preen

.github/workflows/codeql.yml

@@ -58,7 +58,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@0499de31b99561a6d14a36a5f662c2a54f91beee # v4.31.2
+        uses: github/codeql-action/init@4e94bd11f71e507f7f87df81788dff88d1dacbfb # v4.31.0
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
@@ -86,6 +86,6 @@ jobs:
           exit 1
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@0499de31b99561a6d14a36a5f662c2a54f91beee # v4.31.2
+        uses: github/codeql-action/analyze@4e94bd11f71e507f7f87df81788dff88d1dacbfb # v4.31.0
         with:
           category: "/language:${{matrix.language}}"

esphome/__main__.py

@@ -207,14 +207,14 @@ def choose_upload_log_host(
                     if has_mqtt_logging():
                         resolved.append("MQTT")
 
-                    if has_api() and has_non_ip_address() and has_resolvable_address():
+                    if has_api() and has_non_ip_address():
                         resolved.extend(_resolve_with_cache(CORE.address, purpose))
 
                 elif purpose == Purpose.UPLOADING:
                     if has_ota() and has_mqtt_ip_lookup():
                         resolved.append("MQTTIP")
 
-                    if has_ota() and has_non_ip_address() and has_resolvable_address():
+                    if has_ota() and has_non_ip_address():
                         resolved.extend(_resolve_with_cache(CORE.address, purpose))
             else:
                 resolved.append(device)
@@ -318,17 +318,7 @@ def has_resolvable_address() -> bool:
     """Check if CORE.address is resolvable (via mDNS, DNS, or is an IP address)."""
     # Any address (IP, mDNS hostname, or regular DNS hostname) is resolvable
     # The resolve_ip_address() function in helpers.py handles all types via AsyncResolver
-    if CORE.address is None:
-        return False
-
-    if has_ip_address():
-        return True
-
-    if has_mdns():
-        return True
-
-    # .local mDNS hostnames are only resolvable if mDNS is enabled
-    return not CORE.address.endswith(".local")
+    return CORE.address is not None
 
 
 def mqtt_get_ip(config: ConfigType, username: str, password: str, client_id: str):

esphome/components/api/api.proto

@@ -425,7 +425,7 @@ message ListEntitiesFanResponse {
   bool disabled_by_default = 9;
   string icon = 10 [(field_ifdef) = "USE_ENTITY_ICON"];
   EntityCategory entity_category = 11;
-  repeated string supported_preset_modes = 12 [(container_pointer_no_template) = "std::vector<const char *>"];
+  repeated string supported_preset_modes = 12 [(container_pointer) = "std::set"];
   uint32 device_id = 13 [(field_ifdef) = "USE_DEVICES"];
 }
 // Deprecated in API version 1.6 - only used in deprecated fields
@@ -1000,9 +1000,9 @@ message ListEntitiesClimateResponse {
   bool supports_action = 12; // Deprecated: use feature_flags
   repeated ClimateFanMode supported_fan_modes = 13 [(container_pointer_no_template) = "climate::ClimateFanModeMask"];
   repeated ClimateSwingMode supported_swing_modes = 14 [(container_pointer_no_template) = "climate::ClimateSwingModeMask"];
-  repeated string supported_custom_fan_modes = 15 [(container_pointer) = "std::vector"];
+  repeated string supported_custom_fan_modes = 15 [(container_pointer_no_template) = "std::vector<const char *>"];
   repeated ClimatePreset supported_presets = 16 [(container_pointer_no_template) = "climate::ClimatePresetMask"];
-  repeated string supported_custom_presets = 17 [(container_pointer) = "std::vector"];
+  repeated string supported_custom_presets = 17 [(container_pointer_no_template) = "std::vector<const char *>"];
   bool disabled_by_default = 18;
   string icon = 19 [(field_ifdef) = "USE_ENTITY_ICON"];
   EntityCategory entity_category = 20;

esphome/components/api/api_connection.cpp

@@ -410,8 +410,8 @@ 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() && fan->has_preset_mode())
-    msg.set_preset_mode(StringRef(fan->get_preset_mode()));
+  if (traits.supports_preset_modes())
+    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,
@@ -423,7 +423,7 @@ uint16_t APIConnection::try_send_fan_info(EntityBase *entity, APIConnection *con
   msg.supports_speed = traits.supports_speed();
   msg.supports_direction = traits.supports_direction();
   msg.supported_speed_count = traits.supported_speed_count();
-  msg.supported_preset_modes = &traits.supported_preset_modes();
+  msg.supported_preset_modes = &traits.supported_preset_modes_for_api_();
   return fill_and_encode_entity_info(fan, msg, ListEntitiesFanResponse::MESSAGE_TYPE, conn, remaining_size, is_single);
 }
 void APIConnection::fan_command(const FanCommandRequest &msg) {

esphome/components/api/api_pb2.cpp

@@ -355,8 +355,8 @@ void ListEntitiesFanResponse::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_string(10, this->icon_ref_);
 #endif
   buffer.encode_uint32(11, static_cast<uint32_t>(this->entity_category));
-  for (const char *it : *this->supported_preset_modes) {
-    buffer.encode_string(12, it, strlen(it), true);
+  for (const auto &it : *this->supported_preset_modes) {
+    buffer.encode_string(12, it, true);
   }
 #ifdef USE_DEVICES
   buffer.encode_uint32(13, this->device_id);
@@ -376,8 +376,8 @@ void ListEntitiesFanResponse::calculate_size(ProtoSize &size) const {
 #endif
   size.add_uint32(1, static_cast<uint32_t>(this->entity_category));
   if (!this->supported_preset_modes->empty()) {
-    for (const char *it : *this->supported_preset_modes) {
-      size.add_length_force(1, strlen(it));
+    for (const auto &it : *this->supported_preset_modes) {
+      size.add_length_force(1, it.size());
     }
   }
 #ifdef USE_DEVICES
@@ -1179,14 +1179,14 @@ void ListEntitiesClimateResponse::encode(ProtoWriteBuffer buffer) const {
   for (const auto &it : *this->supported_swing_modes) {
     buffer.encode_uint32(14, static_cast<uint32_t>(it), true);
   }
-  for (const auto &it : *this->supported_custom_fan_modes) {
-    buffer.encode_string(15, it, true);
+  for (const char *it : *this->supported_custom_fan_modes) {
+    buffer.encode_string(15, it, strlen(it), true);
   }
   for (const auto &it : *this->supported_presets) {
     buffer.encode_uint32(16, static_cast<uint32_t>(it), true);
   }
-  for (const auto &it : *this->supported_custom_presets) {
-    buffer.encode_string(17, it, true);
+  for (const char *it : *this->supported_custom_presets) {
+    buffer.encode_string(17, it, strlen(it), true);
   }
   buffer.encode_bool(18, this->disabled_by_default);
 #ifdef USE_ENTITY_ICON
@@ -1229,8 +1229,8 @@ void ListEntitiesClimateResponse::calculate_size(ProtoSize &size) const {
     }
   }
   if (!this->supported_custom_fan_modes->empty()) {
-    for (const auto &it : *this->supported_custom_fan_modes) {
-      size.add_length_force(1, it.size());
+    for (const char *it : *this->supported_custom_fan_modes) {
+      size.add_length_force(1, strlen(it));
     }
   }
   if (!this->supported_presets->empty()) {
@@ -1239,8 +1239,8 @@ void ListEntitiesClimateResponse::calculate_size(ProtoSize &size) const {
     }
   }
   if (!this->supported_custom_presets->empty()) {
-    for (const auto &it : *this->supported_custom_presets) {
-      size.add_length_force(2, it.size());
+    for (const char *it : *this->supported_custom_presets) {
+      size.add_length_force(2, strlen(it));
     }
   }
   size.add_bool(2, this->disabled_by_default);

