[esp32] Eliminate dead exception class code via linker wraps

Co-authored-by: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>

.clang-tidy.hash

@@ -1 +1 @@
-15dc295268b2dcf75942f42759b3ddec64eba89f75525698eb39c95a7f4b14ce
+a172e2f65981e98354cc6b5ecf69bdb055dd13602226042ab2c7acd037a2bf41

.github/workflows/codeql.yml

@@ -58,7 +58,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@19b2f06db2b6f5108140aeb04014ef02b648f789 # v4.31.11
+        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@19b2f06db2b6f5108140aeb04014ef02b648f789 # v4.31.11
+        uses: github/codeql-action/analyze@b20883b0cd1f46c72ae0ba6d1090936928f9fa30 # v4.32.0
         with:
           category: "/language:${{matrix.language}}"

esphome/components/bl0940/number/calibration_number.cpp

@@ -9,7 +9,7 @@ static const char *const TAG = "bl0940.number";
 void CalibrationNumber::setup() {
   float value = 0.0f;
   if (this->restore_value_) {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
     if (!this->pref_.load(&value)) {
       value = 0.0f;
     }

esphome/components/climate/climate.cpp

@@ -360,8 +360,7 @@ void Climate::add_on_control_callback(std::function<void(ClimateCall &)> &&callb
 static const uint32_t RESTORE_STATE_VERSION = 0x848EA6ADUL;
 
 optional<ClimateDeviceRestoreState> Climate::restore_state_() {
-  this->rtc_ = global_preferences->make_preference<ClimateDeviceRestoreState>(this->get_preference_hash() ^
-                                                                              RESTORE_STATE_VERSION);
+  this->rtc_ = this->make_entity_preference<ClimateDeviceRestoreState>(RESTORE_STATE_VERSION);
   ClimateDeviceRestoreState recovered{};
   if (!this->rtc_.load(&recovered))
     return {};

esphome/components/cover/cover.cpp

@@ -1,11 +1,11 @@
 #include "cover.h"
 #include "esphome/core/defines.h"
 #include "esphome/core/controller_registry.h"
+#include "esphome/core/log.h"
+#include "esphome/core/progmem.h"
 
 #include <strings.h>
 
-#include "esphome/core/log.h"
-
 namespace esphome::cover {
 
 static const char *const TAG = "cover";
@@ -39,13 +39,13 @@ Cover::Cover() : position{COVER_OPEN} {}
 
 CoverCall::CoverCall(Cover *parent) : parent_(parent) {}
 CoverCall &CoverCall::set_command(const char *command) {
-  if (strcasecmp(command, "OPEN") == 0) {
+  if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("OPEN")) == 0) {
     this->set_command_open();
-  } else if (strcasecmp(command, "CLOSE") == 0) {
+  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("CLOSE")) == 0) {
     this->set_command_close();
-  } else if (strcasecmp(command, "STOP") == 0) {
+  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("STOP")) == 0) {
     this->set_command_stop();
-  } else if (strcasecmp(command, "TOGGLE") == 0) {
+  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("TOGGLE")) == 0) {
     this->set_command_toggle();
   } else {
     ESP_LOGW(TAG, "'%s' - Unrecognized command %s", this->parent_->get_name().c_str(), command);
@@ -187,7 +187,7 @@ void Cover::publish_state(bool save) {
   }
 }
 optional<CoverRestoreState> Cover::restore_state_() {
-  this->rtc_ = global_preferences->make_preference<CoverRestoreState>(this->get_preference_hash());
+  this->rtc_ = this->make_entity_preference<CoverRestoreState>();
   CoverRestoreState recovered{};
   if (!this->rtc_.load(&recovered))
     return {};

esphome/components/duty_time/duty_time_sensor.cpp

@@ -41,7 +41,7 @@ void DutyTimeSensor::setup() {
   uint32_t seconds = 0;
 
   if (this->restore_) {
-    this->pref_ = global_preferences->make_preference<uint32_t>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<uint32_t>();
     this->pref_.load(&seconds);
   }
 

esphome/components/esp32/__init__.py

@@ -1048,6 +1048,19 @@ async def to_code(config):
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ESP_IDF")
         if use_platformio:
             cg.add_platformio_option("framework", "espidf")
+
+        # Wrap std::__throw_* functions to abort immediately, eliminating ~3KB of
+        # exception class overhead. See throw_stubs.cpp for implementation.
+        # ESP-IDF already compiles with -fno-exceptions, so this code was dead anyway.
+        for mangled in [
+            "_ZSt20__throw_length_errorPKc",
+            "_ZSt19__throw_logic_errorPKc",
+            "_ZSt20__throw_out_of_rangePKc",
+            "_ZSt24__throw_out_of_range_fmtPKcz",
+            "_ZSt17__throw_bad_allocv",
+            "_ZSt25__throw_bad_function_callv",
+        ]:
+            cg.add_build_flag(f"-Wl,--wrap={mangled}")
     else:
         cg.add_build_flag("-DUSE_ARDUINO")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ARDUINO")

esphome/components/esp32/throw_stubs.cpp

@@ -0,0 +1,57 @@
+/*
+ * Linker wrap stubs for std::__throw_* functions.
+ *
+ * ESP-IDF compiles with -fno-exceptions, so C++ exceptions always abort.
+ * However, ESP-IDF only wraps low-level functions (__cxa_throw, etc.),
+ * not the std::__throw_* functions that construct exception objects first.
+ * This pulls in ~3KB of dead exception class code that can never run.
+ *
+ * ESP8266 Arduino already solved this: their toolchain rebuilds libstdc++
+ * with throw functions that just call abort(). We achieve the same result
+ * using linker --wrap without requiring toolchain changes.
+ *
+ * These stubs abort immediately with a descriptive message, allowing
+ * the linker to dead-code eliminate the exception class infrastructure.
+ *
+ * Wrapped functions and their callers:
+ * - std::__throw_length_error: std::string::reserve, std::vector::reserve
+ * - std::__throw_logic_error: std::promise, std::packaged_task
+ * - std::__throw_out_of_range: std::string::at, std::vector::at
+ * - std::__throw_out_of_range_fmt: std::bitset::to_ulong
+ * - std::__throw_bad_alloc: operator new
+ * - std::__throw_bad_function_call: std::function::operator()
+ */
+
+#ifdef USE_ESP_IDF
+#include "esp_system.h"
+
+namespace esphome::esp32 {}
+
+// Linker wraps for std::__throw_* - must be extern "C" at global scope.
+// Names must be __wrap_ + mangled name for the linker's --wrap option.
+
+// NOLINTBEGIN(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp,readability-identifier-naming)
+extern "C" {
+
+// std::__throw_length_error(char const*) - called when container size exceeds max_size()
+void __wrap__ZSt20__throw_length_errorPKc(const char *) { esp_system_abort("std::length_error"); }
+
+// std::__throw_logic_error(char const*) - called for logic errors (e.g., promise already satisfied)
+void __wrap__ZSt19__throw_logic_errorPKc(const char *) { esp_system_abort("std::logic_error"); }
+
+// std::__throw_out_of_range(char const*) - called by at() when index is out of bounds
+void __wrap__ZSt20__throw_out_of_rangePKc(const char *) { esp_system_abort("std::out_of_range"); }
+
+// std::__throw_out_of_range_fmt(char const*, ...) - called by bitset::to_ulong when value doesn't fit
+void __wrap__ZSt24__throw_out_of_range_fmtPKcz(const char *, ...) { esp_system_abort("std::out_of_range"); }
+
+// std::__throw_bad_alloc() - called when operator new fails
+void __wrap__ZSt17__throw_bad_allocv() { esp_system_abort("std::bad_alloc"); }
+
+// std::__throw_bad_function_call() - called when invoking empty std::function
+void __wrap__ZSt25__throw_bad_function_callv() { esp_system_abort("std::bad_function_call"); }
+
+}  // extern "C"
+// NOLINTEND(bugprone-reserved-identifier,cert-dcl37-c,cert-dcl51-cpp,readability-identifier-naming)
+
+#endif  // USE_ESP_IDF

esphome/components/factory_reset/factory_reset.cpp

@@ -3,6 +3,7 @@
 #include "esphome/core/application.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/log.h"
+#include "esphome/core/progmem.h"
 
 #include <cinttypes>
 
@@ -19,7 +20,8 @@ static bool was_power_cycled() {
 #endif
 #ifdef USE_ESP8266
   auto reset_reason = EspClass::getResetReason();
-  return strcasecmp(reset_reason.c_str(), "power On") == 0 || strcasecmp(reset_reason.c_str(), "external system") == 0;
+  return ESPHOME_strcasecmp_P(reset_reason.c_str(), ESPHOME_PSTR("power On")) == 0 ||
+         ESPHOME_strcasecmp_P(reset_reason.c_str(), ESPHOME_PSTR("external system")) == 0;
 #endif
 #ifdef USE_LIBRETINY
   auto reason = lt_get_reboot_reason();

esphome/components/fan/fan.cpp

@@ -227,8 +227,7 @@ void Fan::publish_state() {
 constexpr uint32_t RESTORE_STATE_VERSION = 0x71700ABA;
 optional<FanRestoreState> Fan::restore_state_() {
   FanRestoreState recovered{};
-  this->rtc_ =
-      global_preferences->make_preference<FanRestoreState>(this->get_preference_hash() ^ RESTORE_STATE_VERSION);
+  this->rtc_ = this->make_entity_preference<FanRestoreState>(RESTORE_STATE_VERSION);
   bool restored = this->rtc_.load(&recovered);
 
   switch (this->restore_mode_) {

esphome/components/haier/haier_base.cpp

@@ -350,8 +350,7 @@ ClimateTraits HaierClimateBase::traits() { return traits_; }
 
 void HaierClimateBase::initialization() {
   constexpr uint32_t restore_settings_version = 0xA77D21EF;
-  this->base_rtc_ =
-      global_preferences->make_preference<HaierBaseSettings>(this->get_preference_hash() ^ restore_settings_version);
+  this->base_rtc_ = this->make_entity_preference<HaierBaseSettings>(restore_settings_version);
   HaierBaseSettings recovered;
   if (!this->base_rtc_.load(&recovered)) {
     recovered = {false, true};

esphome/components/haier/hon_climate.cpp

@@ -515,8 +515,7 @@ haier_protocol::HaierMessage HonClimate::get_power_message(bool state) {
 void HonClimate::initialization() {
   HaierClimateBase::initialization();
   constexpr uint32_t restore_settings_version = 0x57EB59DDUL;
-  this->hon_rtc_ =
-      global_preferences->make_preference<HonSettings>(this->get_preference_hash() ^ restore_settings_version);
+  this->hon_rtc_ = this->make_entity_preference<HonSettings>(restore_settings_version);
   HonSettings recovered;
   if (this->hon_rtc_.load(&recovered)) {
     this->settings_ = recovered;

esphome/components/http_request/__init__.py

@@ -126,7 +126,7 @@ CONFIG_SCHEMA = cv.All(
             ),
             cv.Optional(CONF_CA_CERTIFICATE_PATH): cv.All(
                 cv.file_,
-                cv.only_on(PLATFORM_HOST),
+                cv.Any(cv.only_on(PLATFORM_HOST), cv.only_on_esp32),
             ),
         }
     ).extend(cv.COMPONENT_SCHEMA),
@@ -160,7 +160,14 @@ async def to_code(config):
         cg.add(var.set_verify_ssl(config[CONF_VERIFY_SSL]))
 
         if config.get(CONF_VERIFY_SSL):
-            esp32.add_idf_sdkconfig_option("CONFIG_MBEDTLS_CERTIFICATE_BUNDLE", True)
+            if ca_cert_path := config.get(CONF_CA_CERTIFICATE_PATH):
+                with open(ca_cert_path, encoding="utf-8") as f:
+                    ca_cert_content = f.read()
+                cg.add(var.set_ca_certificate(ca_cert_content))
+            else:
+                esp32.add_idf_sdkconfig_option(
+                    "CONFIG_MBEDTLS_CERTIFICATE_BUNDLE", True
+                )
 
         esp32.add_idf_sdkconfig_option(
             "CONFIG_ESP_TLS_INSECURE",

esphome/components/http_request/http_request_idf.cpp

@@ -27,8 +27,9 @@ void HttpRequestIDF::dump_config() {
   HttpRequestComponent::dump_config();
   ESP_LOGCONFIG(TAG,
                 "  Buffer Size RX: %u\n"
-                "  Buffer Size TX: %u",
-                this->buffer_size_rx_, this->buffer_size_tx_);
+                "  Buffer Size TX: %u\n"
+                "  Custom CA Certificate: %s",
+                this->buffer_size_rx_, this->buffer_size_tx_, YESNO(this->ca_certificate_ != nullptr));
 }
 
 esp_err_t HttpRequestIDF::http_event_handler(esp_http_client_event_t *evt) {
@@ -88,11 +89,15 @@ std::shared_ptr<HttpContainer> HttpRequestIDF::perform(const std::string &url, c
   config.disable_auto_redirect = !this->follow_redirects_;
   config.max_redirection_count = this->redirect_limit_;
   config.auth_type = HTTP_AUTH_TYPE_BASIC;
-#if CONFIG_MBEDTLS_CERTIFICATE_BUNDLE
   if (secure && this->verify_ssl_) {
-    config.crt_bundle_attach = esp_crt_bundle_attach;
-  }
+    if (this->ca_certificate_ != nullptr) {
+      config.cert_pem = this->ca_certificate_;
+#if CONFIG_MBEDTLS_CERTIFICATE_BUNDLE
+    } else {
+      config.crt_bundle_attach = esp_crt_bundle_attach;
 #endif
+    }
+  }
 
   if (this->useragent_ != nullptr) {
     config.user_agent = this->useragent_;

esphome/components/http_request/http_request_idf.h

@@ -35,6 +35,7 @@ class HttpRequestIDF : public HttpRequestComponent {
   void set_buffer_size_rx(uint16_t buffer_size_rx) { this->buffer_size_rx_ = buffer_size_rx; }
   void set_buffer_size_tx(uint16_t buffer_size_tx) { this->buffer_size_tx_ = buffer_size_tx; }
   void set_verify_ssl(bool verify_ssl) { this->verify_ssl_ = verify_ssl; }
+  void set_ca_certificate(const char *ca_certificate) { this->ca_certificate_ = ca_certificate; }
 
  protected:
   std::shared_ptr<HttpContainer> perform(const std::string &url, const std::string &method, const std::string &body,
@@ -44,6 +45,7 @@ class HttpRequestIDF : public HttpRequestComponent {
   uint16_t buffer_size_rx_{};
   uint16_t buffer_size_tx_{};
   bool verify_ssl_{true};
+  const char *ca_certificate_{nullptr};
 
