Merge branch 'set_time_string_literals' into integration

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

esphome/components/alarm_control_panel/alarm_control_panel.cpp

@@ -67,52 +67,29 @@ void AlarmControlPanel::add_on_ready_callback(std::function<void()> &&callback)
   this->ready_callback_.add(std::move(callback));
 }
 
-void AlarmControlPanel::arm_away(optional<std::string> code) {
+void AlarmControlPanel::arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(),
+                                       const char *code) {
   auto call = this->make_call();
-  call.arm_away();
-  if (code.has_value())
-    call.set_code(code.value());
+  (call.*arm_method)();
+  if (code != nullptr)
+    call.set_code(code);
   call.perform();
 }
 
-void AlarmControlPanel::arm_home(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_home();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
+void AlarmControlPanel::arm_away(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_away, code); }
+
+void AlarmControlPanel::arm_home(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_home, code); }
+
+void AlarmControlPanel::arm_night(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_night, code); }
+
+void AlarmControlPanel::arm_vacation(const char *code) {
+  this->arm_with_code_(&AlarmControlPanelCall::arm_vacation, code);
 }
 
-void AlarmControlPanel::arm_night(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_night();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
+void AlarmControlPanel::arm_custom_bypass(const char *code) {
+  this->arm_with_code_(&AlarmControlPanelCall::arm_custom_bypass, code);
 }
 
-void AlarmControlPanel::arm_vacation(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_vacation();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
-
-void AlarmControlPanel::arm_custom_bypass(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_custom_bypass();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
-
-void AlarmControlPanel::disarm(optional<std::string> code) {
-  auto call = this->make_call();
-  call.disarm();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
+void AlarmControlPanel::disarm(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::disarm, code); }
 
 }  // namespace esphome::alarm_control_panel

esphome/components/alarm_control_panel/alarm_control_panel.h

@@ -76,37 +76,53 @@ class AlarmControlPanel : public EntityBase {
    *
    * @param code The code
    */
-  void arm_away(optional<std::string> code = nullopt);
+  void arm_away(const char *code = nullptr);
+  void arm_away(const optional<std::string> &code) {
+    this->arm_away(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in home mode
    *
    * @param code The code
    */
-  void arm_home(optional<std::string> code = nullopt);
+  void arm_home(const char *code = nullptr);
+  void arm_home(const optional<std::string> &code) {
+    this->arm_home(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in night mode
    *
    * @param code The code
    */
-  void arm_night(optional<std::string> code = nullopt);
+  void arm_night(const char *code = nullptr);
+  void arm_night(const optional<std::string> &code) {
+    this->arm_night(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in vacation mode
    *
    * @param code The code
    */
-  void arm_vacation(optional<std::string> code = nullopt);
+  void arm_vacation(const char *code = nullptr);
+  void arm_vacation(const optional<std::string> &code) {
+    this->arm_vacation(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in custom bypass mode
    *
    * @param code The code
    */
-  void arm_custom_bypass(optional<std::string> code = nullopt);
+  void arm_custom_bypass(const char *code = nullptr);
+  void arm_custom_bypass(const optional<std::string> &code) {
+    this->arm_custom_bypass(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** disarm the alarm
    *
    * @param code The code
    */
-  void disarm(optional<std::string> code = nullopt);
+  void disarm(const char *code = nullptr);
+  void disarm(const optional<std::string> &code) { this->disarm(code.has_value() ? code.value().c_str() : nullptr); }
 
   /** Get the state
    *
@@ -118,6 +134,8 @@ class AlarmControlPanel : public EntityBase {
 
  protected:
   friend AlarmControlPanelCall;
+  // Helper to reduce code duplication for arm/disarm methods
+  void arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(), const char *code);
   // in order to store last panel state in flash
   ESPPreferenceObject pref_;
   // current state

esphome/components/alarm_control_panel/alarm_control_panel_call.cpp

@@ -10,8 +10,10 @@ static const char *const TAG = "alarm_control_panel";
 
 AlarmControlPanelCall::AlarmControlPanelCall(AlarmControlPanel *parent) : parent_(parent) {}
 
-AlarmControlPanelCall &AlarmControlPanelCall::set_code(const std::string &code) {
-  this->code_ = code;
+AlarmControlPanelCall &AlarmControlPanelCall::set_code(const char *code) {
+  if (code != nullptr) {
+    this->code_ = std::string(code);
+  }
   return *this;
 }
 

esphome/components/alarm_control_panel/alarm_control_panel_call.h

@@ -14,7 +14,8 @@ class AlarmControlPanelCall {
  public:
   AlarmControlPanelCall(AlarmControlPanel *parent);
 
-  AlarmControlPanelCall &set_code(const std::string &code);
+  AlarmControlPanelCall &set_code(const char *code);
+  AlarmControlPanelCall &set_code(const std::string &code) { return this->set_code(code.c_str()); }
   AlarmControlPanelCall &arm_away();
   AlarmControlPanelCall &arm_home();
   AlarmControlPanelCall &arm_night();

esphome/components/alarm_control_panel/automation.h

@@ -66,15 +66,7 @@ template<typename... Ts> class ArmAwayAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_away();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_away(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
@@ -86,15 +78,7 @@ template<typename... Ts> class ArmHomeAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_home();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_home(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
@@ -106,15 +90,7 @@ template<typename... Ts> class ArmNightAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_night();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_night(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;

esphome/components/api/api_connection.cpp

@@ -1712,17 +1712,16 @@ void APIConnection::on_home_assistant_state_response(const HomeAssistantStateRes
     }
 
     // Create null-terminated state for callback (parse_number needs null-termination)
-    // HA state max length is 255, so 256 byte buffer covers all cases
-    char state_buf[256];
-    size_t copy_len = msg.state.size();
-    if (copy_len >= sizeof(state_buf)) {
-      copy_len = sizeof(state_buf) - 1;  // Truncate to leave space for null terminator
+    // HA state max length is 255 characters, but attributes can be much longer
+    // Use stack buffer for common case (states), heap fallback for large attributes
+    size_t state_len = msg.state.size();
+    SmallBufferWithHeapFallback<256> state_buf_alloc(state_len + 1);
+    char *state_buf = reinterpret_cast<char *>(state_buf_alloc.get());
+    if (state_len > 0) {
+      memcpy(state_buf, msg.state.c_str(), state_len);
     }
-    if (copy_len > 0) {
-      memcpy(state_buf, msg.state.c_str(), copy_len);
-    }
-    state_buf[copy_len] = '\0';
-    it.callback(StringRef(state_buf, copy_len));
+    state_buf[state_len] = '\0';
+    it.callback(StringRef(state_buf, state_len));
   }
 }
 #endif

esphome/components/bluetooth_proxy/bluetooth_connection.cpp

@@ -135,8 +135,8 @@ void BluetoothConnection::loop() {
   // - For V3_WITH_CACHE: Services are never sent, disable after INIT state
   // - For V3_WITHOUT_CACHE: Disable only after service discovery is complete
   //   (send_service_ == DONE_SENDING_SERVICES, which is only set after services are sent)
-  if (this->state_ != espbt::ClientState::INIT && (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE ||
-                                                   this->send_service_ == DONE_SENDING_SERVICES)) {
+  if (this->state() != espbt::ClientState::INIT && (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE ||
+                                                    this->send_service_ == DONE_SENDING_SERVICES)) {
     this->disable_loop();
   }
 }

esphome/components/cs5460a/cs5460a.h

@@ -76,7 +76,6 @@ class CS5460AComponent : public Component,
   void restart() { restart_(); }
 
   void setup() override;
-  void loop() override {}
   void dump_config() override;
 
  protected:

esphome/components/datetime/date_entity.cpp

@@ -106,9 +106,9 @@ DateCall &DateCall::set_date(uint16_t year, uint8_t month, uint8_t day) {
 
 DateCall &DateCall::set_date(ESPTime time) { return this->set_date(time.year, time.month, time.day_of_month); };
 
-DateCall &DateCall::set_date(const std::string &date) {
+DateCall &DateCall::set_date(const char *date, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(date, val)) {
+  if (!ESPTime::strptime(date, len, val)) {
     ESP_LOGE(TAG, "Could not convert the date string to an ESPTime object");
     return *this;
   }

esphome/components/datetime/date_entity.h

@@ -67,7 +67,9 @@ class DateCall {
   void perform();
   DateCall &set_date(uint16_t year, uint8_t month, uint8_t day);
   DateCall &set_date(ESPTime time);
-  DateCall &set_date(const std::string &date);
+  DateCall &set_date(const char *date, size_t len);
+  DateCall &set_date(const char *date) { return this->set_date(date, strlen(date)); }
+  DateCall &set_date(const std::string &date) { return this->set_date(date.c_str(), date.size()); }
 
   DateCall &set_year(uint16_t year) {
     this->year_ = year;

esphome/components/datetime/datetime_entity.cpp

@@ -163,9 +163,9 @@ DateTimeCall &DateTimeCall::set_datetime(ESPTime datetime) {
                             datetime.second);
 };
 
-DateTimeCall &DateTimeCall::set_datetime(const std::string &datetime) {
+DateTimeCall &DateTimeCall::set_datetime(const char *datetime, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(datetime, val)) {
+  if (!ESPTime::strptime(datetime, len, val)) {
     ESP_LOGE(TAG, "Could not convert the time string to an ESPTime object");
     return *this;
   }

esphome/components/datetime/datetime_entity.h

@@ -71,7 +71,11 @@ class DateTimeCall {
   void perform();
   DateTimeCall &set_datetime(uint16_t year, uint8_t month, uint8_t day, uint8_t hour, uint8_t minute, uint8_t second);
   DateTimeCall &set_datetime(ESPTime datetime);
-  DateTimeCall &set_datetime(const std::string &datetime);
+  DateTimeCall &set_datetime(const char *datetime, size_t len);
+  DateTimeCall &set_datetime(const char *datetime) { return this->set_datetime(datetime, strlen(datetime)); }
+  DateTimeCall &set_datetime(const std::string &datetime) {
+    return this->set_datetime(datetime.c_str(), datetime.size());
+  }
   DateTimeCall &set_datetime(time_t epoch_seconds);
 
   DateTimeCall &set_year(uint16_t year) {

esphome/components/datetime/time_entity.cpp

@@ -74,9 +74,9 @@ TimeCall &TimeCall::set_time(uint8_t hour, uint8_t minute, uint8_t second) {
 
 TimeCall &TimeCall::set_time(ESPTime time) { return this->set_time(time.hour, time.minute, time.second); };
 
-TimeCall &TimeCall::set_time(const std::string &time) {
+TimeCall &TimeCall::set_time(const char *time, size_t len) {
   ESPTime val{};
-  if (!ESPTime::strptime(time, val)) {
+  if (!ESPTime::strptime(time, len, val)) {
     ESP_LOGE(TAG, "Could not convert the time string to an ESPTime object");
     return *this;
   }

esphome/components/datetime/time_entity.h

@@ -69,7 +69,9 @@ class TimeCall {
   void perform();
   TimeCall &set_time(uint8_t hour, uint8_t minute, uint8_t second);
   TimeCall &set_time(ESPTime time);
-  TimeCall &set_time(const std::string &time);
+  TimeCall &set_time(const char *time, size_t len);
+  TimeCall &set_time(const char *time) { return this->set_time(time, strlen(time)); }
+  TimeCall &set_time(const std::string &time) { return this->set_time(time.c_str(), time.size()); }
 
   TimeCall &set_hour(uint8_t hour) {
     this->hour_ = hour;

esphome/components/debug/debug_esp8266.cpp

@@ -3,21 +3,80 @@
 #include "esphome/core/log.h"
 #include <Esp.h>
 
+extern "C" {
+#include <user_interface.h>
+
+// Global reset info struct populated by SDK at boot
+extern struct rst_info resetInfo;
+
+// Core version - either a string pointer or a version number to format as hex
+extern uint32_t core_version;
+extern const char *core_release;
+}
+
 namespace esphome {
 namespace debug {
 
 static const char *const TAG = "debug";
 