esphome/components/api/api_pb2.h

@@ -725,7 +725,7 @@ class ListEntitiesFanResponse final : public InfoResponseProtoMessage {
   bool supports_speed{false};
   bool supports_direction{false};
   int32_t supported_speed_count{0};
-  const std::vector<const char *> *supported_preset_modes{};
+  const std::set<std::string> *supported_preset_modes{};
   void encode(ProtoWriteBuffer buffer) const override;
   void calculate_size(ProtoSize &size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -1384,9 +1384,9 @@ class ListEntitiesClimateResponse final : public InfoResponseProtoMessage {
   bool supports_action{false};
   const climate::ClimateFanModeMask *supported_fan_modes{};
   const climate::ClimateSwingModeMask *supported_swing_modes{};
-  const std::vector<std::string> *supported_custom_fan_modes{};
+  const std::vector<const char *> *supported_custom_fan_modes{};
   const climate::ClimatePresetMask *supported_presets{};
-  const std::vector<std::string> *supported_custom_presets{};
+  const std::vector<const char *> *supported_custom_presets{};
   float visual_current_temperature_step{0.0f};
   bool supports_current_humidity{false};
   bool supports_target_humidity{false};

esphome/components/bedjet/climate/bedjet_climate.h

@@ -50,21 +50,13 @@ class BedJetClimate : public climate::Climate, public BedJetClient, public Polli
         // Climate doesn't have a "TURBO" mode, but we can use the BOOST preset instead.
         climate::CLIMATE_PRESET_BOOST,
     });
+    // String literals are stored in rodata and valid for program lifetime
     traits.set_supported_custom_presets({
-        // We could fetch biodata from bedjet and set these names that way.
-        // But then we have to invert the lookup in order to send the right preset.
-        // For now, we can leave them as M1-3 to match the remote buttons.
-        // EXT HT added to match remote button.
-        "EXT HT",
+        this->heating_mode_ == HEAT_MODE_EXTENDED ? "LTD HT" : "EXT HT",
         "M1",
         "M2",
         "M3",
     });
-    if (this->heating_mode_ == HEAT_MODE_EXTENDED) {
-      traits.add_supported_custom_preset("LTD HT");
-    } else {
-      traits.add_supported_custom_preset("EXT HT");
-    }
     traits.set_visual_min_temperature(19.0);
     traits.set_visual_max_temperature(43.0);
     traits.set_visual_temperature_step(1.0);

esphome/components/climate/climate.cpp

@@ -387,8 +387,8 @@ void Climate::save_state_() {
     const auto &supported = traits.get_supported_custom_fan_modes();
     // std::vector maintains insertion order
     size_t i = 0;
-    for (const auto &mode : supported) {
-      if (mode == custom_fan_mode) {
+    for (const char *mode : supported) {
+      if (strcmp(mode, custom_fan_mode.value().c_str()) == 0) {
         state.custom_fan_mode = i;
         break;
       }
@@ -404,8 +404,8 @@ void Climate::save_state_() {
     const auto &supported = traits.get_supported_custom_presets();
     // std::vector maintains insertion order
     size_t i = 0;
-    for (const auto &preset : supported) {
-      if (preset == custom_preset) {
+    for (const char *preset : supported) {
+      if (strcmp(preset, custom_preset.value().c_str()) == 0) {
         state.custom_preset = i;
         break;
       }
@@ -527,7 +527,7 @@ ClimateCall ClimateDeviceRestoreState::to_call(Climate *climate) {
   if (this->uses_custom_fan_mode) {
     if (this->custom_fan_mode < traits.get_supported_custom_fan_modes().size()) {
       call.fan_mode_.reset();
-      call.custom_fan_mode_ = *std::next(traits.get_supported_custom_fan_modes().cbegin(), this->custom_fan_mode);
+      call.custom_fan_mode_ = std::string(traits.get_supported_custom_fan_modes()[this->custom_fan_mode]);
     }
   } else if (traits.supports_fan_mode(this->fan_mode)) {
     call.set_fan_mode(this->fan_mode);
@@ -535,7 +535,7 @@ ClimateCall ClimateDeviceRestoreState::to_call(Climate *climate) {
   if (this->uses_custom_preset) {
     if (this->custom_preset < traits.get_supported_custom_presets().size()) {
       call.preset_.reset();
-      call.custom_preset_ = *std::next(traits.get_supported_custom_presets().cbegin(), this->custom_preset);
+      call.custom_preset_ = std::string(traits.get_supported_custom_presets()[this->custom_preset]);
     }
   } else if (traits.supports_preset(this->preset)) {
     call.set_preset(this->preset);
@@ -562,7 +562,7 @@ void ClimateDeviceRestoreState::apply(Climate *climate) {
   if (this->uses_custom_fan_mode) {
     if (this->custom_fan_mode < traits.get_supported_custom_fan_modes().size()) {
       climate->fan_mode.reset();
-      climate->custom_fan_mode = *std::next(traits.get_supported_custom_fan_modes().cbegin(), this->custom_fan_mode);
+      climate->custom_fan_mode = std::string(traits.get_supported_custom_fan_modes()[this->custom_fan_mode]);
     }
   } else if (traits.supports_fan_mode(this->fan_mode)) {
     climate->fan_mode = this->fan_mode;
@@ -571,7 +571,7 @@ void ClimateDeviceRestoreState::apply(Climate *climate) {
   if (this->uses_custom_preset) {
     if (this->custom_preset < traits.get_supported_custom_presets().size()) {
       climate->preset.reset();
-      climate->custom_preset = *std::next(traits.get_supported_custom_presets().cbegin(), this->custom_preset);
+      climate->custom_preset = std::string(traits.get_supported_custom_presets()[this->custom_preset]);
     }
   } else if (traits.supports_preset(this->preset)) {
     climate->preset = this->preset;
@@ -656,8 +656,8 @@ void Climate::dump_traits_(const char *tag) {
   }
   if (!traits.get_supported_custom_fan_modes().empty()) {
     ESP_LOGCONFIG(tag, "  Supported custom fan modes:");
-    for (const std::string &s : traits.get_supported_custom_fan_modes())
-      ESP_LOGCONFIG(tag, "  - %s", s.c_str());
+    for (const char *s : traits.get_supported_custom_fan_modes())
+      ESP_LOGCONFIG(tag, "  - %s", s);
   }
   if (!traits.get_supported_presets().empty()) {
     ESP_LOGCONFIG(tag, "  Supported presets:");
@@ -666,8 +666,8 @@ void Climate::dump_traits_(const char *tag) {
   }
   if (!traits.get_supported_custom_presets().empty()) {
     ESP_LOGCONFIG(tag, "  Supported custom presets:");
-    for (const std::string &s : traits.get_supported_custom_presets())
-      ESP_LOGCONFIG(tag, "  - %s", s.c_str());
+    for (const char *s : traits.get_supported_custom_presets())
+      ESP_LOGCONFIG(tag, "  - %s", s);
   }
   if (!traits.get_supported_swing_modes().empty()) {
     ESP_LOGCONFIG(tag, "  Supported swing modes:");

esphome/components/climate/climate_traits.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <cstring>
 #include <vector>
 #include "climate_mode.h"
 #include "esphome/core/finite_set_mask.h"
@@ -18,16 +19,6 @@ using ClimateSwingModeMask =
     FiniteSetMask<ClimateSwingMode, DefaultBitPolicy<ClimateSwingMode, CLIMATE_SWING_HORIZONTAL + 1>>;
 using ClimatePresetMask = FiniteSetMask<ClimatePreset, DefaultBitPolicy<ClimatePreset, CLIMATE_PRESET_ACTIVITY + 1>>;
 