   /// @brief Monitors the http client events to gather response headers
   static esp_err_t http_event_handler(esp_http_client_event_t *evt);

esphome/components/http_request/ota/ota_http_request.cpp

@@ -82,7 +82,7 @@ uint8_t OtaHttpRequestComponent::do_ota_() {
   uint32_t last_progress = 0;
   uint32_t update_start_time = millis();
   md5::MD5Digest md5_receive;
-  std::unique_ptr<char[]> md5_receive_str(new char[33]);
+  char md5_receive_str[33];
 
   if (this->md5_expected_.empty() && !this->http_get_md5_()) {
     return OTA_MD5_INVALID;
@@ -176,14 +176,14 @@ uint8_t OtaHttpRequestComponent::do_ota_() {
 
   // verify MD5 is as expected and act accordingly
   md5_receive.calculate();
-  md5_receive.get_hex(md5_receive_str.get());
-  this->md5_computed_ = md5_receive_str.get();
+  md5_receive.get_hex(md5_receive_str);
+  this->md5_computed_ = md5_receive_str;
   if (strncmp(this->md5_computed_.c_str(), this->md5_expected_.c_str(), MD5_SIZE) != 0) {
     ESP_LOGE(TAG, "MD5 computed: %s - Aborting due to MD5 mismatch", this->md5_computed_.c_str());
     this->cleanup_(std::move(backend), container);
     return ota::OTA_RESPONSE_ERROR_MD5_MISMATCH;
   } else {
-    backend->set_update_md5(md5_receive_str.get());
+    backend->set_update_md5(md5_receive_str);
   }
 
   container->end();

esphome/components/integration/integration_sensor.cpp

@@ -10,7 +10,7 @@ static const char *const TAG = "integration";
 
 void IntegrationSensor::setup() {
   if (this->restore_) {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
     float preference_value = 0;
     this->pref_.load(&preference_value);
     this->result_ = preference_value;

esphome/components/ld2450/ld2450.cpp

@@ -184,7 +184,7 @@ static inline bool validate_header_footer(const uint8_t *header_footer, const ui
 void LD2450Component::setup() {
 #ifdef USE_NUMBER
   if (this->presence_timeout_number_ != nullptr) {
-    this->pref_ = global_preferences->make_preference<float>(this->presence_timeout_number_->get_preference_hash());
+    this->pref_ = this->presence_timeout_number_->make_entity_preference<float>();
     this->set_presence_timeout();
   }
 #endif

esphome/components/libretiny/__init__.py

@@ -191,10 +191,17 @@ def _notify_old_style(config):
 
 
 # The dev and latest branches will be at *least* this version, which is what matters.
+# Use GitHub releases directly to avoid PlatformIO moderation delays.
 ARDUINO_VERSIONS = {
-    "dev": (cv.Version(1, 9, 2), "https://github.com/libretiny-eu/libretiny.git"),
-    "latest": (cv.Version(1, 9, 2), "libretiny"),
-    "recommended": (cv.Version(1, 9, 2), None),
+    "dev": (cv.Version(1, 11, 0), "https://github.com/libretiny-eu/libretiny.git"),
+    "latest": (
+        cv.Version(1, 11, 0),
+        "https://github.com/libretiny-eu/libretiny.git#v1.11.0",
+    ),
+    "recommended": (
+        cv.Version(1, 11, 0),
+        "https://github.com/libretiny-eu/libretiny.git#v1.11.0",
+    ),
 }
 
 

esphome/components/light/addressable_light_wrapper.h

@@ -7,9 +7,7 @@ namespace esphome::light {
 
 class AddressableLightWrapper : public light::AddressableLight {
  public:
-  explicit AddressableLightWrapper(light::LightState *light_state) : light_state_(light_state) {
-    this->wrapper_state_ = new uint8_t[5];  // NOLINT(cppcoreguidelines-owning-memory)
-  }
+  explicit AddressableLightWrapper(light::LightState *light_state) : light_state_(light_state) {}
 
   int32_t size() const override { return 1; }
 
@@ -118,7 +116,7 @@ class AddressableLightWrapper : public light::AddressableLight {
   }
 
   light::LightState *light_state_;
-  uint8_t *wrapper_state_;
+  mutable uint8_t wrapper_state_[5]{};
   ColorMode color_mode_{ColorMode::UNKNOWN};
 };
 

esphome/components/light/light_state.cpp

@@ -44,7 +44,7 @@ void LightState::setup() {
     case LIGHT_RESTORE_DEFAULT_ON:
     case LIGHT_RESTORE_INVERTED_DEFAULT_OFF:
     case LIGHT_RESTORE_INVERTED_DEFAULT_ON:
-      this->rtc_ = global_preferences->make_preference<LightStateRTCState>(this->get_preference_hash());
+      this->rtc_ = this->make_entity_preference<LightStateRTCState>();
       // Attempt to load from preferences, else fall back to default values
       if (!this->rtc_.load(&recovered)) {
         recovered.state = (this->restore_mode_ == LIGHT_RESTORE_DEFAULT_ON ||
@@ -57,7 +57,7 @@ void LightState::setup() {
       break;
     case LIGHT_RESTORE_AND_OFF:
     case LIGHT_RESTORE_AND_ON:
-      this->rtc_ = global_preferences->make_preference<LightStateRTCState>(this->get_preference_hash());
+      this->rtc_ = this->make_entity_preference<LightStateRTCState>();
       this->rtc_.load(&recovered);
       recovered.state = (this->restore_mode_ == LIGHT_RESTORE_AND_ON);
       break;

esphome/components/lvgl/number/lvgl_number.h

@@ -21,7 +21,7 @@ class LVGLNumber : public number::Number, public Component {
   void setup() override {
     float value = this->value_lambda_();
     if (this->restore_) {
-      this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+      this->pref_ = this->make_entity_preference<float>();
       if (this->pref_.load(&value)) {
         this->control_lambda_(value);
       }

esphome/components/lvgl/select/lvgl_select.h

@@ -20,7 +20,7 @@ class LVGLSelect : public select::Select, public Component {
     this->set_options_();
     if (this->restore_) {
       size_t index;
-      this->pref_ = global_preferences->make_preference<size_t>(this->get_preference_hash());
+      this->pref_ = this->make_entity_preference<size_t>();
       if (this->pref_.load(&index))
         this->widget_->set_selected_index(index, LV_ANIM_OFF);
     }

esphome/components/mhz19/mhz19.cpp

@@ -3,8 +3,7 @@
 
 #include <cinttypes>
 
-namespace esphome {
-namespace mhz19 {
+namespace esphome::mhz19 {
 
 static const char *const TAG = "mhz19";
 static const uint8_t MHZ19_REQUEST_LENGTH = 8;
@@ -17,6 +16,19 @@ static const uint8_t MHZ19_COMMAND_DETECTION_RANGE_0_2000PPM[] = {0xFF, 0x01, 0x
 static const uint8_t MHZ19_COMMAND_DETECTION_RANGE_0_5000PPM[] = {0xFF, 0x01, 0x99, 0x00, 0x00, 0x00, 0x13, 0x88};
 static const uint8_t MHZ19_COMMAND_DETECTION_RANGE_0_10000PPM[] = {0xFF, 0x01, 0x99, 0x00, 0x00, 0x00, 0x27, 0x10};
 
+static const LogString *detection_range_to_log_string(MHZ19DetectionRange range) {
+  switch (range) {
+    case MHZ19_DETECTION_RANGE_0_2000PPM:
+      return LOG_STR("0-2000 ppm");
+    case MHZ19_DETECTION_RANGE_0_5000PPM:
+      return LOG_STR("0-5000 ppm");
+    case MHZ19_DETECTION_RANGE_0_10000PPM:
+      return LOG_STR("0-10000 ppm");
+    default:
+      return LOG_STR("default");
+  }
+}
+
 uint8_t mhz19_checksum(const uint8_t *command) {
   uint8_t sum = 0;
   for (uint8_t i = 1; i < MHZ19_REQUEST_LENGTH; i++) {
@@ -91,24 +103,24 @@ void MHZ19Component::abc_disable() {
   this->mhz19_write_command_(MHZ19_COMMAND_ABC_DISABLE, nullptr);
 }
 
-void MHZ19Component::range_set(MHZ19DetectionRange detection_ppm) {
-  switch (detection_ppm) {
-    case MHZ19_DETECTION_RANGE_DEFAULT:
-      ESP_LOGV(TAG, "Using previously set detection range (no change)");
-      break;
+void MHZ19Component::range_set(MHZ19DetectionRange detection_range) {
+  const uint8_t *command;
+  switch (detection_range) {
     case MHZ19_DETECTION_RANGE_0_2000PPM:
-      ESP_LOGD(TAG, "Setting detection range to 0 to 2000ppm");
-      this->mhz19_write_command_(MHZ19_COMMAND_DETECTION_RANGE_0_2000PPM, nullptr);
+      command = MHZ19_COMMAND_DETECTION_RANGE_0_2000PPM;
       break;
     case MHZ19_DETECTION_RANGE_0_5000PPM:
-      ESP_LOGD(TAG, "Setting detection range to 0 to 5000ppm");
-      this->mhz19_write_command_(MHZ19_COMMAND_DETECTION_RANGE_0_5000PPM, nullptr);
+      command = MHZ19_COMMAND_DETECTION_RANGE_0_5000PPM;
       break;
     case MHZ19_DETECTION_RANGE_0_10000PPM:
-      ESP_LOGD(TAG, "Setting detection range to 0 to 10000ppm");
-      this->mhz19_write_command_(MHZ19_COMMAND_DETECTION_RANGE_0_10000PPM, nullptr);
+      command = MHZ19_COMMAND_DETECTION_RANGE_0_10000PPM;
       break;
+    default:
+      ESP_LOGV(TAG, "Using previously set detection range (no change)");
+      return;
   }
+  ESP_LOGD(TAG, "Setting detection range to %s", LOG_STR_ARG(detection_range_to_log_string(detection_range)));
+  this->mhz19_write_command_(command, nullptr);
 }
 
 bool MHZ19Component::mhz19_write_command_(const uint8_t *command, uint8_t *response) {
@@ -140,27 +152,7 @@ void MHZ19Component::dump_config() {
   }
 
   ESP_LOGCONFIG(TAG, "  Warmup time: %" PRIu32 " s", this->warmup_seconds_);
-
-  const char *range_str;
-  switch (this->detection_range_) {
-    case MHZ19_DETECTION_RANGE_DEFAULT:
-      range_str = "default";
-      break;
-    case MHZ19_DETECTION_RANGE_0_2000PPM:
-      range_str = "0 to 2000ppm";
-      break;
-    case MHZ19_DETECTION_RANGE_0_5000PPM:
-      range_str = "0 to 5000ppm";
-      break;
-    case MHZ19_DETECTION_RANGE_0_10000PPM:
-      range_str = "0 to 10000ppm";
-      break;
-    default:
-      range_str = "default";
-      break;
-  }
-  ESP_LOGCONFIG(TAG, "  Detection range: %s", range_str);
+  ESP_LOGCONFIG(TAG, "  Detection range: %s", LOG_STR_ARG(detection_range_to_log_string(this->detection_range_)));
 }
 
-}  // namespace mhz19
-}  // namespace esphome
+}  // namespace esphome::mhz19

esphome/components/mhz19/mhz19.h

@@ -5,8 +5,7 @@
 #include "esphome/components/sensor/sensor.h"
 #include "esphome/components/uart/uart.h"
 
-namespace esphome {
-namespace mhz19 {
+namespace esphome::mhz19 {
 
 enum MHZ19ABCLogic {
   MHZ19_ABC_NONE = 0,
@@ -32,7 +31,7 @@ class MHZ19Component : public PollingComponent, public uart::UARTDevice {
   void calibrate_zero();
   void abc_enable();
   void abc_disable();
-  void range_set(MHZ19DetectionRange detection_ppm);
+  void range_set(MHZ19DetectionRange detection_range);
 
   void set_temperature_sensor(sensor::Sensor *temperature_sensor) { temperature_sensor_ = temperature_sensor; }
   void set_co2_sensor(sensor::Sensor *co2_sensor) { co2_sensor_ = co2_sensor; }
@@ -74,5 +73,4 @@ template<typename... Ts> class MHZ19DetectionRangeSetAction : public Action<Ts..
   void play(const Ts &...x) override { this->parent_->range_set(this->detection_range_.value(x...)); }
 };
 
-}  // namespace mhz19
-}  // namespace esphome
+}  // namespace esphome::mhz19

esphome/components/mqtt/mqtt_alarm_control_panel.cpp

@@ -1,5 +1,6 @@
 #include "mqtt_alarm_control_panel.h"
 #include "esphome/core/log.h"
+#include "esphome/core/progmem.h"
 
