[api] Implement zero-copy string optimization for outgoing protobuf messages (#9790)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
2025-10-30 06:33:51 +00:00 · 2025-07-22 07:33:03 -10:00
parent 71cb429a86
commit a614a68f1a
17 changed files with 863 additions and 628 deletions
--- a/esphome/components/api/api_connection.cpp
+++ b/esphome/components/api/api_connection.cpp
@@ -248,8 +248,10 @@ void APIConnection::loop() {
    if (state_subs_at_ < static_cast<int>(subs.size())) {
      auto &it = subs[state_subs_at_];
      SubscribeHomeAssistantStateResponse resp;
-      resp.entity_id = it.entity_id;
-      resp.attribute = it.attribute.value();
+      resp.set_entity_id(StringRef(it.entity_id));
+      // attribute.value() returns temporary - must store it
+      std::string attribute_value = it.attribute.value();
+      resp.set_attribute(StringRef(attribute_value));
      resp.once = it.once;
      if (this->send_message(resp, SubscribeHomeAssistantStateResponse::MESSAGE_TYPE)) {
        state_subs_at_++;
@@ -260,14 +262,14 @@ void APIConnection::loop() {
  }
 }

-DisconnectResponse APIConnection::disconnect(const DisconnectRequest &msg) {
+bool APIConnection::send_disconnect_response(const DisconnectRequest &msg) {
  // remote initiated disconnect_client
  // don't close yet, we still need to send the disconnect response
  // close will happen on next loop
  ESP_LOGD(TAG, "%s disconnected", this->get_client_combined_info().c_str());
  this->flags_.next_close = true;
  DisconnectResponse resp;
-  return resp;
+  return this->send_message(resp, DisconnectResponse::MESSAGE_TYPE);
 }
 void APIConnection::on_disconnect_response(const DisconnectResponse &value) {
  this->helper_->close();
@@ -344,7 +346,7 @@ uint16_t APIConnection::try_send_binary_sensor_info(EntityBase *entity, APIConne
                                                    bool is_single) {
  auto *binary_sensor = static_cast<binary_sensor::BinarySensor *>(entity);
  ListEntitiesBinarySensorResponse msg;
-  msg.device_class = binary_sensor->get_device_class();
+  msg.set_device_class(binary_sensor->get_device_class_ref());
  msg.is_status_binary_sensor = binary_sensor->is_status_binary_sensor();
  return fill_and_encode_entity_info(binary_sensor, msg, ListEntitiesBinarySensorResponse::MESSAGE_TYPE, conn,
                                     remaining_size, is_single);
@@ -376,7 +378,7 @@ uint16_t APIConnection::try_send_cover_info(EntityBase *entity, APIConnection *c
  msg.supports_position = traits.get_supports_position();
  msg.supports_tilt = traits.get_supports_tilt();
  msg.supports_stop = traits.get_supports_stop();
-  msg.device_class = cover->get_device_class();
+  msg.set_device_class(cover->get_device_class_ref());
  return fill_and_encode_entity_info(cover, msg, ListEntitiesCoverResponse::MESSAGE_TYPE, conn, remaining_size,
                                     is_single);
 }
@@ -411,7 +413,7 @@ uint16_t APIConnection::try_send_fan_state(EntityBase *entity, APIConnection *co
  if (traits.supports_direction())
    msg.direction = static_cast<enums::FanDirection>(fan->direction);
  if (traits.supports_preset_modes())
-    msg.preset_mode = fan->preset_mode;
+    msg.set_preset_mode(StringRef(fan->preset_mode));
  return fill_and_encode_entity_state(fan, msg, FanStateResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }
 uint16_t APIConnection::try_send_fan_info(EntityBase *entity, APIConnection *conn, uint32_t remaining_size,
@@ -468,8 +470,11 @@ uint16_t APIConnection::try_send_light_state(EntityBase *entity, APIConnection *
  resp.color_temperature = values.get_color_temperature();
  resp.cold_white = values.get_cold_white();
  resp.warm_white = values.get_warm_white();
-  if (light->supports_effects())
-    resp.effect = light->get_effect_name();
+  if (light->supports_effects()) {
+    // get_effect_name() returns temporary std::string - must store it
+    std::string effect_name = light->get_effect_name();
+    resp.set_effect(StringRef(effect_name));
+  }
  return fill_and_encode_entity_state(light, resp, LightStateResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }
 uint16_t APIConnection::try_send_light_info(EntityBase *entity, APIConnection *conn, uint32_t remaining_size,
@@ -545,10 +550,10 @@ uint16_t APIConnection::try_send_sensor_info(EntityBase *entity, APIConnection *
                                             bool is_single) {
  auto *sensor = static_cast<sensor::Sensor *>(entity);
  ListEntitiesSensorResponse msg;
-  msg.unit_of_measurement = sensor->get_unit_of_measurement();
+  msg.set_unit_of_measurement(sensor->get_unit_of_measurement_ref());
  msg.accuracy_decimals = sensor->get_accuracy_decimals();
  msg.force_update = sensor->get_force_update();
-  msg.device_class = sensor->get_device_class();
+  msg.set_device_class(sensor->get_device_class_ref());
  msg.state_class = static_cast<enums::SensorStateClass>(sensor->get_state_class());
  return fill_and_encode_entity_info(sensor, msg, ListEntitiesSensorResponse::MESSAGE_TYPE, conn, remaining_size,
                                     is_single);
@@ -575,7 +580,7 @@ uint16_t APIConnection::try_send_switch_info(EntityBase *entity, APIConnection *
  auto *a_switch = static_cast<switch_::Switch *>(entity);
  ListEntitiesSwitchResponse msg;
  msg.assumed_state = a_switch->assumed_state();
-  msg.device_class = a_switch->get_device_class();
+  msg.set_device_class(a_switch->get_device_class_ref());
  return fill_and_encode_entity_info(a_switch, msg, ListEntitiesSwitchResponse::MESSAGE_TYPE, conn, remaining_size,
                                     is_single);
 }
@@ -600,7 +605,7 @@ uint16_t APIConnection::try_send_text_sensor_state(EntityBase *entity, APIConnec
                                                   bool is_single) {
  auto *text_sensor = static_cast<text_sensor::TextSensor *>(entity);
  TextSensorStateResponse resp;
-  resp.state = text_sensor->state;
+  resp.set_state(StringRef(text_sensor->state));
  resp.missing_state = !text_sensor->has_state();
  return fill_and_encode_entity_state(text_sensor, resp, TextSensorStateResponse::MESSAGE_TYPE, conn, remaining_size,
                                      is_single);
@@ -609,7 +614,7 @@ uint16_t APIConnection::try_send_text_sensor_info(EntityBase *entity, APIConnect
                                                  bool is_single) {
  auto *text_sensor = static_cast<text_sensor::TextSensor *>(entity);
  ListEntitiesTextSensorResponse msg;
-  msg.device_class = text_sensor->get_device_class();
+  msg.set_device_class(text_sensor->get_device_class_ref());
  return fill_and_encode_entity_info(text_sensor, msg, ListEntitiesTextSensorResponse::MESSAGE_TYPE, conn,
                                     remaining_size, is_single);
 }
@@ -637,13 +642,19 @@ uint16_t APIConnection::try_send_climate_state(EntityBase *entity, APIConnection
  }
  if (traits.get_supports_fan_modes() && climate->fan_mode.has_value())
    resp.fan_mode = static_cast<enums::ClimateFanMode>(climate->fan_mode.value());
-  if (!traits.get_supported_custom_fan_modes().empty() && climate->custom_fan_mode.has_value())
-    resp.custom_fan_mode = climate->custom_fan_mode.value();
+  if (!traits.get_supported_custom_fan_modes().empty() && climate->custom_fan_mode.has_value()) {
+    // custom_fan_mode.value() returns temporary - must store it
+    std::string custom_fan_mode = climate->custom_fan_mode.value();
+    resp.set_custom_fan_mode(StringRef(custom_fan_mode));
+  }
  if (traits.get_supports_presets() && climate->preset.has_value()) {
    resp.preset = static_cast<enums::ClimatePreset>(climate->preset.value());
  }
-  if (!traits.get_supported_custom_presets().empty() && climate->custom_preset.has_value())
-    resp.custom_preset = climate->custom_preset.value();
+  if (!traits.get_supported_custom_presets().empty() && climate->custom_preset.has_value()) {
+    // custom_preset.value() returns temporary - must store it
+    std::string custom_preset = climate->custom_preset.value();
+    resp.set_custom_preset(StringRef(custom_preset));
+  }
  if (traits.get_supports_swing_modes())
    resp.swing_mode = static_cast<enums::ClimateSwingMode>(climate->swing_mode);
  if (traits.get_supports_current_humidity())
@@ -729,9 +740,9 @@ uint16_t APIConnection::try_send_number_info(EntityBase *entity, APIConnection *
                                             bool is_single) {
  auto *number = static_cast<number::Number *>(entity);
  ListEntitiesNumberResponse msg;
-  msg.unit_of_measurement = number->traits.get_unit_of_measurement();
+  msg.set_unit_of_measurement(number->traits.get_unit_of_measurement_ref());
  msg.mode = static_cast<enums::NumberMode>(number->traits.get_mode());
-  msg.device_class = number->traits.get_device_class();
+  msg.set_device_class(number->traits.get_device_class_ref());
  msg.min_value = number->traits.get_min_value();
  msg.max_value = number->traits.get_max_value();
  msg.step = number->traits.get_step();
@@ -844,7 +855,7 @@ uint16_t APIConnection::try_send_text_state(EntityBase *entity, APIConnection *c
                                            bool is_single) {
  auto *text = static_cast<text::Text *>(entity);
  TextStateResponse resp;
-  resp.state = text->state;
+  resp.set_state(StringRef(text->state));
  resp.missing_state = !text->has_state();
  return fill_and_encode_entity_state(text, resp, TextStateResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }
@@ -856,7 +867,7 @@ uint16_t APIConnection::try_send_text_info(EntityBase *entity, APIConnection *co
  msg.mode = static_cast<enums::TextMode>(text->traits.get_mode());
  msg.min_length = text->traits.get_min_length();
  msg.max_length = text->traits.get_max_length();
-  msg.pattern = text->traits.get_pattern();
+  msg.set_pattern(text->traits.get_pattern_ref());
  return fill_and_encode_entity_info(text, msg, ListEntitiesTextResponse::MESSAGE_TYPE, conn, remaining_size,
                                     is_single);
 }
@@ -877,7 +888,7 @@ uint16_t APIConnection::try_send_select_state(EntityBase *entity, APIConnection
                                              bool is_single) {
  auto *select = static_cast<select::Select *>(entity);
  SelectStateResponse resp;
-  resp.state = select->state;
+  resp.set_state(StringRef(select->state));
  resp.missing_state = !select->has_state();
  return fill_and_encode_entity_state(select, resp, SelectStateResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }
@@ -903,7 +914,7 @@ uint16_t APIConnection::try_send_button_info(EntityBase *entity, APIConnection *
                                             bool is_single) {
  auto *button = static_cast<button::Button *>(entity);
  ListEntitiesButtonResponse msg;
-  msg.device_class = button->get_device_class();
+  msg.set_device_class(button->get_device_class_ref());
  return fill_and_encode_entity_info(button, msg, ListEntitiesButtonResponse::MESSAGE_TYPE, conn, remaining_size,
                                     is_single);
 }
@@ -972,7 +983,7 @@ uint16_t APIConnection::try_send_valve_info(EntityBase *entity, APIConnection *c
  auto *valve = static_cast<valve::Valve *>(entity);
  ListEntitiesValveResponse msg;
  auto traits = valve->get_traits();
-  msg.device_class = valve->get_device_class();
+  msg.set_device_class(valve->get_device_class_ref());
  msg.assumed_state = traits.get_is_assumed_state();
  msg.supports_position = traits.get_supports_position();
  msg.supports_stop = traits.get_supports_stop();
@@ -1014,13 +1025,13 @@ uint16_t APIConnection::try_send_media_player_info(EntityBase *entity, APIConnec
  auto traits = media_player->get_traits();
  msg.supports_pause = traits.get_supports_pause();
  for (auto &supported_format : traits.get_supported_formats()) {
-    MediaPlayerSupportedFormat media_format;
-    media_format.format = supported_format.format;
+    msg.supported_formats.emplace_back();
+    auto &media_format = msg.supported_formats.back();
+    media_format.set_format(StringRef(supported_format.format));
    media_format.sample_rate = supported_format.sample_rate;
    media_format.num_channels = supported_format.num_channels;
    media_format.purpose = static_cast<enums::MediaPlayerFormatPurpose>(supported_format.purpose);
    media_format.sample_bytes = supported_format.sample_bytes;
-    msg.supported_formats.push_back(media_format);
  }
  return fill_and_encode_entity_info(media_player, msg, ListEntitiesMediaPlayerResponse::MESSAGE_TYPE, conn,
                                     remaining_size, is_single);
@@ -1083,6 +1094,12 @@ void APIConnection::on_get_time_response(const GetTimeResponse &value) {
 }
 #endif