-// Lightweight linear search for small vectors (1-20 items)
-// Avoids std::find template overhead
-template<typename T> inline bool vector_contains(const std::vector<T> &vec, const T &value) {
-  for (const auto &item : vec) {
-    if (item == value)
-      return true;
-  }
-  return false;
-}
-
 /** This class contains all static data for climate devices.
  *
  * All climate devices must support these features:
@@ -128,46 +119,46 @@ class ClimateTraits {
 
   void set_supported_fan_modes(ClimateFanModeMask modes) { this->supported_fan_modes_ = modes; }
   void add_supported_fan_mode(ClimateFanMode mode) { this->supported_fan_modes_.insert(mode); }
-  void add_supported_custom_fan_mode(const std::string &mode) { this->supported_custom_fan_modes_.push_back(mode); }
   bool supports_fan_mode(ClimateFanMode fan_mode) const { return this->supported_fan_modes_.count(fan_mode); }
   bool get_supports_fan_modes() const {
     return !this->supported_fan_modes_.empty() || !this->supported_custom_fan_modes_.empty();
   }
   const ClimateFanModeMask &get_supported_fan_modes() const { return this->supported_fan_modes_; }
 
-  void set_supported_custom_fan_modes(std::vector<std::string> supported_custom_fan_modes) {
-    this->supported_custom_fan_modes_ = std::move(supported_custom_fan_modes);
-  }
-  void set_supported_custom_fan_modes(std::initializer_list<std::string> modes) {
+  void set_supported_custom_fan_modes(std::initializer_list<const char *> modes) {
     this->supported_custom_fan_modes_ = modes;
   }
-  template<size_t N> void set_supported_custom_fan_modes(const char *const (&modes)[N]) {
-    this->supported_custom_fan_modes_.assign(modes, modes + N);
+  void set_supported_custom_fan_modes(const std::vector<const char *> &modes) {
+    this->supported_custom_fan_modes_ = modes;
   }
-  const std::vector<std::string> &get_supported_custom_fan_modes() const { return this->supported_custom_fan_modes_; }
+  const std::vector<const char *> &get_supported_custom_fan_modes() const { return this->supported_custom_fan_modes_; }
   bool supports_custom_fan_mode(const std::string &custom_fan_mode) const {
-    return vector_contains(this->supported_custom_fan_modes_, custom_fan_mode);
+    for (const char *mode : this->supported_custom_fan_modes_) {
+      if (strcmp(mode, custom_fan_mode.c_str()) == 0)
+        return true;
+    }
+    return false;
   }
 
   void set_supported_presets(ClimatePresetMask presets) { this->supported_presets_ = presets; }
   void add_supported_preset(ClimatePreset preset) { this->supported_presets_.insert(preset); }
-  void add_supported_custom_preset(const std::string &preset) { this->supported_custom_presets_.push_back(preset); }
   bool supports_preset(ClimatePreset preset) const { return this->supported_presets_.count(preset); }
   bool get_supports_presets() const { return !this->supported_presets_.empty(); }
   const ClimatePresetMask &get_supported_presets() const { return this->supported_presets_; }
 
-  void set_supported_custom_presets(std::vector<std::string> supported_custom_presets) {
-    this->supported_custom_presets_ = std::move(supported_custom_presets);
-  }
-  void set_supported_custom_presets(std::initializer_list<std::string> presets) {
+  void set_supported_custom_presets(std::initializer_list<const char *> presets) {
     this->supported_custom_presets_ = presets;
   }
-  template<size_t N> void set_supported_custom_presets(const char *const (&presets)[N]) {
-    this->supported_custom_presets_.assign(presets, presets + N);
+  void set_supported_custom_presets(const std::vector<const char *> &presets) {
+    this->supported_custom_presets_ = presets;
   }
-  const std::vector<std::string> &get_supported_custom_presets() const { return this->supported_custom_presets_; }
+  const std::vector<const char *> &get_supported_custom_presets() const { return this->supported_custom_presets_; }
   bool supports_custom_preset(const std::string &custom_preset) const {
-    return vector_contains(this->supported_custom_presets_, custom_preset);
+    for (const char *preset : this->supported_custom_presets_) {
+      if (strcmp(preset, custom_preset.c_str()) == 0)
+        return true;
+    }
+    return false;
   }
 
   void set_supported_swing_modes(ClimateSwingModeMask modes) { this->supported_swing_modes_ = modes; }
@@ -239,8 +230,11 @@ class ClimateTraits {
   climate::ClimateFanModeMask supported_fan_modes_;
   climate::ClimateSwingModeMask supported_swing_modes_;
   climate::ClimatePresetMask supported_presets_;
-  std::vector<std::string> supported_custom_fan_modes_;
-  std::vector<std::string> supported_custom_presets_;
+  // Store const char* pointers to avoid std::string overhead
+  // Pointers must remain valid for traits lifetime (typically string literals in rodata,
+  // or pointers to strings with sufficient lifetime like member variables)
+  std::vector<const char *> supported_custom_fan_modes_;
+  std::vector<const char *> supported_custom_presets_;
 };
 
 }  // namespace climate

esphome/components/copy/fan/copy_fan.cpp

@@ -12,7 +12,7 @@ void CopyFan::setup() {
     this->oscillating = source_->oscillating;
     this->speed = source_->speed;
     this->direction = source_->direction;
-    this->set_preset_mode_(source_->get_preset_mode());
+    this->preset_mode = source_->preset_mode;
     this->publish_state();
   });
 
@@ -20,7 +20,7 @@ void CopyFan::setup() {
   this->oscillating = source_->oscillating;
   this->speed = source_->speed;
   this->direction = source_->direction;
-  this->set_preset_mode_(source_->get_preset_mode());
+  this->preset_mode = source_->preset_mode;
   this->publish_state();
 }
 
@@ -49,7 +49,7 @@ void CopyFan::control(const fan::FanCall &call) {
     call2.set_speed(*call.get_speed());
   if (call.get_direction().has_value())
     call2.set_direction(*call.get_direction());
-  if (call.has_preset_mode())
+  if (!call.get_preset_mode().empty())
     call2.set_preset_mode(call.get_preset_mode());
   call2.perform();
 }

esphome/components/fan/automation.h

@@ -212,18 +212,18 @@ class FanPresetSetTrigger : public Trigger<std::string> {
  public:
   FanPresetSetTrigger(Fan *state) {
     state->add_on_state_callback([this, state]() {
-      const auto *preset_mode = state->get_preset_mode();
+      auto preset_mode = state->preset_mode;
       auto should_trigger = preset_mode != this->last_preset_mode_;
       this->last_preset_mode_ = preset_mode;
-      if (should_trigger && preset_mode != nullptr) {
+      if (should_trigger) {
         this->trigger(preset_mode);
       }
     });
-    this->last_preset_mode_ = state->get_preset_mode();
+    this->last_preset_mode_ = state->preset_mode;
   }
 
  protected:
-  const char *last_preset_mode_{nullptr};
+  std::string last_preset_mode_;
 };
 
