->trigger();
+      } else {
+        this->connect_trigger_->trigger();
       }
-#endif
-#ifdef USE_WIFI_CONNECT_TRIGGER
-      if (!this->handled_connected_state_) {
-        this->connect_trigger_.trigger();
-      }
-#endif
       this->handled_connected_state_ = this->is_connected();
     }
-#endif  // USE_WIFI_CONNECT_TRIGGER || USE_WIFI_DISCONNECT_TRIGGER
 
     switch (this->state_) {
       case WIFI_COMPONENT_STATE_COOLDOWN: {
@@ -962,9 +955,12 @@ WiFiAP WiFiComponent::get_sta() const {
   return config ? *config : WiFiAP{};
 }
 void WiFiComponent::save_wifi_sta(const std::string &ssid, const std::string &password) {
+  this->save_wifi_sta(ssid.c_str(), password.c_str());
+}
+void WiFiComponent::save_wifi_sta(const char *ssid, const char *password) {
   SavedWifiSettings save{};  // zero-initialized - all bytes set to \0, guaranteeing null termination
-  strncpy(save.ssid, ssid.c_str(), sizeof(save.ssid) - 1);              // max 32 chars, byte 32 remains \0
-  strncpy(save.password, password.c_str(), sizeof(save.password) - 1);  // max 64 chars, byte 64 remains \0
+  strncpy(save.ssid, ssid, sizeof(save.ssid) - 1);              // max 32 chars, byte 32 remains \0
+  strncpy(save.password, password, sizeof(save.password) - 1);  // max 64 chars, byte 64 remains \0
   this->pref_.save(&save);
   // ensure it's written immediately
   global_preferences->sync();
@@ -1809,11 +1805,11 @@ void WiFiComponent::log_and_adjust_priority_for_failed_connect_() {
   }
 
   // Get SSID for logging (use pointer to avoid copy)
-  const std::string *ssid = nullptr;
+  const char *ssid = nullptr;
   if (this->retry_phase_ == WiFiRetryPhase::SCAN_CONNECTING && !this->scan_result_.empty()) {
-    ssid = &this->scan_result_[0].get_ssid();
+    ssid = this->scan_result_[0].get_ssid().c_str();
   } else if (const WiFiAP *config = this->get_selected_sta_()) {
-    ssid = &config->get_ssid();
+    ssid = config->get_ssid().c_str();
   }
 
   // Only decrease priority on the last attempt for this phase
@@ -1833,8 +1829,8 @@ void WiFiComponent::log_and_adjust_priority_for_failed_connect_() {
   }
   char bssid_s[18];
   format_mac_addr_upper(failed_bssid.value().data(), bssid_s);
-  ESP_LOGD(TAG, "Failed " LOG_SECRET("'%s'") " " LOG_SECRET("(%s)") ", priority %d → %d",
-           ssid != nullptr ? ssid->c_str() : "", bssid_s, old_priority, new_priority);
+  ESP_LOGD(TAG, "Failed " LOG_SECRET("'%s'") " " LOG_SECRET("(%s)") ", priority %d → %d", ssid != nullptr ? ssid : "",
+           bssid_s, old_priority, new_priority);
 
   // After adjusting priority, check if all priorities are now at minimum
   // If so, clear the vector to save memory and reset for fresh start
@@ -2082,10 +2078,14 @@ void WiFiComponent::save_fast_connect_settings_() {
 }
 #endif
 
