Merge branch 'dev' into idf_no_heap_alloc_url

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
Co-authored-by: J. Nick Koston <nick@koston.org>

.clang-tidy.hash

@@ -1 +1 @@
-d272a88e8ca28ae9340a9a03295a566432a52cb696501908f57764475bf7ca65
+d15ae81646ac0ee76b2586716fe697f187281523ee6db566aed26542a9f98d1a

esphome/__main__.py

@@ -1,5 +1,6 @@
 # PYTHON_ARGCOMPLETE_OK
 import argparse
+from collections.abc import Callable
 from datetime import datetime
 import functools
 import getpass
@@ -42,6 +43,7 @@ from esphome.const import (
     CONF_SUBSTITUTIONS,
     CONF_TOPIC,
     ENV_NOGITIGNORE,
+    KEY_NATIVE_IDF,
     PLATFORM_ESP32,
     PLATFORM_ESP8266,
     PLATFORM_RP2040,
@@ -115,6 +117,7 @@ class ArgsProtocol(Protocol):
     configuration: str
     name: str
     upload_speed: str | None
+    native_idf: bool
 
 
 def choose_prompt(options, purpose: str = None):
@@ -499,12 +502,15 @@ def wrap_to_code(name, comp):
     return wrapped
 
 
-def write_cpp(config: ConfigType) -> int:
+def write_cpp(config: ConfigType, native_idf: bool = False) -> int:
     if not get_bool_env(ENV_NOGITIGNORE):
         writer.write_gitignore()
 
+    # Store native_idf flag so esp32 component can check it
+    CORE.data[KEY_NATIVE_IDF] = native_idf
+
     generate_cpp_contents(config)
-    return write_cpp_file()
+    return write_cpp_file(native_idf=native_idf)
 
 
 def generate_cpp_contents(config: ConfigType) -> None:
@@ -518,32 +524,54 @@ def generate_cpp_contents(config: ConfigType) -> None:
     CORE.flush_tasks()
 
 
-def write_cpp_file() -> int:
+def write_cpp_file(native_idf: bool = False) -> int:
     code_s = indent(CORE.cpp_main_section)
     writer.write_cpp(code_s)
 
-    from esphome.build_gen import platformio
+    if native_idf and CORE.is_esp32 and CORE.target_framework == "esp-idf":
+        from esphome.build_gen import espidf
 
-    platformio.write_project()
+        espidf.write_project()
+    else:
+        from esphome.build_gen import platformio
+
+        platformio.write_project()
 
     return 0
 
 
 def compile_program(args: ArgsProtocol, config: ConfigType) -> int:
-    from esphome import platformio_api
+    native_idf = getattr(args, "native_idf", False)
 
     # NOTE: "Build path:" format is parsed by script/ci_memory_impact_extract.py
     # If you change this format, update the regex in that script as well
     _LOGGER.info("Compiling app... Build path: %s", CORE.build_path)
-    rc = platformio_api.run_compile(config, CORE.verbose)
-    if rc != 0:
-        return rc
+
+    if native_idf and CORE.is_esp32 and CORE.target_framework == "esp-idf":
+        from esphome import espidf_api
+
+        rc = espidf_api.run_compile(config, CORE.verbose)
+        if rc != 0:
+            return rc
+
+        # Create factory.bin and ota.bin
+        espidf_api.create_factory_bin()
+        espidf_api.create_ota_bin()
+    else:
+        from esphome import platformio_api
+
+        rc = platformio_api.run_compile(config, CORE.verbose)
+        if rc != 0:
+            return rc
+
+        idedata = platformio_api.get_idedata(config)
+        if idedata is None:
+            return 1
 
     # Check if firmware was rebuilt and emit build_info + create manifest
     _check_and_emit_build_info()
 
-    idedata = platformio_api.get_idedata(config)
-    return 0 if idedata is not None else 1
+    return 0
 
 
 def _check_and_emit_build_info() -> None:
@@ -800,7 +828,8 @@ def command_vscode(args: ArgsProtocol) -> int | None:
 
 
 def command_compile(args: ArgsProtocol, config: ConfigType) -> int | None:
-    exit_code = write_cpp(config)
+    native_idf = getattr(args, "native_idf", False)
+    exit_code = write_cpp(config, native_idf=native_idf)
     if exit_code != 0:
         return exit_code
     if args.only_generate:
@@ -855,7 +884,8 @@ def command_logs(args: ArgsProtocol, config: ConfigType) -> int | None:
 
 
 def command_run(args: ArgsProtocol, config: ConfigType) -> int | None:
-    exit_code = write_cpp(config)
+    native_idf = getattr(args, "native_idf", False)
+    exit_code = write_cpp(config, native_idf=native_idf)
     if exit_code != 0:
         return exit_code
     exit_code = compile_program(args, config)
@@ -936,11 +966,21 @@ def command_dashboard(args: ArgsProtocol) -> int | None:
     return dashboard.start_dashboard(args)
 