+// Get reset reason string from reason code (no heap allocation)
+// Returns LogString* pointing to flash (PROGMEM) on ESP8266
+static const LogString *get_reset_reason_str(uint32_t reason) {
+  switch (reason) {
+    case REASON_DEFAULT_RST:
+      return LOG_STR("Power On");
+    case REASON_WDT_RST:
+      return LOG_STR("Hardware Watchdog");
+    case REASON_EXCEPTION_RST:
+      return LOG_STR("Exception");
+    case REASON_SOFT_WDT_RST:
+      return LOG_STR("Software Watchdog");
+    case REASON_SOFT_RESTART:
+      return LOG_STR("Software/System restart");
+    case REASON_DEEP_SLEEP_AWAKE:
+      return LOG_STR("Deep-Sleep Wake");
+    case REASON_EXT_SYS_RST:
+      return LOG_STR("External System");
+    default:
+      return LOG_STR("Unknown");
+  }
+}
+
+// Size for core version hex buffer
+static constexpr size_t CORE_VERSION_BUFFER_SIZE = 12;
+
+// Get core version string (no heap allocation)
+// Returns either core_release directly or formats core_version as hex into provided buffer
+static const char *get_core_version_str(std::span<char, CORE_VERSION_BUFFER_SIZE> buffer) {
+  if (core_release != nullptr) {
+    return core_release;
+  }
+  snprintf_P(buffer.data(), CORE_VERSION_BUFFER_SIZE, PSTR("%08x"), core_version);
+  return buffer.data();
+}
+
+// Size for reset info buffer
+static constexpr size_t RESET_INFO_BUFFER_SIZE = 200;
+
+// Get detailed reset info string (no heap allocation)
+// For watchdog/exception resets, includes detailed exception info
+static const char *get_reset_info_str(std::span<char, RESET_INFO_BUFFER_SIZE> buffer, uint32_t reason) {
+  if (reason >= REASON_WDT_RST && reason <= REASON_SOFT_WDT_RST) {
+    snprintf_P(buffer.data(), RESET_INFO_BUFFER_SIZE,
+               PSTR("Fatal exception:%d flag:%d (%s) epc1:0x%08x epc2:0x%08x epc3:0x%08x excvaddr:0x%08x depc:0x%08x"),
+               static_cast<int>(resetInfo.exccause), static_cast<int>(reason),
+               LOG_STR_ARG(get_reset_reason_str(reason)), resetInfo.epc1, resetInfo.epc2, resetInfo.epc3,
+               resetInfo.excvaddr, resetInfo.depc);
+    return buffer.data();
+  }
+  return LOG_STR_ARG(get_reset_reason_str(reason));
+}
+
 const char *DebugComponent::get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
-  char *buf = buffer.data();
-#if !defined(CLANG_TIDY)
-  String reason = ESP.getResetReason();  // NOLINT
-  snprintf_P(buf, RESET_REASON_BUFFER_SIZE, PSTR("%s"), reason.c_str());
-  return buf;
-#else
-  buf[0] = '\0';
-  return buf;
-#endif
+  // Copy from flash to provided buffer
+  strncpy_P(buffer.data(), (PGM_P) get_reset_reason_str(resetInfo.reason), RESET_REASON_BUFFER_SIZE - 1);
+  buffer[RESET_REASON_BUFFER_SIZE - 1] = '\0';
+  return buffer.data();
 }
 
 const char *DebugComponent::get_wakeup_cause_(std::span<char, RESET_REASON_BUFFER_SIZE> buffer) {
@@ -33,37 +92,42 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   constexpr size_t size = DEVICE_INFO_BUFFER_SIZE;
   char *buf = buffer.data();
 
-  const char *flash_mode;
+  const LogString *flash_mode;
   switch (ESP.getFlashChipMode()) {  // NOLINT(readability-static-accessed-through-instance)
     case FM_QIO:
-      flash_mode = "QIO";
+      flash_mode = LOG_STR("QIO");
       break;
     case FM_QOUT:
-      flash_mode = "QOUT";
+      flash_mode = LOG_STR("QOUT");
       break;
     case FM_DIO:
-      flash_mode = "DIO";
+      flash_mode = LOG_STR("DIO");
       break;
     case FM_DOUT:
-      flash_mode = "DOUT";
+      flash_mode = LOG_STR("DOUT");
       break;
     default:
-      flash_mode = "UNKNOWN";
+      flash_mode = LOG_STR("UNKNOWN");
   }
-  uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT
-  uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT
-  ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed, flash_mode);
+  uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT(readability-static-accessed-through-instance)
+  uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT(readability-static-accessed-through-instance)
+  ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed,
+           LOG_STR_ARG(flash_mode));
   pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
-                          flash_mode);
+                          LOG_STR_ARG(flash_mode));
 
-#if !defined(CLANG_TIDY)
   char reason_buffer[RESET_REASON_BUFFER_SIZE];
-  const char *reset_reason = get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
+  const char *reset_reason = get_reset_reason_(reason_buffer);
+  char core_version_buffer[CORE_VERSION_BUFFER_SIZE];
+  char reset_info_buffer[RESET_INFO_BUFFER_SIZE];
+  // NOLINTBEGIN(readability-static-accessed-through-instance)
   uint32_t chip_id = ESP.getChipId();
   uint8_t boot_version = ESP.getBootVersion();
   uint8_t boot_mode = ESP.getBootMode();
   uint8_t cpu_freq = ESP.getCpuFreqMHz();
   uint32_t flash_chip_id = ESP.getFlashChipId();
+  const char *sdk_version = ESP.getSdkVersion();
+  // NOLINTEND(readability-static-accessed-through-instance)
 
   ESP_LOGD(TAG,
            "Chip ID: 0x%08" PRIX32 "\n"
@@ -74,19 +138,18 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
            "Flash Chip ID=0x%08" PRIX32 "\n"
            "Reset Reason: %s\n"
            "Reset Info: %s",
-           chip_id, ESP.getSdkVersion(), ESP.getCoreVersion().c_str(), boot_version, boot_mode, cpu_freq, flash_chip_id,
-           reset_reason, ESP.getResetInfo().c_str());
+           chip_id, sdk_version, get_core_version_str(core_version_buffer), boot_version, boot_mode, cpu_freq,
+           flash_chip_id, reset_reason, get_reset_info_str(reset_info_buffer, resetInfo.reason));
 
   pos = buf_append_printf(buf, size, pos, "|Chip: 0x%08" PRIX32, chip_id);
-  pos = buf_append_printf(buf, size, pos, "|SDK: %s", ESP.getSdkVersion());
-  pos = buf_append_printf(buf, size, pos, "|Core: %s", ESP.getCoreVersion().c_str());
+  pos = buf_append_printf(buf, size, pos, "|SDK: %s", sdk_version);
+  pos = buf_append_printf(buf, size, pos, "|Core: %s", get_core_version_str(core_version_buffer));
   pos = buf_append_printf(buf, size, pos, "|Boot: %u", boot_version);
   pos = buf_append_printf(buf, size, pos, "|Mode: %u", boot_mode);
   pos = buf_append_printf(buf, size, pos, "|CPU: %u", cpu_freq);
   pos = buf_append_printf(buf, size, pos, "|Flash: 0x%08" PRIX32, flash_chip_id);
   pos = buf_append_printf(buf, size, pos, "|Reset: %s", reset_reason);
-  pos = buf_append_printf(buf, size, pos, "|%s", ESP.getResetInfo().c_str());
-#endif
+  pos = buf_append_printf(buf, size, pos, "|%s", get_reset_info_str(reset_info_buffer, resetInfo.reason));
 
   return pos;
 }

esphome/components/esp32_ble_client/ble_client_base.cpp

@@ -50,7 +50,7 @@ void BLEClientBase::loop() {
     this->set_state(espbt::ClientState::INIT);
     return;
   }
-  if (this->state_ == espbt::ClientState::INIT) {
+  if (this->state() == espbt::ClientState::INIT) {
     auto ret = esp_ble_gattc_app_register(this->app_id);
     if (ret) {
       ESP_LOGE(TAG, "gattc app register failed. app_id=%d code=%d", this->app_id, ret);
@@ -60,7 +60,7 @@ void BLEClientBase::loop() {
   }
   // If idle, we can disable the loop as connect()
   // will enable it again when a connection is needed.
-  else if (this->state_ == espbt::ClientState::IDLE) {
+  else if (this->state() == espbt::ClientState::IDLE) {
     this->disable_loop();
   }
 }
@@ -86,7 +86,7 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
     return false;
   if (this->address_ == 0 || device.address_uint64() != this->address_)
     return false;
-  if (this->state_ != espbt::ClientState::IDLE)
+  if (this->state() != espbt::ClientState::IDLE)
     return false;
 
   this->log_event_("Found device");
@@ -102,10 +102,10 @@ bool BLEClientBase::parse_device(const espbt::ESPBTDevice &device) {
 
 void BLEClientBase::connect() {
   // Prevent duplicate connection attempts
-  if (this->state_ == espbt::ClientState::CONNECTING || this->state_ == espbt::ClientState::CONNECTED ||
-      this->state_ == espbt::ClientState::ESTABLISHED) {
+  if (this->state() == espbt::ClientState::CONNECTING || this->state() == espbt::ClientState::CONNECTED ||
+      this->state() == espbt::ClientState::ESTABLISHED) {
     ESP_LOGW(TAG, "[%d] [%s] Connection already in progress, state=%s", this->connection_index_, this->address_str_,
-             espbt::client_state_to_string(this->state_));
+             espbt::client_state_to_string(this->state()));
     return;
   }
   ESP_LOGI(TAG, "[%d] [%s] 0x%02x Connecting", this->connection_index_, this->address_str_, this->remote_addr_type_);
@@ -133,12 +133,12 @@ void BLEClientBase::connect() {
 esp_err_t BLEClientBase::pair() { return esp_ble_set_encryption(this->remote_bda_, ESP_BLE_SEC_ENCRYPT); }
 
 void BLEClientBase::disconnect() {
-  if (this->state_ == espbt::ClientState::IDLE || this->state_ == espbt::ClientState::DISCONNECTING) {
+  if (this->state() == espbt::ClientState::IDLE || this->state() == espbt::ClientState::DISCONNECTING) {
     ESP_LOGI(TAG, "[%d] [%s] Disconnect requested, but already %s", this->connection_index_, this->address_str_,
-             espbt::client_state_to_string(this->state_));
+             espbt::client_state_to_string(this->state()));
     return;
   }
-  if (this->state_ == espbt::ClientState::CONNECTING || this->conn_id_ == UNSET_CONN_ID) {
+  if (this->state() == espbt::ClientState::CONNECTING || this->conn_id_ == UNSET_CONN_ID) {
     ESP_LOGD(TAG, "[%d] [%s] Disconnect before connected, disconnect scheduled", this->connection_index_,
              this->address_str_);
     this->want_disconnect_ = true;
@@ -150,7 +150,7 @@ void BLEClientBase::disconnect() {
 void BLEClientBase::unconditional_disconnect() {
   // Disconnect without checking the state.
   ESP_LOGI(TAG, "[%d] [%s] Disconnecting (conn_id: %d).", this->connection_index_, this->address_str_, this->conn_id_);
-  if (this->state_ == espbt::ClientState::DISCONNECTING) {
+  if (this->state() == espbt::ClientState::DISCONNECTING) {
     this->log_error_("Already disconnecting");
     return;
   }
@@ -170,7 +170,7 @@ void BLEClientBase::unconditional_disconnect() {
     this->log_gattc_warning_("esp_ble_gattc_close", err);
   }
 
-  if (this->state_ == espbt::ClientState::DISCOVERED) {
+  if (this->state() == espbt::ClientState::DISCOVERED) {
     this->set_address(0);
     this->set_state(espbt::ClientState::IDLE);
   } else {
@@ -295,18 +295,18 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       // ESP-IDF's BLE stack may send ESP_GATTC_OPEN_EVT after esp_ble_gattc_open() returns an
       // error, if the error occurred at the BTA/GATT layer. This can result in the event
       // arriving after we've already transitioned to IDLE state.
-      if (this->state_ == espbt::ClientState::IDLE) {
+      if (this->state() == espbt::ClientState::IDLE) {
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_OPEN_EVT in IDLE state (status=%d), ignoring", this->connection_index_,
                  this->address_str_, param->open.status);
         break;
       }
 