+bool APIConnection::send_get_time_response(const GetTimeRequest &msg) {
+  GetTimeResponse resp;
+  resp.epoch_seconds = ::time(nullptr);
+  return this->send_message(resp, GetTimeResponse::MESSAGE_TYPE);
+}
+
 #ifdef USE_BLUETOOTH_PROXY
 void APIConnection::subscribe_bluetooth_le_advertisements(const SubscribeBluetoothLEAdvertisementsRequest &msg) {
  bluetooth_proxy::global_bluetooth_proxy->subscribe_api_connection(this, msg.flags);
@@ -1113,12 +1130,12 @@ void APIConnection::bluetooth_gatt_notify(const BluetoothGATTNotifyRequest &msg)
  bluetooth_proxy::global_bluetooth_proxy->bluetooth_gatt_notify(msg);
 }

-BluetoothConnectionsFreeResponse APIConnection::subscribe_bluetooth_connections_free(
+bool APIConnection::send_subscribe_bluetooth_connections_free_response(
    const SubscribeBluetoothConnectionsFreeRequest &msg) {
  BluetoothConnectionsFreeResponse resp;
  resp.free = bluetooth_proxy::global_bluetooth_proxy->get_bluetooth_connections_free();
  resp.limit = bluetooth_proxy::global_bluetooth_proxy->get_bluetooth_connections_limit();
-  return resp;
+  return this->send_message(resp, BluetoothConnectionsFreeResponse::MESSAGE_TYPE);
 }

 void APIConnection::bluetooth_scanner_set_mode(const BluetoothScannerSetModeRequest &msg) {
@@ -1179,28 +1196,27 @@ void APIConnection::on_voice_assistant_announce_request(const VoiceAssistantAnno
  }
 }

-VoiceAssistantConfigurationResponse APIConnection::voice_assistant_get_configuration(
-    const VoiceAssistantConfigurationRequest &msg) {
+bool APIConnection::send_voice_assistant_get_configuration_response(const VoiceAssistantConfigurationRequest &msg) {
  VoiceAssistantConfigurationResponse resp;
  if (!this->check_voice_assistant_api_connection_()) {
-    return resp;
+    return this->send_message(resp, VoiceAssistantConfigurationResponse::MESSAGE_TYPE);
  }

  auto &config = voice_assistant::global_voice_assistant->get_configuration();
  for (auto &wake_word : config.available_wake_words) {
-    VoiceAssistantWakeWord resp_wake_word;
-    resp_wake_word.id = wake_word.id;
-    resp_wake_word.wake_word = wake_word.wake_word;
+    resp.available_wake_words.emplace_back();
+    auto &resp_wake_word = resp.available_wake_words.back();
+    resp_wake_word.set_id(StringRef(wake_word.id));
+    resp_wake_word.set_wake_word(StringRef(wake_word.wake_word));
    for (const auto &lang : wake_word.trained_languages) {
      resp_wake_word.trained_languages.push_back(lang);
    }
-    resp.available_wake_words.push_back(std::move(resp_wake_word));
  }
  for (auto &wake_word_id : config.active_wake_words) {
    resp.active_wake_words.push_back(wake_word_id);
  }
  resp.max_active_wake_words = config.max_active_wake_words;
-  return resp;
+  return this->send_message(resp, VoiceAssistantConfigurationResponse::MESSAGE_TYPE);
 }

 void APIConnection::voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &msg) {
@@ -1273,7 +1289,7 @@ void APIConnection::send_event(event::Event *event, const std::string &event_typ
 uint16_t APIConnection::try_send_event_response(event::Event *event, const std::string &event_type, APIConnection *conn,
                                                uint32_t remaining_size, bool is_single) {
  EventResponse resp;
-  resp.event_type = event_type;
+  resp.set_event_type(StringRef(event_type));
  return fill_and_encode_entity_state(event, resp, EventResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }

@@ -1281,7 +1297,7 @@ uint16_t APIConnection::try_send_event_info(EntityBase *entity, APIConnection *c
                                            bool is_single) {
  auto *event = static_cast<event::Event *>(entity);
  ListEntitiesEventResponse msg;
-  msg.device_class = event->get_device_class();
+  msg.set_device_class(event->get_device_class_ref());
  for (const auto &event_type : event->get_event_types())
    msg.event_types.push_back(event_type);
  return fill_and_encode_entity_info(event, msg, ListEntitiesEventResponse::MESSAGE_TYPE, conn, remaining_size,
@@ -1305,11 +1321,11 @@ uint16_t APIConnection::try_send_update_state(EntityBase *entity, APIConnection
      resp.has_progress = true;
      resp.progress = update->update_info.progress;
    }
-    resp.current_version = update->update_info.current_version;
-    resp.latest_version = update->update_info.latest_version;
-    resp.title = update->update_info.title;
-    resp.release_summary = update->update_info.summary;
-    resp.release_url = update->update_info.release_url;
+    resp.set_current_version(StringRef(update->update_info.current_version));
+    resp.set_latest_version(StringRef(update->update_info.latest_version));
+    resp.set_title(StringRef(update->update_info.title));
+    resp.set_release_summary(StringRef(update->update_info.summary));
+    resp.set_release_url(StringRef(update->update_info.release_url));
  }
  return fill_and_encode_entity_state(update, resp, UpdateStateResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }
@@ -1317,7 +1333,7 @@ uint16_t APIConnection::try_send_update_info(EntityBase *entity, APIConnection *
                                             bool is_single) {
  auto *update = static_cast<update::UpdateEntity *>(entity);
  ListEntitiesUpdateResponse msg;
-  msg.device_class = update->get_device_class();
+  msg.set_device_class(update->get_device_class_ref());
  return fill_and_encode_entity_info(update, msg, ListEntitiesUpdateResponse::MESSAGE_TYPE, conn, remaining_size,
                                     is_single);
 }
@@ -1366,7 +1382,7 @@ void APIConnection::complete_authentication_() {
 #endif
 }

-HelloResponse APIConnection::hello(const HelloRequest &msg) {
+bool APIConnection::send_hello_response(const HelloRequest &msg) {
  this->client_info_.name = msg.client_info;
  this->client_info_.peername = this->helper_->getpeername();
  this->client_api_version_major_ = msg.api_version_major;
@@ -1377,8 +1393,10 @@ HelloResponse APIConnection::hello(const HelloRequest &msg) {
  HelloResponse resp;
  resp.api_version_major = 1;
  resp.api_version_minor = 10;
-  resp.server_info = App.get_name() + " (esphome v" ESPHOME_VERSION ")";
-  resp.name = App.get_name();
+  // Temporary string for concatenation - will be valid during send_message call
+  std::string server_info = App.get_name() + " (esphome v" ESPHOME_VERSION ")";
+  resp.set_server_info(StringRef(server_info));
+  resp.set_name(StringRef(App.get_name()));

 #ifdef USE_API_PASSWORD
  // Password required - wait for authentication
@@ -1388,9 +1406,9 @@ HelloResponse APIConnection::hello(const HelloRequest &msg) {
  this->complete_authentication_();
 #endif

-  return resp;
+  return this->send_message(resp, HelloResponse::MESSAGE_TYPE);
 }
-ConnectResponse APIConnection::connect(const ConnectRequest &msg) {
+bool APIConnection::send_connect_response(const ConnectRequest &msg) {
  bool correct = true;
 #ifdef USE_API_PASSWORD
  correct = this->parent_->check_password(msg.password);
@@ -1402,48 +1420,71 @@ ConnectResponse APIConnection::connect(const ConnectRequest &msg) {
  if (correct) {
    this->complete_authentication_();
  }
-  return resp;
+  return this->send_message(resp, ConnectResponse::MESSAGE_TYPE);
 }
-DeviceInfoResponse APIConnection::device_info(const DeviceInfoRequest &msg) {
+
+bool APIConnection::send_ping_response(const PingRequest &msg) {
+  PingResponse resp;
+  return this->send_message(resp, PingResponse::MESSAGE_TYPE);
+}
+
+bool APIConnection::send_device_info_response(const DeviceInfoRequest &msg) {
  DeviceInfoResponse resp{};
 #ifdef USE_API_PASSWORD
  resp.uses_password = true;
 #endif
-  resp.name = App.get_name();
-  resp.friendly_name = App.get_friendly_name();
+  resp.set_name(StringRef(App.get_name()));
+  resp.set_friendly_name(StringRef(App.get_friendly_name()));
 #ifdef USE_AREAS
-  resp.suggested_area = App.get_area();
+  resp.set_suggested_area(StringRef(App.get_area()));
 #endif
-  resp.mac_address = get_mac_address_pretty();
-  resp.esphome_version = ESPHOME_VERSION;
-  resp.compilation_time = App.get_compilation_time();
+  // mac_address must store temporary string - will be valid during send_message call
+  std::string mac_address = get_mac_address_pretty();
+  resp.set_mac_address(StringRef(mac_address));
+
+  // Compile-time StringRef constants
+  static constexpr auto ESPHOME_VERSION_REF = StringRef::from_lit(ESPHOME_VERSION);
+  resp.set_esphome_version(ESPHOME_VERSION_REF);
+
+  // get_compilation_time() returns temporary std::string - must store it
+  std::string compilation_time = App.get_compilation_time();
+  resp.set_compilation_time(StringRef(compilation_time));
+
+  // Compile-time StringRef constants for manufacturers
 #if defined(USE_ESP8266) || defined(USE_ESP32)
-  resp.manufacturer = "Espressif";
+  static constexpr auto MANUFACTURER = StringRef::from_lit("Espressif");
 #elif defined(USE_RP2040)
-  resp.manufacturer = "Raspberry Pi";
+  static constexpr auto MANUFACTURER = StringRef::from_lit("Raspberry Pi");
 #elif defined(USE_BK72XX)
-  resp.manufacturer = "Beken";
+  static constexpr auto MANUFACTURER = StringRef::from_lit("Beken");
 #elif defined(USE_LN882X)
-  resp.manufacturer = "Lightning";
+  static constexpr auto MANUFACTURER = StringRef::from_lit("Lightning");
 #elif defined(USE_RTL87XX)
-  resp.manufacturer = "Realtek";
+  static constexpr auto MANUFACTURER = StringRef::from_lit("Realtek");
 #elif defined(USE_HOST)
-  resp.manufacturer = "Host";
+  static constexpr auto MANUFACTURER = StringRef::from_lit("Host");
 #endif
-  resp.model = ESPHOME_BOARD;
+  resp.set_manufacturer(MANUFACTURER);
+
+  static constexpr auto MODEL = StringRef::from_lit(ESPHOME_BOARD);
+  resp.set_model(MODEL);
 #ifdef USE_DEEP_SLEEP
  resp.has_deep_sleep = deep_sleep::global_has_deep_sleep;
 #endif
 #ifdef ESPHOME_PROJECT_NAME
-  resp.project_name = ESPHOME_PROJECT_NAME;
-  resp.project_version = ESPHOME_PROJECT_VERSION;
+  static constexpr auto PROJECT_NAME = StringRef::from_lit(ESPHOME_PROJECT_NAME);
+  static constexpr auto PROJECT_VERSION = StringRef::from_lit(ESPHOME_PROJECT_VERSION);
+  resp.set_project_name(PROJECT_NAME);
+  resp.set_project_version(PROJECT_VERSION);
 #endif
 #ifdef USE_WEBSERVER
  resp.webserver_port = USE_WEBSERVER_PORT;
 #endif
 #ifdef USE_BLUETOOTH_PROXY
  resp.bluetooth_proxy_feature_flags = bluetooth_proxy::global_bluetooth_proxy->get_feature_flags();
-  resp.bluetooth_mac_address = bluetooth_proxy::global_bluetooth_proxy->get_bluetooth_mac_address_pretty();
+  // bt_mac must store temporary string - will be valid during send_message call
+  std::string bluetooth_mac = bluetooth_proxy::global_bluetooth_proxy->get_bluetooth_mac_address_pretty();
+  resp.set_bluetooth_mac_address(StringRef(bluetooth_mac));
 #endif
 #ifdef USE_VOICE_ASSISTANT
  resp.voice_assistant_feature_flags = voice_assistant::global_voice_assistant->get_feature_flags();
@@ -1453,23 +1494,25 @@ DeviceInfoResponse APIConnection::device_info(const DeviceInfoRequest &msg) {
 #endif
 #ifdef USE_DEVICES
  for (auto const &device : App.get_devices()) {
-    DeviceInfo device_info;
+    resp.devices.emplace_back();
+    auto &device_info = resp.devices.back();
    device_info.device_id = device->get_device_id();
-    device_info.name = device->get_name();
+    device_info.set_name(StringRef(device->get_name()));
    device_info.area_id = device->get_area_id();
-    resp.devices.push_back(device_info);
  }
 #endif
 #ifdef USE_AREAS
  for (auto const &area : App.get_areas()) {
-    AreaInfo area_info;
+    resp.areas.emplace_back();
+    auto &area_info = resp.areas.back();
    area_info.area_id = area->get_area_id();
-    area_info.name = area->get_name();
-    resp.areas.push_back(area_info);
+    area_info.set_name(StringRef(area->get_name()));
  }
 #endif
-  return resp;
+
+  return this->send_message(resp, DeviceInfoResponse::MESSAGE_TYPE);
 }
+
 void APIConnection::on_home_assistant_state_response(const HomeAssistantStateResponse &msg) {
  for (auto &it : this->parent_->get_state_subs()) {
    if (it.entity_id == msg.entity_id && it.attribute.value() == msg.attribute) {
@@ -1491,23 +1534,21 @@ void APIConnection::execute_service(const ExecuteServiceRequest &msg) {
 }
 #endif
 #ifdef USE_API_NOISE
-NoiseEncryptionSetKeyResponse APIConnection::noise_encryption_set_key(const NoiseEncryptionSetKeyRequest &msg) {
+bool APIConnection::send_noise_encryption_set_key_response(const NoiseEncryptionSetKeyRequest &msg) {
  psk_t psk{};
  NoiseEncryptionSetKeyResponse resp;
  if (base64_decode(msg.key, psk.data(), msg.key.size()) != psk.size()) {
    ESP_LOGW(TAG, "Invalid encryption key length");
    resp.success = false;
-    return resp;
+    return this->send_message(resp, NoiseEncryptionSetKeyResponse::MESSAGE_TYPE);
  }
-
  if (!this->parent_->save_noise_psk(psk, true)) {
    ESP_LOGW(TAG, "Failed to save encryption key");
    resp.success = false;
-    return resp;
+    return this->send_message(resp, NoiseEncryptionSetKeyResponse::MESSAGE_TYPE);
  }
-
  resp.success = true;
-  return resp;
+  return this->send_message(resp, NoiseEncryptionSetKeyResponse::MESSAGE_TYPE);
 }
 #endif
 void APIConnection::subscribe_home_assistant_states(const SubscribeHomeAssistantStatesRequest &msg) {
--- a/esphome/components/api/api_connection.h
+++ b/esphome/components/api/api_connection.h
@@ -148,8 +148,7 @@ class APIConnection : public APIServerConnection {
  void bluetooth_gatt_write_descriptor(const BluetoothGATTWriteDescriptorRequest &msg) override;
  void bluetooth_gatt_get_services(const BluetoothGATTGetServicesRequest &msg) override;
  void bluetooth_gatt_notify(const BluetoothGATTNotifyRequest &msg) override;
-  BluetoothConnectionsFreeResponse subscribe_bluetooth_connections_free(
-      const SubscribeBluetoothConnectionsFreeRequest &msg) override;
+  bool send_subscribe_bluetooth_connections_free_response(const SubscribeBluetoothConnectionsFreeRequest &msg) override;
  void bluetooth_scanner_set_mode(const BluetoothScannerSetModeRequest &msg) override;