 #include "mqtt_const.h"
 
@@ -18,21 +19,21 @@ void MQTTAlarmControlPanelComponent::setup() {
   this->alarm_control_panel_->add_on_state_callback([this]() { this->publish_state(); });
   this->subscribe(this->get_command_topic_(), [this](const std::string &topic, const std::string &payload) {
     auto call = this->alarm_control_panel_->make_call();
-    if (strcasecmp(payload.c_str(), "ARM_AWAY") == 0) {
+    if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("ARM_AWAY")) == 0) {
       call.arm_away();
-    } else if (strcasecmp(payload.c_str(), "ARM_HOME") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("ARM_HOME")) == 0) {
       call.arm_home();
-    } else if (strcasecmp(payload.c_str(), "ARM_NIGHT") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("ARM_NIGHT")) == 0) {
       call.arm_night();
-    } else if (strcasecmp(payload.c_str(), "ARM_VACATION") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("ARM_VACATION")) == 0) {
       call.arm_vacation();
-    } else if (strcasecmp(payload.c_str(), "ARM_CUSTOM_BYPASS") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("ARM_CUSTOM_BYPASS")) == 0) {
       call.arm_custom_bypass();
-    } else if (strcasecmp(payload.c_str(), "DISARM") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("DISARM")) == 0) {
       call.disarm();
-    } else if (strcasecmp(payload.c_str(), "PENDING") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("PENDING")) == 0) {
       call.pending();
-    } else if (strcasecmp(payload.c_str(), "TRIGGERED") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("TRIGGERED")) == 0) {
       call.triggered();
     } else {
       ESP_LOGW(TAG, "'%s': Received unknown command payload %s", this->friendly_name_().c_str(), payload.c_str());
@@ -119,7 +120,8 @@ bool MQTTAlarmControlPanelComponent::publish_state() {
     default:
       state_s = "unknown";
   }
-  return this->publish(this->get_state_topic_(), state_s);
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish(this->get_state_topic_to_(topic_buf), state_s);
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_binary_sensor.cpp

@@ -52,8 +52,9 @@ bool MQTTBinarySensorComponent::publish_state(bool state) {
   if (this->binary_sensor_->is_status_binary_sensor())
     return true;
 
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
   const char *state_s = state ? "ON" : "OFF";
-  return this->publish(this->get_state_topic_(), state_s);
+  return this->publish(this->get_state_topic_to_(topic_buf), state_s);
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_component.cpp

@@ -132,17 +132,29 @@ std::string MQTTComponent::get_command_topic_() const {
 }
 
 bool MQTTComponent::publish(const std::string &topic, const std::string &payload) {
-  return this->publish(topic, payload.data(), payload.size());
+  return this->publish(topic.c_str(), payload.data(), payload.size());
 }
 
 bool MQTTComponent::publish(const std::string &topic, const char *payload, size_t payload_length) {
-  if (topic.empty())
+  return this->publish(topic.c_str(), payload, payload_length);
+}
+
+bool MQTTComponent::publish(const char *topic, const char *payload, size_t payload_length) {
+  if (topic[0] == '\0')
     return false;
   return global_mqtt_client->publish(topic, payload, payload_length, this->qos_, this->retain_);
 }
 
+bool MQTTComponent::publish(const char *topic, const char *payload) {
+  return this->publish(topic, payload, strlen(payload));
+}
+
 bool MQTTComponent::publish_json(const std::string &topic, const json::json_build_t &f) {
-  if (topic.empty())
+  return this->publish_json(topic.c_str(), f);
+}
+
+bool MQTTComponent::publish_json(const char *topic, const json::json_build_t &f) {
+  if (topic[0] == '\0')
     return false;
   return global_mqtt_client->publish_json(topic, f, this->qos_, this->retain_);
 }

esphome/components/mqtt/mqtt_component.h

@@ -157,6 +157,38 @@ class MQTTComponent : public Component {
    */
   bool publish(const std::string &topic, const char *payload, size_t payload_length);
 
+  /** Send a MQTT message (no heap allocation for topic).
+   *
+   * @param topic The topic as C string.
+   * @param payload The payload buffer.
+   * @param payload_length The length of the payload.
+   */
+  bool publish(const char *topic, const char *payload, size_t payload_length);
+
+  /** Send a MQTT message (no heap allocation for topic).
+   *
+   * @param topic The topic as StringRef (for use with get_state_topic_to_()).
+   * @param payload The payload buffer.
+   * @param payload_length The length of the payload.
+   */
+  bool publish(StringRef topic, const char *payload, size_t payload_length) {
+    return this->publish(topic.c_str(), payload, payload_length);
+  }
+
+  /** Send a MQTT message (no heap allocation for topic).
+   *
+   * @param topic The topic as C string.
+   * @param payload The null-terminated payload.
+   */
+  bool publish(const char *topic, const char *payload);
+
+  /** Send a MQTT message (no heap allocation for topic).
+   *
+   * @param topic The topic as StringRef (for use with get_state_topic_to_()).
+   * @param payload The null-terminated payload.
+   */
+  bool publish(StringRef topic, const char *payload) { return this->publish(topic.c_str(), payload); }
+
   /** Construct and send a JSON MQTT message.
    *
    * @param topic The topic.
@@ -164,6 +196,20 @@ class MQTTComponent : public Component {
    */
   bool publish_json(const std::string &topic, const json::json_build_t &f);
 
+  /** Construct and send a JSON MQTT message (no heap allocation for topic).
+   *
+   * @param topic The topic as C string.
+   * @param f The Json Message builder.
+   */
+  bool publish_json(const char *topic, const json::json_build_t &f);
+
+  /** Construct and send a JSON MQTT message (no heap allocation for topic).
+   *
+   * @param topic The topic as StringRef (for use with get_state_topic_to_()).
+   * @param f The Json Message builder.
+   */
+  bool publish_json(StringRef topic, const json::json_build_t &f) { return this->publish_json(topic.c_str(), f); }
+
   /** Subscribe to a MQTT topic.
    *
    * @param topic The topic. Wildcards are currently not supported.

esphome/components/mqtt/mqtt_cover.cpp

@@ -115,7 +115,8 @@ bool MQTTCoverComponent::publish_state() {
                         : this->cover_->position == COVER_OPEN                       ? "open"
                         : traits.get_supports_position()                             ? "open"
                                                                                      : "unknown";
-  if (!this->publish(this->get_state_topic_(), state_s))
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  if (!this->publish(this->get_state_topic_to_(topic_buf), state_s))
     success = false;
   return success;
 }

esphome/components/mqtt/mqtt_date.cpp

@@ -53,7 +53,8 @@ bool MQTTDateComponent::send_initial_state() {
   }
 }
 bool MQTTDateComponent::publish_state(uint16_t year, uint8_t month, uint8_t day) {
-  return this->publish_json(this->get_state_topic_(), [year, month, day](JsonObject root) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish_json(this->get_state_topic_to_(topic_buf), [year, month, day](JsonObject root) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[ESPHOME_F("year")] = year;
     root[ESPHOME_F("month")] = month;

esphome/components/mqtt/mqtt_datetime.cpp

@@ -66,15 +66,17 @@ bool MQTTDateTimeComponent::send_initial_state() {
 }
 bool MQTTDateTimeComponent::publish_state(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute,
                                           uint8_t second) {
-  return this->publish_json(this->get_state_topic_(), [year, month, day, hour, minute, second](JsonObject root) {
-    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
-    root[ESPHOME_F("year")] = year;
-    root[ESPHOME_F("month")] = month;
-    root[ESPHOME_F("day")] = day;
-    root[ESPHOME_F("hour")] = hour;
-    root[ESPHOME_F("minute")] = minute;
-    root[ESPHOME_F("second")] = second;
-  });
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish_json(this->get_state_topic_to_(topic_buf),
+                            [year, month, day, hour, minute, second](JsonObject root) {
+                              // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
+                              root[ESPHOME_F("year")] = year;
+                              root[ESPHOME_F("month")] = month;
+                              root[ESPHOME_F("day")] = day;
+                              root[ESPHOME_F("hour")] = hour;
+                              root[ESPHOME_F("minute")] = minute;
+                              root[ESPHOME_F("second")] = second;
+                            });
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_event.cpp

@@ -44,7 +44,8 @@ void MQTTEventComponent::dump_config() {
 }
 
 bool MQTTEventComponent::publish_event_(const std::string &event_type) {
-  return this->publish_json(this->get_state_topic_(), [event_type](JsonObject root) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish_json(this->get_state_topic_to_(topic_buf), [event_type](JsonObject root) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_EVENT_TYPE] = event_type;
   });

esphome/components/mqtt/mqtt_fan.cpp

@@ -158,9 +158,10 @@ void MQTTFanComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig
   }
 }
 bool MQTTFanComponent::publish_state() {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
   const char *state_s = this->state_->state ? "ON" : "OFF";
   ESP_LOGD(TAG, "'%s' Sending state %s.", this->state_->get_name().c_str(), state_s);
-  this->publish(this->get_state_topic_(), state_s);
+  this->publish(this->get_state_topic_to_(topic_buf), state_s);
   bool failed = false;
   if (this->state_->get_traits().supports_direction()) {
     bool success = this->publish(this->get_direction_state_topic(),

esphome/components/mqtt/mqtt_light.cpp

@@ -34,7 +34,8 @@ void MQTTJSONLightComponent::on_light_remote_values_update() {
 MQTTJSONLightComponent::MQTTJSONLightComponent(LightState *state) : state_(state) {}
 
 bool MQTTJSONLightComponent::publish_state_() {
-  return this->publish_json(this->get_state_topic_(), [this](JsonObject root) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish_json(this->get_state_topic_to_(topic_buf), [this](JsonObject root) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     LightJSONSchema::dump_json(*this->state_, root);
   });

esphome/components/mqtt/mqtt_lock.cpp

@@ -1,5 +1,6 @@
 #include "mqtt_lock.h"
 #include "esphome/core/log.h"
+#include "esphome/core/progmem.h"
 
 #include "mqtt_const.h"
 
@@ -16,11 +17,11 @@ MQTTLockComponent::MQTTLockComponent(lock::Lock *a_lock) : lock_(a_lock) {}
 
 void MQTTLockComponent::setup() {
   this->subscribe(this->get_command_topic_(), [this](const std::string &topic, const std::string &payload) {
-    if (strcasecmp(payload.c_str(), "LOCK") == 0) {
+    if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("LOCK")) == 0) {
       this->lock_->lock();
-    } else if (strcasecmp(payload.c_str(), "UNLOCK") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("UNLOCK")) == 0) {
       this->lock_->unlock();
-    } else if (strcasecmp(payload.c_str(), "OPEN") == 0) {
+    } else if (ESPHOME_strcasecmp_P(payload.c_str(), ESPHOME_PSTR("OPEN")) == 0) {
       this->lock_->open();
     } else {
       ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name_().c_str(), payload.c_str());
@@ -47,13 +48,14 @@ void MQTTLockComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfi
 bool MQTTLockComponent::send_initial_state() { return this->publish_state(); }
 
 bool MQTTLockComponent::publish_state() {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
 #ifdef USE_STORE_LOG_STR_IN_FLASH
   char buf[LOCK_STATE_STR_SIZE];
   strncpy_P(buf, (PGM_P) lock_state_to_string(this->lock_->state), sizeof(buf) - 1);
   buf[sizeof(buf) - 1] = '\0';
-  return this->publish(this->get_state_topic_(), buf);
+  return this->publish(this->get_state_topic_to_(topic_buf), buf);
 #else
-  return this->publish(this->get_state_topic_(), LOG_STR_ARG(lock_state_to_string(this->lock_->state)));
+  return this->publish(this->get_state_topic_to_(topic_buf), LOG_STR_ARG(lock_state_to_string(this->lock_->state)));
 #endif
 }
 

esphome/components/mqtt/mqtt_number.cpp

@@ -74,9 +74,10 @@ bool MQTTNumberComponent::send_initial_state() {
   }
 }
 bool MQTTNumberComponent::publish_state(float value) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
   char buffer[64];
-  buf_append_printf(buffer, sizeof(buffer), 0, "%f", value);
-  return this->publish(this->get_state_topic_(), buffer);
+  size_t len = buf_append_printf(buffer, sizeof(buffer), 0, "%f", value);
+  return this->publish(this->get_state_topic_to_(topic_buf), buffer, len);
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_select.cpp

@@ -50,7 +50,8 @@ bool MQTTSelectComponent::send_initial_state() {
   }
 }
 bool MQTTSelectComponent::publish_state(const std::string &value) {
-  return this->publish(this->get_state_topic_(), value);
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish(this->get_state_topic_to_(topic_buf), value.data(), value.size());
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_sensor.cpp

@@ -79,12 +79,13 @@ bool MQTTSensorComponent::send_initial_state() {
   }
 }
 bool MQTTSensorComponent::publish_state(float value) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
   if (mqtt::global_mqtt_client->is_publish_nan_as_none() && std::isnan(value))
-    return this->publish(this->get_state_topic_(), "None", 4);
+    return this->publish(this->get_state_topic_to_(topic_buf), "None", 4);
   int8_t accuracy = this->sensor_->get_accuracy_decimals();
   char buf[VALUE_ACCURACY_MAX_LEN];
   size_t len = value_accuracy_to_buf(buf, value, accuracy);
-  return this->publish(this->get_state_topic_(), buf, len);
+  return this->publish(this->get_state_topic_to_(topic_buf), buf, len);
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_switch.cpp