 }  // namespace fan

esphome/components/fan/fan.cpp

@@ -17,27 +17,6 @@ const LogString *fan_direction_to_string(FanDirection direction) {
   }
 }
 
-FanCall &FanCall::set_preset_mode(const std::string &preset_mode) { return this->set_preset_mode(preset_mode.c_str()); }
-
-FanCall &FanCall::set_preset_mode(const char *preset_mode) {
-  if (preset_mode == nullptr || strlen(preset_mode) == 0) {
-    this->preset_mode_ = nullptr;
-    return *this;
-  }
-
-  // Find and validate pointer from traits immediately
-  auto traits = this->parent_.get_traits();
-  const char *validated_mode = traits.find_preset_mode(preset_mode);
-  if (validated_mode != nullptr) {
-    this->preset_mode_ = validated_mode;  // Store pointer from traits
-  } else {
-    // Preset mode not found in traits - log warning and don't set
-    ESP_LOGW(TAG, "%s: Preset mode '%s' not supported", this->parent_.get_name().c_str(), preset_mode);
-    this->preset_mode_ = nullptr;
-  }
-  return *this;
-}
-
 void FanCall::perform() {
   ESP_LOGD(TAG, "'%s' - Setting:", this->parent_.get_name().c_str());
   this->validate_();
@@ -53,8 +32,8 @@ void FanCall::perform() {
   if (this->direction_.has_value()) {
     ESP_LOGD(TAG, "  Direction: %s", LOG_STR_ARG(fan_direction_to_string(*this->direction_)));
   }
-  if (this->has_preset_mode()) {
-    ESP_LOGD(TAG, "  Preset Mode: %s", this->preset_mode_);
+  if (!this->preset_mode_.empty()) {
+    ESP_LOGD(TAG, "  Preset Mode: %s", this->preset_mode_.c_str());
   }
   this->parent_.control(*this);
 }
@@ -67,15 +46,23 @@ void FanCall::validate_() {
 
     // https://developers.home-assistant.io/docs/core/entity/fan/#preset-modes
     // "Manually setting a speed must disable any set preset mode"
-    this->preset_mode_ = nullptr;
+    this->preset_mode_.clear();
+  }
+
+  if (!this->preset_mode_.empty()) {
+    const auto &preset_modes = traits.supported_preset_modes();
+    if (preset_modes.find(this->preset_mode_) == preset_modes.end()) {
+      ESP_LOGW(TAG, "%s: Preset mode '%s' not supported", this->parent_.get_name().c_str(), this->preset_mode_.c_str());
+      this->preset_mode_.clear();
+    }
   }
 
   // when turning on...
   if (!this->parent_.state && this->binary_state_.has_value() &&
       *this->binary_state_
       // ..,and no preset mode will be active...
-      && !this->has_preset_mode() &&
-      this->parent_.get_preset_mode() == nullptr
+      && this->preset_mode_.empty() &&
+      this->parent_.preset_mode.empty()
       // ...and neither current nor new speed is available...
       && traits.supports_speed() && this->parent_.speed == 0 && !this->speed_.has_value()) {
     // ...set speed to 100%
@@ -105,12 +92,11 @@ FanCall FanRestoreState::to_call(Fan &fan) {
   call.set_speed(this->speed);
   call.set_direction(this->direction);
 
-  auto traits = fan.get_traits();
-  if (traits.supports_preset_modes()) {
+  if (fan.get_traits().supports_preset_modes()) {
     // Use stored preset index to get preset name
-    const auto &preset_modes = traits.supported_preset_modes();
+    const auto &preset_modes = fan.get_traits().supported_preset_modes();
     if (this->preset_mode < preset_modes.size()) {
-      call.set_preset_mode(preset_modes[this->preset_mode]);
+      call.set_preset_mode(*std::next(preset_modes.begin(), this->preset_mode));
     }
   }
   return call;
@@ -121,12 +107,13 @@ void FanRestoreState::apply(Fan &fan) {
   fan.speed = this->speed;
   fan.direction = this->direction;
 
-  // Use stored preset index to get preset name from traits
-  const auto &preset_modes = fan.get_traits().supported_preset_modes();
-  if (this->preset_mode < preset_modes.size()) {
-    fan.set_preset_mode_(preset_modes[this->preset_mode]);
+  if (fan.get_traits().supports_preset_modes()) {
+    // Use stored preset index to get preset name
+    const auto &preset_modes = fan.get_traits().supported_preset_modes();
+    if (this->preset_mode < preset_modes.size()) {
+      fan.preset_mode = *std::next(preset_modes.begin(), this->preset_mode);
+    }
   }
-
   fan.publish_state();
 }
 
@@ -135,29 +122,6 @@ FanCall Fan::turn_off() { return this->make_call().set_state(false); }
 FanCall Fan::toggle() { return this->make_call().set_state(!this->state); }
 FanCall Fan::make_call() { return FanCall(*this); }
 
-const char *Fan::find_preset_mode_(const char *preset_mode) { return this->get_traits().find_preset_mode(preset_mode); }
-
-bool Fan::set_preset_mode_(const char *preset_mode) {
-  if (preset_mode == nullptr) {
-    // Treat nullptr as clearing the preset mode
-    if (this->preset_mode_ == nullptr) {
-      return false;  // No change
-    }
-    this->clear_preset_mode_();
-    return true;
-  }
-  const char *validated = this->find_preset_mode_(preset_mode);
-  if (validated == nullptr || this->preset_mode_ == validated) {
-    return false;  // Preset mode not supported or no change
-  }
-  this->preset_mode_ = validated;
-  return true;
-}
-
-bool Fan::set_preset_mode_(const std::string &preset_mode) { return this->set_preset_mode_(preset_mode.c_str()); }
-
-void Fan::clear_preset_mode_() { this->preset_mode_ = nullptr; }
-
 void Fan::add_on_state_callback(std::function<void()> &&callback) { this->state_callback_.add(std::move(callback)); }
 void Fan::publish_state() {
   auto traits = this->get_traits();
@@ -173,9 +137,8 @@ void Fan::publish_state() {
   if (traits.supports_direction()) {
     ESP_LOGD(TAG, "  Direction: %s", LOG_STR_ARG(fan_direction_to_string(this->direction)));
   }
-  const char *preset = this->get_preset_mode();
-  if (traits.supports_preset_modes() && preset != nullptr) {
-    ESP_LOGD(TAG, "  Preset Mode: %s", preset);
+  if (traits.supports_preset_modes() && !this->preset_mode.empty()) {
+    ESP_LOGD(TAG, "  Preset Mode: %s", this->preset_mode.c_str());
   }
   this->state_callback_.call();
   this->save_state_();
@@ -219,24 +182,18 @@ void Fan::save_state_() {
     return;
   }
 