 #endif
@@ -167,8 +166,7 @@ class APIConnection : public APIServerConnection {
  void on_voice_assistant_audio(const VoiceAssistantAudio &msg) override;
  void on_voice_assistant_timer_event_response(const VoiceAssistantTimerEventResponse &msg) override;
  void on_voice_assistant_announce_request(const VoiceAssistantAnnounceRequest &msg) override;
-  VoiceAssistantConfigurationResponse voice_assistant_get_configuration(
-      const VoiceAssistantConfigurationRequest &msg) override;
+  bool send_voice_assistant_get_configuration_response(const VoiceAssistantConfigurationRequest &msg) override;
  void voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &msg) override;
 #endif

@@ -195,11 +193,11 @@ class APIConnection : public APIServerConnection {
 #ifdef USE_HOMEASSISTANT_TIME
  void on_get_time_response(const GetTimeResponse &value) override;
 #endif
-  HelloResponse hello(const HelloRequest &msg) override;
-  ConnectResponse connect(const ConnectRequest &msg) override;
-  DisconnectResponse disconnect(const DisconnectRequest &msg) override;
-  PingResponse ping(const PingRequest &msg) override { return {}; }
-  DeviceInfoResponse device_info(const DeviceInfoRequest &msg) override;
+  bool send_hello_response(const HelloRequest &msg) override;
+  bool send_connect_response(const ConnectRequest &msg) override;
+  bool send_disconnect_response(const DisconnectRequest &msg) override;
+  bool send_ping_response(const PingRequest &msg) override;
+  bool send_device_info_response(const DeviceInfoRequest &msg) override;
  void list_entities(const ListEntitiesRequest &msg) override { this->list_entities_iterator_.begin(); }
  void subscribe_states(const SubscribeStatesRequest &msg) override {
    this->flags_.state_subscription = true;
@@ -214,15 +212,12 @@ class APIConnection : public APIServerConnection {
    this->flags_.service_call_subscription = true;
  }
  void subscribe_home_assistant_states(const SubscribeHomeAssistantStatesRequest &msg) override;
-  GetTimeResponse get_time(const GetTimeRequest &msg) override {
-    // TODO
-    return {};
-  }
+  bool send_get_time_response(const GetTimeRequest &msg) override;
 #ifdef USE_API_SERVICES
  void execute_service(const ExecuteServiceRequest &msg) override;
 #endif
 #ifdef USE_API_NOISE
-  NoiseEncryptionSetKeyResponse noise_encryption_set_key(const NoiseEncryptionSetKeyRequest &msg) override;
+  bool send_noise_encryption_set_key_response(const NoiseEncryptionSetKeyRequest &msg) override;
 #endif

  bool is_authenticated() override {
@@ -313,14 +308,17 @@ class APIConnection : public APIServerConnection {
                                              APIConnection *conn, uint32_t remaining_size, bool is_single) {
    // Set common fields that are shared by all entity types
    msg.key = entity->get_object_id_hash();
-    msg.object_id = entity->get_object_id();
+    // IMPORTANT: get_object_id() may return a temporary std::string
+    std::string object_id = entity->get_object_id();
+    msg.set_object_id(StringRef(object_id));

-    if (entity->has_own_name())
-      msg.name = entity->get_name();
+    if (entity->has_own_name()) {
+      msg.set_name(entity->get_name());
+    }

-      // Set common EntityBase properties
+    // Set common EntityBase properties
 #ifdef USE_ENTITY_ICON
-    msg.icon = entity->get_icon();
+    msg.set_icon(entity->get_icon_ref());
 #endif
    msg.disabled_by_default = entity->is_disabled_by_default();
    msg.entity_category = static_cast<enums::EntityCategory>(entity->get_entity_category());
--- a/esphome/components/api/api_pb2.cpp
+++ b/esphome/components/api/api_pb2.cpp
--- a/esphome/components/api/api_pb2.h
+++ b/esphome/components/api/api_pb2.h
@@ -3,6 +3,7 @@
 #pragma once

 #include "esphome/core/defines.h"
+#include "esphome/core/string_ref.h"

 #include "proto.h"