 
-def command_update_all(args: ArgsProtocol) -> int | None:
+def run_multiple_configs(
+    files: list, command_builder: Callable[[str], list[str]]
+) -> int:
+    """Run a command for each configuration file in a subprocess.
+
+    Args:
+        files: List of configuration files to process.
+        command_builder: Callable that takes a file path and returns a command list.
+
+    Returns:
+        Number of failed files.
+    """
     import click
 
     success = {}
-    files = list_yaml_files(args.configuration)
     twidth = 60
 
     def print_bar(middle_text):
@@ -950,17 +990,19 @@ def command_update_all(args: ArgsProtocol) -> int | None:
         safe_print(f"{half_line}{middle_text}{half_line}")
 
     for f in files:
-        safe_print(f"Updating {color(AnsiFore.CYAN, str(f))}")
+        f_path = Path(f) if not isinstance(f, Path) else f
+
+        if any(f_path.name == x for x in SECRETS_FILES):
+            _LOGGER.warning("Skipping secrets file %s", f_path)
+            continue
+
+        safe_print(f"Processing {color(AnsiFore.CYAN, str(f))}")
         safe_print("-" * twidth)
         safe_print()
-        if CORE.dashboard:
-            rc = run_external_process(
-                "esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"
-            )
-        else:
-            rc = run_external_process(
-                "esphome", "run", f, "--no-logs", "--device", "OTA"
-            )
+
+        cmd = command_builder(f)
+        rc = run_external_process(*cmd)
+
         if rc == 0:
             print_bar(f"[{color(AnsiFore.BOLD_GREEN, 'SUCCESS')}] {str(f)}")
             success[f] = True
@@ -975,6 +1017,8 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     print_bar(f"[{color(AnsiFore.BOLD_WHITE, 'SUMMARY')}]")
     failed = 0
     for f in files:
+        if f not in success:
+            continue  # Skipped file
         if success[f]:
             safe_print(f"  - {str(f)}: {color(AnsiFore.GREEN, 'SUCCESS')}")
         else:
@@ -983,6 +1027,17 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     return failed
 
 
+def command_update_all(args: ArgsProtocol) -> int | None:
+    files = list_yaml_files(args.configuration)
+
+    def build_command(f):
+        if CORE.dashboard:
+            return ["esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"]
+        return ["esphome", "run", f, "--no-logs", "--device", "OTA"]
+
+    return run_multiple_configs(files, build_command)
+
+
 def command_idedata(args: ArgsProtocol, config: ConfigType) -> int:
     import json
 
@@ -1284,6 +1339,11 @@ def parse_args(argv):
         help="Only generate source code, do not compile.",
         action="store_true",
     )
+    parser_compile.add_argument(
+        "--native-idf",
+        help="Build with native ESP-IDF instead of PlatformIO (ESP32 esp-idf framework only).",
+        action="store_true",
+    )
 
     parser_upload = subparsers.add_parser(
         "upload",
@@ -1365,6 +1425,11 @@ def parse_args(argv):
         help="Reset the device before starting serial logs.",
         default=os.getenv("ESPHOME_SERIAL_LOGGING_RESET"),
     )
+    parser_run.add_argument(
+        "--native-idf",
+        help="Build with native ESP-IDF instead of PlatformIO (ESP32 esp-idf framework only).",
+        action="store_true",
+    )
 
     parser_clean = subparsers.add_parser(
         "clean-mqtt",
@@ -1533,38 +1598,48 @@ def run_esphome(argv):
 
     _LOGGER.info("ESPHome %s", const.__version__)
 
-    for conf_path in args.configuration:
-        conf_path = Path(conf_path)
-        if any(conf_path.name == x for x in SECRETS_FILES):
-            _LOGGER.warning("Skipping secrets file %s", conf_path)
-            continue
+    # Multiple configurations: use subprocesses to avoid state leakage
+    # between compilations (e.g., LVGL touchscreen state in module globals)
+    if len(args.configuration) > 1:
+        # Build command by reusing argv, replacing all configs with single file
+        # argv[0] is the program path, skip it since we prefix with "esphome"
+        def build_command(f):
+            return (
+                ["esphome"]
+                + [arg for arg in argv[1:] if arg not in args.configuration]
+                + [str(f)]
+            )
 
-        CORE.config_path = conf_path
-        CORE.dashboard = args.dashboard
+        return run_multiple_configs(args.configuration, build_command)
 
-        # For logs command, skip updating external components
-        skip_external = args.command == "logs"
-        config = read_config(
-            dict(args.substitution) if args.substitution else {},
-            skip_external_update=skip_external,
-        )
-        if config is None:
-            return 2
-        CORE.config = config
+    # Single configuration
+    conf_path = Path(args.configuration[0])
+    if any(conf_path.name == x for x in SECRETS_FILES):
+        _LOGGER.warning("Skipping secrets file %s", conf_path)
+        return 0
 
-        if args.command not in POST_CONFIG_ACTIONS:
-            safe_print(f"Unknown command {args.command}")
+    CORE.config_path = conf_path
+    CORE.dashboard = args.dashboard
 
-        try:
-            rc = POST_CONFIG_ACTIONS[args.command](args, config)
-        except EsphomeError as e:
-            _LOGGER.error(e, exc_info=args.verbose)
-            return 1
-        if rc != 0:
-            return rc
+    # For logs command, skip updating external components
+    skip_external = args.command == "logs"
+    config = read_config(
+        dict(args.substitution) if args.substitution else {},
+        skip_external_update=skip_external,
+    )
+    if config is None:
+        return 2
+    CORE.config = config
 