-  auto traits = this->get_traits();
-
   FanRestoreState state{};
   state.state = this->state;
   state.oscillating = this->oscillating;
   state.speed = this->speed;
   state.direction = this->direction;
 
-  const char *preset = this->get_preset_mode();
-  if (preset != nullptr) {
-    const auto &preset_modes = traits.supported_preset_modes();
-    // Find index of current preset mode (pointer comparison is safe since preset is from traits)
-    for (size_t i = 0; i < preset_modes.size(); i++) {
-      if (preset_modes[i] == preset) {
-        state.preset_mode = i;
-        break;
-      }
-    }
+  if (this->get_traits().supports_preset_modes() && !this->preset_mode.empty()) {
+    const auto &preset_modes = this->get_traits().supported_preset_modes();
+    // Store index of current preset mode
+    auto preset_iterator = preset_modes.find(this->preset_mode);
+    if (preset_iterator != preset_modes.end())
+      state.preset_mode = std::distance(preset_modes.begin(), preset_iterator);
   }
 
   this->rtc_.save(&state);
@@ -259,8 +216,8 @@ void Fan::dump_traits_(const char *tag, const char *prefix) {
   }
   if (traits.supports_preset_modes()) {
     ESP_LOGCONFIG(tag, "%s  Supported presets:", prefix);
-    for (const char *s : traits.supported_preset_modes())
-      ESP_LOGCONFIG(tag, "%s    - %s", prefix, s);
+    for (const std::string &s : traits.supported_preset_modes())
+      ESP_LOGCONFIG(tag, "%s    - %s", prefix, s.c_str());
   }
 }
 

esphome/components/fan/fan.h

@@ -70,10 +70,11 @@ class FanCall {
     return *this;
   }
   optional<FanDirection> get_direction() const { return this->direction_; }
-  FanCall &set_preset_mode(const std::string &preset_mode);
-  FanCall &set_preset_mode(const char *preset_mode);
-  const char *get_preset_mode() const { return this->preset_mode_; }
-  bool has_preset_mode() const { return this->preset_mode_ != nullptr; }
+  FanCall &set_preset_mode(const std::string &preset_mode) {
+    this->preset_mode_ = preset_mode;
+    return *this;
+  }
+  std::string get_preset_mode() const { return this->preset_mode_; }
 
   void perform();
 
@@ -85,7 +86,7 @@ class FanCall {
   optional<bool> oscillating_;
   optional<int> speed_;
   optional<FanDirection> direction_{};
-  const char *preset_mode_{nullptr};  // Pointer to string in traits (after validation)
+  std::string preset_mode_{};
 };
 
 struct FanRestoreState {
@@ -111,6 +112,8 @@ class Fan : public EntityBase {
   int speed{0};
   /// The current direction of the fan
   FanDirection direction{FanDirection::FORWARD};
+  // The current preset mode of the fan
+  std::string preset_mode{};
 
   FanCall turn_on();
   FanCall turn_off();
@@ -127,15 +130,8 @@ class Fan : public EntityBase {
   /// Set the restore mode of this fan.
   void set_restore_mode(FanRestoreMode restore_mode) { this->restore_mode_ = restore_mode; }
 
-  /// Get the current preset mode (returns pointer to string stored in traits, or nullptr if not set)
-  const char *get_preset_mode() const { return this->preset_mode_; }
-
-  /// Check if a preset mode is currently active
-  bool has_preset_mode() const { return this->preset_mode_ != nullptr; }
-
  protected:
   friend FanCall;
-  friend struct FanRestoreState;
 
   virtual void control(const FanCall &call) = 0;
 
@@ -144,19 +140,9 @@ class Fan : public EntityBase {
 
   void dump_traits_(const char *tag, const char *prefix);
 
-  /// Set the preset mode (finds and stores pointer from traits). Returns true if changed.
-  bool set_preset_mode_(const char *preset_mode);
-  /// Set the preset mode (finds and stores pointer from traits). Returns true if changed.
-  bool set_preset_mode_(const std::string &preset_mode);
-  /// Clear the preset mode
-  void clear_preset_mode_();
-  /// Find and return the matching preset mode pointer from traits, or nullptr if not found.
-  const char *find_preset_mode_(const char *preset_mode);
-
   CallbackManager<void()> state_callback_{};
   ESPPreferenceObject rtc_;
   FanRestoreMode restore_mode_;
-  const char *preset_mode_{nullptr};
 };
 
 }  // namespace fan

esphome/components/fan/fan_traits.h

@@ -1,11 +1,16 @@
+#include <set>
+#include <utility>
+
 #pragma once
 
-#include <cstring>
-#include <vector>
-#include <initializer_list>
-
 namespace esphome {
 
+#ifdef USE_API
+namespace api {
+class APIConnection;
+}  // namespace api
+#endif
+
 namespace fan {
 
 class FanTraits {
@@ -31,38 +36,27 @@ class FanTraits {
   /// Set whether this fan supports changing direction
   void set_direction(bool direction) { this->direction_ = direction; }
   /// Return the preset modes supported by the fan.
-  const std::vector<const char *> &supported_preset_modes() const { return this->preset_modes_; }
-  /// Set the preset modes supported by the fan (from initializer list).
-  void set_supported_preset_modes(std::initializer_list<const char *> preset_modes) {
-    this->preset_modes_ = preset_modes;
-  }
-  /// Set the preset modes supported by the fan (from vector).
-  void set_supported_preset_modes(const std::vector<const char *> &preset_modes) { this->preset_modes_ = preset_modes; }
-
-  // Deleted overloads to catch incorrect std::string usage at compile time with clear error messages
-  void set_supported_preset_modes(const std::vector<std::string> &preset_modes) = delete;
-  void set_supported_preset_modes(std::initializer_list<std::string> preset_modes) = delete;
-
+  std::set<std::string> supported_preset_modes() const { return this->preset_modes_; }
+  /// Set the preset modes supported by the fan.
+  void set_supported_preset_modes(const std::set<std::string> &preset_modes) { this->preset_modes_ = preset_modes; }
   /// Return if preset modes are supported
   bool supports_preset_modes() const { return !this->preset_modes_.empty(); }
-  /// Find and return the matching preset mode pointer from supported modes, or nullptr if not found.
-  const char *find_preset_mode(const char *preset_mode) const {
-    if (preset_mode == nullptr)
-      return nullptr;
-    for (const char *mode : this->preset_modes_) {
-      if (strcmp(mode, preset_mode) == 0) {
-        return mode;  // Return pointer from traits
-      }
-    }
-    return nullptr;
-  }
 
  protected:
+#ifdef USE_API
+  // The API connection is a friend class to access internal methods
+  friend class api::APIConnection;
+  // This method returns a reference to the internal preset modes set.
+  // It is used by the API to avoid copying data when encoding messages.
+  // Warning: Do not use this method outside of the API connection code.
+  // It returns a reference to internal data that can be invalidated.
+  const std::set<std::string> &supported_preset_modes_for_api_() const { return this->preset_modes_; }
+#endif
   bool oscillation_{false};
   bool speed_{false};
   bool direction_{false};
   int speed_count_{};
-  std::vector<const char *> preset_modes_{};
+  std::set<std::string> preset_modes_{};
 };
 