@@ -52,8 +52,9 @@ void MQTTSwitchComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
 bool MQTTSwitchComponent::send_initial_state() { return this->publish_state(this->switch_->state); }
 
 bool MQTTSwitchComponent::publish_state(bool state) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
   const char *state_s = state ? "ON" : "OFF";
-  return this->publish(this->get_state_topic_(), state_s);
+  return this->publish(this->get_state_topic_to_(topic_buf), state_s);
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_text.cpp

@@ -53,7 +53,8 @@ bool MQTTTextComponent::send_initial_state() {
   }
 }
 bool MQTTTextComponent::publish_state(const std::string &value) {
-  return this->publish(this->get_state_topic_(), value);
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish(this->get_state_topic_to_(topic_buf), value.data(), value.size());
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_text_sensor.cpp

@@ -31,7 +31,10 @@ void MQTTTextSensor::dump_config() {
   LOG_MQTT_COMPONENT(true, false);
 }
 
-bool MQTTTextSensor::publish_state(const std::string &value) { return this->publish(this->get_state_topic_(), value); }
+bool MQTTTextSensor::publish_state(const std::string &value) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish(this->get_state_topic_to_(topic_buf), value.data(), value.size());
+}
 bool MQTTTextSensor::send_initial_state() {
   if (this->sensor_->has_state()) {
     return this->publish_state(this->sensor_->state);

esphome/components/mqtt/mqtt_time.cpp

@@ -53,7 +53,8 @@ bool MQTTTimeComponent::send_initial_state() {
   }
 }
 bool MQTTTimeComponent::publish_state(uint8_t hour, uint8_t minute, uint8_t second) {
-  return this->publish_json(this->get_state_topic_(), [hour, minute, second](JsonObject root) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish_json(this->get_state_topic_to_(topic_buf), [hour, minute, second](JsonObject root) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[ESPHOME_F("hour")] = hour;
     root[ESPHOME_F("minute")] = minute;

esphome/components/mqtt/mqtt_update.cpp

@@ -28,7 +28,8 @@ void MQTTUpdateComponent::setup() {
 }
 
 bool MQTTUpdateComponent::publish_state() {
-  return this->publish_json(this->get_state_topic_(), [this](JsonObject root) {
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  return this->publish_json(this->get_state_topic_to_(topic_buf), [this](JsonObject root) {
     root[ESPHOME_F("installed_version")] = this->update_->update_info.current_version;
     root[ESPHOME_F("latest_version")] = this->update_->update_info.latest_version;
     root[ESPHOME_F("title")] = this->update_->update_info.title;

esphome/components/mqtt/mqtt_valve.cpp

@@ -84,7 +84,8 @@ bool MQTTValveComponent::publish_state() {
                         : this->valve_->position == VALVE_OPEN                       ? "open"
                         : traits.get_supports_position()                             ? "open"
                                                                                      : "unknown";
-  if (!this->publish(this->get_state_topic_(), state_s))
+  char topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  if (!this->publish(this->get_state_topic_to_(topic_buf), state_s))
     success = false;
   return success;
 }

esphome/components/nfc/binary_sensor/nfc_binary_sensor.cpp

@@ -40,7 +40,7 @@ void NfcTagBinarySensor::set_tag_name(const std::string &str) {
   this->match_tag_name_ = true;
 }
 
-void NfcTagBinarySensor::set_uid(const std::vector<uint8_t> &uid) { this->uid_ = uid; }
+void NfcTagBinarySensor::set_uid(const NfcTagUid &uid) { this->uid_ = uid; }
 
 bool NfcTagBinarySensor::tag_match_ndef_string(const std::shared_ptr<NdefMessage> &msg) {
   for (const auto &record : msg->get_records()) {
@@ -63,7 +63,7 @@ bool NfcTagBinarySensor::tag_match_tag_name(const std::shared_ptr<NdefMessage> &
   return false;
 }
 
-bool NfcTagBinarySensor::tag_match_uid(const std::vector<uint8_t> &data) {
+bool NfcTagBinarySensor::tag_match_uid(const NfcTagUid &data) {
   if (data.size() != this->uid_.size()) {
     return false;
   }

esphome/components/nfc/binary_sensor/nfc_binary_sensor.h

@@ -19,11 +19,11 @@ class NfcTagBinarySensor : public binary_sensor::BinarySensor,
 
   void set_ndef_match_string(const std::string &str);
   void set_tag_name(const std::string &str);
-  void set_uid(const std::vector<uint8_t> &uid);
+  void set_uid(const NfcTagUid &uid);
 
   bool tag_match_ndef_string(const std::shared_ptr<NdefMessage> &msg);
   bool tag_match_tag_name(const std::shared_ptr<NdefMessage> &msg);
-  bool tag_match_uid(const std::vector<uint8_t> &data);
+  bool tag_match_uid(const NfcTagUid &data);
 
   void tag_off(NfcTag &tag) override;
   void tag_on(NfcTag &tag) override;
@@ -31,7 +31,7 @@ class NfcTagBinarySensor : public binary_sensor::BinarySensor,
  protected:
   bool match_tag_name_{false};
   std::string match_string_;
-  std::vector<uint8_t> uid_;
+  NfcTagUid uid_;
 };
 
 }  // namespace nfc

esphome/components/nfc/nfc.cpp

@@ -8,19 +8,23 @@ namespace nfc {
 
 static const char *const TAG = "nfc";
 
-char *format_uid_to(char *buffer, const std::vector<uint8_t> &uid) {
+char *format_uid_to(char *buffer, std::span<const uint8_t> uid) {
   return format_hex_pretty_to(buffer, FORMAT_UID_BUFFER_SIZE, uid.data(), uid.size(), '-');
 }
 
-char *format_bytes_to(char *buffer, const std::vector<uint8_t> &bytes) {
+char *format_bytes_to(char *buffer, std::span<const uint8_t> bytes) {
   return format_hex_pretty_to(buffer, FORMAT_BYTES_BUFFER_SIZE, bytes.data(), bytes.size(), ' ');
 }
 
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 // Deprecated wrappers intentionally use heap-allocating version for backward compatibility
-std::string format_uid(const std::vector<uint8_t> &uid) { return format_hex_pretty(uid, '-', false); }        // NOLINT
-std::string format_bytes(const std::vector<uint8_t> &bytes) { return format_hex_pretty(bytes, ' ', false); }  // NOLINT
+std::string format_uid(std::span<const uint8_t> uid) {
+  return format_hex_pretty(uid.data(), uid.size(), '-', false);  // NOLINT
+}
+std::string format_bytes(std::span<const uint8_t> bytes) {
+  return format_hex_pretty(bytes.data(), bytes.size(), ' ', false);  // NOLINT
+}
 #pragma GCC diagnostic pop
 
 uint8_t guess_tag_type(uint8_t uid_length) {

esphome/components/nfc/nfc.h

@@ -6,6 +6,7 @@
 #include "ndef_record.h"
 #include "nfc_tag.h"
 
+#include <span>
 #include <vector>
 
 namespace esphome {
@@ -56,19 +57,19 @@ static const uint8_t MAD_KEY[6] = {0xA0, 0xA1, 0xA2, 0xA3, 0xA4, 0xA5};
 /// Max UID size is 10 bytes, formatted as "XX-XX-XX-XX-XX-XX-XX-XX-XX-XX\0" = 30 chars
 static constexpr size_t FORMAT_UID_BUFFER_SIZE = 30;
 /// Format UID to buffer with '-' separator (e.g., "04-11-22-33"). Returns buffer for inline use.
-char *format_uid_to(char *buffer, const std::vector<uint8_t> &uid);
+char *format_uid_to(char *buffer, std::span<const uint8_t> uid);
 
 /// Buffer size for format_bytes_to (64 bytes max = 192 chars with space separator)
 static constexpr size_t FORMAT_BYTES_BUFFER_SIZE = 192;
 /// Format bytes to buffer with ' ' separator (e.g., "04 11 22 33"). Returns buffer for inline use.
-char *format_bytes_to(char *buffer, const std::vector<uint8_t> &bytes);
+char *format_bytes_to(char *buffer, std::span<const uint8_t> bytes);
 
 // Remove before 2026.6.0
 ESPDEPRECATED("Use format_uid_to() with stack buffer instead. Removed in 2026.6.0", "2025.12.0")
-std::string format_uid(const std::vector<uint8_t> &uid);
+std::string format_uid(std::span<const uint8_t> uid);
 // Remove before 2026.6.0
 ESPDEPRECATED("Use format_bytes_to() with stack buffer instead. Removed in 2026.6.0", "2025.12.0")
-std::string format_bytes(const std::vector<uint8_t> &bytes);
+std::string format_bytes(std::span<const uint8_t> bytes);
 
 uint8_t guess_tag_type(uint8_t uid_length);
 uint8_t get_mifare_classic_ndef_start_index(std::vector<uint8_t> &data);

esphome/components/nfc/nfc_tag.h

@@ -10,26 +10,27 @@
 namespace esphome {
 namespace nfc {
 
+// NFC UIDs are 4, 7, or 10 bytes depending on tag type
+static constexpr size_t NFC_UID_MAX_LENGTH = 10;
+using NfcTagUid = StaticVector<uint8_t, NFC_UID_MAX_LENGTH>;
+
 class NfcTag {
  public:
-  NfcTag() {
-    this->uid_ = {};
-    this->tag_type_ = "Unknown";
-  };
-  NfcTag(std::vector<uint8_t> &uid) {
+  NfcTag() { this->tag_type_ = "Unknown"; };
+  NfcTag(const NfcTagUid &uid) {
     this->uid_ = uid;
     this->tag_type_ = "Unknown";
   };
-  NfcTag(std::vector<uint8_t> &uid, const std::string &tag_type) {
+  NfcTag(const NfcTagUid &uid, const std::string &tag_type) {
     this->uid_ = uid;
     this->tag_type_ = tag_type;
   };
-  NfcTag(std::vector<uint8_t> &uid, const std::string &tag_type, std::unique_ptr<nfc::NdefMessage> ndef_message) {
+  NfcTag(const NfcTagUid &uid, const std::string &tag_type, std::unique_ptr<nfc::NdefMessage> ndef_message) {
     this->uid_ = uid;
     this->tag_type_ = tag_type;
     this->ndef_message_ = std::move(ndef_message);
   };
-  NfcTag(std::vector<uint8_t> &uid, const std::string &tag_type, std::vector<uint8_t> &ndef_data) {
+  NfcTag(const NfcTagUid &uid, const std::string &tag_type, std::vector<uint8_t> &ndef_data) {
     this->uid_ = uid;
     this->tag_type_ = tag_type;
     this->ndef_message_ = make_unique<NdefMessage>(ndef_data);
@@ -41,14 +42,14 @@ class NfcTag {
       ndef_message_ = make_unique<NdefMessage>(*rhs.ndef_message_);
   }
 
-  std::vector<uint8_t> &get_uid() { return this->uid_; };
+  NfcTagUid &get_uid() { return this->uid_; };
   const std::string &get_tag_type() { return this->tag_type_; };
   bool has_ndef_message() { return this->ndef_message_ != nullptr; };
   const std::shared_ptr<NdefMessage> &get_ndef_message() { return this->ndef_message_; };
   void set_ndef_message(std::unique_ptr<NdefMessage> ndef_message) { this->ndef_message_ = std::move(ndef_message); };
 
  protected:
-  std::vector<uint8_t> uid_;
+  NfcTagUid uid_;
   std::string tag_type_;
   std::shared_ptr<NdefMessage> ndef_message_;
 };

esphome/components/number/automation.cpp

@@ -14,8 +14,7 @@ void ValueRangeTrigger::setup() {
   float local_min = this->min_.value(0.0);
   float local_max = this->max_.value(0.0);
   convert hash = {.from = (local_max - local_min)};
-  uint32_t myhash = hash.to ^ this->parent_->get_preference_hash();
-  this->rtc_ = global_preferences->make_preference<bool>(myhash);
+  this->rtc_ = this->parent_->make_entity_preference<bool>(hash.to);
   bool initial_state;
   if (this->rtc_.load(&initial_state)) {
     this->previous_in_range_ = initial_state;

esphome/components/opentherm/number/opentherm_number.cpp

@@ -17,7 +17,7 @@ void OpenthermNumber::setup() {
   if (!this->restore_value_) {
     value = this->initial_value_;
   } else {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
     if (!this->pref_.load(&value)) {
       if (!std::isnan(this->initial_value_)) {
         value = this->initial_value_;

esphome/components/pn532/pn532.cpp

@@ -168,11 +168,11 @@ void PN532::loop() {
   }
 
   uint8_t nfcid_length = read[5];
-  std::vector<uint8_t> nfcid(read.begin() + 6, read.begin() + 6 + nfcid_length);
-  if (read.size() < 6U + nfcid_length) {
+  if (nfcid_length > nfc::NFC_UID_MAX_LENGTH || read.size() < 6U + nfcid_length) {
     // oops, pn532 returned invalid data
     return;
   }
+  nfc::NfcTagUid nfcid(read.begin() + 6, read.begin() + 6 + nfcid_length);
 
   bool report = true;
   for (auto *bin_sens : this->binary_sensors_) {
@@ -358,7 +358,7 @@ void PN532::turn_off_rf_() {
   });
 }
 
-std::unique_ptr<nfc::NfcTag> PN532::read_tag_(std::vector<uint8_t> &uid) {
+std::unique_ptr<nfc::NfcTag> PN532::read_tag_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
 
   if (type == nfc::TAG_TYPE_MIFARE_CLASSIC) {
@@ -393,7 +393,7 @@ void PN532::write_mode(nfc::NdefMessage *message) {
   ESP_LOGD(TAG, "Waiting to write next tag");
 }
 