-        CORE.reset()
-    return 0
+    if args.command not in POST_CONFIG_ACTIONS:
+        safe_print(f"Unknown command {args.command}")
+        return 1
+
+    try:
+        return POST_CONFIG_ACTIONS[args.command](args, config)
+    except EsphomeError as e:
+        _LOGGER.error(e, exc_info=args.verbose)
+        return 1
 
 
 def main():

esphome/build_gen/espidf.py

@@ -0,0 +1,139 @@
+"""ESP-IDF direct build generator for ESPHome."""
+
+import json
+from pathlib import Path
+
+from esphome.components.esp32 import get_esp32_variant
+from esphome.core import CORE
+from esphome.helpers import mkdir_p, write_file_if_changed
+
+
+def get_available_components() -> list[str] | None:
+    """Get list of available ESP-IDF components from project_description.json.
+
+    Returns only internal ESP-IDF components, excluding external/managed
+    components (from idf_component.yml).
+    """
+    project_desc = Path(CORE.build_path) / "build" / "project_description.json"
+    if not project_desc.exists():
+        return None
+
+    try:
+        with open(project_desc, encoding="utf-8") as f:
+            data = json.load(f)
+
+        component_info = data.get("build_component_info", {})
+
+        result = []
+        for name, info in component_info.items():
+            # Exclude our own src component
+            if name == "src":
+                continue
+
+            # Exclude managed/external components
+            comp_dir = info.get("dir", "")
+            if "managed_components" in comp_dir:
+                continue
+
+            result.append(name)
+
+        return result
+    except (json.JSONDecodeError, OSError):
+        return None
+
+
+def has_discovered_components() -> bool:
+    """Check if we have discovered components from a previous configure."""
+    return get_available_components() is not None
+
+
+def get_project_cmakelists() -> str:
+    """Generate the top-level CMakeLists.txt for ESP-IDF project."""
+    # Get IDF target from ESP32 variant (e.g., ESP32S3 -> esp32s3)
+    variant = get_esp32_variant()
+    idf_target = variant.lower().replace("-", "")
+
+    return f"""\
+# Auto-generated by ESPHome
+cmake_minimum_required(VERSION 3.16)
+
+set(IDF_TARGET {idf_target})
+set(EXTRA_COMPONENT_DIRS ${{CMAKE_SOURCE_DIR}}/src)
+
+include($ENV{{IDF_PATH}}/tools/cmake/project.cmake)
+project({CORE.name})
+"""
+
+
+def get_component_cmakelists(minimal: bool = False) -> str:
+    """Generate the main component CMakeLists.txt."""
+    idf_requires = [] if minimal else (get_available_components() or [])
+    requires_str = " ".join(idf_requires)
+
+    # Extract compile definitions from build flags (-DXXX -> XXX)
+    compile_defs = [flag[2:] for flag in CORE.build_flags if flag.startswith("-D")]
+    compile_defs_str = "\n    ".join(compile_defs) if compile_defs else ""
+
+    # Extract compile options (-W flags, excluding linker flags)
+    compile_opts = [
+        flag
+        for flag in CORE.build_flags
+        if flag.startswith("-W") and not flag.startswith("-Wl,")
+    ]
+    compile_opts_str = "\n    ".join(compile_opts) if compile_opts else ""
+
+    # Extract linker options (-Wl, flags)
+    link_opts = [flag for flag in CORE.build_flags if flag.startswith("-Wl,")]
+    link_opts_str = "\n    ".join(link_opts) if link_opts else ""
+
+    return f"""\
+# Auto-generated by ESPHome
+file(GLOB_RECURSE app_sources
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/*.cpp"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/*.c"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/esphome/*.cpp"
+    "${{CMAKE_CURRENT_SOURCE_DIR}}/esphome/*.c"
+)
+
+idf_component_register(
+    SRCS ${{app_sources}}
+    INCLUDE_DIRS "." "esphome"
+    REQUIRES {requires_str}
+)
+
+# Apply C++ standard
+target_compile_features(${{COMPONENT_LIB}} PUBLIC cxx_std_20)
+
+# ESPHome compile definitions
+target_compile_definitions(${{COMPONENT_LIB}} PUBLIC
+    {compile_defs_str}
+)
+
+# ESPHome compile options
+target_compile_options(${{COMPONENT_LIB}} PUBLIC
+    {compile_opts_str}
+)
+
+# ESPHome linker options
+target_link_options(${{COMPONENT_LIB}} PUBLIC
+    {link_opts_str}
+)
+"""
+
+
+def write_project(minimal: bool = False) -> None:
+    """Write ESP-IDF project files."""
+    mkdir_p(CORE.build_path)
+    mkdir_p(CORE.relative_src_path())
+
+    # Write top-level CMakeLists.txt
+    write_file_if_changed(
+        CORE.relative_build_path("CMakeLists.txt"),
+        get_project_cmakelists(),
+    )
+
+    # Write component CMakeLists.txt in src/
+    write_file_if_changed(
+        CORE.relative_src_path("CMakeLists.txt"),
+        get_component_cmakelists(minimal=minimal),
+    )

esphome/codegen.py

@@ -69,6 +69,7 @@ from esphome.cpp_types import (  # noqa: F401
     JsonObjectConst,
     Parented,
     PollingComponent,
+    StringRef,
     arduino_json_ns,
     bool_,
     const_char_ptr,

esphome/components/am43/am43_base.cpp

@@ -1,21 +1,12 @@
 #include "am43_base.h"
+#include "esphome/core/helpers.h"
 #include <cstring>
-#include <cstdio>
 
 namespace esphome {
 namespace am43 {
 
 const uint8_t START_PACKET[5] = {0x00, 0xff, 0x00, 0x00, 0x9a};
 