@@ -269,12 +270,15 @@ enum UpdateCommand : uint32_t {
 class InfoResponseProtoMessage : public ProtoMessage {
 public:
  ~InfoResponseProtoMessage() override = default;
-  std::string object_id{};
+  StringRef object_id_ref_{};
+  void set_object_id(const StringRef &ref) { this->object_id_ref_ = ref; }
  uint32_t key{0};
-  std::string name{};
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
  bool disabled_by_default{false};
 #ifdef USE_ENTITY_ICON
-  std::string icon{};
+  StringRef icon_ref_{};
+  void set_icon(const StringRef &ref) { this->icon_ref_ = ref; }
 #endif
  enums::EntityCategory entity_category{};
 #ifdef USE_DEVICES
@@ -332,8 +336,10 @@ class HelloResponse : public ProtoMessage {
 #endif
  uint32_t api_version_major{0};
  uint32_t api_version_minor{0};
-  std::string server_info{};
-  std::string name{};
+  StringRef server_info_ref_{};
+  void set_server_info(const StringRef &ref) { this->server_info_ref_ = ref; }
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -442,7 +448,8 @@ class DeviceInfoRequest : public ProtoDecodableMessage {
 class AreaInfo : public ProtoMessage {
 public:
  uint32_t area_id{0};
-  std::string name{};
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -456,7 +463,8 @@ class AreaInfo : public ProtoMessage {
 class DeviceInfo : public ProtoMessage {
 public:
  uint32_t device_id{0};
-  std::string name{};
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
  uint32_t area_id{0};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -477,19 +485,26 @@ class DeviceInfoResponse : public ProtoMessage {
 #ifdef USE_API_PASSWORD
  bool uses_password{false};
 #endif
-  std::string name{};
-  std::string mac_address{};
-  std::string esphome_version{};
-  std::string compilation_time{};
-  std::string model{};
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
+  StringRef mac_address_ref_{};
+  void set_mac_address(const StringRef &ref) { this->mac_address_ref_ = ref; }
+  StringRef esphome_version_ref_{};
+  void set_esphome_version(const StringRef &ref) { this->esphome_version_ref_ = ref; }
+  StringRef compilation_time_ref_{};
+  void set_compilation_time(const StringRef &ref) { this->compilation_time_ref_ = ref; }
+  StringRef model_ref_{};
+  void set_model(const StringRef &ref) { this->model_ref_ = ref; }
 #ifdef USE_DEEP_SLEEP
  bool has_deep_sleep{false};
 #endif
 #ifdef ESPHOME_PROJECT_NAME
-  std::string project_name{};
+  StringRef project_name_ref_{};
+  void set_project_name(const StringRef &ref) { this->project_name_ref_ = ref; }
 #endif
 #ifdef ESPHOME_PROJECT_NAME
-  std::string project_version{};
+  StringRef project_version_ref_{};
+  void set_project_version(const StringRef &ref) { this->project_version_ref_ = ref; }
 #endif
 #ifdef USE_WEBSERVER
  uint32_t webserver_port{0};
@@ -497,16 +512,20 @@ class DeviceInfoResponse : public ProtoMessage {
 #ifdef USE_BLUETOOTH_PROXY
  uint32_t bluetooth_proxy_feature_flags{0};
 #endif
-  std::string manufacturer{};
-  std::string friendly_name{};
+  StringRef manufacturer_ref_{};
+  void set_manufacturer(const StringRef &ref) { this->manufacturer_ref_ = ref; }
+  StringRef friendly_name_ref_{};
+  void set_friendly_name(const StringRef &ref) { this->friendly_name_ref_ = ref; }
 #ifdef USE_VOICE_ASSISTANT
  uint32_t voice_assistant_feature_flags{0};
 #endif
 #ifdef USE_AREAS
-  std::string suggested_area{};
+  StringRef suggested_area_ref_{};
+  void set_suggested_area(const StringRef &ref) { this->suggested_area_ref_ = ref; }
 #endif
 #ifdef USE_BLUETOOTH_PROXY
-  std::string bluetooth_mac_address{};
+  StringRef bluetooth_mac_address_ref_{};
+  void set_bluetooth_mac_address(const StringRef &ref) { this->bluetooth_mac_address_ref_ = ref; }
 #endif
 #ifdef USE_API_NOISE
  bool api_encryption_supported{false};
@@ -575,7 +594,8 @@ class ListEntitiesBinarySensorResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_binary_sensor_response"; }
 #endif
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  bool is_status_binary_sensor{false};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -614,7 +634,8 @@ class ListEntitiesCoverResponse : public InfoResponseProtoMessage {
  bool assumed_state{false};
  bool supports_position{false};
  bool supports_tilt{false};
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  bool supports_stop{false};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -695,7 +716,8 @@ class FanStateResponse : public StateResponseProtoMessage {
  bool oscillating{false};
  enums::FanDirection direction{};
  int32_t speed_level{0};
-  std::string preset_mode{};
+  StringRef preset_mode_ref_{};
+  void set_preset_mode(const StringRef &ref) { this->preset_mode_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -769,7 +791,8 @@ class LightStateResponse : public StateResponseProtoMessage {
  float color_temperature{0.0f};
  float cold_white{0.0f};
  float warm_white{0.0f};
-  std::string effect{};
+  StringRef effect_ref_{};
+  void set_effect(const StringRef &ref) { this->effect_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -829,10 +852,12 @@ class ListEntitiesSensorResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_sensor_response"; }
 #endif
-  std::string unit_of_measurement{};
+  StringRef unit_of_measurement_ref_{};
+  void set_unit_of_measurement(const StringRef &ref) { this->unit_of_measurement_ref_ = ref; }
  int32_t accuracy_decimals{0};
  bool force_update{false};
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  enums::SensorStateClass state_class{};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -869,7 +894,8 @@ class ListEntitiesSwitchResponse : public InfoResponseProtoMessage {
  const char *message_name() const override { return "list_entities_switch_response"; }
 #endif
  bool assumed_state{false};
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -919,7 +945,8 @@ class ListEntitiesTextSensorResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_text_sensor_response"; }
 #endif
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -935,7 +962,8 @@ class TextSensorStateResponse : public StateResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "text_sensor_state_response"; }
 #endif
-  std::string state{};
+  StringRef state_ref_{};
+  void set_state(const StringRef &ref) { this->state_ref_ = ref; }
  bool missing_state{false};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -1032,8 +1060,10 @@ class SubscribeHomeassistantServicesRequest : public ProtoDecodableMessage {
 };
 class HomeassistantServiceMap : public ProtoMessage {
 public:
-  std::string key{};
-  std::string value{};
+  StringRef key_ref_{};
+  void set_key(const StringRef &ref) { this->key_ref_ = ref; }
+  StringRef value_ref_{};
+  void set_value(const StringRef &ref) { this->value_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1049,7 +1079,8 @@ class HomeassistantServiceResponse : public ProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "homeassistant_service_response"; }
 #endif
-  std::string service{};
+  StringRef service_ref_{};
+  void set_service(const StringRef &ref) { this->service_ref_ = ref; }
  std::vector<HomeassistantServiceMap> data{};
  std::vector<HomeassistantServiceMap> data_template{};
  std::vector<HomeassistantServiceMap> variables{};
@@ -1082,8 +1113,10 @@ class SubscribeHomeAssistantStateResponse : public ProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "subscribe_home_assistant_state_response"; }
 #endif
-  std::string entity_id{};
-  std::string attribute{};
+  StringRef entity_id_ref_{};
+  void set_entity_id(const StringRef &ref) { this->entity_id_ref_ = ref; }
+  StringRef attribute_ref_{};
+  void set_attribute(const StringRef &ref) { this->attribute_ref_ = ref; }
  bool once{false};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -1143,7 +1176,8 @@ class GetTimeResponse : public ProtoDecodableMessage {
 #ifdef USE_API_SERVICES
 class ListEntitiesServicesArgument : public ProtoMessage {
 public:
-  std::string name{};
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
  enums::ServiceArgType type{};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -1160,7 +1194,8 @@ class ListEntitiesServicesResponse : public ProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_services_response"; }
 #endif
-  std::string name{};
+  StringRef name_ref_{};
+  void set_name(const StringRef &ref) { this->name_ref_ = ref; }
  uint32_t key{0};
  std::vector<ListEntitiesServicesArgument> args{};
  void encode(ProtoWriteBuffer buffer) const override;
@@ -1312,9 +1347,11 @@ class ClimateStateResponse : public StateResponseProtoMessage {
  enums::ClimateAction action{};
  enums::ClimateFanMode fan_mode{};
  enums::ClimateSwingMode swing_mode{};
-  std::string custom_fan_mode{};
+  StringRef custom_fan_mode_ref_{};
+  void set_custom_fan_mode(const StringRef &ref) { this->custom_fan_mode_ref_ = ref; }
  enums::ClimatePreset preset{};
-  std::string custom_preset{};
+  StringRef custom_preset_ref_{};
+  void set_custom_preset(const StringRef &ref) { this->custom_preset_ref_ = ref; }
  float current_humidity{0.0f};
  float target_humidity{0.0f};
  void encode(ProtoWriteBuffer buffer) const override;
@@ -1373,9 +1410,11 @@ class ListEntitiesNumberResponse : public InfoResponseProtoMessage {
  float min_value{0.0f};
  float max_value{0.0f};
  float step{0.0f};
-  std::string unit_of_measurement{};
+  StringRef unit_of_measurement_ref_{};
+  void set_unit_of_measurement(const StringRef &ref) { this->unit_of_measurement_ref_ = ref; }
  enums::NumberMode mode{};
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1442,7 +1481,8 @@ class SelectStateResponse : public StateResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "select_state_response"; }
 #endif
-  std::string state{};
+  StringRef state_ref_{};
+  void set_state(const StringRef &ref) { this->state_ref_ = ref; }
  bool missing_state{false};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -1541,7 +1581,8 @@ class ListEntitiesLockResponse : public InfoResponseProtoMessage {
  bool assumed_state{false};
  bool supports_open{false};
  bool requires_code{false};
-  std::string code_format{};
+  StringRef code_format_ref_{};
+  void set_code_format(const StringRef &ref) { this->code_format_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1594,7 +1635,8 @@ class ListEntitiesButtonResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_button_response"; }
 #endif
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1622,7 +1664,8 @@ class ButtonCommandRequest : public CommandProtoMessage {
 #ifdef USE_MEDIA_PLAYER
 class MediaPlayerSupportedFormat : public ProtoMessage {
 public:
-  std::string format{};
+  StringRef format_ref_{};
+  void set_format(const StringRef &ref) { this->format_ref_ = ref; }
  uint32_t sample_rate{0};
  uint32_t num_channels{0};
  enums::MediaPlayerFormatPurpose purpose{};
@@ -2219,10 +2262,12 @@ class VoiceAssistantRequest : public ProtoMessage {
  const char *message_name() const override { return "voice_assistant_request"; }
 #endif
  bool start{false};
-  std::string conversation_id{};
+  StringRef conversation_id_ref_{};
+  void set_conversation_id(const StringRef &ref) { this->conversation_id_ref_ = ref; }
  uint32_t flags{0};
  VoiceAssistantAudioSettings audio_settings{};
-  std::string wake_word_phrase{};
+  StringRef wake_word_phrase_ref_{};
+  void set_wake_word_phrase(const StringRef &ref) { this->wake_word_phrase_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -2358,8 +2403,10 @@ class VoiceAssistantAnnounceFinished : public ProtoMessage {
 };
 class VoiceAssistantWakeWord : public ProtoMessage {
 public:
-  std::string id{};
-  std::string wake_word{};
+  StringRef id_ref_{};
+  void set_id(const StringRef &ref) { this->id_ref_ = ref; }
+  StringRef wake_word_ref_{};
+  void set_wake_word(const StringRef &ref) { this->wake_word_ref_ = ref; }
  std::vector<std::string> trained_languages{};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -2480,7 +2527,8 @@ class ListEntitiesTextResponse : public InfoResponseProtoMessage {
 #endif
  uint32_t min_length{0};
  uint32_t max_length{0};
-  std::string pattern{};
+  StringRef pattern_ref_{};
+  void set_pattern(const StringRef &ref) { this->pattern_ref_ = ref; }
  enums::TextMode mode{};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -2497,7 +2545,8 @@ class TextStateResponse : public StateResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "text_state_response"; }
 #endif
-  std::string state{};
+  StringRef state_ref_{};
+  void set_state(const StringRef &ref) { this->state_ref_ = ref; }
  bool missing_state{false};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -2641,7 +2690,8 @@ class ListEntitiesEventResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_event_response"; }
 #endif
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  std::vector<std::string> event_types{};
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
@@ -2658,7 +2708,8 @@ class EventResponse : public StateResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "event_response"; }
 #endif
-  std::string event_type{};
+  StringRef event_type_ref_{};
+  void set_event_type(const StringRef &ref) { this->event_type_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -2676,7 +2727,8 @@ class ListEntitiesValveResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_valve_response"; }
 #endif
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  bool assumed_state{false};
  bool supports_position{false};
  bool supports_stop{false};
@@ -2782,7 +2834,8 @@ class ListEntitiesUpdateResponse : public InfoResponseProtoMessage {
 #ifdef HAS_PROTO_MESSAGE_DUMP
  const char *message_name() const override { return "list_entities_update_response"; }
 #endif
-  std::string device_class{};
+  StringRef device_class_ref_{};
+  void set_device_class(const StringRef &ref) { this->device_class_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -2802,11 +2855,16 @@ class UpdateStateResponse : public StateResponseProtoMessage {
  bool in_progress{false};
  bool has_progress{false};
  float progress{0.0f};
-  std::string current_version{};
-  std::string latest_version{};
-  std::string title{};
-  std::string release_summary{};
-  std::string release_url{};
+  StringRef current_version_ref_{};
+  void set_current_version(const StringRef &ref) { this->current_version_ref_ = ref; }
+  StringRef latest_version_ref_{};
+  void set_latest_version(const StringRef &ref) { this->latest_version_ref_ = ref; }
+  StringRef title_ref_{};
+  void set_title(const StringRef &ref) { this->title_ref_ = ref; }
+  StringRef release_summary_ref_{};
+  void set_release_summary(const StringRef &ref) { this->release_summary_ref_ = ref; }
+  StringRef release_url_ref_{};
+  void set_release_url(const StringRef &ref) { this->release_url_ref_ = ref; }
  void encode(ProtoWriteBuffer buffer) const override;
  void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
--- a/esphome/components/api/api_pb2_dump.cpp
+++ b/esphome/components/api/api_pb2_dump.cpp
--- a/esphome/components/api/api_pb2_service.cpp
+++ b/esphome/components/api/api_pb2_service.cpp
@@ -597,33 +597,28 @@ void APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type,
 }