 }  // namespace fan

esphome/components/hbridge/fan/hbridge_fan.cpp

@@ -57,7 +57,7 @@ void HBridgeFan::control(const fan::FanCall &call) {
     this->oscillating = *call.get_oscillating();
   if (call.get_direction().has_value())
     this->direction = *call.get_direction();
-  this->set_preset_mode_(call.get_preset_mode());
+  this->preset_mode = call.get_preset_mode();
 
   this->write_state_();
   this->publish_state();

esphome/components/hbridge/fan/hbridge_fan.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <set>
+
 #include "esphome/core/automation.h"
 #include "esphome/components/output/binary_output.h"
 #include "esphome/components/output/float_output.h"
@@ -20,7 +22,7 @@ class HBridgeFan : public Component, public fan::Fan {
   void set_pin_a(output::FloatOutput *pin_a) { pin_a_ = pin_a; }
   void set_pin_b(output::FloatOutput *pin_b) { pin_b_ = pin_b; }
   void set_enable_pin(output::FloatOutput *enable) { enable_ = enable; }
-  void set_preset_modes(std::initializer_list<const char *> presets) { preset_modes_ = presets; }
+  void set_preset_modes(const std::set<std::string> &presets) { preset_modes_ = presets; }
 
   void setup() override;
   void dump_config() override;
@@ -36,7 +38,7 @@ class HBridgeFan : public Component, public fan::Fan {
   int speed_count_{};
   DecayMode decay_mode_{DECAY_MODE_SLOW};
   fan::FanTraits traits_;
-  std::vector<const char *> preset_modes_{};
+  std::set<std::string> preset_modes_{};
 
   void control(const fan::FanCall &call) override;
   void write_state_();

esphome/components/midea/ac_adapter.cpp

@@ -8,9 +8,9 @@ namespace midea {
 namespace ac {
 
 const char *const Constants::TAG = "midea";
-const std::string Constants::FREEZE_PROTECTION = "freeze protection";
-const std::string Constants::SILENT = "silent";
-const std::string Constants::TURBO = "turbo";
+const char *const Constants::FREEZE_PROTECTION = "freeze protection";
+const char *const Constants::SILENT = "silent";
+const char *const Constants::TURBO = "turbo";
 
 ClimateMode Converters::to_climate_mode(MideaMode mode) {
   switch (mode) {
@@ -108,7 +108,7 @@ bool Converters::is_custom_midea_fan_mode(MideaFanMode mode) {
   }
 }
 
-const std::string &Converters::to_custom_climate_fan_mode(MideaFanMode mode) {
+const char *Converters::to_custom_climate_fan_mode(MideaFanMode mode) {
   switch (mode) {
     case MideaFanMode::FAN_SILENT:
       return Constants::SILENT;
@@ -151,7 +151,7 @@ ClimatePreset Converters::to_climate_preset(MideaPreset preset) {
 
 bool Converters::is_custom_midea_preset(MideaPreset preset) { return preset == MideaPreset::PRESET_FREEZE_PROTECTION; }
 
-const std::string &Converters::to_custom_climate_preset(MideaPreset preset) { return Constants::FREEZE_PROTECTION; }
+const char *Converters::to_custom_climate_preset(MideaPreset preset) { return Constants::FREEZE_PROTECTION; }
 
 MideaPreset Converters::to_midea_preset(const std::string &preset) { return MideaPreset::PRESET_FREEZE_PROTECTION; }
 
@@ -169,7 +169,7 @@ void Converters::to_climate_traits(ClimateTraits &traits, const dudanov::midea::
   if (capabilities.supportEcoPreset())
     traits.add_supported_preset(ClimatePreset::CLIMATE_PRESET_ECO);
   if (capabilities.supportFrostProtectionPreset())
-    traits.add_supported_custom_preset(Constants::FREEZE_PROTECTION);
+    traits.set_supported_custom_presets({Constants::FREEZE_PROTECTION});
 }
 
 }  // namespace ac

esphome/components/midea/ac_adapter.h

@@ -20,9 +20,9 @@ using MideaPreset = dudanov::midea::ac::Preset;
 class Constants {
  public:
   static const char *const TAG;
-  static const std::string FREEZE_PROTECTION;
-  static const std::string SILENT;
-  static const std::string TURBO;
+  static const char *const FREEZE_PROTECTION;
+  static const char *const SILENT;
+  static const char *const TURBO;
 };
 
 class Converters {
@@ -35,12 +35,12 @@ class Converters {
   static MideaPreset to_midea_preset(const std::string &preset);
   static bool is_custom_midea_preset(MideaPreset preset);
   static ClimatePreset to_climate_preset(MideaPreset preset);
-  static const std::string &to_custom_climate_preset(MideaPreset preset);
+  static const char *to_custom_climate_preset(MideaPreset preset);
   static MideaFanMode to_midea_fan_mode(ClimateFanMode fan_mode);
   static MideaFanMode to_midea_fan_mode(const std::string &fan_mode);
   static bool is_custom_midea_fan_mode(MideaFanMode fan_mode);
   static ClimateFanMode to_climate_fan_mode(MideaFanMode fan_mode);
-  static const std::string &to_custom_climate_fan_mode(MideaFanMode fan_mode);
+  static const char *to_custom_climate_fan_mode(MideaFanMode fan_mode);
   static void to_climate_traits(ClimateTraits &traits, const dudanov::midea::ac::Capabilities &capabilities);
 };
 

esphome/components/midea/air_conditioner.cpp

@@ -84,8 +84,10 @@ ClimateTraits AirConditioner::traits() {
   traits.set_supported_modes(this->supported_modes_);
   traits.set_supported_swing_modes(this->supported_swing_modes_);
   traits.set_supported_presets(this->supported_presets_);
-  traits.set_supported_custom_presets(this->supported_custom_presets_);
-  traits.set_supported_custom_fan_modes(this->supported_custom_fan_modes_);
+  if (!this->supported_custom_presets_.empty())
+    traits.set_supported_custom_presets(this->supported_custom_presets_);
+  if (!this->supported_custom_fan_modes_.empty())
+    traits.set_supported_custom_fan_modes(this->supported_custom_fan_modes_);
   /* + MINIMAL SET OF CAPABILITIES */
   traits.add_supported_fan_mode(ClimateFanMode::CLIMATE_FAN_AUTO);
   traits.add_supported_fan_mode(ClimateFanMode::CLIMATE_FAN_LOW);

esphome/components/midea/air_conditioner.h

@@ -46,8 +46,8 @@ class AirConditioner : public ApplianceBase<dudanov::midea::ac::AirConditioner>,
   void set_supported_modes(ClimateModeMask modes) { this->supported_modes_ = modes; }
   void set_supported_swing_modes(ClimateSwingModeMask modes) { this->supported_swing_modes_ = modes; }
   void set_supported_presets(ClimatePresetMask presets) { this->supported_presets_ = presets; }
-  void set_custom_presets(const std::vector<std::string> &presets) { this->supported_custom_presets_ = presets; }
-  void set_custom_fan_modes(const std::vector<std::string> &modes) { this->supported_custom_fan_modes_ = modes; }
+  void set_custom_presets(std::initializer_list<const char *> presets) { this->supported_custom_presets_ = presets; }
+  void set_custom_fan_modes(std::initializer_list<const char *> modes) { this->supported_custom_fan_modes_ = modes; }
 