-std::string pkt_to_hex(const uint8_t *data, uint16_t len) {
-  char buf[64];
-  memset(buf, 0, 64);
-  for (int i = 0; i < len; i++)
-    sprintf(&buf[i * 2], "%02x", data[i]);
-  std::string ret = buf;
-  return ret;
-}
-
 Am43Packet *Am43Encoder::get_battery_level_request() {
   uint8_t data = 0x1;
   return this->encode_(0xA2, &data, 1);
@@ -73,7 +64,9 @@ Am43Packet *Am43Encoder::encode_(uint8_t command, uint8_t *data, uint8_t length)
   memcpy(&this->packet_.data[7], data, length);
   this->packet_.length = length + 7;
   this->checksum_();
-  ESP_LOGV("am43", "ENC(%d): 0x%s", packet_.length, pkt_to_hex(packet_.data, packet_.length).c_str());
+  char hex_buf[format_hex_size(sizeof(this->packet_.data))];
+  ESP_LOGV("am43", "ENC(%d): 0x%s", this->packet_.length,
+           format_hex_to(hex_buf, this->packet_.data, this->packet_.length));
   return &this->packet_;
 }
 
@@ -88,7 +81,8 @@ void Am43Decoder::decode(const uint8_t *data, uint16_t length) {
   this->has_set_state_response_ = false;
   this->has_position_ = false;
   this->has_pin_response_ = false;
-  ESP_LOGV("am43", "DEC(%d): 0x%s", length, pkt_to_hex(data, length).c_str());
+  char hex_buf[format_hex_size(24)];  // Max expected packet size
+  ESP_LOGV("am43", "DEC(%d): 0x%s", length, format_hex_to(hex_buf, data, length));
 
   if (length < 2 || data[0] != 0x9a)
     return;

esphome/components/anova/anova_base.cpp

@@ -18,31 +18,31 @@ AnovaPacket *AnovaCodec::clean_packet_() {
 
 AnovaPacket *AnovaCodec::get_read_device_status_request() {
   this->current_query_ = READ_DEVICE_STATUS;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_DEVICE_STATUS);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_DEVICE_STATUS);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_target_temp_request() {
   this->current_query_ = READ_TARGET_TEMPERATURE;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_TARGET_TEMP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_TARGET_TEMP);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_current_temp_request() {
   this->current_query_ = READ_CURRENT_TEMPERATURE;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_CURRENT_TEMP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_CURRENT_TEMP);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_unit_request() {
   this->current_query_ = READ_UNIT;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_UNIT);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_UNIT);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_data_request() {
   this->current_query_ = READ_DATA;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_DATA);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_DATA);
   return this->clean_packet_();
 }
 
@@ -50,25 +50,25 @@ AnovaPacket *AnovaCodec::get_set_target_temp_request(float temperature) {
   this->current_query_ = SET_TARGET_TEMPERATURE;
   if (this->fahrenheit_)
     temperature = ctof(temperature);
-  sprintf((char *) this->packet_.data, CMD_SET_TARGET_TEMP, temperature);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), CMD_SET_TARGET_TEMP, temperature);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_set_unit_request(char unit) {
   this->current_query_ = SET_UNIT;
-  sprintf((char *) this->packet_.data, CMD_SET_TEMP_UNIT, unit);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), CMD_SET_TEMP_UNIT, unit);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_start_request() {
   this->current_query_ = START;
-  sprintf((char *) this->packet_.data, CMD_START);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_START);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_stop_request() {
   this->current_query_ = STOP;
-  sprintf((char *) this->packet_.data, CMD_STOP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_STOP);
   return this->clean_packet_();
 }
 

esphome/components/api/api_connection.cpp

@@ -1715,7 +1715,7 @@ void APIConnection::on_home_assistant_state_response(const HomeAssistantStateRes
     // HA state max length is 255 characters, but attributes can be much longer
     // Use stack buffer for common case (states), heap fallback for large attributes
     size_t state_len = msg.state.size();
-    SmallBufferWithHeapFallback<256> state_buf_alloc(state_len + 1);
+    SmallBufferWithHeapFallback<MAX_STATE_LEN + 1> state_buf_alloc(state_len + 1);
     char *state_buf = reinterpret_cast<char *>(state_buf_alloc.get());
     if (state_len > 0) {
       memcpy(state_buf, msg.state.c_str(), state_len);

esphome/components/api/api_frame_helper_noise.cpp

@@ -3,6 +3,7 @@
 #ifdef USE_API_NOISE
 #include "api_connection.h"  // For ClientInfo struct
 #include "esphome/core/application.h"
+#include "esphome/core/entity_base.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
@@ -256,28 +257,30 @@ APIError APINoiseFrameHelper::state_action_() {
   }
   if (state_ == State::SERVER_HELLO) {
     // send server hello
-    constexpr size_t mac_len = 13;  // 12 hex chars + null terminator
     const std::string &name = App.get_name();
-    char mac[mac_len];
+    char mac[MAC_ADDRESS_BUFFER_SIZE];
     get_mac_address_into_buffer(mac);
 
     // Calculate positions and sizes
     size_t name_len = name.size() + 1;  // including null terminator
     size_t name_offset = 1;
     size_t mac_offset = name_offset + name_len;
-    size_t total_size = 1 + name_len + mac_len;
+    size_t total_size = 1 + name_len + MAC_ADDRESS_BUFFER_SIZE;
 