-bool PN532::clean_tag_(std::vector<uint8_t> &uid) {
+bool PN532::clean_tag_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   if (type == nfc::TAG_TYPE_MIFARE_CLASSIC) {
     return this->format_mifare_classic_mifare_(uid);
@@ -404,7 +404,7 @@ bool PN532::clean_tag_(std::vector<uint8_t> &uid) {
   return false;
 }
 
-bool PN532::format_tag_(std::vector<uint8_t> &uid) {
+bool PN532::format_tag_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   if (type == nfc::TAG_TYPE_MIFARE_CLASSIC) {
     return this->format_mifare_classic_ndef_(uid);
@@ -415,7 +415,7 @@ bool PN532::format_tag_(std::vector<uint8_t> &uid) {
   return false;
 }
 
-bool PN532::write_tag_(std::vector<uint8_t> &uid, nfc::NdefMessage *message) {
+bool PN532::write_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   if (type == nfc::TAG_TYPE_MIFARE_CLASSIC) {
     return this->write_mifare_classic_tag_(uid, message);
@@ -448,7 +448,7 @@ void PN532::dump_config() {
   }
 }
 
-bool PN532BinarySensor::process(std::vector<uint8_t> &data) {
+bool PN532BinarySensor::process(const nfc::NfcTagUid &data) {
   if (data.size() != this->uid_.size())
     return false;
 

esphome/components/pn532/pn532.h

@@ -69,28 +69,28 @@ class PN532 : public PollingComponent {
   virtual bool read_data(std::vector<uint8_t> &data, uint8_t len) = 0;
   virtual bool read_response(uint8_t command, std::vector<uint8_t> &data) = 0;
 
-  std::unique_ptr<nfc::NfcTag> read_tag_(std::vector<uint8_t> &uid);
+  std::unique_ptr<nfc::NfcTag> read_tag_(nfc::NfcTagUid &uid);
 
-  bool format_tag_(std::vector<uint8_t> &uid);
-  bool clean_tag_(std::vector<uint8_t> &uid);
-  bool write_tag_(std::vector<uint8_t> &uid, nfc::NdefMessage *message);
+  bool format_tag_(nfc::NfcTagUid &uid);
+  bool clean_tag_(nfc::NfcTagUid &uid);
+  bool write_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message);
 
-  std::unique_ptr<nfc::NfcTag> read_mifare_classic_tag_(std::vector<uint8_t> &uid);
+  std::unique_ptr<nfc::NfcTag> read_mifare_classic_tag_(nfc::NfcTagUid &uid);
   bool read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
   bool write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &data);
-  bool auth_mifare_classic_block_(std::vector<uint8_t> &uid, uint8_t block_num, uint8_t key_num, const uint8_t *key);
-  bool format_mifare_classic_mifare_(std::vector<uint8_t> &uid);
-  bool format_mifare_classic_ndef_(std::vector<uint8_t> &uid);
-  bool write_mifare_classic_tag_(std::vector<uint8_t> &uid, nfc::NdefMessage *message);
+  bool auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, uint8_t key_num, const uint8_t *key);
+  bool format_mifare_classic_mifare_(nfc::NfcTagUid &uid);
+  bool format_mifare_classic_ndef_(nfc::NfcTagUid &uid);
+  bool write_mifare_classic_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message);
 
-  std::unique_ptr<nfc::NfcTag> read_mifare_ultralight_tag_(std::vector<uint8_t> &uid);
+  std::unique_ptr<nfc::NfcTag> read_mifare_ultralight_tag_(nfc::NfcTagUid &uid);
   bool read_mifare_ultralight_bytes_(uint8_t start_page, uint16_t num_bytes, std::vector<uint8_t> &data);
   bool is_mifare_ultralight_formatted_(const std::vector<uint8_t> &page_3_to_6);
   uint16_t read_mifare_ultralight_capacity_();
   bool find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                     uint8_t &message_start_index);
   bool write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
-  bool write_mifare_ultralight_tag_(std::vector<uint8_t> &uid, nfc::NdefMessage *message);
+  bool write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message);
   bool clean_mifare_ultralight_();
 
   bool updates_enabled_{true};
@@ -98,7 +98,7 @@ class PN532 : public PollingComponent {
   std::vector<PN532BinarySensor *> binary_sensors_;
   std::vector<nfc::NfcOnTagTrigger *> triggers_ontag_;
   std::vector<nfc::NfcOnTagTrigger *> triggers_ontagremoved_;
-  std::vector<uint8_t> current_uid_;
+  nfc::NfcTagUid current_uid_;
   nfc::NdefMessage *next_task_message_to_write_;
   uint32_t rd_start_time_{0};
   enum PN532ReadReady rd_ready_ { WOULDBLOCK };
@@ -118,9 +118,9 @@ class PN532 : public PollingComponent {
 
 class PN532BinarySensor : public binary_sensor::BinarySensor {
  public:
-  void set_uid(const std::vector<uint8_t> &uid) { uid_ = uid; }
+  void set_uid(const nfc::NfcTagUid &uid) { uid_ = uid; }
 
-  bool process(std::vector<uint8_t> &data);
+  bool process(const nfc::NfcTagUid &data);
 
   void on_scan_end() {
     if (!this->found_) {
@@ -130,7 +130,7 @@ class PN532BinarySensor : public binary_sensor::BinarySensor {
   }
 
  protected:
-  std::vector<uint8_t> uid_;
+  nfc::NfcTagUid uid_;
   bool found_{false};
 };
 

esphome/components/pn532/pn532_mifare_classic.cpp

@@ -8,7 +8,7 @@ namespace pn532 {
 
 static const char *const TAG = "pn532.mifare_classic";
 
-std::unique_ptr<nfc::NfcTag> PN532::read_mifare_classic_tag_(std::vector<uint8_t> &uid) {
+std::unique_ptr<nfc::NfcTag> PN532::read_mifare_classic_tag_(nfc::NfcTagUid &uid) {
   uint8_t current_block = 4;
   uint8_t message_start_index = 0;
   uint32_t message_length = 0;
@@ -82,8 +82,7 @@ bool PN532::read_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t> &
   return true;
 }
 
-bool PN532::auth_mifare_classic_block_(std::vector<uint8_t> &uid, uint8_t block_num, uint8_t key_num,
-                                       const uint8_t *key) {
+bool PN532::auth_mifare_classic_block_(nfc::NfcTagUid &uid, uint8_t block_num, uint8_t key_num, const uint8_t *key) {
   std::vector<uint8_t> data({
       PN532_COMMAND_INDATAEXCHANGE,
       0x01,       // One card
@@ -106,7 +105,7 @@ bool PN532::auth_mifare_classic_block_(std::vector<uint8_t> &uid, uint8_t block_
   return true;
 }
 
-bool PN532::format_mifare_classic_mifare_(std::vector<uint8_t> &uid) {
+bool PN532::format_mifare_classic_mifare_(nfc::NfcTagUid &uid) {
   std::vector<uint8_t> blank_buffer(
       {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
   std::vector<uint8_t> trailer_buffer(
@@ -141,7 +140,7 @@ bool PN532::format_mifare_classic_mifare_(std::vector<uint8_t> &uid) {
   return !error;
 }
 
-bool PN532::format_mifare_classic_ndef_(std::vector<uint8_t> &uid) {
+bool PN532::format_mifare_classic_ndef_(nfc::NfcTagUid &uid) {
   std::vector<uint8_t> empty_ndef_message(
       {0x03, 0x03, 0xD0, 0x00, 0x00, 0xFE, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00});
   std::vector<uint8_t> blank_block(
@@ -216,7 +215,7 @@ bool PN532::write_mifare_classic_block_(uint8_t block_num, std::vector<uint8_t>
   return true;
 }
 
-bool PN532::write_mifare_classic_tag_(std::vector<uint8_t> &uid, nfc::NdefMessage *message) {
+bool PN532::write_mifare_classic_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message) {
   auto encoded = message->encode();
 
   uint32_t message_length = encoded.size();

esphome/components/pn532/pn532_mifare_ultralight.cpp

@@ -8,7 +8,7 @@ namespace pn532 {
 
 static const char *const TAG = "pn532.mifare_ultralight";
 
-std::unique_ptr<nfc::NfcTag> PN532::read_mifare_ultralight_tag_(std::vector<uint8_t> &uid) {
+std::unique_ptr<nfc::NfcTag> PN532::read_mifare_ultralight_tag_(nfc::NfcTagUid &uid) {
   std::vector<uint8_t> data;
   // pages 3 to 6 contain various info we are interested in -- do one read to grab it all
   if (!this->read_mifare_ultralight_bytes_(3, nfc::MIFARE_ULTRALIGHT_PAGE_SIZE * nfc::MIFARE_ULTRALIGHT_READ_SIZE,
@@ -114,7 +114,7 @@ bool PN532::find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6
   return false;
 }
 
-bool PN532::write_mifare_ultralight_tag_(std::vector<uint8_t> &uid, nfc::NdefMessage *message) {
+bool PN532::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, nfc::NdefMessage *message) {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
 
   auto encoded = message->encode();

esphome/components/pn7150/pn7150.cpp

@@ -478,7 +478,7 @@ uint8_t PN7150::read_endpoint_data_(nfc::NfcTag &tag) {
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7150::clean_endpoint_(std::vector<uint8_t> &uid) {
+uint8_t PN7150::clean_endpoint_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   switch (type) {
     case nfc::TAG_TYPE_MIFARE_CLASSIC:
@@ -494,7 +494,7 @@ uint8_t PN7150::clean_endpoint_(std::vector<uint8_t> &uid) {
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7150::format_endpoint_(std::vector<uint8_t> &uid) {
+uint8_t PN7150::format_endpoint_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   switch (type) {
     case nfc::TAG_TYPE_MIFARE_CLASSIC:
@@ -510,7 +510,7 @@ uint8_t PN7150::format_endpoint_(std::vector<uint8_t> &uid) {
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7150::write_endpoint_(std::vector<uint8_t> &uid, std::shared_ptr<nfc::NdefMessage> &message) {
+uint8_t PN7150::write_endpoint_(nfc::NfcTagUid &uid, std::shared_ptr<nfc::NdefMessage> &message) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   switch (type) {
     case nfc::TAG_TYPE_MIFARE_CLASSIC:
@@ -534,7 +534,7 @@ std::unique_ptr<nfc::NfcTag> PN7150::build_tag_(const uint8_t mode_tech, const s
         ESP_LOGE(TAG, "UID length cannot be zero");
         return nullptr;
       }
-      std::vector<uint8_t> uid(data.begin() + 3, data.begin() + 3 + uid_length);
+      nfc::NfcTagUid uid(data.begin() + 3, data.begin() + 3 + uid_length);
       const auto *tag_type_str =
           nfc::guess_tag_type(uid_length) == nfc::TAG_TYPE_MIFARE_CLASSIC ? nfc::MIFARE_CLASSIC : nfc::NFC_FORUM_TYPE_2;
       return make_unique<nfc::NfcTag>(uid, tag_type_str);
@@ -543,7 +543,7 @@ std::unique_ptr<nfc::NfcTag> PN7150::build_tag_(const uint8_t mode_tech, const s
   return nullptr;
 }
 
-optional<size_t> PN7150::find_tag_uid_(const std::vector<uint8_t> &uid) {
+optional<size_t> PN7150::find_tag_uid_(const nfc::NfcTagUid &uid) {
   if (!this->discovered_endpoint_.empty()) {
     for (size_t i = 0; i < this->discovered_endpoint_.size(); i++) {
       auto existing_tag_uid = this->discovered_endpoint_[i].tag->get_uid();

esphome/components/pn7150/pn7150.h

@@ -203,12 +203,12 @@ class PN7150 : public nfc::Nfcc, public Component {
   void select_endpoint_();
 
   uint8_t read_endpoint_data_(nfc::NfcTag &tag);
-  uint8_t clean_endpoint_(std::vector<uint8_t> &uid);
-  uint8_t format_endpoint_(std::vector<uint8_t> &uid);
-  uint8_t write_endpoint_(std::vector<uint8_t> &uid, std::shared_ptr<nfc::NdefMessage> &message);
+  uint8_t clean_endpoint_(nfc::NfcTagUid &uid);
+  uint8_t format_endpoint_(nfc::NfcTagUid &uid);
+  uint8_t write_endpoint_(nfc::NfcTagUid &uid, std::shared_ptr<nfc::NdefMessage> &message);
 
   std::unique_ptr<nfc::NfcTag> build_tag_(uint8_t mode_tech, const std::vector<uint8_t> &data);
-  optional<size_t> find_tag_uid_(const std::vector<uint8_t> &uid);
+  optional<size_t> find_tag_uid_(const nfc::NfcTagUid &uid);
   void purge_old_tags_();
   void erase_tag_(uint8_t tag_index);
 