  protected:
   void control(const ClimateCall &call) override;
@@ -55,8 +55,8 @@ class AirConditioner : public ApplianceBase<dudanov::midea::ac::AirConditioner>,
   ClimateModeMask supported_modes_{};
   ClimateSwingModeMask supported_swing_modes_{};
   ClimatePresetMask supported_presets_{};
-  std::vector<std::string> supported_custom_presets_{};
-  std::vector<std::string> supported_custom_fan_modes_{};
+  std::vector<const char *> supported_custom_presets_{};
+  std::vector<const char *> supported_custom_fan_modes_{};
   Sensor *outdoor_sensor_{nullptr};
   Sensor *humidity_sensor_{nullptr};
   Sensor *power_sensor_{nullptr};

esphome/components/speed/fan/speed_fan.cpp

@@ -29,7 +29,7 @@ void SpeedFan::control(const fan::FanCall &call) {
     this->oscillating = *call.get_oscillating();
   if (call.get_direction().has_value())
     this->direction = *call.get_direction();
-  this->set_preset_mode_(call.get_preset_mode());
+  this->preset_mode = call.get_preset_mode();
 
   this->write_state_();
   this->publish_state();

esphome/components/speed/fan/speed_fan.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <set>
+
 #include "esphome/core/component.h"
 #include "esphome/components/output/binary_output.h"
 #include "esphome/components/output/float_output.h"
@@ -16,7 +18,7 @@ class SpeedFan : public Component, public fan::Fan {
   void set_output(output::FloatOutput *output) { this->output_ = output; }
   void set_oscillating(output::BinaryOutput *oscillating) { this->oscillating_ = oscillating; }
   void set_direction(output::BinaryOutput *direction) { this->direction_ = direction; }
-  void set_preset_modes(std::initializer_list<const char *> presets) { this->preset_modes_ = presets; }
+  void set_preset_modes(const std::set<std::string> &presets) { this->preset_modes_ = presets; }
   fan::FanTraits get_traits() override { return this->traits_; }
 
  protected:
@@ -28,7 +30,7 @@ class SpeedFan : public Component, public fan::Fan {
   output::BinaryOutput *direction_{nullptr};
   int speed_count_{};
   fan::FanTraits traits_;
-  std::vector<const char *> preset_modes_{};
+  std::set<std::string> preset_modes_{};
 };
 
 }  // namespace speed

esphome/components/template/fan/template_fan.cpp

@@ -29,7 +29,7 @@ void TemplateFan::control(const fan::FanCall &call) {
     this->oscillating = *call.get_oscillating();
   if (call.get_direction().has_value() && this->has_direction_)
     this->direction = *call.get_direction();
-  this->set_preset_mode_(call.get_preset_mode());
+  this->preset_mode = call.get_preset_mode();
 
   this->publish_state();
 }

esphome/components/template/fan/template_fan.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <set>
+
 #include "esphome/core/component.h"
 #include "esphome/components/fan/fan.h"
 
@@ -14,7 +16,7 @@ class TemplateFan : public Component, public fan::Fan {
   void set_has_direction(bool has_direction) { this->has_direction_ = has_direction; }
   void set_has_oscillating(bool has_oscillating) { this->has_oscillating_ = has_oscillating; }
   void set_speed_count(int count) { this->speed_count_ = count; }
-  void set_preset_modes(std::initializer_list<const char *> presets) { this->preset_modes_ = presets; }
+  void set_preset_modes(const std::set<std::string> &presets) { this->preset_modes_ = presets; }
   fan::FanTraits get_traits() override { return this->traits_; }
 
  protected:
@@ -24,7 +26,7 @@ class TemplateFan : public Component, public fan::Fan {
   bool has_direction_{false};
   int speed_count_{0};
   fan::FanTraits traits_;
-  std::vector<const char *> preset_modes_{};
+  std::set<std::string> preset_modes_{};
 };
 
 }  // namespace template_

esphome/components/thermostat/climate.py

@@ -9,6 +9,8 @@ from esphome.const import (
     CONF_COOL_DEADBAND,
     CONF_COOL_MODE,
     CONF_COOL_OVERRUN,
+    CONF_CUSTOM_FAN_MODES,
+    CONF_CUSTOM_PRESETS,
     CONF_DEFAULT_MODE,
     CONF_DEFAULT_TARGET_TEMPERATURE_HIGH,
     CONF_DEFAULT_TARGET_TEMPERATURE_LOW,
@@ -658,6 +660,8 @@ CONFIG_SCHEMA = cv.All(
                 }
             ),
             cv.Optional(CONF_PRESET): cv.ensure_list(PRESET_CONFIG_SCHEMA),
+            cv.Optional(CONF_CUSTOM_FAN_MODES): cv.ensure_list(cv.string_strict),
+            cv.Optional(CONF_CUSTOM_PRESETS): cv.ensure_list(cv.string_strict),
             cv.Optional(CONF_ON_BOOT_RESTORE_FROM): validate_on_boot_restore_from,
             cv.Optional(CONF_PRESET_CHANGE): automation.validate_automation(
                 single=True
@@ -1008,3 +1012,22 @@ async def to_code(config):
         await automation.build_automation(
             var.get_preset_change_trigger(), [], config[CONF_PRESET_CHANGE]
         )
+
+    # Collect custom preset names from preset map (non-standard) and custom_presets list
+    custom_preset_names = [
+        preset_config[CONF_NAME]
+        for preset_config in config.get(CONF_PRESET, [])
+        if preset_config[CONF_NAME].upper() not in climate.CLIMATE_PRESETS
+    ]
+    custom_preset_names.extend(config.get(CONF_CUSTOM_PRESETS, []))
+    if custom_preset_names:
+        cg.add(var.set_custom_presets(custom_preset_names))
+
+    # Collect custom fan modes (filter out standard enum fan modes)
+    custom_fan_modes = [
+        mode
+        for mode in config.get(CONF_CUSTOM_FAN_MODES, [])
+        if mode.upper() not in climate.CLIMATE_FAN_MODES
+    ]
+    if custom_fan_modes:
+        cg.add(var.set_custom_fan_modes(custom_fan_modes))

esphome/components/thermostat/thermostat_climate.cpp

@@ -321,8 +321,12 @@ climate::ClimateTraits ThermostatClimate::traits() {
   for (auto &it : this->preset_config_) {
     traits.add_supported_preset(it.first);
   }
-  for (auto &it : this->custom_preset_config_) {
-    traits.add_supported_custom_preset(it.first);
+  // Custom presets and fan modes are set directly from Python (includes both map entries and additional lists)
+  if (!this->additional_custom_presets_.empty()) {
+    traits.set_supported_custom_presets(this->additional_custom_presets_);
+  }
+  if (!this->additional_custom_fan_modes_.empty()) {
+    traits.set_supported_custom_fan_modes(this->additional_custom_fan_modes_);
   }
   return traits;
 }
@@ -1248,6 +1252,14 @@ void ThermostatClimate::set_custom_preset_config(const std::string &name,
   this->custom_preset_config_[name] = config;
 }
 