-    auto msg = std::make_unique<uint8_t[]>(total_size);
+    // 1 (proto) + name (max ESPHOME_DEVICE_NAME_MAX_LEN) + 1 (name null)
+    // + mac (MAC_ADDRESS_BUFFER_SIZE - 1) + 1 (mac null)
+    constexpr size_t max_msg_size = 1 + ESPHOME_DEVICE_NAME_MAX_LEN + 1 + MAC_ADDRESS_BUFFER_SIZE;
+    uint8_t msg[max_msg_size];
 
     // chosen proto
     msg[0] = 0x01;
 
     // node name, terminated by null byte
-    std::memcpy(msg.get() + name_offset, name.c_str(), name_len);
+    std::memcpy(msg + name_offset, name.c_str(), name_len);
     // node mac, terminated by null byte
-    std::memcpy(msg.get() + mac_offset, mac, mac_len);
+    std::memcpy(msg + mac_offset, mac, MAC_ADDRESS_BUFFER_SIZE);
 
-    aerr = write_frame_(msg.get(), total_size);
+    aerr = write_frame_(msg, total_size);
     if (aerr != APIError::OK)
       return aerr;
 
@@ -353,35 +356,32 @@ APIError APINoiseFrameHelper::state_action_() {
   return APIError::OK;
 }
 void APINoiseFrameHelper::send_explicit_handshake_reject_(const LogString *reason) {
+  // Max reject message: "Bad handshake packet len" (24) + 1 (failure byte) = 25 bytes
+  uint8_t data[32];
+  data[0] = 0x01;  // failure
+
 #ifdef USE_STORE_LOG_STR_IN_FLASH
   // On ESP8266 with flash strings, we need to use PROGMEM-aware functions
   size_t reason_len = strlen_P(reinterpret_cast<PGM_P>(reason));
-  size_t data_size = reason_len + 1;
-  auto data = std::make_unique<uint8_t[]>(data_size);
-  data[0] = 0x01;  // failure
-
-  // Copy error message from PROGMEM
   if (reason_len > 0) {
-    memcpy_P(data.get() + 1, reinterpret_cast<PGM_P>(reason), reason_len);
+    memcpy_P(data + 1, reinterpret_cast<PGM_P>(reason), reason_len);
   }
 #else
   // Normal memory access
   const char *reason_str = LOG_STR_ARG(reason);
   size_t reason_len = strlen(reason_str);
-  size_t data_size = reason_len + 1;
-  auto data = std::make_unique<uint8_t[]>(data_size);
-  data[0] = 0x01;  // failure
-
-  // Copy error message in bulk
   if (reason_len > 0) {
-    std::memcpy(data.get() + 1, reason_str, reason_len);
+    // NOLINTNEXTLINE(bugprone-not-null-terminated-result) - binary protocol, not a C string
+    std::memcpy(data + 1, reason_str, reason_len);
   }
 #endif
 
+  size_t data_size = reason_len + 1;
+
   // temporarily remove failed state
   auto orig_state = state_;
   state_ = State::EXPLICIT_REJECT;
-  write_frame_(data.get(), data_size);
+  write_frame_(data, data_size);
   state_ = orig_state;
 }
 APIError APINoiseFrameHelper::read_packet(ReadPacketBuffer *buffer) {

esphome/components/bluetooth_proxy/bluetooth_connection.cpp

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

esphome/components/captive_portal/captive_portal.cpp

@@ -96,10 +96,16 @@ void CaptivePortal::start() {
 }
 
 void CaptivePortal::handleRequest(AsyncWebServerRequest *req) {
-  if (req->url() == ESPHOME_F("/config.json")) {
+#ifdef USE_ESP32
+  char url_buf[AsyncWebServerRequest::URL_BUF_SIZE];
+  StringRef url = req->url_to(url_buf);
+#else
+  const auto &url = req->url();
+#endif
+  if (url == ESPHOME_F("/config.json")) {
     this->handle_config(req);
     return;
-  } else if (req->url() == ESPHOME_F("/wifisave")) {
+  } else if (url == ESPHOME_F("/wifisave")) {
     this->handle_wifisave(req);
     return;
   }

esphome/components/cc1101/cc1101.cpp

@@ -152,6 +152,13 @@ void CC1101Component::setup() {
   }
 }
 
+void CC1101Component::call_listeners_(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi) {
+  for (auto &listener : this->listeners_) {
+    listener->on_packet(packet, freq_offset, rssi, lqi);
+  }
+  this->packet_trigger_->trigger(packet, freq_offset, rssi, lqi);
+}
+
 void CC1101Component::loop() {
   if (this->state_.PKT_FORMAT != static_cast<uint8_t>(PacketFormat::PACKET_FORMAT_FIFO) || this->gdo0_pin_ == nullptr ||
       !this->gdo0_pin_->digital_read()) {
@@ -198,7 +205,7 @@ void CC1101Component::loop() {
   bool crc_ok = (this->state_.LQI & STATUS_CRC_OK_MASK) != 0;
   uint8_t lqi = this->state_.LQI & STATUS_LQI_MASK;
   if (this->state_.CRC_EN == 0 || crc_ok) {
-    this->packet_trigger_->trigger(this->packet_, freq_offset, rssi, lqi);
+    this->call_listeners_(this->packet_, freq_offset, rssi, lqi);
   }
 
   // Return to rx

esphome/components/cc1101/cc1101.h

@@ -11,6 +11,11 @@ namespace esphome::cc1101 {
 
 enum class CC1101Error { NONE = 0, TIMEOUT, PARAMS, CRC_ERROR, FIFO_OVERFLOW, PLL_LOCK };
 