-      if (this->state_ != espbt::ClientState::CONNECTING) {
+      if (this->state() != espbt::ClientState::CONNECTING) {
         // This should not happen but lets log it in case it does
         // because it means we have a bad assumption about how the
         // ESP BT stack works.
         ESP_LOGE(TAG, "[%d] [%s] ESP_GATTC_OPEN_EVT in %s state (status=%d)", this->connection_index_,
-                 this->address_str_, espbt::client_state_to_string(this->state_), param->open.status);
+                 this->address_str_, espbt::client_state_to_string(this->state()), param->open.status);
       }
       if (param->open.status != ESP_GATT_OK && param->open.status != ESP_GATT_ALREADY_OPEN) {
         this->log_gattc_warning_("Connection open", param->open.status);
@@ -327,7 +327,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
       if (this->connection_type_ == espbt::ConnectionType::V3_WITH_CACHE) {
         // Cached connections already connected with medium parameters, no update needed
         // only set our state, subclients might have more stuff to do yet.
-        this->state_ = espbt::ClientState::ESTABLISHED;
+        this->set_state_internal_(espbt::ClientState::ESTABLISHED);
         break;
       }
       // For V3_WITHOUT_CACHE, we already set fast params before connecting
@@ -356,7 +356,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
         return false;
       // Check if we were disconnected while waiting for service discovery
       if (param->disconnect.reason == ESP_GATT_CONN_TERMINATE_PEER_USER &&
-          this->state_ == espbt::ClientState::CONNECTED) {
+          this->state() == espbt::ClientState::CONNECTED) {
         this->log_warning_("Remote closed during discovery");
       } else {
         ESP_LOGD(TAG, "[%d] [%s] ESP_GATTC_DISCONNECT_EVT, reason 0x%02x", this->connection_index_, this->address_str_,
@@ -433,7 +433,7 @@ bool BLEClientBase::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_
 #endif
       }
       ESP_LOGI(TAG, "[%d] [%s] Service discovery complete", this->connection_index_, this->address_str_);
-      this->state_ = espbt::ClientState::ESTABLISHED;
+      this->set_state_internal_(espbt::ClientState::ESTABLISHED);
       break;
     }
     case ESP_GATTC_READ_DESCR_EVT: {

esphome/components/esp32_ble_client/ble_client_base.h

@@ -44,7 +44,7 @@ class BLEClientBase : public espbt::ESPBTClient, public Component {
   void unconditional_disconnect();
   void release_services();
 
-  bool connected() { return this->state_ == espbt::ClientState::ESTABLISHED; }
+  bool connected() { return this->state() == espbt::ClientState::ESTABLISHED; }
 
   void set_auto_connect(bool auto_connect) { this->auto_connect_ = auto_connect; }
 

esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp

@@ -105,15 +105,13 @@ void ESP32BLETracker::loop() {
   }
 
   // Check for scan timeout - moved here from scheduler to avoid false reboots
-  // when the loop is blocked
+  // when the loop is blocked. This must run every iteration for safety.
   if (this->scanner_state_ == ScannerState::RUNNING) {
     switch (this->scan_timeout_state_) {
       case ScanTimeoutState::MONITORING: {
-        uint32_t now = App.get_loop_component_start_time();
-        uint32_t timeout_ms = this->scan_duration_ * 2000;
         // Robust time comparison that handles rollover correctly
         // This works because unsigned arithmetic wraps around predictably
-        if ((now - this->scan_start_time_) > timeout_ms) {
+        if ((App.get_loop_component_start_time() - this->scan_start_time_) > this->scan_timeout_ms_) {
           // First time we've seen the timeout exceeded - wait one more loop iteration
           // This ensures all components have had a chance to process pending events
           // This is because esp32_ble may not have run yet and called
@@ -128,13 +126,31 @@ void ESP32BLETracker::loop() {
         ESP_LOGE(TAG, "Scan never terminated, rebooting");
         App.reboot();
         break;
-
       case ScanTimeoutState::INACTIVE:
-        // This case should be unreachable - scanner and timeout states are always synchronized
         break;
     }
   }
 
+  // Fast path: skip expensive client state counting and processing
+  // if no state has changed since last loop iteration.
+  //
+  // How state changes ensure we reach the code below:
+  // - handle_scanner_failure_(): scanner_state_ becomes FAILED via set_scanner_state_(), or
+  //   scan_set_param_failed_ requires scanner_state_==RUNNING which can only be reached via
+  //   set_scanner_state_(RUNNING) in gap_scan_start_complete_() (scan params are set during
+  //   STARTING, not RUNNING, so version is always incremented before this condition is true)
+  // - start_scan_(): scanner_state_ becomes IDLE via set_scanner_state_() in cleanup_scan_state_()
+  // - try_promote_discovered_clients_(): client enters DISCOVERED via set_state(), or
+  //   connecting client finishes (state change), or scanner reaches RUNNING/IDLE
+  //
+  // All conditions that affect the logic below are tied to state changes that increment
+  // state_version_, so the fast path is safe.
+  if (this->state_version_ == this->last_processed_version_) {
+    return;
+  }
+  this->last_processed_version_ = this->state_version_;
+
+  // State changed - do full processing
   ClientStateCounts counts = this->count_client_states_();
   if (counts != this->client_state_counts_) {
     this->client_state_counts_ = counts;
@@ -142,6 +158,7 @@ void ESP32BLETracker::loop() {
              this->client_state_counts_.discovered, this->client_state_counts_.disconnecting);
   }
 
+  // Scanner failure: reached when set_scanner_state_(FAILED) or scan_set_param_failed_ set
   if (this->scanner_state_ == ScannerState::FAILED ||
       (this->scan_set_param_failed_ && this->scanner_state_ == ScannerState::RUNNING)) {
     this->handle_scanner_failure_();
@@ -160,6 +177,8 @@ void ESP32BLETracker::loop() {
 
   */
 
+  // Start scan: reached when scanner_state_ becomes IDLE (via set_scanner_state_()) and
+  // all clients are idle (their state changes increment version when they finish)
   if (this->scanner_state_ == ScannerState::IDLE && !counts.connecting && !counts.disconnecting && !counts.discovered) {
 #ifdef USE_ESP32_BLE_SOFTWARE_COEXISTENCE
     this->update_coex_preference_(false);
@@ -168,8 +187,9 @@ void ESP32BLETracker::loop() {
       this->start_scan_(false);  // first = false
     }
   }
-  // If there is a discovered client and no connecting
-  // clients, then promote the discovered client to ready to connect.
+  // Promote discovered clients: reached when a client's state becomes DISCOVERED (via set_state()),
+  // or when a blocking condition clears (connecting client finishes, scanner reaches RUNNING/IDLE).
+  // All these trigger state_version_ increment, so we'll process and check promotion eligibility.
   // We check both RUNNING and IDLE states because:
   // - RUNNING: gap_scan_event_handler initiates stop_scan_() but promotion can happen immediately
   // - IDLE: Scanner has already stopped (naturally or by gap_scan_event_handler)
@@ -236,6 +256,7 @@ void ESP32BLETracker::start_scan_(bool first) {
   // Start timeout monitoring in loop() instead of using scheduler
   // This prevents false reboots when the loop is blocked
   this->scan_start_time_ = App.get_loop_component_start_time();
+  this->scan_timeout_ms_ = this->scan_duration_ * 2000;
   this->scan_timeout_state_ = ScanTimeoutState::MONITORING;
 
   esp_err_t err = esp_ble_gap_set_scan_params(&this->scan_params_);
@@ -253,6 +274,10 @@ void ESP32BLETracker::start_scan_(bool first) {
 void ESP32BLETracker::register_client(ESPBTClient *client) {
 #ifdef ESPHOME_ESP32_BLE_TRACKER_CLIENT_COUNT
   client->app_id = ++this->app_id_;
+  // Give client a pointer to our state_version_ so it can notify us of state changes.
+  // This enables loop() fast-path optimization - we skip expensive work when no state changed.
+  // Safe because ESP32BLETracker (singleton) outlives all registered clients.
+  client->set_tracker_state_version(&this->state_version_);
   this->clients_.push_back(client);
   this->recalculate_advertisement_parser_types();
 #endif
@@ -382,6 +407,7 @@ void ESP32BLETracker::gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_i
 
 void ESP32BLETracker::set_scanner_state_(ScannerState state) {
   this->scanner_state_ = state;
+  this->state_version_++;
   for (auto *listener : this->scanner_state_listeners_) {
     listener->on_scanner_state(state);
   }

esphome/components/esp32_ble_tracker/esp32_ble_tracker.h

@@ -216,6 +216,19 @@ enum class ConnectionType : uint8_t {
   V3_WITHOUT_CACHE
 };
 
+/// Base class for BLE GATT clients that connect to remote devices.
+///
+/// State Change Tracking Design:
+/// -----------------------------
+/// ESP32BLETracker::loop() needs to know when client states change to avoid
+/// expensive polling. Rather than checking all clients every iteration (~7000/min),
+/// we use a version counter owned by ESP32BLETracker that clients increment on
+/// state changes. The tracker compares versions to skip work when nothing changed.
+///
+/// Ownership: ESP32BLETracker owns state_version_. Clients hold a non-owning
+/// pointer (tracker_state_version_) set during register_client(). Clients
+/// increment the counter through this pointer when their state changes.
+/// The pointer may be null if the client is not registered with a tracker.
 class ESPBTClient : public ESPBTDeviceListener {
  public:
   virtual bool gattc_event_handler(esp_gattc_cb_event_t event, esp_gatt_if_t gattc_if,
@@ -225,26 +238,49 @@ class ESPBTClient : public ESPBTDeviceListener {
   virtual void disconnect() = 0;
   bool disconnect_pending() const { return this->want_disconnect_; }
   void cancel_pending_disconnect() { this->want_disconnect_ = false; }
+
+  /// Set the client state with IDLE handling (clears want_disconnect_).
+  /// Notifies the tracker of state change for loop optimization.
   virtual void set_state(ClientState st) {
-    this->state_ = st;
+    this->set_state_internal_(st);
     if (st == ClientState::IDLE) {
       this->want_disconnect_ = false;
     }
   }
-  ClientState state() const { return state_; }
+  ClientState state() const { return this->state_; }
+
+  /// Called by ESP32BLETracker::register_client() to enable state change notifications.
+  /// The pointer must remain valid for the lifetime of the client (guaranteed since
+  /// ESP32BLETracker is a singleton that outlives all clients).
+  void set_tracker_state_version(uint8_t *version) { this->tracker_state_version_ = version; }
 
   // Memory optimized layout
   uint8_t app_id;  // App IDs are small integers assigned sequentially
 
  protected:
-  // Group 1: 1-byte types
-  ClientState state_{ClientState::INIT};
+  /// Set state without IDLE handling - use for direct state transitions.
+  /// Increments the tracker's state version counter to signal that loop()
+  /// should do full processing on the next iteration.
+  void set_state_internal_(ClientState st) {
+    this->state_ = st;
+    // Notify tracker that state changed (tracker_state_version_ is owned by ESP32BLETracker)
+    if (this->tracker_state_version_ != nullptr) {
+      (*this->tracker_state_version_)++;
+    }
+  }
+
   // want_disconnect_ is set to true when a disconnect is requested
   // while the client is connecting. This is used to disconnect the
   // client as soon as we get the connection id (conn_id_) from the
   // ESP_GATTC_OPEN_EVT event.
   bool want_disconnect_{false};
-  // 2 bytes used, 2 bytes padding
+
+ private:
+  ClientState state_{ClientState::INIT};
+  /// Non-owning pointer to ESP32BLETracker::state_version_. When this client's
+  /// state changes, we increment the tracker's counter to signal that loop()
+  /// should perform full processing. Null if client not registered with tracker.
+  uint8_t *tracker_state_version_{nullptr};
 };
 
 class ESP32BLETracker : public Component,
@@ -380,6 +416,16 @@ class ESP32BLETracker : public Component,
   // Group 4: 1-byte types (enums, uint8_t, bool)
   uint8_t app_id_{0};
   uint8_t scan_start_fail_count_{0};
+  /// Version counter for loop() fast-path optimization. Incremented when:
+  /// - Scanner state changes (via set_scanner_state_())
+  /// - Any registered client's state changes (clients hold pointer to this counter)
+  /// Owned by this class; clients receive non-owning pointer via register_client().
+  /// When loop() sees state_version_ == last_processed_version_, it skips expensive
+  /// client state counting and takes the fast path (just timeout check + return).
+  uint8_t state_version_{0};
+  /// Last state_version_ value when loop() did full processing. Compared against
+  /// state_version_ to detect if any state changed since last iteration.
+  uint8_t last_processed_version_{0};
   ScannerState scanner_state_{ScannerState::IDLE};
   bool scan_continuous_;
   bool scan_active_;
@@ -396,6 +442,8 @@ class ESP32BLETracker : public Component,
     EXCEEDED_WAIT,  // Timeout exceeded, waiting one loop before reboot
   };
   uint32_t scan_start_time_{0};
+  /// Precomputed timeout value: scan_duration_ * 2000
+  uint32_t scan_timeout_ms_{0};
   ScanTimeoutState scan_timeout_state_{ScanTimeoutState::INACTIVE};
 };
 

esphome/components/esp8266/core.cpp

@@ -6,7 +6,11 @@
 #include "esphome/core/helpers.h"
 #include "preferences.h"
 #include <Arduino.h>
-#include <Esp.h>
+#include <core_esp8266_features.h>
+
+extern "C" {
+#include <user_interface.h>
+}
 