-void WiFiAP::set_ssid(const std::string &ssid) { this->ssid_ = ssid; }
+void WiFiAP::set_ssid(const std::string &ssid) { this->ssid_ = CompactString(ssid.c_str(), ssid.size()); }
+void WiFiAP::set_ssid(const char *ssid) { this->ssid_ = CompactString(ssid, strlen(ssid)); }
 void WiFiAP::set_bssid(const bssid_t &bssid) { this->bssid_ = bssid; }
 void WiFiAP::clear_bssid() { this->bssid_ = {}; }
-void WiFiAP::set_password(const std::string &password) { this->password_ = password; }
+void WiFiAP::set_password(const std::string &password) {
+  this->password_ = CompactString(password.c_str(), password.size());
+}
+void WiFiAP::set_password(const char *password) { this->password_ = CompactString(password, strlen(password)); }
 #ifdef USE_WIFI_WPA2_EAP
 void WiFiAP::set_eap(optional<EAPAuth> eap_auth) { this->eap_ = std::move(eap_auth); }
 #endif
@@ -2095,10 +2095,8 @@ void WiFiAP::clear_channel() { this->channel_ = 0; }
 void WiFiAP::set_manual_ip(optional<ManualIP> manual_ip) { this->manual_ip_ = manual_ip; }
 #endif
 void WiFiAP::set_hidden(bool hidden) { this->hidden_ = hidden; }
-const std::string &WiFiAP::get_ssid() const { return this->ssid_; }
 const bssid_t &WiFiAP::get_bssid() const { return this->bssid_; }
 bool WiFiAP::has_bssid() const { return this->bssid_ != bssid_t{}; }
-const std::string &WiFiAP::get_password() const { return this->password_; }
 #ifdef USE_WIFI_WPA2_EAP
 const optional<EAPAuth> &WiFiAP::get_eap() const { return this->eap_; }
 #endif
@@ -2109,12 +2107,12 @@ const optional<ManualIP> &WiFiAP::get_manual_ip() const { return this->manual_ip
 #endif
 bool WiFiAP::get_hidden() const { return this->hidden_; }
 
-WiFiScanResult::WiFiScanResult(const bssid_t &bssid, std::string ssid, uint8_t channel, int8_t rssi, bool with_auth,
-                               bool is_hidden)
+WiFiScanResult::WiFiScanResult(const bssid_t &bssid, const char *ssid, size_t ssid_len, uint8_t channel, int8_t rssi,
+                               bool with_auth, bool is_hidden)
     : bssid_(bssid),
       channel_(channel),
       rssi_(rssi),
-      ssid_(std::move(ssid)),
+      ssid_(ssid, ssid_len),
       with_auth_(with_auth),
       is_hidden_(is_hidden) {}
 bool WiFiScanResult::matches(const WiFiAP &config) const {
@@ -2157,7 +2155,6 @@ bool WiFiScanResult::matches(const WiFiAP &config) const {
 bool WiFiScanResult::get_matches() const { return this->matches_; }
 void WiFiScanResult::set_matches(bool matches) { this->matches_ = matches; }
 const bssid_t &WiFiScanResult::get_bssid() const { return this->bssid_; }
-const std::string &WiFiScanResult::get_ssid() const { return this->ssid_; }
 uint8_t WiFiScanResult::get_channel() const { return this->channel_; }
 int8_t WiFiScanResult::get_rssi() const { return this->rssi_; }
 bool WiFiScanResult::get_with_auth() const { return this->with_auth_; }
@@ -2230,7 +2227,7 @@ void WiFiComponent::process_roaming_scan_() {
 
   for (const auto &result : this->scan_result_) {
     // Must be same SSID, different BSSID
-    if (current_ssid != result.get_ssid() || result.get_bssid() == current_bssid)
+    if (result.get_ssid() != current_ssid.c_str() || result.get_bssid() == current_bssid)
       continue;
 
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE

esphome/components/wifi/wifi_component.h

@@ -175,9 +175,13 @@ template<typename T> using wifi_scan_vector_t = FixedVector<T>;
 class WiFiAP {
  public:
   void set_ssid(const std::string &ssid);
+  void set_ssid(const char *ssid);
+  void set_ssid(const CompactString &ssid) { this->ssid_ = ssid; }
   void set_bssid(const bssid_t &bssid);
   void clear_bssid();
   void set_password(const std::string &password);
+  void set_password(const char *password);
+  void set_password(const CompactString &password) { this->password_ = password; }
 #ifdef USE_WIFI_WPA2_EAP
   void set_eap(optional<EAPAuth> eap_auth);
 #endif  // USE_WIFI_WPA2_EAP
@@ -188,10 +192,10 @@ class WiFiAP {
   void set_manual_ip(optional<ManualIP> manual_ip);
 #endif
   void set_hidden(bool hidden);
-  const std::string &get_ssid() const;
+  const CompactString &get_ssid() const { return this->ssid_; }
+  const CompactString &get_password() const { return this->password_; }
   const bssid_t &get_bssid() const;
   bool has_bssid() const;
-  const std::string &get_password() const;
 #ifdef USE_WIFI_WPA2_EAP
   const optional<EAPAuth> &get_eap() const;
 #endif  // USE_WIFI_WPA2_EAP
@@ -204,8 +208,8 @@ class WiFiAP {
   bool get_hidden() const;
 