+class CC1101Listener {
+ public:
+  virtual void on_packet(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi) = 0;
+};
+
 class CC1101Component : public Component,
                         public spi::SPIDevice<spi::BIT_ORDER_MSB_FIRST, spi::CLOCK_POLARITY_LOW,
                                               spi::CLOCK_PHASE_LEADING, spi::DATA_RATE_1MHZ> {
@@ -73,6 +78,7 @@ class CC1101Component : public Component,
 
   // Packet mode operations
   CC1101Error transmit_packet(const std::vector<uint8_t> &packet);
+  void register_listener(CC1101Listener *listener) { this->listeners_.push_back(listener); }
   Trigger<std::vector<uint8_t>, float, float, uint8_t> *get_packet_trigger() const { return this->packet_trigger_; }
 
  protected:
@@ -89,9 +95,11 @@ class CC1101Component : public Component,
   InternalGPIOPin *gdo0_pin_{nullptr};
 
   // Packet handling
+  void call_listeners_(const std::vector<uint8_t> &packet, float freq_offset, float rssi, uint8_t lqi);
   Trigger<std::vector<uint8_t>, float, float, uint8_t> *packet_trigger_{
       new Trigger<std::vector<uint8_t>, float, float, uint8_t>()};
   std::vector<uint8_t> packet_;
+  std::vector<CC1101Listener *> listeners_;
 
   // Low-level Helpers
   uint8_t strobe_(Command cmd);

esphome/components/cs5460a/cs5460a.h

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

esphome/components/datetime/date_entity.cpp

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

esphome/components/datetime/date_entity.h

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

esphome/components/datetime/datetime_entity.cpp

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

esphome/components/datetime/datetime_entity.h

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

esphome/components/datetime/time_entity.cpp

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

esphome/components/datetime/time_entity.h

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

esphome/components/debug/debug_component.cpp

@@ -30,7 +30,7 @@ void DebugComponent::dump_config() {
 
   char device_info_buffer[DEVICE_INFO_BUFFER_SIZE];
   ESP_LOGD(TAG, "ESPHome version %s", ESPHOME_VERSION);
-  size_t pos = buf_append(device_info_buffer, DEVICE_INFO_BUFFER_SIZE, 0, "%s", ESPHOME_VERSION);
+  size_t pos = buf_append_printf(device_info_buffer, DEVICE_INFO_BUFFER_SIZE, 0, "%s", ESPHOME_VERSION);
 
   this->free_heap_ = get_free_heap_();
   ESP_LOGD(TAG, "Free Heap Size: %" PRIu32 " bytes", this->free_heap_);

esphome/components/debug/debug_component.h

@@ -5,12 +5,6 @@
 #include "esphome/core/helpers.h"
 #include "esphome/core/macros.h"
 #include <span>
-#include <cstdarg>
-#include <cstdio>
-#include <algorithm>
-#ifdef USE_ESP8266
-#include <pgmspace.h>
-#endif
 
 #ifdef USE_SENSOR
 #include "esphome/components/sensor/sensor.h"
@@ -25,40 +19,7 @@ namespace debug {
 static constexpr size_t DEVICE_INFO_BUFFER_SIZE = 256;
 static constexpr size_t RESET_REASON_BUFFER_SIZE = 128;
 
-#ifdef USE_ESP8266
-// ESP8266: Use vsnprintf_P to keep format strings in flash (PROGMEM)
-// Format strings must be wrapped with PSTR() macro
-inline size_t buf_append_p(char *buf, size_t size, size_t pos, PGM_P fmt, ...) {
-  if (pos >= size) {
-    return size;
-  }
-  va_list args;
-  va_start(args, fmt);
-  int written = vsnprintf_P(buf + pos, size - pos, fmt, args);
-  va_end(args);
-  if (written < 0) {
-    return pos;  // encoding error
-  }
-  return std::min(pos + static_cast<size_t>(written), size);
-}
-#define buf_append(buf, size, pos, fmt, ...) buf_append_p(buf, size, pos, PSTR(fmt), ##__VA_ARGS__)
-#else
-/// Safely append formatted string to buffer, returning new position (capped at size)
-__attribute__((format(printf, 4, 5))) inline size_t buf_append(char *buf, size_t size, size_t pos, const char *fmt,
-                                                               ...) {
-  if (pos >= size) {
-    return size;
-  }
-  va_list args;
-  va_start(args, fmt);
-  int written = vsnprintf(buf + pos, size - pos, fmt, args);
-  va_end(args);
-  if (written < 0) {
-    return pos;  // encoding error
-  }
-  return std::min(pos + static_cast<size_t>(written), size);
-}
-#endif
+// buf_append_printf is now provided by esphome/core/helpers.h
 
 class DebugComponent : public PollingComponent {
  public:

esphome/components/debug/debug_esp32.cpp

@@ -173,8 +173,8 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   uint32_t flash_size = ESP.getFlashChipSize() / 1024;       // NOLINT
   uint32_t flash_speed = ESP.getFlashChipSpeed() / 1000000;  // NOLINT
   ESP_LOGD(TAG, "Flash Chip: Size=%" PRIu32 "kB Speed=%" PRIu32 "MHz Mode=%s", flash_size, flash_speed, flash_mode);
-  pos = buf_append(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
-                   flash_mode);
+  pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 "kB Speed:%" PRIu32 "MHz Mode:%s", flash_size, flash_speed,
+                          flash_mode);
 #endif
 
   esp_chip_info_t info;
@@ -182,52 +182,52 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   const char *model = ESPHOME_VARIANT;
 