 namespace esphome {
 
@@ -16,23 +20,19 @@ void IRAM_ATTR HOT delay(uint32_t ms) { ::delay(ms); }
 uint32_t IRAM_ATTR HOT micros() { return ::micros(); }
 void IRAM_ATTR HOT delayMicroseconds(uint32_t us) { delay_microseconds_safe(us); }
 void arch_restart() {
-  ESP.restart();  // NOLINT(readability-static-accessed-through-instance)
+  system_restart();
   // restart() doesn't always end execution
   while (true) {  // NOLINT(clang-diagnostic-unreachable-code)
     yield();
   }
 }
 void arch_init() {}
-void IRAM_ATTR HOT arch_feed_wdt() {
-  ESP.wdtFeed();  // NOLINT(readability-static-accessed-through-instance)
-}
+void IRAM_ATTR HOT arch_feed_wdt() { system_soft_wdt_feed(); }
 
 uint8_t progmem_read_byte(const uint8_t *addr) {
   return pgm_read_byte(addr);  // NOLINT
 }
-uint32_t IRAM_ATTR HOT arch_get_cpu_cycle_count() {
-  return ESP.getCycleCount();  // NOLINT(readability-static-accessed-through-instance)
-}
+uint32_t IRAM_ATTR HOT arch_get_cpu_cycle_count() { return esp_get_cycle_count(); }
 uint32_t arch_get_cpu_freq_hz() { return F_CPU; }
 
 void force_link_symbols() {

esphome/components/globals/__init__.py

@@ -6,6 +6,7 @@ from esphome.const import (
     CONF_INITIAL_VALUE,
     CONF_RESTORE_VALUE,
     CONF_TYPE,
+    CONF_UPDATE_INTERVAL,
     CONF_VALUE,
 )
 from esphome.core import CoroPriority, coroutine_with_priority
@@ -13,25 +14,37 @@ from esphome.core import CoroPriority, coroutine_with_priority
 CODEOWNERS = ["@esphome/core"]
 globals_ns = cg.esphome_ns.namespace("globals")
 GlobalsComponent = globals_ns.class_("GlobalsComponent", cg.Component)
-RestoringGlobalsComponent = globals_ns.class_("RestoringGlobalsComponent", cg.Component)
+RestoringGlobalsComponent = globals_ns.class_(
+    "RestoringGlobalsComponent", cg.PollingComponent
+)
 RestoringGlobalStringComponent = globals_ns.class_(
-    "RestoringGlobalStringComponent", cg.Component
+    "RestoringGlobalStringComponent", cg.PollingComponent
 )
 GlobalVarSetAction = globals_ns.class_("GlobalVarSetAction", automation.Action)
 
 CONF_MAX_RESTORE_DATA_LENGTH = "max_restore_data_length"
 
 
+def validate_update_interval(config):
+    if CONF_UPDATE_INTERVAL in config and not config.get(CONF_RESTORE_VALUE, False):
+        raise cv.Invalid("update_interval requires restore_value to be true")
+    return config
+
+
 MULTI_CONF = True
-CONFIG_SCHEMA = cv.Schema(
-    {
-        cv.Required(CONF_ID): cv.declare_id(GlobalsComponent),
-        cv.Required(CONF_TYPE): cv.string_strict,
-        cv.Optional(CONF_INITIAL_VALUE): cv.string_strict,
-        cv.Optional(CONF_RESTORE_VALUE, default=False): cv.boolean,
-        cv.Optional(CONF_MAX_RESTORE_DATA_LENGTH): cv.int_range(0, 254),
-    }
-).extend(cv.COMPONENT_SCHEMA)
+CONFIG_SCHEMA = cv.All(
+    cv.Schema(
+        {
+            cv.Required(CONF_ID): cv.declare_id(GlobalsComponent),
+            cv.Required(CONF_TYPE): cv.string_strict,
+            cv.Optional(CONF_INITIAL_VALUE): cv.string_strict,
+            cv.Optional(CONF_RESTORE_VALUE, default=False): cv.boolean,
+            cv.Optional(CONF_MAX_RESTORE_DATA_LENGTH): cv.int_range(0, 254),
+            cv.Optional(CONF_UPDATE_INTERVAL): cv.update_interval,
+        }
+    ).extend(cv.COMPONENT_SCHEMA),
+    validate_update_interval,
+)
 
 
 # Run with low priority so that namespaces are registered first
@@ -65,6 +78,8 @@ async def to_code(config):
             value = value.encode()
         hash_ = int(hashlib.md5(value).hexdigest()[:8], 16)
         cg.add(glob.set_name_hash(hash_))
+        if CONF_UPDATE_INTERVAL in config:
+            cg.add(glob.set_update_interval(config[CONF_UPDATE_INTERVAL]))
 
 
 @automation.register_action(

esphome/components/globals/globals_component.h

@@ -5,8 +5,7 @@
 #include "esphome/core/helpers.h"
 #include <cstring>
 
-namespace esphome {
-namespace globals {
+namespace esphome::globals {
 
 template<typename T> class GlobalsComponent : public Component {
  public:
@@ -24,13 +23,14 @@ template<typename T> class GlobalsComponent : public Component {
   T value_{};
 };
 
-template<typename T> class RestoringGlobalsComponent : public Component {
+template<typename T> class RestoringGlobalsComponent : public PollingComponent {
  public:
   using value_type = T;
-  explicit RestoringGlobalsComponent() = default;
-  explicit RestoringGlobalsComponent(T initial_value) : value_(initial_value) {}
+  explicit RestoringGlobalsComponent() : PollingComponent(1000) {}
+  explicit RestoringGlobalsComponent(T initial_value) : PollingComponent(1000), value_(initial_value) {}
   explicit RestoringGlobalsComponent(
-      std::array<typename std::remove_extent<T>::type, std::extent<T>::value> initial_value) {
+      std::array<typename std::remove_extent<T>::type, std::extent<T>::value> initial_value)
+      : PollingComponent(1000) {
     memcpy(this->value_, initial_value.data(), sizeof(T));
   }
 
@@ -44,7 +44,7 @@ template<typename T> class RestoringGlobalsComponent : public Component {
 
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
-  void loop() override { store_value_(); }
+  void update() override { store_value_(); }
 
   void on_shutdown() override { store_value_(); }
 
@@ -66,13 +66,14 @@ template<typename T> class RestoringGlobalsComponent : public Component {
 };
 
 // Use with string or subclasses of strings
-template<typename T, uint8_t SZ> class RestoringGlobalStringComponent : public Component {
+template<typename T, uint8_t SZ> class RestoringGlobalStringComponent : public PollingComponent {
  public:
   using value_type = T;
-  explicit RestoringGlobalStringComponent() = default;
-  explicit RestoringGlobalStringComponent(T initial_value) { this->value_ = initial_value; }
+  explicit RestoringGlobalStringComponent() : PollingComponent(1000) {}
+  explicit RestoringGlobalStringComponent(T initial_value) : PollingComponent(1000) { this->value_ = initial_value; }
   explicit RestoringGlobalStringComponent(
-      std::array<typename std::remove_extent<T>::type, std::extent<T>::value> initial_value) {
+      std::array<typename std::remove_extent<T>::type, std::extent<T>::value> initial_value)
+      : PollingComponent(1000) {
     memcpy(this->value_, initial_value.data(), sizeof(T));
   }
 
@@ -90,7 +91,7 @@ template<typename T, uint8_t SZ> class RestoringGlobalStringComponent : public C
 
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
-  void loop() override { store_value_(); }
+  void update() override { store_value_(); }
 
   void on_shutdown() override { store_value_(); }
 
@@ -144,5 +145,4 @@ template<typename T> T &id(GlobalsComponent<T> *value) { return value->value();
 template<typename T> T &id(RestoringGlobalsComponent<T> *value) { return value->value(); }
 template<typename T, uint8_t SZ> T &id(RestoringGlobalStringComponent<T, SZ> *value) { return value->value(); }
 
-}  // namespace globals
-}  // namespace esphome
+}  // namespace esphome::globals

esphome/components/i2c/i2c.cpp

@@ -42,8 +42,8 @@ ErrorCode I2CDevice::read_register16(uint16_t a_register, uint8_t *data, size_t
 }
 
 ErrorCode I2CDevice::write_register(uint8_t a_register, const uint8_t *data, size_t len) const {
-  SmallBufferWithHeapFallback<17> buffer_alloc;  // Most I2C writes are <= 16 bytes
-  uint8_t *buffer = buffer_alloc.get(len + 1);
+  SmallBufferWithHeapFallback<17> buffer_alloc(len + 1);  // Most I2C writes are <= 16 bytes
+  uint8_t *buffer = buffer_alloc.get();
 
   buffer[0] = a_register;
   std::copy(data, data + len, buffer + 1);
@@ -51,8 +51,8 @@ ErrorCode I2CDevice::write_register(uint8_t a_register, const uint8_t *data, siz
 }
 
 ErrorCode I2CDevice::write_register16(uint16_t a_register, const uint8_t *data, size_t len) const {
-  SmallBufferWithHeapFallback<18> buffer_alloc;  // Most I2C writes are <= 16 bytes + 2 for register
-  uint8_t *buffer = buffer_alloc.get(len + 2);
+  SmallBufferWithHeapFallback<18> buffer_alloc(len + 2);  // Most I2C writes are <= 16 bytes + 2 for register
+  uint8_t *buffer = buffer_alloc.get();
 
   buffer[0] = a_register >> 8;
   buffer[1] = a_register;

esphome/components/i2c/i2c_bus.h

@@ -11,22 +11,6 @@
 namespace esphome {
 namespace i2c {
 
-/// @brief Helper class for efficient buffer allocation - uses stack for small sizes, heap for large
-template<size_t STACK_SIZE> class SmallBufferWithHeapFallback {
- public:
-  uint8_t *get(size_t size) {
-    if (size <= STACK_SIZE) {
-      return this->stack_buffer_;
-    }
-    this->heap_buffer_ = std::unique_ptr<uint8_t[]>(new uint8_t[size]);
-    return this->heap_buffer_.get();
-  }
-
- private:
-  uint8_t stack_buffer_[STACK_SIZE];
-  std::unique_ptr<uint8_t[]> heap_buffer_;
-};
-
 /// @brief Error codes returned by I2CBus and I2CDevice methods
 enum ErrorCode {
   NO_ERROR = 0,                ///< No error found during execution of method
@@ -92,8 +76,8 @@ class I2CBus {
       total_len += read_buffers[i].len;
     }
 
-    SmallBufferWithHeapFallback<128> buffer_alloc;  // Most I2C reads are small
-    uint8_t *buffer = buffer_alloc.get(total_len);
+    SmallBufferWithHeapFallback<128> buffer_alloc(total_len);  // Most I2C reads are small
+    uint8_t *buffer = buffer_alloc.get();
 
     auto err = this->write_readv(address, nullptr, 0, buffer, total_len);
     if (err != ERROR_OK)
@@ -116,8 +100,8 @@ class I2CBus {
       total_len += write_buffers[i].len;
     }
 
-    SmallBufferWithHeapFallback<128> buffer_alloc;  // Most I2C writes are small
-    uint8_t *buffer = buffer_alloc.get(total_len);
+    SmallBufferWithHeapFallback<128> buffer_alloc(total_len);  // Most I2C writes are small
+    uint8_t *buffer = buffer_alloc.get();
 
     size_t pos = 0;
     for (size_t i = 0; i != count; i++) {

esphome/components/lock/lock.cpp

@@ -28,16 +28,14 @@ const LogString *lock_state_to_string(LockState state) {
 Lock::Lock() : state(LOCK_STATE_NONE) {}
 LockCall Lock::make_call() { return LockCall(this); }
 
-void Lock::lock() {
+void Lock::set_state_(LockState state) {
   auto call = this->make_call();
-  call.set_state(LOCK_STATE_LOCKED);
-  this->control(call);
-}
-void Lock::unlock() {
-  auto call = this->make_call();
-  call.set_state(LOCK_STATE_UNLOCKED);
+  call.set_state(state);
   this->control(call);
 }
+
+void Lock::lock() { this->set_state_(LOCK_STATE_LOCKED); }
+void Lock::unlock() { this->set_state_(LOCK_STATE_UNLOCKED); }
 void Lock::open() {
   if (traits.get_supports_open()) {
     ESP_LOGD(TAG, "'%s' Opening.", this->get_name().c_str());

esphome/components/lock/lock.h

@@ -156,6 +156,9 @@ class Lock : public EntityBase {
  protected:
   friend LockCall;
 