@@ -251,7 +251,7 @@ class PN7150 : public nfc::Nfcc, public Component {
   uint8_t find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                        uint8_t &message_start_index);
   uint8_t write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
-  uint8_t write_mifare_ultralight_tag_(std::vector<uint8_t> &uid, const std::shared_ptr<nfc::NdefMessage> &message);
+  uint8_t write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message);
   uint8_t clean_mifare_ultralight_();
 
   enum NfcTask : uint8_t {

esphome/components/pn7150/pn7150_mifare_ultralight.cpp

@@ -115,8 +115,7 @@ uint8_t PN7150::find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7150::write_mifare_ultralight_tag_(std::vector<uint8_t> &uid,
-                                             const std::shared_ptr<nfc::NdefMessage> &message) {
+uint8_t PN7150::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message) {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
 
   auto encoded = message->encode();

esphome/components/pn7160/pn7160.cpp

@@ -506,7 +506,7 @@ uint8_t PN7160::read_endpoint_data_(nfc::NfcTag &tag) {
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7160::clean_endpoint_(std::vector<uint8_t> &uid) {
+uint8_t PN7160::clean_endpoint_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   switch (type) {
     case nfc::TAG_TYPE_MIFARE_CLASSIC:
@@ -522,7 +522,7 @@ uint8_t PN7160::clean_endpoint_(std::vector<uint8_t> &uid) {
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7160::format_endpoint_(std::vector<uint8_t> &uid) {
+uint8_t PN7160::format_endpoint_(nfc::NfcTagUid &uid) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   switch (type) {
     case nfc::TAG_TYPE_MIFARE_CLASSIC:
@@ -538,7 +538,7 @@ uint8_t PN7160::format_endpoint_(std::vector<uint8_t> &uid) {
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7160::write_endpoint_(std::vector<uint8_t> &uid, std::shared_ptr<nfc::NdefMessage> &message) {
+uint8_t PN7160::write_endpoint_(nfc::NfcTagUid &uid, std::shared_ptr<nfc::NdefMessage> &message) {
   uint8_t type = nfc::guess_tag_type(uid.size());
   switch (type) {
     case nfc::TAG_TYPE_MIFARE_CLASSIC:
@@ -562,7 +562,7 @@ std::unique_ptr<nfc::NfcTag> PN7160::build_tag_(const uint8_t mode_tech, const s
         ESP_LOGE(TAG, "UID length cannot be zero");
         return nullptr;
       }
-      std::vector<uint8_t> uid(data.begin() + 3, data.begin() + 3 + uid_length);
+      nfc::NfcTagUid uid(data.begin() + 3, data.begin() + 3 + uid_length);
       const auto *tag_type_str =
           nfc::guess_tag_type(uid_length) == nfc::TAG_TYPE_MIFARE_CLASSIC ? nfc::MIFARE_CLASSIC : nfc::NFC_FORUM_TYPE_2;
       return make_unique<nfc::NfcTag>(uid, tag_type_str);
@@ -571,7 +571,7 @@ std::unique_ptr<nfc::NfcTag> PN7160::build_tag_(const uint8_t mode_tech, const s
   return nullptr;
 }
 
-optional<size_t> PN7160::find_tag_uid_(const std::vector<uint8_t> &uid) {
+optional<size_t> PN7160::find_tag_uid_(const nfc::NfcTagUid &uid) {
   if (!this->discovered_endpoint_.empty()) {
     for (size_t i = 0; i < this->discovered_endpoint_.size(); i++) {
       auto existing_tag_uid = this->discovered_endpoint_[i].tag->get_uid();

esphome/components/pn7160/pn7160.h

@@ -220,12 +220,12 @@ class PN7160 : public nfc::Nfcc, public Component {
   void select_endpoint_();
 
   uint8_t read_endpoint_data_(nfc::NfcTag &tag);
-  uint8_t clean_endpoint_(std::vector<uint8_t> &uid);
-  uint8_t format_endpoint_(std::vector<uint8_t> &uid);
-  uint8_t write_endpoint_(std::vector<uint8_t> &uid, std::shared_ptr<nfc::NdefMessage> &message);
+  uint8_t clean_endpoint_(nfc::NfcTagUid &uid);
+  uint8_t format_endpoint_(nfc::NfcTagUid &uid);
+  uint8_t write_endpoint_(nfc::NfcTagUid &uid, std::shared_ptr<nfc::NdefMessage> &message);
 
   std::unique_ptr<nfc::NfcTag> build_tag_(uint8_t mode_tech, const std::vector<uint8_t> &data);
-  optional<size_t> find_tag_uid_(const std::vector<uint8_t> &uid);
+  optional<size_t> find_tag_uid_(const nfc::NfcTagUid &uid);
   void purge_old_tags_();
   void erase_tag_(uint8_t tag_index);
 
@@ -268,7 +268,7 @@ class PN7160 : public nfc::Nfcc, public Component {
   uint8_t find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_to_6, uint8_t &message_length,
                                        uint8_t &message_start_index);
   uint8_t write_mifare_ultralight_page_(uint8_t page_num, std::vector<uint8_t> &write_data);
-  uint8_t write_mifare_ultralight_tag_(std::vector<uint8_t> &uid, const std::shared_ptr<nfc::NdefMessage> &message);
+  uint8_t write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message);
   uint8_t clean_mifare_ultralight_();
 
   enum NfcTask : uint8_t {

esphome/components/pn7160/pn7160_mifare_ultralight.cpp

@@ -115,8 +115,7 @@ uint8_t PN7160::find_mifare_ultralight_ndef_(const std::vector<uint8_t> &page_3_
   return nfc::STATUS_FAILED;
 }
 
-uint8_t PN7160::write_mifare_ultralight_tag_(std::vector<uint8_t> &uid,
-                                             const std::shared_ptr<nfc::NdefMessage> &message) {
+uint8_t PN7160::write_mifare_ultralight_tag_(nfc::NfcTagUid &uid, const std::shared_ptr<nfc::NdefMessage> &message) {
   uint32_t capacity = this->read_mifare_ultralight_capacity_();
 
   auto encoded = message->encode();

esphome/components/rotary_encoder/rotary_encoder.cpp

@@ -132,7 +132,7 @@ void RotaryEncoderSensor::setup() {
   int32_t initial_value = 0;
   switch (this->restore_mode_) {
     case ROTARY_ENCODER_RESTORE_DEFAULT_ZERO:
-      this->rtc_ = global_preferences->make_preference<int32_t>(this->get_preference_hash());
+      this->rtc_ = this->make_entity_preference<int32_t>();
       if (!this->rtc_.load(&initial_value)) {
         initial_value = 0;
       }

esphome/components/rp2040/preferences.cpp

@@ -8,7 +8,6 @@
 #include "preferences.h"
 
 #include <cstring>
-#include <vector>
 
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
@@ -25,6 +24,9 @@ static bool s_flash_dirty = false;          // NOLINT(cppcoreguidelines-avoid-no
 
 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;
+
 extern "C" uint8_t _EEPROM_start;
 
 template<class It> uint8_t calculate_crc(It first, It last, uint32_t type) {
@@ -42,12 +44,14 @@ class RP2040PreferenceBackend : public ESPPreferenceBackend {
   uint32_t type = 0;
 
   bool save(const uint8_t *data, size_t len) override {
-    std::vector<uint8_t> buffer;
-    buffer.resize(len + 1);
-    memcpy(buffer.data(), data, len);
-    buffer[buffer.size() - 1] = calculate_crc(buffer.begin(), buffer.end() - 1, type);
+    const size_t buffer_size = len + 1;
+    SmallBufferWithHeapFallback<PREF_BUFFER_SIZE> buffer_alloc(buffer_size);
+    uint8_t *buffer = buffer_alloc.get();
 
-    for (uint32_t i = 0; i < len + 1; i++) {
+    memcpy(buffer, data, len);
+    buffer[len] = calculate_crc(buffer, buffer + len, type);
+
+    for (size_t i = 0; i < buffer_size; i++) {
       uint32_t j = offset + i;
       if (j >= RP2040_FLASH_STORAGE_SIZE)
         return false;
@@ -60,22 +64,23 @@ class RP2040PreferenceBackend : public ESPPreferenceBackend {
     return true;
   }
   bool load(uint8_t *data, size_t len) override {
-    std::vector<uint8_t> buffer;
-    buffer.resize(len + 1);
+    const size_t buffer_size = len + 1;
+    SmallBufferWithHeapFallback<PREF_BUFFER_SIZE> buffer_alloc(buffer_size);
+    uint8_t *buffer = buffer_alloc.get();
 
-    for (size_t i = 0; i < len + 1; i++) {
+    for (size_t i = 0; i < buffer_size; i++) {
       uint32_t j = offset + i;
       if (j >= RP2040_FLASH_STORAGE_SIZE)
         return false;
       buffer[i] = s_flash_storage[j];
     }
 
-    uint8_t crc = calculate_crc(buffer.begin(), buffer.end() - 1, type);
-    if (buffer[buffer.size() - 1] != crc) {
+    uint8_t crc = calculate_crc(buffer, buffer + len, type);
+    if (buffer[len] != crc) {
       return false;
     }
 
-    memcpy(data, buffer.data(), len);
+    memcpy(data, buffer, len);
     return true;
   }
 };

esphome/components/sensor/automation.h

@@ -39,7 +39,7 @@ class ValueRangeTrigger : public Trigger<float>, public Component {
   template<typename V> void set_max(V max) { this->max_ = max; }
 
   void setup() override {
-    this->rtc_ = global_preferences->make_preference<bool>(this->parent_->get_preference_hash());
+    this->rtc_ = this->parent_->make_entity_preference<bool>();
     bool initial_state;
     if (this->rtc_.load(&initial_state)) {
       this->previous_in_range_ = initial_state;

esphome/components/sml/constants.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <array>
 #include <cstdint>
 
 namespace esphome {
@@ -21,7 +22,7 @@ enum SmlMessageType : uint16_t { SML_PUBLIC_OPEN_RES = 0x0101, SML_GET_LIST_RES
 const uint16_t START_MASK = 0x55aa;  // 0x1b 1b 1b 1b 01 01 01 01
 const uint16_t END_MASK = 0x0157;    // 0x1b 1b 1b 1b 1a
 
-const std::vector<uint8_t> START_SEQ = {0x1b, 0x1b, 0x1b, 0x1b, 0x01, 0x01, 0x01, 0x01};
+constexpr std::array<uint8_t, 8> START_SEQ = {0x1b, 0x1b, 0x1b, 0x1b, 0x01, 0x01, 0x01, 0x01};
 
 }  // namespace sml
 }  // namespace esphome

esphome/components/socket/lwip_raw_tcp_impl.cpp

@@ -29,6 +29,14 @@ void socket_delay(uint32_t ms) {
   // Use esp_delay with a callback that checks if socket data arrived.
   // This allows the delay to exit early when socket_wake() is called by
   // lwip recv_fn/accept_fn callbacks, reducing socket latency.
+  //
+  // When ms is 0, we must use delay(0) because esp_delay(0, callback)
+  // exits immediately without yielding, which can cause watchdog timeouts
+  // when the main loop runs in high-frequency mode (e.g., during light effects).
+  if (ms == 0) {
+    delay(0);
+    return;
+  }
   s_socket_woke = false;
   esp_delay(ms, []() { return !s_socket_woke; });
 }

esphome/components/speaker/media_player/speaker_media_player.cpp

@@ -55,7 +55,7 @@ void SpeakerMediaPlayer::setup() {
 
   this->media_control_command_queue_ = xQueueCreate(MEDIA_CONTROLS_QUEUE_LENGTH, sizeof(MediaCallCommand));
 
-  this->pref_ = global_preferences->make_preference<VolumeRestoreState>(this->get_preference_hash());
+  this->pref_ = this->make_entity_preference<VolumeRestoreState>();
 
   VolumeRestoreState volume_restore_state;
   if (this->pref_.load(&volume_restore_state)) {

esphome/components/sprinkler/sprinkler.cpp

@@ -16,7 +16,7 @@ void SprinklerControllerNumber::setup() {
   if (!this->restore_value_) {
     value = this->initial_value_;
   } else {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
     if (!this->pref_.load(&value)) {
       if (!std::isnan(this->initial_value_)) {
         value = this->initial_value_;

esphome/components/switch/switch.cpp

@@ -34,7 +34,7 @@ optional<bool> Switch::get_initial_state() {
   if (!(restore_mode & RESTORE_MODE_PERSISTENT_MASK))
     return {};
 
-  this->rtc_ = global_preferences->make_preference<bool>(this->get_preference_hash());
+  this->rtc_ = this->make_entity_preference<bool>();
   bool initial_state;
   if (!this->rtc_.load(&initial_state))
     return {};

esphome/components/template/alarm_control_panel/template_alarm_control_panel.cpp

@@ -82,7 +82,7 @@ void TemplateAlarmControlPanel::setup() {
   this->current_state_ = ACP_STATE_DISARMED;
   if (this->restore_mode_ == ALARM_CONTROL_PANEL_RESTORE_DEFAULT_DISARMED) {
     uint8_t value;
-    this->pref_ = global_preferences->make_preference<uint8_t>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<uint8_t>();
     if (this->pref_.load(&value)) {
       this->current_state_ = static_cast<alarm_control_panel::AlarmControlPanelState>(value);
     }

esphome/components/template/datetime/template_date.cpp

@@ -18,8 +18,7 @@ void TemplateDate::setup() {
     state = this->initial_value_;
   } else {
     datetime::DateEntityRestoreState temp;
-    this->pref_ =
-        global_preferences->make_preference<datetime::DateEntityRestoreState>(194434030U ^ this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<datetime::DateEntityRestoreState>(194434030U);
     if (this->pref_.load(&temp)) {
       temp.apply(this);
       return;

esphome/components/template/datetime/template_datetime.cpp

@@ -18,8 +18,7 @@ void TemplateDateTime::setup() {
     state = this->initial_value_;
   } else {
     datetime::DateTimeEntityRestoreState temp;
-    this->pref_ = global_preferences->make_preference<datetime::DateTimeEntityRestoreState>(
-        194434090U ^ this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<datetime::DateTimeEntityRestoreState>(194434090U);
     if (this->pref_.load(&temp)) {
       temp.apply(this);
       return;

esphome/components/template/datetime/template_time.cpp

@@ -18,8 +18,7 @@ void TemplateTime::setup() {
     state = this->initial_value_;
   } else {
     datetime::TimeEntityRestoreState temp;
-    this->pref_ =
-        global_preferences->make_preference<datetime::TimeEntityRestoreState>(194434060U ^ this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<datetime::TimeEntityRestoreState>(194434060U);
     if (this->pref_.load(&temp)) {
       temp.apply(this);
       return;