  protected:
-  std::string ssid_;
-  std::string password_;
+  CompactString ssid_;
+  CompactString password_;
 #ifdef USE_WIFI_WPA2_EAP
   optional<EAPAuth> eap_;
 #endif  // USE_WIFI_WPA2_EAP
@@ -221,14 +225,15 @@ class WiFiAP {
 
 class WiFiScanResult {
  public:
-  WiFiScanResult(const bssid_t &bssid, std::string ssid, uint8_t channel, int8_t rssi, bool with_auth, bool is_hidden);
+  WiFiScanResult(const bssid_t &bssid, const char *ssid, size_t ssid_len, uint8_t channel, int8_t rssi, bool with_auth,
+                 bool is_hidden);
 
   bool matches(const WiFiAP &config) const;
 
   bool get_matches() const;
   void set_matches(bool matches);
   const bssid_t &get_bssid() const;
-  const std::string &get_ssid() const;
+  const CompactString &get_ssid() const { return this->ssid_; }
   uint8_t get_channel() const;
   int8_t get_rssi() const;
   bool get_with_auth() const;
@@ -242,7 +247,7 @@ class WiFiScanResult {
   bssid_t bssid_;
   uint8_t channel_;
   int8_t rssi_;
-  std::string ssid_;
+  CompactString ssid_;
   int8_t priority_{0};
   bool matches_{false};
   bool with_auth_;
@@ -381,6 +386,10 @@ class WiFiComponent : public Component {
   void set_passive_scan(bool passive);
 
   void save_wifi_sta(const std::string &ssid, const std::string &password);
+  void save_wifi_sta(const char *ssid, const char *password);
+  void save_wifi_sta(const CompactString &ssid, const CompactString &password) {
+    this->save_wifi_sta(ssid.c_str(), password.c_str());
+  }
 
   // ========== INTERNAL METHODS ==========
   // (In most use cases you won't need these)
@@ -454,12 +463,8 @@ class WiFiComponent : public Component {
   void set_keep_scan_results(bool keep_scan_results) { this->keep_scan_results_ = keep_scan_results; }
   void set_post_connect_roaming(bool enabled) { this->post_connect_roaming_ = enabled; }
 
-#ifdef USE_WIFI_CONNECT_TRIGGER
-  Trigger<> *get_connect_trigger() { return &this->connect_trigger_; }
-#endif
-#ifdef USE_WIFI_DISCONNECT_TRIGGER
-  Trigger<> *get_disconnect_trigger() { return &this->disconnect_trigger_; }
-#endif
+  Trigger<> *get_connect_trigger() const { return this->connect_trigger_; };
+  Trigger<> *get_disconnect_trigger() const { return this->disconnect_trigger_; };
 
   int32_t get_wifi_channel();
 
@@ -545,7 +550,7 @@ class WiFiComponent : public Component {
   int8_t find_first_non_hidden_index_() const;
   /// Check if an SSID was seen in the most recent scan results
   /// Used to skip hidden mode for SSIDs we know are visible
-  bool ssid_was_seen_in_scan_(const std::string &ssid) const;
+  bool ssid_was_seen_in_scan_(const CompactString &ssid) const;
   /// Check if full scan results are needed (captive portal active, improv, listeners)
   bool needs_full_scan_results_() const;
   /// Check if network matches any configured network (for scan result filtering)
@@ -710,9 +715,7 @@ class WiFiComponent : public Component {
 