+  /// Helper for lock/unlock convenience methods
+  void set_state_(LockState state);
+
   /** Perform the open latch action with hardware. This method is optional to implement
    * when creating a new lock.
    *

esphome/components/logger/logger.h

@@ -234,6 +234,7 @@ class Logger : public Component {
 #endif
 
  protected:
+  void write_msg_(const char *msg, size_t len);
   // RAII guard for recursion flags - sets flag on construction, clears on destruction
   class RecursionGuard {
    public:
@@ -260,7 +261,6 @@ class Logger : public Component {
 #endif
 #endif
   void process_messages_();
-  void write_msg_(const char *msg, size_t len);
 
   // Format a log message with printf-style arguments and write it to a buffer with header, footer, and null terminator
   // It's the caller's responsibility to initialize buffer_at (typically to 0)

esphome/components/modbus_controller/modbus_controller.h

@@ -271,9 +271,9 @@ class ServerRegister {
 
   // Formats a raw value into a string representation based on the value type for debugging
   std::string format_value(int64_t value) const {
-    // max 48: float with %.1f can be up to 42 chars (3.4e38 → 38 integer digits + decimal + 1 digit + sign + null)
-    // int64_t max is 20 chars + sign + null = 22, so 48 covers both
-    char buf[48];
+    // max 44: float with %.1f can be up to 42 chars (3.4e38 → 39 integer digits + sign + decimal + 1 digit)
+    // plus null terminator = 43, rounded to 44 for 4-byte alignment
+    char buf[44];
     switch (this->value_type) {
       case SensorValueType::U_WORD:
       case SensorValueType::U_DWORD:

esphome/components/mqtt/mqtt_alarm_control_panel.cpp

@@ -43,7 +43,7 @@ void MQTTAlarmControlPanelComponent::setup() {
 
 void MQTTAlarmControlPanelComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT alarm_control_panel '%s':", this->alarm_control_panel_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
   ESP_LOGCONFIG(TAG,
                 "  Supported Features: %" PRIu32 "\n"
                 "  Requires Code to Disarm: %s\n"

esphome/components/mqtt/mqtt_binary_sensor.cpp

@@ -19,7 +19,7 @@ void MQTTBinarySensorComponent::setup() {
 
 void MQTTBinarySensorComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Binary Sensor '%s':", this->binary_sensor_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 MQTTBinarySensorComponent::MQTTBinarySensorComponent(binary_sensor::BinarySensor *binary_sensor)
     : binary_sensor_(binary_sensor) {

esphome/components/mqtt/mqtt_client.cpp

@@ -406,6 +406,12 @@ void MQTTClientComponent::loop() {
 
         this->last_connected_ = now;
         this->resubscribe_subscriptions_();
+
+        // Process pending resends for all MQTT components centrally
+        // This is more efficient than each component polling in its own loop
+        for (MQTTComponent *component : this->children_) {
+          component->process_resend();
+        }
       }
       break;
   }

esphome/components/mqtt/mqtt_component.cpp

@@ -27,20 +27,23 @@ inline char *append_char(char *p, char c) {
 // Max lengths for stack-based topic building.
 // These limits are enforced at Python config validation time in mqtt/__init__.py
 // using cv.Length() validators for topic_prefix and discovery_prefix.
-// MQTT_COMPONENT_TYPE_MAX_LEN and MQTT_SUFFIX_MAX_LEN are defined in mqtt_component.h.
+// MQTT_COMPONENT_TYPE_MAX_LEN, MQTT_SUFFIX_MAX_LEN, and MQTT_DEFAULT_TOPIC_MAX_LEN are in mqtt_component.h.
 // ESPHOME_DEVICE_NAME_MAX_LEN and OBJECT_ID_MAX_LEN are defined in entity_base.h.
 // This ensures the stack buffers below are always large enough.
-static constexpr size_t TOPIC_PREFIX_MAX_LEN = 64;      // Validated in Python: cv.Length(max=64)
 static constexpr size_t DISCOVERY_PREFIX_MAX_LEN = 64;  // Validated in Python: cv.Length(max=64)
-
-// Stack buffer sizes - safe because all inputs are length-validated at config time
-// Format: prefix + "/" + type + "/" + object_id + "/" + suffix + null
-static constexpr size_t DEFAULT_TOPIC_MAX_LEN =
-    TOPIC_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1 + MQTT_SUFFIX_MAX_LEN + 1;
 // Format: prefix + "/" + type + "/" + name + "/" + object_id + "/config" + null
 static constexpr size_t DISCOVERY_TOPIC_MAX_LEN = DISCOVERY_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 +
                                                   ESPHOME_DEVICE_NAME_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 7 + 1;
 
+// Function implementation of LOG_MQTT_COMPONENT macro to reduce code size
+void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic) {
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  if (state_topic)
+    ESP_LOGCONFIG(tag, "  State Topic: '%s'", obj->get_state_topic_to_(buf).c_str());
+  if (command_topic)
+    ESP_LOGCONFIG(tag, "  Command Topic: '%s'", obj->get_command_topic_to_(buf).c_str());
+}
+
 void MQTTComponent::set_qos(uint8_t qos) { this->qos_ = qos; }
 
 void MQTTComponent::set_subscribe_qos(uint8_t qos) { this->subscribe_qos_ = qos; }
@@ -69,19 +72,18 @@ std::string MQTTComponent::get_discovery_topic_(const MQTTDiscoveryInfo &discove
   return std::string(buf, p - buf);
 }
 
-std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) const {
+StringRef MQTTComponent::get_default_topic_for_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf, const char *suffix,
+                                                   size_t suffix_len) const {
   const std::string &topic_prefix = global_mqtt_client->get_topic_prefix();
   if (topic_prefix.empty()) {
-    // If the topic_prefix is null, the default topic should be null
-    return "";
+    return StringRef();  // Empty topic_prefix means no default topic
   }
 
   const char *comp_type = this->component_type();
   char object_id_buf[OBJECT_ID_MAX_LEN];
   StringRef object_id = this->get_default_object_id_to_(object_id_buf);
 
-  char buf[DEFAULT_TOPIC_MAX_LEN];
-  char *p = buf;
+  char *p = buf.data();
 
   p = append_str(p, topic_prefix.data(), topic_prefix.size());
   p = append_char(p, '/');
@@ -89,21 +91,44 @@ std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) con
   p = append_char(p, '/');
   p = append_str(p, object_id.c_str(), object_id.size());
   p = append_char(p, '/');
-  p = append_str(p, suffix.data(), suffix.size());
+  p = append_str(p, suffix, suffix_len);
+  *p = '\0';
 
-  return std::string(buf, p - buf);
+  return StringRef(buf.data(), p - buf.data());
+}
+
+std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) const {
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_default_topic_for_to_(buf, suffix.data(), suffix.size());
+  return std::string(ref.c_str(), ref.size());
+}
+
+StringRef MQTTComponent::get_state_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const {
+  if (this->custom_state_topic_.has_value()) {
+    // Returns ref to existing data for static/value, uses buf only for lambda case
+    return this->custom_state_topic_.ref_or_copy_to(buf.data(), buf.size());
+  }
+  return this->get_default_topic_for_to_(buf, "state", 5);
+}
+
+StringRef MQTTComponent::get_command_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const {
+  if (this->custom_command_topic_.has_value()) {
+    // Returns ref to existing data for static/value, uses buf only for lambda case
+    return this->custom_command_topic_.ref_or_copy_to(buf.data(), buf.size());
+  }
+  return this->get_default_topic_for_to_(buf, "command", 7);
 }
 
 std::string MQTTComponent::get_state_topic_() const {
-  if (this->custom_state_topic_.has_value())
-    return this->custom_state_topic_.value();
-  return this->get_default_topic_for_("state");
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_state_topic_to_(buf);
+  return std::string(ref.c_str(), ref.size());
 }
 
 std::string MQTTComponent::get_command_topic_() const {
-  if (this->custom_command_topic_.has_value())
-    return this->custom_command_topic_.value();
-  return this->get_default_topic_for_("command");
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_command_topic_to_(buf);
+  return std::string(ref.c_str(), ref.size());
 }
 
 bool MQTTComponent::publish(const std::string &topic, const std::string &payload) {
@@ -168,10 +193,14 @@ bool MQTTComponent::send_discovery_() {
             break;
         }
 
-        if (config.state_topic)
-          root[MQTT_STATE_TOPIC] = this->get_state_topic_();
-        if (config.command_topic)
-          root[MQTT_COMMAND_TOPIC] = this->get_command_topic_();
+        if (config.state_topic) {
+          char state_topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+          root[MQTT_STATE_TOPIC] = this->get_state_topic_to_(state_topic_buf);
+        }
+        if (config.command_topic) {
+          char command_topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+          root[MQTT_COMMAND_TOPIC] = this->get_command_topic_to_(command_topic_buf);
+        }
         if (this->command_retain_)
           root[MQTT_COMMAND_RETAIN] = true;
 
@@ -309,7 +338,9 @@ void MQTTComponent::set_availability(std::string topic, std::string payload_avai
 }
 void MQTTComponent::disable_availability() { this->set_availability("", "", ""); }
 void MQTTComponent::call_setup() {
-  if (this->is_internal())
+  // Cache is_internal result once during setup - topics don't change after this
+  this->is_internal_ = this->compute_is_internal_();
+  if (this->is_internal_)
     return;
 
   this->setup();
@@ -329,16 +360,12 @@ void MQTTComponent::call_setup() {
   }
 }
 
-void MQTTComponent::call_loop() {
-  if (this->is_internal())
+void MQTTComponent::process_resend() {
+  // Called by MQTTClientComponent when connected to process pending resends
+  // Note: is_internal() check not needed - internal components are never registered
+  if (!this->resend_state_)
     return;
 
-  this->loop();
-
-  if (!this->resend_state_ || !this->is_connected_()) {
-    return;
-  }
-
   this->resend_state_ = false;
   if (this->is_discovery_enabled()) {
     if (!this->send_discovery_()) {
@@ -365,26 +392,28 @@ StringRef MQTTComponent::get_default_object_id_to_(std::span<char, OBJECT_ID_MAX
 }
 StringRef MQTTComponent::get_icon_ref_() const { return this->get_entity()->get_icon_ref(); }
 bool MQTTComponent::is_disabled_by_default_() const { return this->get_entity()->is_disabled_by_default(); }
-bool MQTTComponent::is_internal() {
+bool MQTTComponent::compute_is_internal_() {
   if (this->custom_state_topic_.has_value()) {
-    // If the custom state_topic is null, return true as it is internal and should not publish
+    // If the custom state_topic is empty, return true as it is internal and should not publish
     // else, return false, as it is explicitly set to a topic, so it is not internal and should publish
-    return this->get_state_topic_().empty();
+    // Using is_empty() avoids heap allocation for non-lambda cases
+    return this->custom_state_topic_.is_empty();
   }
 
   if (this->custom_command_topic_.has_value()) {
-    // If the custom command_topic is null, return true as it is internal and should not publish
+    // If the custom command_topic is empty, return true as it is internal and should not publish
     // else, return false, as it is explicitly set to a topic, so it is not internal and should publish
-    return this->get_command_topic_().empty();
+    // Using is_empty() avoids heap allocation for non-lambda cases
+    return this->custom_command_topic_.is_empty();
   }
 
-  // No custom topics have been set
-  if (this->get_default_topic_for_("").empty()) {
-    // If the default topic prefix is null, then the component, by default, is internal and should not publish
+  // No custom topics have been set - check topic_prefix directly to avoid allocation
+  if (global_mqtt_client->get_topic_prefix().empty()) {
+    // If the default topic prefix is empty, then the component, by default, is internal and should not publish
     return true;
   }
 
-  // Use ESPHome's component internal state if topic_prefix is not null with no custom state_topic or command_topic
+  // Use ESPHome's component internal state if topic_prefix is not empty with no custom state_topic or command_topic
   return this->get_entity()->is_internal();
 }
 

esphome/components/mqtt/mqtt_component.h

@@ -20,17 +20,22 @@ struct SendDiscoveryConfig {
   bool command_topic{true};  ///< If the command topic should be included. Default to true.
 };
 
-// Max lengths for stack-based topic building (must match mqtt_component.cpp)
+// Max lengths for stack-based topic building.
+// These limits are enforced at Python config validation time in mqtt/__init__.py
+// using cv.Length() validators for topic_prefix and discovery_prefix.
+// This ensures the stack buffers are always large enough.
 static constexpr size_t MQTT_COMPONENT_TYPE_MAX_LEN = 20;
 static constexpr size_t MQTT_SUFFIX_MAX_LEN = 32;
+static constexpr size_t MQTT_TOPIC_PREFIX_MAX_LEN = 64;  // Validated in Python: cv.Length(max=64)
+// Stack buffer size - safe because all inputs are length-validated at config time
+// Format: prefix + "/" + type + "/" + object_id + "/" + suffix + null
+static constexpr size_t MQTT_DEFAULT_TOPIC_MAX_LEN =
+    MQTT_TOPIC_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1 + MQTT_SUFFIX_MAX_LEN + 1;
 