+void ThermostatClimate::set_custom_fan_modes(std::initializer_list<const char *> custom_fan_modes) {
+  this->additional_custom_fan_modes_ = custom_fan_modes;
+}
+
+void ThermostatClimate::set_custom_presets(std::initializer_list<const char *> custom_presets) {
+  this->additional_custom_presets_ = custom_presets;
+}
+
 ThermostatClimate::ThermostatClimate()
     : cool_action_trigger_(new Trigger<>()),
       supplemental_cool_action_trigger_(new Trigger<>()),

esphome/components/thermostat/thermostat_climate.h

@@ -133,6 +133,8 @@ class ThermostatClimate : public climate::Climate, public Component {
 
   void set_preset_config(climate::ClimatePreset preset, const ThermostatClimateTargetTempConfig &config);
   void set_custom_preset_config(const std::string &name, const ThermostatClimateTargetTempConfig &config);
+  void set_custom_fan_modes(std::initializer_list<const char *> custom_fan_modes);
+  void set_custom_presets(std::initializer_list<const char *> custom_presets);
 
   Trigger<> *get_cool_action_trigger() const;
   Trigger<> *get_supplemental_cool_action_trigger() const;
@@ -537,6 +539,10 @@ class ThermostatClimate : public climate::Climate, public Component {
   std::map<climate::ClimatePreset, ThermostatClimateTargetTempConfig> preset_config_{};
   /// The set of custom preset configurations this thermostat supports (eg. "My Custom Preset")
   std::map<std::string, ThermostatClimateTargetTempConfig> custom_preset_config_{};
+  /// Additional custom fan modes to expose (beyond those with actions)
+  std::vector<const char *> additional_custom_fan_modes_{};
+  /// Additional custom presets to expose (beyond those in custom_preset_config_)
+  std::vector<const char *> additional_custom_presets_{};
 };
 
 }  // namespace thermostat

script/api_protobuf/api_protobuf.py

@@ -1610,8 +1610,9 @@ class RepeatedTypeInfo(TypeInfo):
             # Other types need the actual value
             # Special handling for const char* elements
             if self._use_pointer and "const char" in self._container_no_template:
+                field_id_size = self.calculate_field_id_size()
                 o += f"  for (const char *it : {container_ref}) {{\n"
-                o += "    size.add_length_force(1, strlen(it));\n"
+                o += f"    size.add_length_force({field_id_size}, strlen(it));\n"
             else:
                 auto_ref = "" if self._ti_is_bool else "&"
                 o += f"  for (const auto {auto_ref}it : {container_ref}) {{\n"

tests/components/thermostat/common.yaml

@@ -15,6 +15,12 @@ climate:
       - name: Away
         default_target_temperature_low: 16°C
         default_target_temperature_high: 20°C
+    custom_fan_modes:
+      - "Custom Fan 1"
+      - "Custom Fan 2"
+    custom_presets:
+      - "Custom Preset 1"
+      - "Custom Preset 2"
     idle_action:
       - logger.log: idle_action
     cool_action:

tests/integration/fixtures/climate_custom_fan_modes_and_presets.yaml

@@ -0,0 +1,39 @@
+esphome:
+  name: climate-custom-modes-test
+host:
+api:
+logger:
+
+sensor:
+  - platform: template
+    id: thermostat_sensor
+    lambda: "return 22.0;"
+
+climate:
+  - platform: thermostat
+    id: test_thermostat
+    name: Test Thermostat Custom Modes
+    sensor: thermostat_sensor
+    preset:
+      - name: Away
+        default_target_temperature_low: 16°C
+        default_target_temperature_high: 20°C
+    custom_fan_modes:
+      - "Turbo"
+      - "Silent"
+      - "Sleep Mode"
+    custom_presets:
+      - "Eco Plus"
+      - "Comfort"
+      - "Vacation Mode"
+    idle_action:
+      - logger.log: idle_action
+    cool_action:
+      - logger.log: cool_action
+    heat_action:
+      - logger.log: heat_action
+    min_cooling_off_time: 10s
+    min_cooling_run_time: 10s
+    min_heating_off_time: 10s
+    min_heating_run_time: 10s
+    min_idle_time: 10s

tests/integration/test_climate_custom_modes.py

@@ -0,0 +1,51 @@
+"""Integration test for climate custom fan modes and presets."""
+
+from __future__ import annotations
+
+from aioesphomeapi import ClimateInfo, ClimatePreset
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_climate_custom_fan_modes_and_presets(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test that custom fan modes and presets are properly exposed via API."""
+    async with run_compiled(yaml_config), api_client_connected() as client:
+        # Get entities and services
+        entities, services = await client.list_entities_services()
+        climate_infos = [e for e in entities if isinstance(e, ClimateInfo)]
+        assert len(climate_infos) == 1, "Expected exactly 1 climate entity"
+
+        test_climate = climate_infos[0]
+
+        # Verify custom fan modes are exposed
+        custom_fan_modes = test_climate.supported_custom_fan_modes
+        assert len(custom_fan_modes) == 3, (
+            f"Expected 3 custom fan modes, got {len(custom_fan_modes)}"
+        )
+        assert "Turbo" in custom_fan_modes, "Expected 'Turbo' in custom fan modes"
+        assert "Silent" in custom_fan_modes, "Expected 'Silent' in custom fan modes"
+        assert "Sleep Mode" in custom_fan_modes, (
+            "Expected 'Sleep Mode' in custom fan modes"
+        )
+
+        # Verify enum presets are exposed (from preset: config map)
+        assert ClimatePreset.AWAY in test_climate.supported_presets, (
+            "Expected AWAY in enum presets"
+        )
+
+        # Verify custom string presets are exposed (from custom_presets: config list)
+        custom_presets = test_climate.supported_custom_presets
+        assert len(custom_presets) == 3, (
+            f"Expected 3 custom presets, got {len(custom_presets)}: {custom_presets}"
+        )
+        assert "Eco Plus" in custom_presets, "Expected 'Eco Plus' in custom presets"
+        assert "Comfort" in custom_presets, "Expected 'Comfort' in custom presets"
+        assert "Vacation Mode" in custom_presets, (
+            "Expected 'Vacation Mode' in custom presets"
+        )

tests/unit_tests/test_main.py

@@ -744,7 +744,7 @@ def test_choose_upload_log_host_ota_local_all_options() -> None:
         check_default=None,
         purpose=Purpose.UPLOADING,
     )
-    assert result == ["MQTTIP"]
+    assert result == ["MQTTIP", "test.local"]
 
 
 @pytest.mark.usefixtures("mock_serial_ports")
@@ -794,7 +794,7 @@ def test_choose_upload_log_host_ota_local_all_options_logging() -> None:
         check_default=None,
         purpose=Purpose.LOGGING,
     )
-    assert result == ["MQTTIP", "MQTT"]
+    assert result == ["MQTTIP", "MQTT", "test.local"]
 
 
 @pytest.mark.usefixtures("mock_no_mqtt_logging")
@@ -1564,7 +1564,7 @@ def test_has_resolvable_address() -> None:
     setup_core(
         config={CONF_MDNS: {CONF_DISABLED: True}}, address="esphome-device.local"
     )
-    assert has_resolvable_address() is False
+    assert has_resolvable_address() is True
 
     # Test with mDNS disabled and regular DNS hostname (resolvable)
     setup_core(config={CONF_MDNS: {CONF_DISABLED: True}}, address="device.example.com")