esphome/components/template/number/template_number.cpp

@@ -13,7 +13,7 @@ void TemplateNumber::setup() {
   if (!this->restore_value_) {
     value = this->initial_value_;
   } else {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
     if (!this->pref_.load(&value)) {
       if (!std::isnan(this->initial_value_)) {
         value = this->initial_value_;

esphome/components/template/select/template_select.cpp

@@ -11,7 +11,7 @@ void TemplateSelect::setup() {
 
   size_t index = this->initial_option_index_;
   if (this->restore_value_) {
-    this->pref_ = global_preferences->make_preference<size_t>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<size_t>();
     size_t restored_index;
     if (this->pref_.load(&restored_index) && this->has_index(restored_index)) {
       index = restored_index;

esphome/components/template/text/template_text.cpp

@@ -20,7 +20,14 @@ void TemplateText::setup() {
 
   // Need std::string for pref_->setup() to fill from flash
   std::string value{this->initial_value_ != nullptr ? this->initial_value_ : ""};
+  // For future hash migration: use migrate_entity_preference_() with:
+  //   old_key = get_preference_hash() + extra
+  //   new_key = get_preference_hash_v2() + extra
+  // See: https://github.com/esphome/backlog/issues/85
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
   uint32_t key = this->get_preference_hash();
+#pragma GCC diagnostic pop
   key += this->traits.get_min_length() << 2;
   key += this->traits.get_max_length() << 4;
   key += fnv1_hash(this->traits.get_pattern_c_str()) << 6;

esphome/components/tm1638/tm1638.cpp

@@ -35,9 +35,6 @@ void TM1638Component::setup() {
   this->set_intensity(intensity_);
 
   this->reset_();  // all LEDs off
-
-  for (uint8_t i = 0; i < 8; i++)  // zero fill print buffer
-    this->buffer_[i] = 0;
 }
 
 void TM1638Component::dump_config() {

esphome/components/tm1638/tm1638.h

@@ -70,7 +70,7 @@ class TM1638Component : public PollingComponent {
   GPIOPin *clk_pin_;
   GPIOPin *stb_pin_;
   GPIOPin *dio_pin_;
-  uint8_t *buffer_ = new uint8_t[8];
+  uint8_t buffer_[8]{};
   tm1638_writer_t writer_{};
   std::vector<KeyListener *> listeners_{};
 };

esphome/components/total_daily_energy/total_daily_energy.cpp

@@ -10,7 +10,7 @@ void TotalDailyEnergy::setup() {
   float initial_value = 0;
 
   if (this->restore_) {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
     this->pref_.load(&initial_value);
   }
   this->publish_state_and_save(initial_value);

esphome/components/tuya/number/tuya_number.cpp

@@ -8,7 +8,7 @@ static const char *const TAG = "tuya.number";
 
 void TuyaNumber::setup() {
   if (this->restore_value_) {
-    this->pref_ = global_preferences->make_preference<float>(this->get_preference_hash());
+    this->pref_ = this->make_entity_preference<float>();
   }
 
   this->parent_->register_listener(this->number_id_, [this](const TuyaDatapoint &datapoint) {

esphome/components/uln2003/uln2003.cpp

@@ -1,11 +1,23 @@
 #include "uln2003.h"
 #include "esphome/core/log.h"
 
-namespace esphome {
-namespace uln2003 {
+namespace esphome::uln2003 {
 
 static const char *const TAG = "uln2003.stepper";
 
+static const LogString *step_mode_to_log_string(ULN2003StepMode mode) {
+  switch (mode) {
+    case ULN2003_STEP_MODE_FULL_STEP:
+      return LOG_STR("FULL STEP");
+    case ULN2003_STEP_MODE_HALF_STEP:
+      return LOG_STR("HALF STEP");
+    case ULN2003_STEP_MODE_WAVE_DRIVE:
+      return LOG_STR("WAVE DRIVE");
+    default:
+      return LOG_STR("UNKNOWN");
+  }
+}
+
 void ULN2003::setup() {
   this->pin_a_->setup();
   this->pin_b_->setup();
@@ -42,22 +54,7 @@ void ULN2003::dump_config() {
   LOG_PIN("  Pin B: ", this->pin_b_);
   LOG_PIN("  Pin C: ", this->pin_c_);
   LOG_PIN("  Pin D: ", this->pin_d_);
-  const char *step_mode_s;
-  switch (this->step_mode_) {
-    case ULN2003_STEP_MODE_FULL_STEP:
-      step_mode_s = "FULL STEP";
-      break;
-    case ULN2003_STEP_MODE_HALF_STEP:
-      step_mode_s = "HALF STEP";
-      break;
-    case ULN2003_STEP_MODE_WAVE_DRIVE:
-      step_mode_s = "WAVE DRIVE";
-      break;
-    default:
-      step_mode_s = "UNKNOWN";
-      break;
-  }
-  ESP_LOGCONFIG(TAG, "  Step Mode: %s", step_mode_s);
+  ESP_LOGCONFIG(TAG, "  Step Mode: %s", LOG_STR_ARG(step_mode_to_log_string(this->step_mode_)));
 }
 void ULN2003::write_step_(int32_t step) {
   int32_t n = this->step_mode_ == ULN2003_STEP_MODE_HALF_STEP ? 8 : 4;
@@ -90,5 +87,4 @@ void ULN2003::write_step_(int32_t step) {
   this->pin_d_->digital_write((res >> 3) & 1);
 }
 
-}  // namespace uln2003
-}  // namespace esphome
+}  // namespace esphome::uln2003

esphome/components/uln2003/uln2003.h

@@ -4,8 +4,7 @@
 #include "esphome/core/hal.h"
 #include "esphome/components/stepper/stepper.h"
 
-namespace esphome {
-namespace uln2003 {
+namespace esphome::uln2003 {
 
 enum ULN2003StepMode {
   ULN2003_STEP_MODE_FULL_STEP,
@@ -40,5 +39,4 @@ class ULN2003 : public stepper::Stepper, public Component {
   int32_t current_uln_pos_{0};
 };
 
-}  // namespace uln2003
-}  // namespace esphome
+}  // namespace esphome::uln2003

esphome/components/valve/valve.cpp

@@ -2,6 +2,8 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/controller_registry.h"
 #include "esphome/core/log.h"
+#include "esphome/core/progmem.h"
+
 #include <strings.h>
 
 namespace esphome {
@@ -38,13 +40,13 @@ Valve::Valve() : position{VALVE_OPEN} {}
 
 ValveCall::ValveCall(Valve *parent) : parent_(parent) {}
 ValveCall &ValveCall::set_command(const char *command) {
-  if (strcasecmp(command, "OPEN") == 0) {
+  if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("OPEN")) == 0) {
     this->set_command_open();
-  } else if (strcasecmp(command, "CLOSE") == 0) {
+  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("CLOSE")) == 0) {
     this->set_command_close();
-  } else if (strcasecmp(command, "STOP") == 0) {
+  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("STOP")) == 0) {
     this->set_command_stop();
-  } else if (strcasecmp(command, "TOGGLE") == 0) {
+  } else if (ESPHOME_strcasecmp_P(command, ESPHOME_PSTR("TOGGLE")) == 0) {
     this->set_command_toggle();
   } else {
     ESP_LOGW(TAG, "'%s' - Unrecognized command %s", this->parent_->get_name().c_str(), command);
@@ -161,7 +163,7 @@ void Valve::publish_state(bool save) {
   }
 }
 optional<ValveRestoreState> Valve::restore_state_() {
-  this->rtc_ = global_preferences->make_preference<ValveRestoreState>(this->get_preference_hash());
+  this->rtc_ = this->make_entity_preference<ValveRestoreState>();
   ValveRestoreState recovered{};
   if (!this->rtc_.load(&recovered))
     return {};

esphome/components/water_heater/water_heater.cpp

@@ -185,7 +185,7 @@ void WaterHeater::publish_state() {
 }
 
 optional<WaterHeaterCall> WaterHeater::restore_state_() {
-  this->pref_ = global_preferences->make_preference<SavedWaterHeaterState>(this->get_preference_hash());
+  this->pref_ = this->make_entity_preference<SavedWaterHeaterState>();
   SavedWaterHeaterState recovered{};
   if (!this->pref_.load(&recovered))
     return {};

esphome/components/web_server_base/__init__.py

@@ -48,4 +48,4 @@ async def to_code(config):
         if CORE.is_libretiny:
             CORE.add_platformio_option("lib_ignore", ["ESPAsyncTCP", "RPAsyncTCP"])
         # https://github.com/ESP32Async/ESPAsyncWebServer/blob/main/library.json
-        cg.add_library("ESP32Async/ESPAsyncWebServer", "3.7.10")
+        cg.add_library("ESP32Async/ESPAsyncWebServer", "3.9.5")

esphome/components/web_server_idf/utils.cpp

@@ -78,8 +78,11 @@ optional<std::string> query_key_value(const std::string &query_url, const std::s
     return {};
   }
 
-  // Use stack buffer for typical query strings, heap fallback for large ones
-  SmallBufferWithHeapFallback<256, char> val(query_url.size());
+  auto val = std::unique_ptr<char[]>(new char[query_url.size()]);
+  if (!val) {
+    ESP_LOGE(TAG, "Not enough memory to the query key value");
+    return {};
+  }
 
   if (httpd_query_key_value(query_url.c_str(), key.c_str(), val.get(), query_url.size()) != ESP_OK) {
     return {};

esphome/components/web_server_idf/web_server_idf.cpp

@@ -352,15 +352,14 @@ bool AsyncWebServerRequest::authenticate(const char *username, const char *passw
   memcpy(user_info + user_len + 1, password, pass_len);
   user_info[user_info_len] = '\0';
 
-  // Base64 output size is ceil(input_len * 4/3) + 1, with input bounded to 256 bytes
-  // max output is ceil(256 * 4/3) + 1 = 343 bytes, use 350 for safety
-  constexpr size_t max_digest_len = 350;
-  char digest[max_digest_len];
-  size_t out;
-  esp_crypto_base64_encode(reinterpret_cast<uint8_t *>(digest), max_digest_len, &out,
+  size_t n = 0, out;
+  esp_crypto_base64_encode(nullptr, 0, &n, reinterpret_cast<const uint8_t *>(user_info), user_info_len);
+
+  auto digest = std::unique_ptr<char[]>(new char[n + 1]);
+  esp_crypto_base64_encode(reinterpret_cast<uint8_t *>(digest.get()), n, &out,
                            reinterpret_cast<const uint8_t *>(user_info), user_info_len);
 
-  return strcmp(digest, auth_str + auth_prefix_len) == 0;
+  return strcmp(digest.get(), auth_str + auth_prefix_len) == 0;
 }
 
 void AsyncWebServerRequest::requestAuthentication(const char *realm) const {
@@ -870,12 +869,12 @@ esp_err_t AsyncWebServer::handle_multipart_upload_(httpd_req_t *r, const char *c
     }
   });
 
-  // Process data - use stack buffer to avoid heap allocation
-  char buffer[MULTIPART_CHUNK_SIZE];
+  // Process data
+  std::unique_ptr<char[]> buffer(new char[MULTIPART_CHUNK_SIZE]);
   size_t bytes_since_yield = 0;
 
   for (size_t remaining = r->content_len; remaining > 0;) {
-    int recv_len = httpd_req_recv(r, buffer, std::min(remaining, MULTIPART_CHUNK_SIZE));
+    int recv_len = httpd_req_recv(r, buffer.get(), std::min(remaining, MULTIPART_CHUNK_SIZE));
 
     if (recv_len <= 0) {
       httpd_resp_send_err(r, recv_len == HTTPD_SOCK_ERR_TIMEOUT ? HTTPD_408_REQ_TIMEOUT : HTTPD_400_BAD_REQUEST,
@@ -883,7 +882,7 @@ esp_err_t AsyncWebServer::handle_multipart_upload_(httpd_req_t *r, const char *c
       return recv_len == HTTPD_SOCK_ERR_TIMEOUT ? ESP_ERR_TIMEOUT : ESP_FAIL;
     }
 