-#define LOG_MQTT_COMPONENT(state_topic, command_topic) \
-  if (state_topic) { \
-    ESP_LOGCONFIG(TAG, "  State Topic: '%s'", this->get_state_topic_().c_str()); \
-  } \
-  if (command_topic) { \
-    ESP_LOGCONFIG(TAG, "  Command Topic: '%s'", this->get_command_topic_().c_str()); \
-  }
+class MQTTComponent;  // Forward declaration
+void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic);
+
+#define LOG_MQTT_COMPONENT(state_topic, command_topic) log_mqtt_component(TAG, this, state_topic, command_topic)
 
 // Macro to define component_type() with compile-time length verification
 // Usage: MQTT_COMPONENT_TYPE(MQTTSensorComponent, "sensor")
@@ -74,6 +79,8 @@ static constexpr size_t MQTT_SUFFIX_MAX_LEN = 32;
  * a clean separation.
  */
 class MQTTComponent : public Component {
+  friend void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic);
+
  public:
   /// Constructs a MQTTComponent.
   explicit MQTTComponent();
@@ -81,8 +88,6 @@ class MQTTComponent : public Component {
   /// Override setup_ so that we can call send_discovery() when needed.
   void call_setup() override;
 
-  void call_loop() override;
-
   void call_dump_config() override;
 
   /// Send discovery info the Home Assistant, override this.
@@ -90,7 +95,8 @@ class MQTTComponent : public Component {
 
   virtual bool send_initial_state() = 0;
 
-  virtual bool is_internal();
+  /// Returns cached is_internal result (computed once during setup).
+  bool is_internal() const { return this->is_internal_; }
 
   /// Set QOS for state messages.
   void set_qos(uint8_t qos);
@@ -133,6 +139,9 @@ class MQTTComponent : public Component {
   /// Internal method for the MQTT client base to schedule a resend of the state on reconnect.
   void schedule_resend_state();
 
+  /// Process pending resend if needed (called by MQTTClientComponent)
+  void process_resend();
+
   /** Send a MQTT message.
    *
    * @param topic The topic.
@@ -178,7 +187,16 @@ class MQTTComponent : public Component {
   /// Helper method to get the discovery topic for this component.
   std::string get_discovery_topic_(const MQTTDiscoveryInfo &discovery_info) const;
 
-  /** Get this components state/command/... topic.
+  /** Get this components state/command/... topic into a buffer.
+   *
+   * @param buf The buffer to write to (must be exactly MQTT_DEFAULT_TOPIC_MAX_LEN).
+   * @param suffix The suffix/key such as "state" or "command".
+   * @return StringRef pointing to the buffer with the topic.
+   */
+  StringRef get_default_topic_for_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf, const char *suffix,
+                                      size_t suffix_len) const;
+
+  /** Get this components state/command/... topic (allocates std::string).
    *
    * @param suffix The suffix/key such as "state" or "command".
    * @return The full topic.
@@ -199,10 +217,20 @@ class MQTTComponent : public Component {
   /// Get whether the underlying Entity is disabled by default
   bool is_disabled_by_default_() const;
 
-  /// Get the MQTT topic that new states will be shared to.
+  /// Get the MQTT state topic into a buffer (no heap allocation for non-lambda custom topics).
+  /// @param buf Buffer of exactly MQTT_DEFAULT_TOPIC_MAX_LEN bytes.
+  /// @return StringRef pointing to the topic in the buffer.
+  StringRef get_state_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const;
+
+  /// Get the MQTT command topic into a buffer (no heap allocation for non-lambda custom topics).
+  /// @param buf Buffer of exactly MQTT_DEFAULT_TOPIC_MAX_LEN bytes.
+  /// @return StringRef pointing to the topic in the buffer.
+  StringRef get_command_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const;
+
+  /// Get the MQTT topic that new states will be shared to (allocates std::string).
   std::string get_state_topic_() const;
 
-  /// Get the MQTT topic for listening to commands.
+  /// Get the MQTT topic for listening to commands (allocates std::string).
   std::string get_command_topic_() const;
 
   bool is_connected_() const;
@@ -220,12 +248,18 @@ class MQTTComponent : public Component {
 
   std::unique_ptr<Availability> availability_;
 
-  bool command_retain_{false};
-  bool retain_{true};
-  uint8_t qos_{0};
-  uint8_t subscribe_qos_{0};
-  bool discovery_enabled_{true};
-  bool resend_state_{false};
+  // Packed bitfields - QoS values are 0-2, bools are flags
+  uint8_t qos_ : 2 {0};
+  uint8_t subscribe_qos_ : 2 {0};
+  bool command_retain_ : 1 {false};
+  bool retain_ : 1 {true};
+  bool discovery_enabled_ : 1 {true};
+  bool resend_state_ : 1 {false};
+  bool is_internal_ : 1 {false};  ///< Cached result of compute_is_internal_(), set during setup
+
+  /// Compute is_internal status based on topics and entity state.
+  /// Called once during setup to cache the result.
+  bool compute_is_internal_();
 };
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_cover.cpp

@@ -51,7 +51,7 @@ void MQTTCoverComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT cover '%s':", this->cover_->get_name().c_str());
   auto traits = this->cover_->get_traits();
   bool has_command_topic = traits.get_supports_position() || !traits.get_supports_tilt();
-  LOG_MQTT_COMPONENT(true, has_command_topic)
+  LOG_MQTT_COMPONENT(true, has_command_topic);
   if (traits.get_supports_position()) {
     ESP_LOGCONFIG(TAG,
                   "  Position State Topic: '%s'\n"

esphome/components/mqtt/mqtt_date.cpp

@@ -36,7 +36,7 @@ void MQTTDateComponent::setup() {
 
 void MQTTDateComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Date '%s':", this->date_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTDateComponent, "date")

esphome/components/mqtt/mqtt_datetime.cpp

@@ -47,7 +47,7 @@ void MQTTDateTimeComponent::setup() {
 
 void MQTTDateTimeComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT DateTime '%s':", this->datetime_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTDateTimeComponent, "datetime")

esphome/components/mqtt/mqtt_light.cpp

@@ -90,7 +90,7 @@ void MQTTJSONLightComponent::send_discovery(JsonObject root, mqtt::SendDiscovery
 bool MQTTJSONLightComponent::send_initial_state() { return this->publish_state_(); }
 void MQTTJSONLightComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Light '%s':", this->state_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 }  // namespace esphome::mqtt

esphome/components/mqtt/mqtt_number.cpp

@@ -30,7 +30,7 @@ void MQTTNumberComponent::setup() {
 
 void MQTTNumberComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Number '%s':", this->number_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTNumberComponent, "number")

esphome/components/mqtt/mqtt_select.cpp

@@ -25,7 +25,7 @@ void MQTTSelectComponent::setup() {
 
 void MQTTSelectComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Select '%s':", this->select_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTSelectComponent, "select")

esphome/components/mqtt/mqtt_sensor.cpp

@@ -28,7 +28,7 @@ void MQTTSensorComponent::dump_config() {
   if (this->get_expire_after() > 0) {
     ESP_LOGCONFIG(TAG, "  Expire After: %" PRIu32 "s", this->get_expire_after() / 1000);
   }
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTSensorComponent, "sensor")

esphome/components/mqtt/mqtt_text.cpp

@@ -26,7 +26,7 @@ void MQTTTextComponent::setup() {
 
 void MQTTTextComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT text '%s':", this->text_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTTextComponent, "text")

esphome/components/mqtt/mqtt_time.cpp

@@ -36,7 +36,7 @@ void MQTTTimeComponent::setup() {
 
 void MQTTTimeComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Time '%s':", this->time_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTTimeComponent, "time")

esphome/components/mqtt/mqtt_valve.cpp

@@ -39,7 +39,7 @@ void MQTTValveComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT valve '%s':", this->valve_->get_name().c_str());
   auto traits = this->valve_->get_traits();
   bool has_command_topic = traits.get_supports_position();
-  LOG_MQTT_COMPONENT(true, has_command_topic)
+  LOG_MQTT_COMPONENT(true, has_command_topic);
   if (traits.get_supports_position()) {
     ESP_LOGCONFIG(TAG,
                   "  Position State Topic: '%s'\n"

esphome/components/pipsolar/output/pipsolar_output.cpp

@@ -8,12 +8,12 @@ namespace pipsolar {
 static const char *const TAG = "pipsolar.output";
 
 void PipsolarOutput::write_state(float state) {
-  char tmp[10];
+  char tmp[16];
   snprintf(tmp, sizeof(tmp), this->set_command_, state);
 
   if (std::find(this->possible_values_.begin(), this->possible_values_.end(), state) != this->possible_values_.end()) {
     ESP_LOGD(TAG, "Will write: %s out of value %f / %02.0f", tmp, state, state);
-    this->parent_->queue_command(tmp);
+    this->parent_->queue_command(std::string(tmp));
   } else {
     ESP_LOGD(TAG, "Will not write: %s as it is not in list of allowed values", tmp);
   }

esphome/components/pipsolar/pipsolar.cpp

@@ -45,20 +45,20 @@ void Pipsolar::loop() {
         } else {
           ESP_LOGD(TAG, "command not successful");
         }
-        this->command_queue_[this->command_queue_position_].clear();
+        this->command_queue_[this->command_queue_position_] = std::string("");
         this->command_queue_position_ = (command_queue_position_ + 1) % COMMAND_QUEUE_LENGTH;
         this->state_ = STATE_IDLE;
       } else {
         // crc failed
         // no log message necessary, check_incoming_crc_() logs
-        this->command_queue_[this->command_queue_position_].clear();
+        this->command_queue_[this->command_queue_position_] = std::string("");
         this->command_queue_position_ = (command_queue_position_ + 1) % COMMAND_QUEUE_LENGTH;
         this->state_ = STATE_IDLE;
       }
     } else {
       ESP_LOGD(TAG, "command %s response length not OK: with length %zu",
                this->command_queue_[this->command_queue_position_].c_str(), this->read_pos_);
-      this->command_queue_[this->command_queue_position_].clear();
+      this->command_queue_[this->command_queue_position_] = std::string("");
       this->command_queue_position_ = (command_queue_position_ + 1) % COMMAND_QUEUE_LENGTH;
       this->state_ = STATE_IDLE;
     }
@@ -127,7 +127,7 @@ void Pipsolar::loop() {
       const char *command = this->command_queue_[this->command_queue_position_].c_str();
       this->command_start_millis_ = millis();
       ESP_LOGD(TAG, "command %s timeout", command);
-      this->command_queue_[this->command_queue_position_].clear();
+      this->command_queue_[this->command_queue_position_] = std::string("");
       this->command_queue_position_ = (command_queue_position_ + 1) % COMMAND_QUEUE_LENGTH;
       this->state_ = STATE_IDLE;
       return;
@@ -722,7 +722,7 @@ void Pipsolar::publish_binary_sensor_(esphome::optional<bool> b, binary_sensor::
   }
 }
 
-esphome::optional<bool> Pipsolar::get_bit_(const std::string &bits, uint8_t bit_pos) {
+esphome::optional<bool> Pipsolar::get_bit_(std::string bits, uint8_t bit_pos) {
   if (bit_pos >= bits.length()) {
     return {};
   }

esphome/components/pipsolar/pipsolar.h

@@ -224,7 +224,7 @@ class Pipsolar : public uart::UARTDevice, public PollingComponent {
 
   void publish_binary_sensor_(esphome::optional<bool> b, binary_sensor::BinarySensor *sensor);
 