   // Group all boolean values together
   bool has_ap_{false};
-#if defined(USE_WIFI_CONNECT_TRIGGER) || defined(USE_WIFI_DISCONNECT_TRIGGER)
   bool handled_connected_state_{false};
-#endif
   bool error_from_callback_{false};
   bool scan_done_{false};
   bool ap_setup_{false};
@@ -739,12 +742,9 @@ class WiFiComponent : public Component {
   SemaphoreHandle_t high_performance_semaphore_{nullptr};
 #endif
 
-#ifdef USE_WIFI_CONNECT_TRIGGER
-  Trigger<> connect_trigger_;
-#endif
-#ifdef USE_WIFI_DISCONNECT_TRIGGER
-  Trigger<> disconnect_trigger_;
-#endif
+  // Pointers at the end (naturally aligned)
+  Trigger<> *connect_trigger_{new Trigger<>()};
+  Trigger<> *disconnect_trigger_{new Trigger<>()};
 
  private:
   // Stores a pointer to a string literal (static storage duration).

esphome/components/wifi/wifi_component_esp8266.cpp

@@ -784,8 +784,8 @@ void WiFiComponent::wifi_scan_done_callback_(void *arg, STATUS status) {
     const char *ssid_cstr = reinterpret_cast<const char *>(it->ssid);
     if (needs_full || this->matches_configured_network_(ssid_cstr, it->bssid)) {
       this->scan_result_.emplace_back(
-          bssid_t{it->bssid[0], it->bssid[1], it->bssid[2], it->bssid[3], it->bssid[4], it->bssid[5]},
-          std::string(ssid_cstr, it->ssid_len), it->channel, it->rssi, it->authmode != AUTH_OPEN, it->is_hidden != 0);
+          bssid_t{it->bssid[0], it->bssid[1], it->bssid[2], it->bssid[3], it->bssid[4], it->bssid[5]}, ssid_cstr,
+          it->ssid_len, it->channel, it->rssi, it->authmode != AUTH_OPEN, it->is_hidden != 0);
     } else {
       this->log_discarded_scan_result_(ssid_cstr, it->bssid, it->rssi, it->channel);
     }

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -870,8 +870,7 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
       if (needs_full || this->matches_configured_network_(ssid_cstr, record.bssid)) {
         bssid_t bssid;
         std::copy(record.bssid, record.bssid + 6, bssid.begin());
-        std::string ssid(ssid_cstr);
-        this->scan_result_.emplace_back(bssid, std::move(ssid), record.primary, record.rssi,
+        this->scan_result_.emplace_back(bssid, ssid_cstr, strlen(ssid_cstr), record.primary, record.rssi,
                                         record.authmode != WIFI_AUTH_OPEN, ssid_cstr[0] == '\0');
       } else {
         this->log_discarded_scan_result_(ssid_cstr, record.bssid, record.rssi, record.primary);

esphome/components/wifi/wifi_component_libretiny.cpp

@@ -694,7 +694,7 @@ void WiFiComponent::wifi_scan_done_callback_() {
       auto &ap = scan->ap[i];
       this->scan_result_.emplace_back(bssid_t{ap.bssid.addr[0], ap.bssid.addr[1], ap.bssid.addr[2], ap.bssid.addr[3],
                                               ap.bssid.addr[4], ap.bssid.addr[5]},
-                                      std::string(ssid_cstr), ap.channel, ap.rssi, ap.auth != WIFI_AUTH_OPEN,
+                                      ssid_cstr, strlen(ssid_cstr), ap.channel, ap.rssi, ap.auth != WIFI_AUTH_OPEN,
                                       ssid_cstr[0] == '\0');
     } else {
       auto &ap = scan->ap[i];

esphome/components/wifi/wifi_component_pico_w.cpp

@@ -149,9 +149,8 @@ void WiFiComponent::wifi_scan_result(void *env, const cyw43_ev_scan_result_t *re
 