 void APIServerConnection::on_hello_request(const HelloRequest &msg) {
-  HelloResponse ret = this->hello(msg);
-  if (!this->send_message(ret, HelloResponse::MESSAGE_TYPE)) {
+  if (!this->send_hello_response(msg)) {
    this->on_fatal_error();
  }
 }
 void APIServerConnection::on_connect_request(const ConnectRequest &msg) {
-  ConnectResponse ret = this->connect(msg);
-  if (!this->send_message(ret, ConnectResponse::MESSAGE_TYPE)) {
+  if (!this->send_connect_response(msg)) {
    this->on_fatal_error();
  }
 }
 void APIServerConnection::on_disconnect_request(const DisconnectRequest &msg) {
-  DisconnectResponse ret = this->disconnect(msg);
-  if (!this->send_message(ret, DisconnectResponse::MESSAGE_TYPE)) {
+  if (!this->send_disconnect_response(msg)) {
    this->on_fatal_error();
  }
 }
 void APIServerConnection::on_ping_request(const PingRequest &msg) {
-  PingResponse ret = this->ping(msg);
-  if (!this->send_message(ret, PingResponse::MESSAGE_TYPE)) {
+  if (!this->send_ping_response(msg)) {
    this->on_fatal_error();
  }
 }
 void APIServerConnection::on_device_info_request(const DeviceInfoRequest &msg) {
  if (this->check_connection_setup_()) {
-    DeviceInfoResponse ret = this->device_info(msg);
-    if (!this->send_message(ret, DeviceInfoResponse::MESSAGE_TYPE)) {
+    if (!this->send_device_info_response(msg)) {
      this->on_fatal_error();
    }
  }
@@ -656,8 +651,7 @@ void APIServerConnection::on_subscribe_home_assistant_states_request(const Subsc
 }
 void APIServerConnection::on_get_time_request(const GetTimeRequest &msg) {
  if (this->check_connection_setup_()) {
-    GetTimeResponse ret = this->get_time(msg);
-    if (!this->send_message(ret, GetTimeResponse::MESSAGE_TYPE)) {
+    if (!this->send_get_time_response(msg)) {
      this->on_fatal_error();
    }
  }
@@ -672,8 +666,7 @@ void APIServerConnection::on_execute_service_request(const ExecuteServiceRequest
 #ifdef USE_API_NOISE
 void APIServerConnection::on_noise_encryption_set_key_request(const NoiseEncryptionSetKeyRequest &msg) {
  if (this->check_authenticated_()) {
-    NoiseEncryptionSetKeyResponse ret = this->noise_encryption_set_key(msg);
-    if (!this->send_message(ret, NoiseEncryptionSetKeyResponse::MESSAGE_TYPE)) {
+    if (!this->send_noise_encryption_set_key_response(msg)) {
      this->on_fatal_error();
    }
  }
@@ -866,8 +859,7 @@ void APIServerConnection::on_bluetooth_gatt_notify_request(const BluetoothGATTNo
 void APIServerConnection::on_subscribe_bluetooth_connections_free_request(
    const SubscribeBluetoothConnectionsFreeRequest &msg) {
  if (this->check_authenticated_()) {
-    BluetoothConnectionsFreeResponse ret = this->subscribe_bluetooth_connections_free(msg);
-    if (!this->send_message(ret, BluetoothConnectionsFreeResponse::MESSAGE_TYPE)) {
+    if (!this->send_subscribe_bluetooth_connections_free_response(msg)) {
      this->on_fatal_error();
    }
  }
@@ -898,8 +890,7 @@ void APIServerConnection::on_subscribe_voice_assistant_request(const SubscribeVo
 #ifdef USE_VOICE_ASSISTANT
 void APIServerConnection::on_voice_assistant_configuration_request(const VoiceAssistantConfigurationRequest &msg) {
  if (this->check_authenticated_()) {
-    VoiceAssistantConfigurationResponse ret = this->voice_assistant_get_configuration(msg);
-    if (!this->send_message(ret, VoiceAssistantConfigurationResponse::MESSAGE_TYPE)) {
+    if (!this->send_voice_assistant_get_configuration_response(msg)) {
      this->on_fatal_error();
    }
  }
--- a/esphome/components/api/api_pb2_service.h
+++ b/esphome/components/api/api_pb2_service.h
@@ -207,22 +207,22 @@ class APIServerConnectionBase : public ProtoService {