-  esphome::optional<bool> get_bit_(const std::string &bits, uint8_t bit_pos);
+  esphome::optional<bool> get_bit_(std::string bits, uint8_t bit_pos);
 
   std::string command_queue_[COMMAND_QUEUE_LENGTH];
   uint8_t command_queue_position_ = 0;

esphome/components/sim800l/sim800l.cpp

@@ -51,7 +51,7 @@ void Sim800LComponent::update() {
   } else if (state_ == STATE_RECEIVED_SMS) {
     // Serial Buffer should have flushed.
     // Send cmd to delete received sms
-    char delete_cmd[20];  // "AT+CMGD=" (8) + int (max 11) + null = 20
+    char delete_cmd[20];  // "AT+CMGD=" (8) + uint8_t (max 3) + null = 12 <= 20
     buf_append_printf(delete_cmd, sizeof(delete_cmd), 0, "AT+CMGD=%d", this->parse_index_);
     this->send_cmd_(delete_cmd);
     this->state_ = STATE_CHECK_SMS;

esphome/components/sml/sml_parser.cpp

@@ -106,7 +106,7 @@ std::string bytes_repr(const BytesView &buffer) {
   for (auto const value : buffer) {
     // max 3: 2 hex digits + null
     char hex_buf[3];
-    snprintf(hex_buf, sizeof(hex_buf), "%02x", value & 0xff);
+    snprintf(hex_buf, sizeof(hex_buf), "%02x", static_cast<unsigned int>(value));
     repr += hex_buf;
   }
   return repr;

esphome/components/status/binary_sensor.py

@@ -7,14 +7,14 @@ DEPENDENCIES = ["network"]
 
 status_ns = cg.esphome_ns.namespace("status")
 StatusBinarySensor = status_ns.class_(
-    "StatusBinarySensor", binary_sensor.BinarySensor, cg.Component
+    "StatusBinarySensor", binary_sensor.BinarySensor, cg.PollingComponent
 )
 
 CONFIG_SCHEMA = binary_sensor.binary_sensor_schema(
     StatusBinarySensor,
     device_class=DEVICE_CLASS_CONNECTIVITY,
     entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
-).extend(cv.COMPONENT_SCHEMA)
+).extend(cv.polling_component_schema("1s"))
 
 
 async def to_code(config):

esphome/components/status/status_binary_sensor.cpp

@@ -10,12 +10,11 @@
 #include "esphome/components/api/api_server.h"
 #endif
 
-namespace esphome {
-namespace status {
+namespace esphome::status {
 
 static const char *const TAG = "status";
 
-void StatusBinarySensor::loop() {
+void StatusBinarySensor::update() {
   bool status = network::is_connected();
 #ifdef USE_MQTT
   if (mqtt::global_mqtt_client != nullptr) {
@@ -33,5 +32,4 @@ void StatusBinarySensor::loop() {
 void StatusBinarySensor::setup() { this->publish_initial_state(false); }
 void StatusBinarySensor::dump_config() { LOG_BINARY_SENSOR("", "Status Binary Sensor", this); }
 
-}  // namespace status
-}  // namespace esphome
+}  // namespace esphome::status

esphome/components/status/status_binary_sensor.h

@@ -3,12 +3,11 @@
 #include "esphome/core/component.h"
 #include "esphome/components/binary_sensor/binary_sensor.h"
 
-namespace esphome {
-namespace status {
+namespace esphome::status {
 
-class StatusBinarySensor : public binary_sensor::BinarySensor, public Component {
+class StatusBinarySensor : public binary_sensor::BinarySensor, public PollingComponent {
  public:
-  void loop() override;
+  void update() override;
 
   void setup() override;
   void dump_config() override;
@@ -16,5 +15,4 @@ class StatusBinarySensor : public binary_sensor::BinarySensor, public Component
   bool is_status_binary_sensor() const override { return true; }
 };
 
-}  // namespace status
-}  // namespace esphome
+}  // namespace esphome::status

esphome/components/teleinfo/sensor/teleinfo_sensor.cpp

@@ -4,7 +4,8 @@ namespace esphome {
 namespace teleinfo {
 
 static const char *const TAG = "teleinfo_sensor";
-void TeleInfoSensor::publish_val(const char *val) {
+TeleInfoSensor::TeleInfoSensor(const char *tag) { this->tag = std::string(tag); }
+void TeleInfoSensor::publish_val(const std::string &val) {
   auto newval = parse_number<float>(val).value_or(0.0f);
   publish_state(newval);
 }

esphome/components/teleinfo/sensor/teleinfo_sensor.h

@@ -7,8 +7,8 @@ namespace teleinfo {
 
 class TeleInfoSensor : public TeleInfoListener, public sensor::Sensor, public Component {
  public:
-  TeleInfoSensor(const char *tag) { this->tag = tag; }
-  void publish_val(const char *val) override;
+  TeleInfoSensor(const char *tag);
+  void publish_val(const std::string &val) override;
   void dump_config() override;
 };
 

esphome/components/teleinfo/teleinfo.cpp

@@ -172,15 +172,15 @@ void TeleInfo::loop() {
         /* Advance buf_finger to end of group */
         buf_finger += field_len + 1 + 1 + 1;
 
-        publish_value_(tag_, val_);
+        publish_value_(std::string(tag_), std::string(val_));
       }
       state_ = OFF;
       break;
   }
 }
-void TeleInfo::publish_value_(const char *tag, const char *val) {
+void TeleInfo::publish_value_(const std::string &tag, const std::string &val) {
   for (auto *element : teleinfo_listeners_) {
-    if (strcmp(tag, element->tag) != 0)
+    if (tag != element->tag)
       continue;
     element->publish_val(val);
   }

esphome/components/teleinfo/teleinfo.h

@@ -18,8 +18,8 @@ static const uint16_t MAX_TIMESTAMP_SIZE = 14;
 
 class TeleInfoListener {
  public:
-  const char *tag{nullptr};
-  virtual void publish_val(const char *val){};
+  std::string tag;
+  virtual void publish_val(const std::string &val){};
 };
 class TeleInfo : public PollingComponent, public uart::UARTDevice {
  public:
@@ -48,7 +48,7 @@ class TeleInfo : public PollingComponent, public uart::UARTDevice {
   } state_{OFF};
   bool read_chars_until_(bool drop, uint8_t c);
   bool check_crc_(const char *grp, const char *grp_end);
-  void publish_value_(const char *tag, const char *val);
+  void publish_value_(const std::string &tag, const std::string &val);
 };
 }  // namespace teleinfo
 }  // namespace esphome

esphome/components/teleinfo/text_sensor/teleinfo_text_sensor.cpp

@@ -4,7 +4,8 @@ namespace esphome {
 namespace teleinfo {
 
 static const char *const TAG = "teleinfo_text_sensor";
-void TeleInfoTextSensor::publish_val(const char *val) { publish_state(val); }
+TeleInfoTextSensor::TeleInfoTextSensor(const char *tag) { this->tag = std::string(tag); }
+void TeleInfoTextSensor::publish_val(const std::string &val) { publish_state(val); }
 void TeleInfoTextSensor::dump_config() { LOG_TEXT_SENSOR("  ", "Teleinfo Text Sensor", this); }
 }  // namespace teleinfo
 }  // namespace esphome

esphome/components/teleinfo/text_sensor/teleinfo_text_sensor.h

@@ -5,8 +5,8 @@ namespace esphome {
 namespace teleinfo {
 class TeleInfoTextSensor : public TeleInfoListener, public text_sensor::TextSensor, public Component {
  public:
-  TeleInfoTextSensor(const char *tag) { this->tag = tag; }
-  void publish_val(const char *val) override;
+  TeleInfoTextSensor(const char *tag);
+  void publish_val(const std::string &val) override;
   void dump_config() override;
 };
 }  // namespace teleinfo

esphome/components/tuya/text_sensor/tuya_text_sensor.cpp

@@ -24,7 +24,7 @@ void TuyaTextSensor::setup() {
       }
       case TuyaDatapointType::ENUM: {
         char buf[4];  // uint8_t max is 3 digits + null
-        snprintf(buf, sizeof(buf), "%u", datapoint.value_enum);
+        buf_append_printf(buf, sizeof(buf), 0, "%u", datapoint.value_enum);
         ESP_LOGD(TAG, "MCU reported text sensor %u is: %s", datapoint.id, buf);
         this->publish_state(buf);
         break;

esphome/components/wifi/wifi_component_esp8266.cpp

@@ -920,7 +920,16 @@ bssid_t WiFiComponent::wifi_bssid() {
   }
   return bssid;
 }
-std::string WiFiComponent::wifi_ssid() { return WiFi.SSID().c_str(); }
+std::string WiFiComponent::wifi_ssid() {
+  struct station_config conf {};
+  if (!wifi_station_get_config(&conf)) {
+    return "";
+  }
+  // conf.ssid is uint8[32], not null-terminated if full
+  auto *ssid_s = reinterpret_cast<const char *>(conf.ssid);
+  size_t len = strnlen(ssid_s, sizeof(conf.ssid));
+  return {ssid_s, len};
+}
 const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer) {
   struct station_config conf {};
   if (!wifi_station_get_config(&conf)) {
@@ -934,16 +943,24 @@ const char *WiFiComponent::wifi_ssid_to(std::span<char, SSID_BUFFER_SIZE> buffer
   return buffer.data();
 }
 int8_t WiFiComponent::wifi_rssi() {
-  if (WiFi.status() != WL_CONNECTED)
+  if (wifi_station_get_connect_status() != STATION_GOT_IP)
     return WIFI_RSSI_DISCONNECTED;
-  int8_t rssi = WiFi.RSSI();
+  sint8 rssi = wifi_station_get_rssi();
   // Values >= 31 are error codes per NONOS SDK API, not valid RSSI readings
   return rssi >= 31 ? WIFI_RSSI_DISCONNECTED : rssi;
 }
-int32_t WiFiComponent::get_wifi_channel() { return WiFi.channel(); }
-network::IPAddress WiFiComponent::wifi_subnet_mask_() { return {(const ip_addr_t *) WiFi.subnetMask()}; }
-network::IPAddress WiFiComponent::wifi_gateway_ip_() { return {(const ip_addr_t *) WiFi.gatewayIP()}; }
-network::IPAddress WiFiComponent::wifi_dns_ip_(int num) { return {(const ip_addr_t *) WiFi.dnsIP(num)}; }
+int32_t WiFiComponent::get_wifi_channel() { return wifi_get_channel(); }
+network::IPAddress WiFiComponent::wifi_subnet_mask_() {
+  struct ip_info ip {};
+  wifi_get_ip_info(STATION_IF, &ip);
+  return network::IPAddress(&ip.netmask);
+}
+network::IPAddress WiFiComponent::wifi_gateway_ip_() {
+  struct ip_info ip {};
+  wifi_get_ip_info(STATION_IF, &ip);
+  return network::IPAddress(&ip.gw);
+}
+network::IPAddress WiFiComponent::wifi_dns_ip_(int num) { return network::IPAddress(dns_getserver(num)); }
 void WiFiComponent::wifi_loop_() {}
 
 }  // namespace esphome::wifi

esphome/components/wifi/wifi_component_libretiny.cpp

@@ -660,21 +660,27 @@ void WiFiComponent::wifi_scan_done_callback_() {
   this->scan_result_.clear();
   this->scan_done_ = true;
 
-  int16_t num = WiFi.scanComplete();
-  if (num < 0)
+  // Access scan data directly to avoid String allocation from WiFi.SSID(i)
+  // WiFi.scan is public in LibreTiny (WiFi.h)
+  if (WiFi.scan == nullptr || WiFi.scan->running)
     return;
 
-  this->scan_result_.init(static_cast<unsigned int>(num));
-  for (int i = 0; i < num; i++) {
-    String ssid = WiFi.SSID(i);
-    wifi_auth_mode_t authmode = WiFi.encryptionType(i);
-    int32_t rssi = WiFi.RSSI(i);
-    uint8_t *bssid = WiFi.BSSID(i);
-    int32_t channel = WiFi.channel(i);
+  uint8_t num = WiFi.scan->count;
+  if (num == 0) {
+    WiFi.scanDelete();
+    return;
+  }
 
-    this->scan_result_.emplace_back(bssid_t{bssid[0], bssid[1], bssid[2], bssid[3], bssid[4], bssid[5]},
-                                    std::string(ssid.c_str()), channel, rssi, authmode != WIFI_AUTH_OPEN,
-                                    ssid.length() == 0);
+  this->scan_result_.init(num);
+  for (uint8_t i = 0; i < num; i++) {
+    const auto &ap = WiFi.scan->ap[i];
+    const char *ssid_cstr = ap.ssid;
+    size_t ssid_len = ssid_cstr ? strlen(ssid_cstr) : 0;
+
+    this->scan_result_.emplace_back(bssid_t{ap.bssid.addr[0], ap.bssid.addr[1], ap.bssid.addr[2], ap.bssid.addr[3],
+                                            ap.bssid.addr[4], ap.bssid.addr[5]},
+                                    std::string(ssid_cstr ? ssid_cstr : "", ssid_len), ap.channel, ap.rssi,
+                                    ap.auth != WIFI_AUTH_OPEN, ssid_len == 0);
   }
   WiFi.scanDelete();
 #ifdef USE_WIFI_SCAN_RESULTS_LISTENERS

esphome/core/automation.h

@@ -4,6 +4,7 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/string_ref.h"
 #include <concepts>
 #include <functional>
 #include <utility>
@@ -190,15 +191,55 @@ template<typename T, typename... X> class TemplatableValue {
   /// Get the static string pointer (only valid if is_static_string() returns true)
   const char *get_static_string() const { return this->static_str_; }
 