   bssid_t bssid;
   std::copy(result->bssid, result->bssid + 6, bssid.begin());
-  std::string ssid(ssid_cstr);
-  WiFiScanResult res(bssid, std::move(ssid), result->channel, result->rssi, result->auth_mode != CYW43_AUTH_OPEN,
-                     ssid_cstr[0] == '\0');
+  WiFiScanResult res(bssid, ssid_cstr, strlen(ssid_cstr), result->channel, result->rssi,
+                     result->auth_mode != CYW43_AUTH_OPEN, ssid_cstr[0] == '\0');
   if (std::find(this->scan_result_.begin(), this->scan_result_.end(), res) == this->scan_result_.end()) {
     this->scan_result_.push_back(res);
   }

esphome/components/wifi_info/wifi_info_text_sensor.cpp

@@ -89,7 +89,7 @@ void ScanResultsWiFiInfo::on_wifi_scan_results(const wifi::wifi_scan_vector_t<wi
   for (const auto &scan : results) {
     if (scan.get_is_hidden())
       continue;
-    const std::string &ssid = scan.get_ssid();
+    const auto &ssid = scan.get_ssid();
     // Max space: ssid + ": " (2) + "-128" (4) + "dB\n" (3) = ssid + 9
     if (ptr + ssid.size() + 9 > end)
       break;

esphome/components/zephyr/preferences.cpp

@@ -152,11 +152,10 @@ class ZephyrPreferences : public ESPPreferences {
   }
 };
 
-static ZephyrPreferences s_preferences;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
-
 void setup_preferences() {
-  global_preferences = &s_preferences;
-  s_preferences.open();
+  auto *prefs = new ZephyrPreferences();  // NOLINT(cppcoreguidelines-owning-memory)
+  global_preferences = prefs;
+  prefs->open();
 }
 
 }  // namespace zephyr

esphome/core/defines.h

@@ -227,8 +227,6 @@
 #define USE_WIFI_SCAN_RESULTS_LISTENERS
 #define USE_WIFI_CONNECT_STATE_LISTENERS
 #define USE_WIFI_POWER_SAVE_LISTENERS
-#define USE_WIFI_CONNECT_TRIGGER
-#define USE_WIFI_DISCONNECT_TRIGGER
 #define ESPHOME_WIFI_IP_STATE_LISTENERS 2
 #define ESPHOME_WIFI_SCAN_RESULTS_LISTENERS 2
 #define ESPHOME_WIFI_CONNECT_STATE_LISTENERS 2

esphome/core/helpers.cpp

@@ -13,6 +13,7 @@
 #include <cstdarg>
 #include <cstdio>
 #include <cstring>
+#include <new>
 
 #ifdef USE_ESP32
 #include "rom/crc.h"
@@ -858,4 +859,60 @@ void IRAM_ATTR HOT delay_microseconds_safe(uint32_t us) {
     ;
 }
 
+// CompactString implementation
+CompactString::CompactString(const char *str, size_t len) {
+  if (len > MAX_LENGTH) {
+    len = MAX_LENGTH;  // Clamp to max valid length
+  }
+
+  this->length_ = len;
+  if (len <= INLINE_CAPACITY) {
+    // Store inline with null terminator
+    this->is_heap_ = 0;
+    if (len > 0) {
+      std::memcpy(this->storage_, str, len);
+    }
+    this->storage_[len] = '\0';
+  } else {
+    // Heap allocate with null terminator
+    this->is_heap_ = 1;
+    char *heap_data = new char[len + 1];  // NOLINT(cppcoreguidelines-owning-memory)
+    std::memcpy(heap_data, str, len);
+    heap_data[len] = '\0';
+    this->set_heap_ptr_(heap_data);
+  }
+}
+
+CompactString::CompactString(const CompactString &other) : CompactString(other.data(), other.size()) {}
+
+CompactString &CompactString::operator=(const CompactString &other) {
+  if (this != &other) {
+    this->~CompactString();
+    new (this) CompactString(other);
+  }
+  return *this;
+}
+
+CompactString::CompactString(CompactString &&other) noexcept : length_(other.length_), is_heap_(other.is_heap_) {
+  // Copy full storage (includes null terminator for inline, or pointer for heap)
+  std::memcpy(this->storage_, other.storage_, INLINE_CAPACITY + 1);
+  other.length_ = 0;
+  other.is_heap_ = 0;
+  other.storage_[0] = '\0';
+}
+
+CompactString &CompactString::operator=(CompactString &&other) noexcept {
+  if (this != &other) {
+    this->~CompactString();
+    new (this) CompactString(std::move(other));
+  }
+  return *this;
+}
+
+CompactString::~CompactString() {
+  if (this->is_heap_) {
+    delete[] this->get_heap_ptr_();  // NOLINT(cppcoreguidelines-owning-memory)
+  }
+}
+
 }  // namespace esphome