 class APIServerConnection : public APIServerConnectionBase {
 public:
-  virtual HelloResponse hello(const HelloRequest &msg) = 0;
-  virtual ConnectResponse connect(const ConnectRequest &msg) = 0;
-  virtual DisconnectResponse disconnect(const DisconnectRequest &msg) = 0;
-  virtual PingResponse ping(const PingRequest &msg) = 0;
-  virtual DeviceInfoResponse device_info(const DeviceInfoRequest &msg) = 0;
+  virtual bool send_hello_response(const HelloRequest &msg) = 0;
+  virtual bool send_connect_response(const ConnectRequest &msg) = 0;
+  virtual bool send_disconnect_response(const DisconnectRequest &msg) = 0;
+  virtual bool send_ping_response(const PingRequest &msg) = 0;
+  virtual bool send_device_info_response(const DeviceInfoRequest &msg) = 0;
  virtual void list_entities(const ListEntitiesRequest &msg) = 0;
  virtual void subscribe_states(const SubscribeStatesRequest &msg) = 0;
  virtual void subscribe_logs(const SubscribeLogsRequest &msg) = 0;
  virtual void subscribe_homeassistant_services(const SubscribeHomeassistantServicesRequest &msg) = 0;
  virtual void subscribe_home_assistant_states(const SubscribeHomeAssistantStatesRequest &msg) = 0;
-  virtual GetTimeResponse get_time(const GetTimeRequest &msg) = 0;
+  virtual bool send_get_time_response(const GetTimeRequest &msg) = 0;
 #ifdef USE_API_SERVICES
  virtual void execute_service(const ExecuteServiceRequest &msg) = 0;
 #endif
 #ifdef USE_API_NOISE
-  virtual NoiseEncryptionSetKeyResponse noise_encryption_set_key(const NoiseEncryptionSetKeyRequest &msg) = 0;
+  virtual bool send_noise_encryption_set_key_response(const NoiseEncryptionSetKeyRequest &msg) = 0;
 #endif
 #ifdef USE_BUTTON
  virtual void button_command(const ButtonCommandRequest &msg) = 0;
@@ -303,7 +303,7 @@ class APIServerConnection : public APIServerConnectionBase {
  virtual void bluetooth_gatt_notify(const BluetoothGATTNotifyRequest &msg) = 0;
 #endif
 #ifdef USE_BLUETOOTH_PROXY
-  virtual BluetoothConnectionsFreeResponse subscribe_bluetooth_connections_free(
+  virtual bool send_subscribe_bluetooth_connections_free_response(
      const SubscribeBluetoothConnectionsFreeRequest &msg) = 0;
 #endif
 #ifdef USE_BLUETOOTH_PROXY
@@ -316,8 +316,7 @@ class APIServerConnection : public APIServerConnectionBase {
  virtual void subscribe_voice_assistant(const SubscribeVoiceAssistantRequest &msg) = 0;
 #endif
 #ifdef USE_VOICE_ASSISTANT
-  virtual VoiceAssistantConfigurationResponse voice_assistant_get_configuration(
-      const VoiceAssistantConfigurationRequest &msg) = 0;
+  virtual bool send_voice_assistant_get_configuration_response(const VoiceAssistantConfigurationRequest &msg) = 0;
 #endif
 #ifdef USE_VOICE_ASSISTANT
  virtual void voice_assistant_set_configuration(const VoiceAssistantSetConfiguration &msg) = 0;
--- a/esphome/components/api/custom_api_device.h
+++ b/esphome/components/api/custom_api_device.h
@@ -148,7 +148,7 @@ class CustomAPIDevice {
   */
  void call_homeassistant_service(const std::string &service_name) {
    HomeassistantServiceResponse resp;
-    resp.service = service_name;
+    resp.set_service(StringRef(service_name));
    global_api_server->send_homeassistant_service_call(resp);
  }

@@ -168,12 +168,12 @@ class CustomAPIDevice {
   */
  void call_homeassistant_service(const std::string &service_name, const std::map<std::string, std::string> &data) {
    HomeassistantServiceResponse resp;
-    resp.service = service_name;
+    resp.set_service(StringRef(service_name));
    for (auto &it : data) {
-      HomeassistantServiceMap kv;
-      kv.key = it.first;
-      kv.value = it.second;
-      resp.data.push_back(kv);
+      resp.data.emplace_back();
+      auto &kv = resp.data.back();
+      kv.set_key(StringRef(it.first));
+      kv.set_value(StringRef(it.second));
    }
    global_api_server->send_homeassistant_service_call(resp);
  }
@@ -190,7 +190,7 @@ class CustomAPIDevice {
   */
  void fire_homeassistant_event(const std::string &event_name) {
    HomeassistantServiceResponse resp;
-    resp.service = event_name;
+    resp.set_service(StringRef(event_name));
    resp.is_event = true;
    global_api_server->send_homeassistant_service_call(resp);
  }
@@ -210,13 +210,13 @@ class CustomAPIDevice {
   */
  void fire_homeassistant_event(const std::string &service_name, const std::map<std::string, std::string> &data) {
    HomeassistantServiceResponse resp;
-    resp.service = service_name;
+    resp.set_service(StringRef(service_name));
    resp.is_event = true;
    for (auto &it : data) {
-      HomeassistantServiceMap kv;
-      kv.key = it.first;
-      kv.value = it.second;
-      resp.data.push_back(kv);
+      resp.data.emplace_back();
+      auto &kv = resp.data.back();
+      kv.set_key(StringRef(it.first));
+      kv.set_value(StringRef(it.second));
    }
    global_api_server->send_homeassistant_service_call(resp);
  }
--- a/esphome/components/api/homeassistant_service.h
+++ b/esphome/components/api/homeassistant_service.h
@@ -59,25 +59,29 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts

  void play(Ts... x) override {
    HomeassistantServiceResponse resp;
-    resp.service = this->service_.value(x...);
+    std::string service_value = this->service_.value(x...);
+    resp.set_service(StringRef(service_value));
    resp.is_event = this->is_event_;
    for (auto &it : this->data_) {
-      HomeassistantServiceMap kv;
-      kv.key = it.key;
-      kv.value = it.value.value(x...);
-      resp.data.push_back(kv);
+      resp.data.emplace_back();
+      auto &kv = resp.data.back();
+      kv.set_key(StringRef(it.key));
+      std::string value = it.value.value(x...);
+      kv.set_value(StringRef(value));
    }
    for (auto &it : this->data_template_) {
-      HomeassistantServiceMap kv;
-      kv.key = it.key;
-      kv.value = it.value.value(x...);
-      resp.data_template.push_back(kv);
+      resp.data_template.emplace_back();
+      auto &kv = resp.data_template.back();
+      kv.set_key(StringRef(it.key));
+      std::string value = it.value.value(x...);
+      kv.set_value(StringRef(value));
    }
    for (auto &it : this->variables_) {
-      HomeassistantServiceMap kv;
-      kv.key = it.key;
-      kv.value = it.value.value(x...);
-      resp.variables.push_back(kv);
+      resp.variables.emplace_back();
+      auto &kv = resp.variables.back();
+      kv.set_key(StringRef(it.key));
+      std::string value = it.value.value(x...);
+      kv.set_value(StringRef(value));
    }
    this->parent_->send_homeassistant_service_call(resp);
  }
--- a/esphome/components/api/proto.h
+++ b/esphome/components/api/proto.h
@@ -3,6 +3,7 @@
 #include "esphome/core/component.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
+#include "esphome/core/string_ref.h"

 #include <cassert>
 #include <cstring>
@@ -15,6 +16,37 @@
 namespace esphome {
 namespace api {

+/*
+ * StringRef Ownership Model for API Protocol Messages
+ * ===================================================
+ *
+ * StringRef is used for zero-copy string handling in outgoing (SOURCE_SERVER) messages.
+ * It holds a pointer and length to existing string data without copying.
+ *
+ * CRITICAL: The referenced string data MUST remain valid until message encoding completes.
+ *
+ * Safe StringRef Patterns:
+ * 1. String literals: StringRef("literal") - Always safe (static storage duration)
+ * 2. Member variables: StringRef(this->member_string_) - Safe if object outlives encoding
+ * 3. Global/static strings: StringRef(GLOBAL_CONSTANT) - Always safe
+ * 4. Local variables: Safe ONLY if encoding happens before function returns:
+ *    std::string temp = compute_value();
+ *    msg.set_field(StringRef(temp));
+ *    return this->send_message(msg);  // temp is valid during encoding
+ *
+ * Unsafe Patterns (WILL cause crashes/corruption):
+ * 1. Temporaries: msg.set_field(StringRef(obj.get_string())) // get_string() returns by value
+ * 2. Optional values: msg.set_field(StringRef(optional.value())) // value() returns a copy
+ * 3. Concatenation: msg.set_field(StringRef(str1 + str2)) // Result is temporary
+ *
+ * For unsafe patterns, store in a local variable first:
+ *    std::string temp = optional.value();  // or get_string() or str1 + str2
+ *    msg.set_field(StringRef(temp));
+ *
+ * The send_*_response pattern ensures proper lifetime management by encoding
+ * within the same function scope where temporaries are created.
+ */
+
 /// Representation of a VarInt - in ProtoBuf should be 64bit but we only use 32bit
 class ProtoVarInt {
 public:
@@ -218,6 +250,9 @@ class ProtoWriteBuffer {
  void encode_string(uint32_t field_id, const std::string &value, bool force = false) {
    this->encode_string(field_id, value.data(), value.size(), force);
  }
+  void encode_string(uint32_t field_id, const StringRef &ref, bool force = false) {
+    this->encode_string(field_id, ref.c_str(), ref.size(), force);
+  }
  void encode_bytes(uint32_t field_id, const uint8_t *data, size_t len, bool force = false) {
    this->encode_string(field_id, reinterpret_cast<const char *>(data), len, force);
  }
@@ -669,17 +704,16 @@ class ProtoSize {
  // sint64 type is not supported by ESPHome API to reduce overhead on embedded systems