-    if (reader->parse(buffer, recv_len) != static_cast<size_t>(recv_len)) {
+    if (reader->parse(buffer.get(), recv_len) != static_cast<size_t>(recv_len)) {
       ESP_LOGW(TAG, "Multipart parser error");
       httpd_resp_send_err(r, HTTPD_400_BAD_REQUEST, nullptr);
       return ESP_FAIL;

esphome/components/wifi/wifi_component.cpp

@@ -746,16 +746,32 @@ void WiFiComponent::setup_ap_config_() {
     return;
 
   if (this->ap_.get_ssid().empty()) {
-    std::string name = App.get_name();
-    if (name.length() > 32) {
+    // Build AP SSID from app name without heap allocation
+    // WiFi SSID max is 32 bytes, with MAC suffix we keep first 25 + last 7
+    static constexpr size_t AP_SSID_MAX_LEN = 32;
+    static constexpr size_t AP_SSID_PREFIX_LEN = 25;
+    static constexpr size_t AP_SSID_SUFFIX_LEN = 7;
+
+    const std::string &app_name = App.get_name();
+    const char *name_ptr = app_name.c_str();
+    size_t name_len = app_name.length();
+
+    if (name_len <= AP_SSID_MAX_LEN) {
+      // Name fits, use directly
+      this->ap_.set_ssid(name_ptr);
+    } else {
+      // Name too long, need to truncate into stack buffer
+      char ssid_buf[AP_SSID_MAX_LEN + 1];
       if (App.is_name_add_mac_suffix_enabled()) {
         // Keep first 25 chars and last 7 chars (MAC suffix), remove middle
-        name.erase(25, name.length() - 32);
+        memcpy(ssid_buf, name_ptr, AP_SSID_PREFIX_LEN);
+        memcpy(ssid_buf + AP_SSID_PREFIX_LEN, name_ptr + name_len - AP_SSID_SUFFIX_LEN, AP_SSID_SUFFIX_LEN);
       } else {
-        name.resize(32);
+        memcpy(ssid_buf, name_ptr, AP_SSID_MAX_LEN);
       }
+      ssid_buf[AP_SSID_MAX_LEN] = '\0';
+      this->ap_.set_ssid(ssid_buf);
     }
-    this->ap_.set_ssid(name);
   }
   this->ap_setup_ = this->wifi_start_ap_(this->ap_);
 

esphome/core/entity_base.cpp

@@ -92,6 +92,48 @@ StringRef EntityBase::get_object_id_to(std::span<char, OBJECT_ID_MAX_LEN> buf) c
 
 uint32_t EntityBase::get_object_id_hash() { return this->object_id_hash_; }
 
+// Migrate preference data from old_key to new_key if they differ.
+// This helper is exposed so callers with custom key computation (like TextPrefs)
+// can use it for manual migration. See: https://github.com/esphome/backlog/issues/85
+//
+// FUTURE IMPLEMENTATION:
+// This will require raw load/save methods on ESPPreferenceObject that take uint8_t* and size.
+//   void EntityBase::migrate_entity_preference_(size_t size, uint32_t old_key, uint32_t new_key) {
+//     if (old_key == new_key)
+//       return;
+//     auto old_pref = global_preferences->make_preference(size, old_key);
+//     auto new_pref = global_preferences->make_preference(size, new_key);
+//     SmallBufferWithHeapFallback<64> buffer(size);
+//     if (old_pref.load(buffer.data(), size)) {
+//       new_pref.save(buffer.data(), size);
+//     }
+//   }
+
+ESPPreferenceObject EntityBase::make_entity_preference_(size_t size, uint32_t version) {
+  // This helper centralizes preference creation to enable fixing hash collisions.
+  // See: https://github.com/esphome/backlog/issues/85
+  //
+  // COLLISION PROBLEM: get_preference_hash() uses fnv1_hash on sanitized object_id.
+  // Multiple entity names can sanitize to the same object_id:
+  //   - "Living Room" and "living_room" both become "living_room"
+  //   - UTF-8 names like "温度" and "湿度" both become "__" (underscores)
+  // This causes entities to overwrite each other's stored preferences.
+  //
+  // FUTURE MIGRATION: When implementing get_preference_hash_v2() that hashes
+  // the original entity name (not sanitized object_id):
+  //
+  //   uint32_t old_key = this->get_preference_hash() ^ version;
+  //   uint32_t new_key = this->get_preference_hash_v2() ^ version;
+  //   this->migrate_entity_preference_(size, old_key, new_key);
+  //   return global_preferences->make_preference(size, new_key);
+  //
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+  uint32_t key = this->get_preference_hash() ^ version;
+#pragma GCC diagnostic pop
+  return global_preferences->make_preference(size, key);
+}
+
 std::string EntityBase_DeviceClass::get_device_class() {
   if (this->device_class_ == nullptr) {
     return "";

esphome/core/entity_base.h

@@ -6,6 +6,7 @@
 #include "string_ref.h"
 #include "helpers.h"
 #include "log.h"
+#include "preferences.h"
 
 #ifdef USE_DEVICES
 #include "device.h"
@@ -138,7 +139,12 @@ class EntityBase {
    * from previous versions, so existing single-device configurations will continue to work.
    *
    * @return uint32_t The unique hash for preferences, including device_id if available.
+   * @deprecated Use make_entity_preference<T>() instead, or preferences won't be migrated.
+   * See https://github.com/esphome/backlog/issues/85
    */
+  ESPDEPRECATED("Use make_entity_preference<T>() instead, or preferences won't be migrated. "
+                "See https://github.com/esphome/backlog/issues/85. Will be removed in 2027.1.0.",
+                "2026.7.0")
   uint32_t get_preference_hash() {
 #ifdef USE_DEVICES
     // Combine object_id_hash with device_id to ensure uniqueness across devices
@@ -151,7 +157,19 @@ class EntityBase {
 #endif
   }
 
+  /// Create a preference object for storing this entity's state/settings.
+  /// @tparam T The type of data to store (must be trivially copyable)
+  /// @param version Optional version hash XORed with preference key (change when struct layout changes)
+  template<typename T> ESPPreferenceObject make_entity_preference(uint32_t version = 0) {
+    static_assert(std::is_trivially_copyable<T>::value, "T must be trivially copyable");
+    return this->make_entity_preference_(sizeof(T), version);
+  }
+
  protected:
+  /// Non-template helper for make_entity_preference() to avoid code bloat.
+  /// When preference hash algorithm changes, migration logic goes here.
+  ESPPreferenceObject make_entity_preference_(size_t size, uint32_t version);
+
   void calc_object_id_();
 
   StringRef name_;

esphome/core/helpers.cpp

@@ -3,6 +3,7 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/log.h"
+#include "esphome/core/progmem.h"
 #include "esphome/core/string_ref.h"
 
 #include <strings.h>
@@ -451,15 +452,15 @@ std::string format_bin(const uint8_t *data, size_t length) {
 }
 
 ParseOnOffState parse_on_off(const char *str, const char *on, const char *off) {
-  if (on == nullptr && strcasecmp(str, "on") == 0)
+  if (on == nullptr && ESPHOME_strcasecmp_P(str, ESPHOME_PSTR("on")) == 0)
     return PARSE_ON;
   if (on != nullptr && strcasecmp(str, on) == 0)
     return PARSE_ON;
-  if (off == nullptr && strcasecmp(str, "off") == 0)
+  if (off == nullptr && ESPHOME_strcasecmp_P(str, ESPHOME_PSTR("off")) == 0)
     return PARSE_OFF;
   if (off != nullptr && strcasecmp(str, off) == 0)
     return PARSE_OFF;
-  if (strcasecmp(str, "toggle") == 0)
+  if (ESPHOME_strcasecmp_P(str, ESPHOME_PSTR("toggle")) == 0)
     return PARSE_TOGGLE;
 
   return PARSE_NONE;

esphome/core/helpers.h

@@ -148,6 +148,25 @@ template<typename T, size_t N> class StaticVector {
   size_t count_{0};
 
  public:
+  // Default constructor
+  StaticVector() = default;
+
+  // Iterator range constructor
+  template<typename InputIt> StaticVector(InputIt first, InputIt last) {
+    while (first != last && count_ < N) {
+      data_[count_++] = *first++;
+    }
+  }
+
+  // Initializer list constructor
+  StaticVector(std::initializer_list<T> init) {
+    for (const auto &val : init) {
+      if (count_ >= N)
+        break;
+      data_[count_++] = val;
+    }
+  }
+
   // Minimal vector-compatible interface - only what we actually use
   void push_back(const T &value) {
     if (count_ < N) {
@@ -155,6 +174,17 @@ template<typename T, size_t N> class StaticVector {
     }
   }
 
+  // Clear all elements
+  void clear() { count_ = 0; }
+
+  // Assign from iterator range
+  template<typename InputIt> void assign(InputIt first, InputIt last) {
+    count_ = 0;
+    while (first != last && count_ < N) {
+      data_[count_++] = *first++;
+    }
+  }
+
   // Return reference to next element and increment count (with bounds checking)
   T &emplace_next() {
     if (count_ >= N) {
@@ -186,6 +216,10 @@ template<typename T, size_t N> class StaticVector {
   reverse_iterator rend() { return reverse_iterator(begin()); }
   const_reverse_iterator rbegin() const { return const_reverse_iterator(end()); }
   const_reverse_iterator rend() const { return const_reverse_iterator(begin()); }
+
+  // Conversion to std::span for compatibility with span-based APIs
+  operator std::span<T>() { return std::span<T>(data_.data(), count_); }
+  operator std::span<const T>() const { return std::span<const T>(data_.data(), count_); }
 };
 
 /// Fixed-capacity vector - allocates once at runtime, never reallocates
@@ -655,9 +689,11 @@ inline uint32_t fnv1_hash_object_id(const char *str, size_t len) {
 }
 
 /// snprintf-like function returning std::string of maximum length \p len (excluding null terminator).
+/// @warning Allocates heap memory. Use snprintf() with a stack buffer instead.
 std::string __attribute__((format(printf, 1, 3))) str_snprintf(const char *fmt, size_t len, ...);
 
 /// sprintf-like function returning std::string.
+/// @warning Allocates heap memory. Use snprintf() with a stack buffer instead.
 std::string __attribute__((format(printf, 1, 2))) str_sprintf(const char *fmt, ...);
 
 #ifdef USE_ESP8266

esphome/core/progmem.h

@@ -12,6 +12,10 @@
 #define ESPHOME_strncpy_P strncpy_P
 #define ESPHOME_strncat_P strncat_P
 #define ESPHOME_snprintf_P snprintf_P
+#define ESPHOME_strcmp_P strcmp_P
+#define ESPHOME_strcasecmp_P strcasecmp_P
+#define ESPHOME_strncmp_P strncmp_P
+#define ESPHOME_strncasecmp_P strncasecmp_P
 // Type for pointers to PROGMEM strings (for use with ESPHOME_F return values)
 using ProgmemStr = const __FlashStringHelper *;
 #else
@@ -21,6 +25,10 @@ using ProgmemStr = const __FlashStringHelper *;
 #define ESPHOME_strncpy_P strncpy
 #define ESPHOME_strncat_P strncat
 #define ESPHOME_snprintf_P snprintf
+#define ESPHOME_strcmp_P strcmp
+#define ESPHOME_strcasecmp_P strcasecmp
+#define ESPHOME_strncmp_P strncmp
+#define ESPHOME_strncasecmp_P strncasecmp
 // Type for pointers to strings (no PROGMEM on non-ESP8266 platforms)
 using ProgmemStr = const char *;
 #endif

esphome/espota2.py

@@ -154,6 +154,12 @@ def check_error(data: list[int] | bytes, expect: int | list[int] | None) -> None
     """
     if not expect:
         return
+    if not data:
+        raise OTAError(
+            "Error: Device closed connection without responding. "
+            "This may indicate the device ran out of memory, "
+            "a network issue, or the connection was interrupted."
+        )
     dat = data[0]
     if dat == RESPONSE_ERROR_MAGIC:
         raise OTAError("Error: Invalid magic byte")

platformio.ini

@@ -114,7 +114,7 @@ lib_deps =
     ESP8266WiFi                           ; wifi (Arduino built-in)
     Update                                ; ota (Arduino built-in)
     ESP32Async/ESPAsyncTCP@2.0.0          ; async_tcp
-    ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
+    ESP32Async/ESPAsyncWebServer@3.9.5    ; web_server_base
     makuna/NeoPixelBus@2.7.3              ; neopixelbus
     ESP8266HTTPClient                     ; http_request (Arduino built-in)
     ESP8266mDNS                           ; mdns (Arduino built-in)
@@ -201,7 +201,7 @@ framework = arduino
 lib_deps =
     ${common:arduino.lib_deps}
     bblanchon/ArduinoJson@7.4.2           ; json
-    ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
+    ESP32Async/ESPAsyncWebServer@3.9.5    ; web_server_base
 build_flags =
     ${common:arduino.build_flags}
     -DUSE_RP2040
@@ -212,12 +212,12 @@ build_unflags =
 ; This are common settings for the LibreTiny (all variants) using Arduino.
 [common:libretiny-arduino]
 extends = common:arduino
-platform = libretiny@1.9.2
+platform = https://github.com/libretiny-eu/libretiny.git#v1.11.0
 framework = arduino
 lib_compat_mode = soft
 lib_deps =
     bblanchon/ArduinoJson@7.4.2           ; json
-    ESP32Async/ESPAsyncWebServer@3.7.8    ; web_server_base
+    ESP32Async/ESPAsyncWebServer@3.9.5    ; web_server_base
     droscy/esp_wireguard@0.4.2            ; wireguard
 build_flags =
     ${common:arduino.build_flags}

pyproject.toml

@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools==80.10.1", "wheel>=0.43,<0.47"]
+requires = ["setuptools==80.10.2", "wheel>=0.43,<0.47"]
 build-backend = "setuptools.build_meta"
 
 [project]

requirements.txt

@@ -12,7 +12,7 @@ platformio==6.1.18  # When updating platformio, also update /docker/Dockerfile
 esptool==5.1.0
 click==8.1.7
 esphome-dashboard==20260110.0
-aioesphomeapi==43.13.0
+aioesphomeapi==43.14.0
 zeroconf==0.148.0
 puremagic==1.30
 ruamel.yaml==0.19.1 # dashboard_import

script/ci-custom.py

@@ -692,6 +692,8 @@ HEAP_ALLOCATING_HELPERS = {
     "str_truncate": "removal (function is unused)",
     "str_upper_case": "removal (function is unused)",
     "str_snake_case": "removal (function is unused)",
+    "str_sprintf": "snprintf() with a stack buffer",
+    "str_snprintf": "snprintf() with a stack buffer",
 }
 
 
@@ -710,7 +712,9 @@ HEAP_ALLOCATING_HELPERS = {
     r"str_sanitize(?!_)|"
     r"str_truncate|"
     r"str_upper_case|"
-    r"str_snake_case"
+    r"str_snake_case|"
+    r"str_sprintf|"
+    r"str_snprintf"
     r")\s*\(" + CPP_RE_EOL,
     include=cpp_include,
     exclude=[

tests/components/http_request/test-custom-ca.esp32-idf.yaml

@@ -0,0 +1,7 @@
+substitutions:
+  verify_ssl: "true"
+
+http_request:
+  ca_certificate_path: $component_dir/test_ca.pem
+
+<<: !include common.yaml