   // Build features string
-  pos = buf_append(buf, size, pos, "|Chip: %s Features:", model);
+  pos = buf_append_printf(buf, size, pos, "|Chip: %s Features:", model);
   bool first_feature = true;
   for (const auto &feature : CHIP_FEATURES) {
     if (info.features & feature.bit) {
-      pos = buf_append(buf, size, pos, "%s%s", first_feature ? "" : ", ", feature.name);
+      pos = buf_append_printf(buf, size, pos, "%s%s", first_feature ? "" : ", ", feature.name);
       first_feature = false;
       info.features &= ~feature.bit;
     }
   }
   if (info.features != 0) {
-    pos = buf_append(buf, size, pos, "%sOther:0x%" PRIx32, first_feature ? "" : ", ", info.features);
+    pos = buf_append_printf(buf, size, pos, "%sOther:0x%" PRIx32, first_feature ? "" : ", ", info.features);
   }
   ESP_LOGD(TAG, "Chip: Model=%s, Cores=%u, Revision=%u", model, info.cores, info.revision);
-  pos = buf_append(buf, size, pos, " Cores:%u Revision:%u", info.cores, info.revision);
+  pos = buf_append_printf(buf, size, pos, " Cores:%u Revision:%u", info.cores, info.revision);
 
   uint32_t cpu_freq_mhz = arch_get_cpu_freq_hz() / 1000000;
   ESP_LOGD(TAG, "CPU Frequency: %" PRIu32 " MHz", cpu_freq_mhz);
-  pos = buf_append(buf, size, pos, "|CPU Frequency: %" PRIu32 " MHz", cpu_freq_mhz);
+  pos = buf_append_printf(buf, size, pos, "|CPU Frequency: %" PRIu32 " MHz", cpu_freq_mhz);
 
   // Framework detection
 #ifdef USE_ARDUINO
   ESP_LOGD(TAG, "Framework: Arduino");
-  pos = buf_append(buf, size, pos, "|Framework: Arduino");
+  pos = buf_append_printf(buf, size, pos, "|Framework: Arduino");
 #elif defined(USE_ESP32)
   ESP_LOGD(TAG, "Framework: ESP-IDF");
-  pos = buf_append(buf, size, pos, "|Framework: ESP-IDF");
+  pos = buf_append_printf(buf, size, pos, "|Framework: ESP-IDF");
 #else
   ESP_LOGW(TAG, "Framework: UNKNOWN");
-  pos = buf_append(buf, size, pos, "|Framework: UNKNOWN");
+  pos = buf_append_printf(buf, size, pos, "|Framework: UNKNOWN");
 #endif
 
   ESP_LOGD(TAG, "ESP-IDF Version: %s", esp_get_idf_version());
-  pos = buf_append(buf, size, pos, "|ESP-IDF: %s", esp_get_idf_version());
+  pos = buf_append_printf(buf, size, pos, "|ESP-IDF: %s", esp_get_idf_version());
 
   uint8_t mac[6];
   get_mac_address_raw(mac);
   ESP_LOGD(TAG, "EFuse MAC: %02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
-  pos = buf_append(buf, size, pos, "|EFuse MAC: %02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3], mac[4],
-                   mac[5]);
+  pos = buf_append_printf(buf, size, pos, "|EFuse MAC: %02X:%02X:%02X:%02X:%02X:%02X", mac[0], mac[1], mac[2], mac[3],
+                          mac[4], mac[5]);
 
   char reason_buffer[RESET_REASON_BUFFER_SIZE];
   const char *reset_reason = get_reset_reason_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
-  pos = buf_append(buf, size, pos, "|Reset: %s", reset_reason);
+  pos = buf_append_printf(buf, size, pos, "|Reset: %s", reset_reason);
 
   const char *wakeup_cause = get_wakeup_cause_(std::span<char, RESET_REASON_BUFFER_SIZE>(reason_buffer));
-  pos = buf_append(buf, size, pos, "|Wakeup: %s", wakeup_cause);
+  pos = buf_append_printf(buf, size, pos, "|Wakeup: %s", wakeup_cause);
 
   return pos;
 }

esphome/components/debug/debug_esp8266.cpp

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

esphome/components/debug/debug_libretiny.cpp

@@ -36,12 +36,12 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
            lt_get_version(), lt_cpu_get_model_name(), lt_cpu_get_model(), lt_cpu_get_freq_mhz(), mac_id,
            lt_get_board_code(), flash_kib, ram_kib, reset_reason);
 