  /**
-   * @brief Calculates and adds the size of a string/bytes field to the total message size
+   * @brief Calculates and adds the size of a string field using length
   */
-  static inline void add_string_field(uint32_t &total_size, uint32_t field_id_size, const std::string &str) {
+  static inline void add_string_field(uint32_t &total_size, uint32_t field_id_size, size_t len) {
    // Skip calculation if string is empty
-    if (str.empty()) {
+    if (len == 0) {
      return;  // No need to update total_size
    }

-    // Calculate and directly add to total_size
-    const uint32_t str_size = static_cast<uint32_t>(str.size());
-    total_size += field_id_size + varint(str_size) + str_size;
+    // Field ID + length varint + string bytes
+    total_size += field_id_size + varint(static_cast<uint32_t>(len)) + static_cast<uint32_t>(len);
  }

  /**
--- a/esphome/components/api/user_services.h
+++ b/esphome/components/api/user_services.h
@@ -33,14 +33,14 @@ template<typename... Ts> class UserServiceBase : public UserServiceDescriptor {

  ListEntitiesServicesResponse encode_list_service_response() override {
    ListEntitiesServicesResponse msg;
-    msg.name = this->name_;
+    msg.set_name(StringRef(this->name_));
    msg.key = this->key_;
    std::array<enums::ServiceArgType, sizeof...(Ts)> arg_types = {to_service_arg_type<Ts>()...};
    for (int i = 0; i < sizeof...(Ts); i++) {
-      ListEntitiesServicesArgument arg;
+      msg.args.emplace_back();
+      auto &arg = msg.args.back();
      arg.type = arg_types[i];
-      arg.name = this->arg_names_[i];
-      msg.args.push_back(arg);
+      arg.set_name(StringRef(this->arg_names_[i]));
    }
    return msg;
  }
--- a/esphome/components/homeassistant/number/homeassistant_number.cpp
+++ b/esphome/components/homeassistant/number/homeassistant_number.cpp
@@ -83,18 +83,24 @@ void HomeassistantNumber::control(float value) {

  this->publish_state(value);

+  static constexpr auto SERVICE_NAME = StringRef::from_lit("number.set_value");
+  static constexpr auto ENTITY_ID_KEY = StringRef::from_lit("entity_id");
+  static constexpr auto VALUE_KEY = StringRef::from_lit("value");
+
  api::HomeassistantServiceResponse resp;
-  resp.service = "number.set_value";
+  resp.set_service(SERVICE_NAME);

-  api::HomeassistantServiceMap entity_id;
-  entity_id.key = "entity_id";
-  entity_id.value = this->entity_id_;
-  resp.data.push_back(entity_id);
+  resp.data.emplace_back();
+  auto &entity_id = resp.data.back();
+  entity_id.set_key(ENTITY_ID_KEY);
+  entity_id.set_value(StringRef(this->entity_id_));

-  api::HomeassistantServiceMap entity_value;
-  entity_value.key = "value";
-  entity_value.value = to_string(value);
-  resp.data.push_back(entity_value);
+  resp.data.emplace_back();
+  auto &entity_value = resp.data.back();
+  entity_value.set_key(VALUE_KEY);
+  // to_string() returns a temporary - must store it to avoid dangling reference
+  std::string value_str = to_string(value);
+  entity_value.set_value(StringRef(value_str));

  api::global_api_server->send_homeassistant_service_call(resp);
 }
--- a/esphome/components/homeassistant/switch/homeassistant_switch.cpp
+++ b/esphome/components/homeassistant/switch/homeassistant_switch.cpp
@@ -40,17 +40,21 @@ void HomeassistantSwitch::write_state(bool state) {
    return;
  }

+  static constexpr auto SERVICE_ON = StringRef::from_lit("homeassistant.turn_on");
+  static constexpr auto SERVICE_OFF = StringRef::from_lit("homeassistant.turn_off");
+  static constexpr auto ENTITY_ID_KEY = StringRef::from_lit("entity_id");
+
  api::HomeassistantServiceResponse resp;
  if (state) {
-    resp.service = "homeassistant.turn_on";
+    resp.set_service(SERVICE_ON);
  } else {
-    resp.service = "homeassistant.turn_off";
+    resp.set_service(SERVICE_OFF);
  }

-  api::HomeassistantServiceMap entity_id_kv;
-  entity_id_kv.key = "entity_id";
-  entity_id_kv.value = this->entity_id_;
-  resp.data.push_back(entity_id_kv);
+  resp.data.emplace_back();
+  auto &entity_id_kv = resp.data.back();
+  entity_id_kv.set_key(ENTITY_ID_KEY);
+  entity_id_kv.set_value(StringRef(this->entity_id_));

  api::global_api_server->send_homeassistant_service_call(resp);
 }
--- a/esphome/components/text/text_traits.h
+++ b/esphome/components/text/text_traits.h
@@ -3,6 +3,7 @@
 #include <utility>

 #include "esphome/core/helpers.h"
+#include "esphome/core/string_ref.h"

 namespace esphome {
 namespace text {
@@ -23,6 +24,7 @@ class TextTraits {
  // Set/get the pattern.
  void set_pattern(std::string pattern) { this->pattern_ = std::move(pattern); }
  std::string get_pattern() const { return this->pattern_; }
+  StringRef get_pattern_ref() const { return StringRef(this->pattern_); }

  // Set/get the frontend mode.
  void set_mode(TextMode mode) { this->mode_ = mode; }
--- a/esphome/components/voice_assistant/voice_assistant.cpp
+++ b/esphome/components/voice_assistant/voice_assistant.cpp
@@ -238,10 +238,10 @@ void VoiceAssistant::loop() {

      api::VoiceAssistantRequest msg;
      msg.start = true;
-      msg.conversation_id = this->conversation_id_;
+      msg.set_conversation_id(StringRef(this->conversation_id_));
      msg.flags = flags;
      msg.audio_settings = audio_settings;
-      msg.wake_word_phrase = this->wake_word_;
+      msg.set_wake_word_phrase(StringRef(this->wake_word_));
      this->wake_word_ = "";

      // Reset media player state tracking
--- a/esphome/core/entity_base.h
+++ b/esphome/core/entity_base.h
@@ -54,6 +54,14 @@ class EntityBase {
  // Get/set this entity's icon
  std::string get_icon() const;
  void set_icon(const char *icon);
+  StringRef get_icon_ref() const {
+    static constexpr auto EMPTY_STRING = StringRef::from_lit("");
+#ifdef USE_ENTITY_ICON
+    return this->icon_c_str_ == nullptr ? EMPTY_STRING : StringRef(this->icon_c_str_);
+#else
+    return EMPTY_STRING;
+#endif
+  }

 #ifdef USE_DEVICES
  // Get/set this entity's device id
@@ -105,6 +113,11 @@ class EntityBase_DeviceClass {  // NOLINT(readability-identifier-naming)
  std::string get_device_class();
  /// Manually set the device class.
  void set_device_class(const char *device_class);
+  /// Get the device class as StringRef
+  StringRef get_device_class_ref() const {
+    static constexpr auto EMPTY_STRING = StringRef::from_lit("");
+    return this->device_class_ == nullptr ? EMPTY_STRING : StringRef(this->device_class_);
+  }

 protected:
  const char *device_class_{nullptr};  ///< Device class override
@@ -116,6 +129,11 @@ class EntityBase_UnitOfMeasurement {  // NOLINT(readability-identifier-naming)
  std::string get_unit_of_measurement();
  /// Manually set the unit of measurement.
  void set_unit_of_measurement(const char *unit_of_measurement);
+  /// Get the unit of measurement as StringRef
+  StringRef get_unit_of_measurement_ref() const {
+    static constexpr auto EMPTY_STRING = StringRef::from_lit("");
+    return this->unit_of_measurement_ == nullptr ? EMPTY_STRING : StringRef(this->unit_of_measurement_);
+  }

 protected:
  const char *unit_of_measurement_{nullptr};  ///< Unit of measurement override