- protected:
-  enum : uint8_t {
-    NONE,
-    VALUE,
-    LAMBDA,
-    STATELESS_LAMBDA,
-    STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
-  } type_;
+  /// Check if the string value is empty without allocating (for std::string specialization).
+  /// For NONE, returns true. For STATIC_STRING/VALUE, checks without allocation.
+  /// For LAMBDA/STATELESS_LAMBDA, must call value() which may allocate.
+  bool is_empty() const requires std::same_as<T, std::string> {
+    switch (this->type_) {
+      case NONE:
+        return true;
+      case STATIC_STRING:
+        return this->static_str_ == nullptr || this->static_str_[0] == '\0';
+      case VALUE:
+        return this->value_->empty();
+      default:  // LAMBDA/STATELESS_LAMBDA - must call value()
+        return this->value().empty();
+    }
+  }
 
+  /// Get a StringRef to the string value without heap allocation when possible.
+  /// For STATIC_STRING/VALUE, returns reference to existing data (no allocation).
+  /// For LAMBDA/STATELESS_LAMBDA, calls value(), copies to provided buffer, returns ref to buffer.
+  /// @param lambda_buf Buffer used only for lambda case (must remain valid while StringRef is used).
+  /// @param lambda_buf_size Size of the buffer.
+  /// @return StringRef pointing to the string data.
+  StringRef ref_or_copy_to(char *lambda_buf, size_t lambda_buf_size) const requires std::same_as<T, std::string> {
+    switch (this->type_) {
+      case NONE:
+        return StringRef();
+      case STATIC_STRING:
+        if (this->static_str_ == nullptr)
+          return StringRef();
+        return StringRef(this->static_str_, strlen(this->static_str_));
+      case VALUE:
+        return StringRef(this->value_->data(), this->value_->size());
+      default: {  // LAMBDA/STATELESS_LAMBDA - must call value() and copy
+        std::string result = this->value();
+        size_t copy_len = std::min(result.size(), lambda_buf_size - 1);
+        memcpy(lambda_buf, result.data(), copy_len);
+        lambda_buf[copy_len] = '\0';
+        return StringRef(lambda_buf, copy_len);
+      }
+    }
+  }
+
+ protected : enum : uint8_t {
+   NONE,
+   VALUE,
+   LAMBDA,
+   STATELESS_LAMBDA,
+   STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
+ } type_;
   // For std::string, use heap pointer to minimize union size (4 bytes vs 12+).
   // For other types, store value inline as before.
   using ValueStorage = std::conditional_t<USE_HEAP_STORAGE, T *, T>;

esphome/core/helpers.h

@@ -441,6 +441,35 @@ template<typename T> class FixedVector {
   const T *end() const { return data_ + size_; }
 };
 
+/// @brief Helper class for efficient buffer allocation - uses stack for small sizes, heap for large
+/// This is useful when most operations need a small buffer but occasionally need larger ones.
+/// The stack buffer avoids heap allocation in the common case, while heap fallback handles edge cases.
+template<size_t STACK_SIZE> class SmallBufferWithHeapFallback {
+ public:
+  explicit SmallBufferWithHeapFallback(size_t size) {
+    if (size <= STACK_SIZE) {
+      this->buffer_ = this->stack_buffer_;
+    } else {
+      this->heap_buffer_ = new uint8_t[size];
+      this->buffer_ = this->heap_buffer_;
+    }
+  }
+  ~SmallBufferWithHeapFallback() { delete[] this->heap_buffer_; }
+
+  // Delete copy and move operations to prevent double-delete
+  SmallBufferWithHeapFallback(const SmallBufferWithHeapFallback &) = delete;
+  SmallBufferWithHeapFallback &operator=(const SmallBufferWithHeapFallback &) = delete;
+  SmallBufferWithHeapFallback(SmallBufferWithHeapFallback &&) = delete;
+  SmallBufferWithHeapFallback &operator=(SmallBufferWithHeapFallback &&) = delete;
+
+  uint8_t *get() { return this->buffer_; }
+
+ private:
+  uint8_t stack_buffer_[STACK_SIZE];
+  uint8_t *heap_buffer_{nullptr};
+  uint8_t *buffer_;
+};
+
 ///@}
 
 /// @name Mathematics

esphome/core/time.cpp

@@ -67,7 +67,7 @@ std::string ESPTime::strftime(const char *format) {
 
 std::string ESPTime::strftime(const std::string &format) { return this->strftime(format.c_str()); }
 
-bool ESPTime::strptime(const std::string &time_to_parse, ESPTime &esp_time) {
+bool ESPTime::strptime(const char *time_to_parse, size_t len, ESPTime &esp_time) {
   uint16_t year;
   uint8_t month;
   uint8_t day;
@@ -75,40 +75,41 @@ bool ESPTime::strptime(const std::string &time_to_parse, ESPTime &esp_time) {
   uint8_t minute;
   uint8_t second;
   int num;
+  const int ilen = static_cast<int>(len);
 
-  if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %02hhu:%02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
-             &hour,                                                                                      // NOLINT
-             &minute,                                                                                    // NOLINT
-             &second, &num) == 6 &&                                                                      // NOLINT
-      num == static_cast<int>(time_to_parse.size())) {
+  if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %02hhu:%02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
+             &hour,                                                                              // NOLINT
+             &minute,                                                                            // NOLINT
+             &second, &num) == 6 &&                                                              // NOLINT
+      num == ilen) {
     esp_time.year = year;
     esp_time.month = month;
     esp_time.day_of_month = day;
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = second;
-  } else if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
-                    &hour,                                                                               // NOLINT
-                    &minute, &num) == 5 &&                                                               // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %02hhu:%02hhu %n", &year, &month, &day,  // NOLINT
+                    &hour,                                                                       // NOLINT
+                    &minute, &num) == 5 &&                                                       // NOLINT
+             num == ilen) {
     esp_time.year = year;
     esp_time.month = month;
     esp_time.day_of_month = day;
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = 0;
-  } else if (sscanf(time_to_parse.c_str(), "%02hhu:%02hhu:%02hhu %n", &hour, &minute, &second, &num) == 3 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%02hhu:%02hhu:%02hhu %n", &hour, &minute, &second, &num) == 3 &&  // NOLINT
+             num == ilen) {
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = second;
-  } else if (sscanf(time_to_parse.c_str(), "%02hhu:%02hhu %n", &hour, &minute, &num) == 2 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%02hhu:%02hhu %n", &hour, &minute, &num) == 2 &&  // NOLINT
+             num == ilen) {
     esp_time.hour = hour;
     esp_time.minute = minute;
     esp_time.second = 0;
-  } else if (sscanf(time_to_parse.c_str(), "%04hu-%02hhu-%02hhu %n", &year, &month, &day, &num) == 3 &&  // NOLINT
-             num == static_cast<int>(time_to_parse.size())) {
+  } else if (sscanf(time_to_parse, "%04hu-%02hhu-%02hhu %n", &year, &month, &day, &num) == 3 &&  // NOLINT
+             num == ilen) {
     esp_time.year = year;
     esp_time.month = month;
     esp_time.day_of_month = day;

esphome/core/time.h

@@ -2,6 +2,7 @@
 
 #include <cstdint>
 #include <cstdlib>
+#include <cstring>
 #include <ctime>
 #include <span>
 #include <string>
@@ -80,11 +81,20 @@ struct ESPTime {
   }
 
   /** Convert a string to ESPTime struct as specified by the format argument.
-   * @param time_to_parse null-terminated c string formatet like this: 2020-08-25 05:30:00.
+   * @param time_to_parse c string formatted like this: 2020-08-25 05:30:00.
+   * @param len length of the string (not including null terminator if present)
    * @param esp_time an instance of a ESPTime struct
-   * @return the success sate of the parsing
+   * @return the success state of the parsing
    */
-  static bool strptime(const std::string &time_to_parse, ESPTime &esp_time);
+  static bool strptime(const char *time_to_parse, size_t len, ESPTime &esp_time);
+  /// @copydoc strptime(const char *, size_t, ESPTime &)
+  static bool strptime(const char *time_to_parse, ESPTime &esp_time) {
+    return strptime(time_to_parse, strlen(time_to_parse), esp_time);
+  }
+  /// @copydoc strptime(const char *, size_t, ESPTime &)
+  static bool strptime(const std::string &time_to_parse, ESPTime &esp_time) {
+    return strptime(time_to_parse.c_str(), time_to_parse.size(), esp_time);
+  }
 
   /// Convert a C tm struct instance with a C unix epoch timestamp to an ESPTime instance.
   static ESPTime from_c_tm(struct tm *c_tm, time_t c_time);

tests/integration/fixtures/api_homeassistant.yaml

@@ -108,6 +108,25 @@ text_sensor:
             format: "HA Empty state updated: %s"
             args: ['x.c_str()']
 
+  # Test long attribute handling (>255 characters)
+  # HA states are limited to 255 chars, but attributes are not
+  - platform: homeassistant
+    name: "HA Long Attribute"
+    entity_id: sensor.long_data
+    attribute: long_value
+    id: ha_long_attribute
+    on_value:
+      then:
+        - logger.log:
+            format: "HA Long attribute received, length: %d"
+            args: ['x.size()']
+        # Log the first 50 and last 50 chars to verify no truncation
+        - lambda: |-
+            if (x.size() >= 100) {
+              ESP_LOGI("test", "Long attribute first 50 chars: %.50s", x.c_str());
+              ESP_LOGI("test", "Long attribute last 50 chars: %s", x.c_str() + x.size() - 50);
+            }
+
 # Number component for testing HA number control
 number:
   - platform: template

tests/integration/test_api_homeassistant.py

@@ -40,6 +40,7 @@ async def test_api_homeassistant(
     humidity_update_future = loop.create_future()
     motion_update_future = loop.create_future()
     weather_update_future = loop.create_future()
+    long_attr_future = loop.create_future()
 
     # Number future
     ha_number_future = loop.create_future()
@@ -58,6 +59,7 @@ async def test_api_homeassistant(
     humidity_update_pattern = re.compile(r"HA Humidity state updated: ([\d.]+)")
     motion_update_pattern = re.compile(r"HA Motion state changed: (ON|OFF)")
     weather_update_pattern = re.compile(r"HA Weather condition updated: (\w+)")
+    long_attr_pattern = re.compile(r"HA Long attribute received, length: (\d+)")
 
     # Number pattern
     ha_number_pattern = re.compile(r"Setting HA number to: ([\d.]+)")
@@ -143,8 +145,14 @@ async def test_api_homeassistant(
         elif not weather_update_future.done() and weather_update_pattern.search(line):
             weather_update_future.set_result(line)
 
-        # Check number pattern
-        elif not ha_number_future.done() and ha_number_pattern.search(line):
+        # Check long attribute pattern - separate if since it can come at different times
+        if not long_attr_future.done():
+            match = long_attr_pattern.search(line)
+            if match:
+                long_attr_future.set_result(int(match.group(1)))
+
+        # Check number pattern - separate if since it can come at different times
+        if not ha_number_future.done():
             match = ha_number_pattern.search(line)
             if match:
                 ha_number_future.set_result(match.group(1))
@@ -179,6 +187,14 @@ async def test_api_homeassistant(
         client.send_home_assistant_state("binary_sensor.external_motion", "", "ON")
         client.send_home_assistant_state("weather.home", "condition", "sunny")
 
+        # Send a long attribute (300 characters) to test that attributes aren't truncated
+        # HA states are limited to 255 chars, but attributes are NOT limited
+        # This tests the fix for the 256-byte buffer truncation bug
+        long_attr_value = "X" * 300  # 300 chars - enough to expose truncation bug
+        client.send_home_assistant_state(
+            "sensor.long_data", "long_value", long_attr_value
+        )
+
         # Test edge cases for zero-copy implementation safety
         # Empty entity_id should be silently ignored (no crash)
         client.send_home_assistant_state("", "", "should_be_ignored")
@@ -225,6 +241,13 @@ async def test_api_homeassistant(
             number_value = await asyncio.wait_for(ha_number_future, timeout=5.0)
             assert number_value == "42.5", f"Unexpected number value: {number_value}"
 
+            # Long attribute test - verify 300 chars weren't truncated to 255
+            long_attr_len = await asyncio.wait_for(long_attr_future, timeout=5.0)
+            assert long_attr_len == 300, (
+                f"Long attribute was truncated! Expected 300 chars, got {long_attr_len}. "
+                "This indicates the 256-byte truncation bug."
+            )
+
             # Wait for completion
             await asyncio.wait_for(tests_complete_future, timeout=5.0)