esphome/core/helpers.h

@@ -1784,4 +1784,58 @@ template<typename T, enable_if_t<std::is_pointer<T *>::value, int> = 0> T &id(T
 
 ///@}
 
+/// 20-byte string: 18 chars inline + null, heap for longer. Always null-terminated.
+class CompactString {
+ public:
+  static constexpr uint8_t MAX_LENGTH = 127;
+  static constexpr uint8_t INLINE_CAPACITY = 18;          // 18 chars + null terminator fits in 19 bytes
+  static constexpr uint8_t BUFFER_SIZE = MAX_LENGTH + 1;  // For external buffer (128 bytes)
+
+  CompactString() : length_(0), is_heap_(0) { this->storage_[0] = '\0'; }
+  CompactString(const char *str, size_t len);
+  CompactString(const CompactString &other);
+  CompactString(CompactString &&other) noexcept;
+  CompactString &operator=(const CompactString &other);
+  CompactString &operator=(CompactString &&other) noexcept;
+  ~CompactString();
+
+  const char *data() const { return this->is_heap_ ? this->get_heap_ptr_() : this->storage_; }
+  const char *c_str() const { return this->data(); }  // Always null-terminated
+  size_t size() const { return this->length_; }
+  bool empty() const { return this->length_ == 0; }
+
+  // Implicit conversion to std::string for backwards compatibility
+  operator std::string() const { return std::string(this->data(), this->size()); }
+
+  bool operator==(const CompactString &other) const {
+    return this->size() == other.size() && std::memcmp(this->data(), other.data(), this->size()) == 0;
+  }
+  bool operator==(const std::string &other) const {
+    return this->size() == other.size() && std::memcmp(this->data(), other.data(), this->size()) == 0;
+  }
+  bool operator==(const char *other) const {
+    return this->size() == std::strlen(other) && std::memcmp(this->data(), other, this->size()) == 0;
+  }
+  bool operator!=(const CompactString &other) const { return !(*this == other); }
+  bool operator!=(const std::string &other) const { return !(*this == other); }
+  bool operator!=(const char *other) const { return !(*this == other); }
+
+ protected:
+  char *get_heap_ptr_() const {
+    char *ptr;
+    std::memcpy(&ptr, this->storage_, sizeof(ptr));
+    return ptr;
+  }
+  void set_heap_ptr_(char *ptr) { std::memcpy(this->storage_, &ptr, sizeof(ptr)); }
+
+  // Storage for string data. When is_heap_=0, contains the string directly (null-terminated).
+  // When is_heap_=1, first sizeof(char*) bytes contain pointer to heap allocation.
+  char storage_[INLINE_CAPACITY + 1];  // 19 bytes: 18 chars + null terminator
+  uint8_t length_ : 7;                 // String length (0-127)
+  uint8_t is_heap_ : 1;                // 1 if using heap pointer, 0 if using inline storage
+  // Total size: 20 bytes (19 bytes storage + 1 byte bitfields)
+};
+
+static_assert(sizeof(CompactString) == 20, "CompactString must be exactly 20 bytes");
+
 }  // namespace esphome

tests/components/wifi/common.yaml

@@ -26,7 +26,3 @@ wifi:
     - ssid: MySSID3
       password: password3
       priority: 0
-  on_connect:
-    - logger.log: "WiFi connected!"
-  on_disconnect:
-    - logger.log: "WiFi disconnected!"