-  pos = buf_append(buf, size, pos, "|Version: %s", LT_BANNER_STR + 10);
-  pos = buf_append(buf, size, pos, "|Reset Reason: %s", reset_reason);
-  pos = buf_append(buf, size, pos, "|Chip Name: %s", lt_cpu_get_model_name());
-  pos = buf_append(buf, size, pos, "|Chip ID: 0x%06" PRIX32, mac_id);
-  pos = buf_append(buf, size, pos, "|Flash: %" PRIu32 " KiB", flash_kib);
-  pos = buf_append(buf, size, pos, "|RAM: %" PRIu32 " KiB", ram_kib);
+  pos = buf_append_printf(buf, size, pos, "|Version: %s", LT_BANNER_STR + 10);
+  pos = buf_append_printf(buf, size, pos, "|Reset Reason: %s", reset_reason);
+  pos = buf_append_printf(buf, size, pos, "|Chip Name: %s", lt_cpu_get_model_name());
+  pos = buf_append_printf(buf, size, pos, "|Chip ID: 0x%06" PRIX32, mac_id);
+  pos = buf_append_printf(buf, size, pos, "|Flash: %" PRIu32 " KiB", flash_kib);
+  pos = buf_append_printf(buf, size, pos, "|RAM: %" PRIu32 " KiB", ram_kib);
 
   return pos;
 }

esphome/components/debug/debug_rp2040.cpp

@@ -19,7 +19,7 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
 
   uint32_t cpu_freq = rp2040.f_cpu();
   ESP_LOGD(TAG, "CPU Frequency: %" PRIu32, cpu_freq);
-  pos = buf_append(buf, size, pos, "|CPU Frequency: %" PRIu32, cpu_freq);
+  pos = buf_append_printf(buf, size, pos, "|CPU Frequency: %" PRIu32, cpu_freq);
 
   return pos;
 }

esphome/components/debug/debug_zephyr.cpp

@@ -20,9 +20,9 @@ static size_t append_reset_reason(char *buf, size_t size, size_t pos, bool set,
     return pos;
   }
   if (pos > 0) {
-    pos = buf_append(buf, size, pos, ", ");
+    pos = buf_append_printf(buf, size, pos, ", ");
   }
-  return buf_append(buf, size, pos, "%s", reason);
+  return buf_append_printf(buf, size, pos, "%s", reason);
 }
 
 static inline uint32_t read_mem_u32(uintptr_t addr) {
@@ -140,7 +140,7 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
   const char *supply_status =
       (nrf_power_mainregstatus_get(NRF_POWER) == NRF_POWER_MAINREGSTATUS_NORMAL) ? "Normal voltage." : "High voltage.";
   ESP_LOGD(TAG, "Main supply status: %s", supply_status);
-  pos = buf_append(buf, size, pos, "|Main supply status: %s", supply_status);
+  pos = buf_append_printf(buf, size, pos, "|Main supply status: %s", supply_status);
 
   // Regulator stage 0
   if (nrf_power_mainregstatus_get(NRF_POWER) == NRF_POWER_MAINREGSTATUS_HIGH) {
@@ -172,16 +172,16 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
         reg0_voltage = "???V";
     }
     ESP_LOGD(TAG, "Regulator stage 0: %s, %s", reg0_type, reg0_voltage);
-    pos = buf_append(buf, size, pos, "|Regulator stage 0: %s, %s", reg0_type, reg0_voltage);
+    pos = buf_append_printf(buf, size, pos, "|Regulator stage 0: %s, %s", reg0_type, reg0_voltage);
   } else {
     ESP_LOGD(TAG, "Regulator stage 0: disabled");
-    pos = buf_append(buf, size, pos, "|Regulator stage 0: disabled");
+    pos = buf_append_printf(buf, size, pos, "|Regulator stage 0: disabled");
   }
 
   // Regulator stage 1
   const char *reg1_type = nrf_power_dcdcen_get(NRF_POWER) ? "DC/DC" : "LDO";
   ESP_LOGD(TAG, "Regulator stage 1: %s", reg1_type);
-  pos = buf_append(buf, size, pos, "|Regulator stage 1: %s", reg1_type);
+  pos = buf_append_printf(buf, size, pos, "|Regulator stage 1: %s", reg1_type);
 
   // USB power state
   const char *usb_state;
@@ -195,7 +195,7 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
     usb_state = "disconnected";
   }
   ESP_LOGD(TAG, "USB power state: %s", usb_state);
-  pos = buf_append(buf, size, pos, "|USB power state: %s", usb_state);
+  pos = buf_append_printf(buf, size, pos, "|USB power state: %s", usb_state);
 
   // Power-fail comparator
   bool enabled;
@@ -300,14 +300,14 @@ size_t DebugComponent::get_device_info_(std::span<char, DEVICE_INFO_BUFFER_SIZE>
           break;
       }
       ESP_LOGD(TAG, "Power-fail comparator: %s, VDDH: %s", pof_voltage, vddh_voltage);
-      pos = buf_append(buf, size, pos, "|Power-fail comparator: %s, VDDH: %s", pof_voltage, vddh_voltage);
+      pos = buf_append_printf(buf, size, pos, "|Power-fail comparator: %s, VDDH: %s", pof_voltage, vddh_voltage);
     } else {
       ESP_LOGD(TAG, "Power-fail comparator: %s", pof_voltage);
-      pos = buf_append(buf, size, pos, "|Power-fail comparator: %s", pof_voltage);
+      pos = buf_append_printf(buf, size, pos, "|Power-fail comparator: %s", pof_voltage);
     }
   } else {
     ESP_LOGD(TAG, "Power-fail comparator: disabled");
-    pos = buf_append(buf, size, pos, "|Power-fail comparator: disabled");
+    pos = buf_append_printf(buf, size, pos, "|Power-fail comparator: disabled");
   }
 
   auto package = [](uint32_t value) {

esphome/components/dfrobot_sen0395/commands.h

@@ -75,8 +75,8 @@ class SetLatencyCommand : public Command {
 class SensorCfgStartCommand : public Command {
  public:
   SensorCfgStartCommand(bool startup_mode) : startup_mode_(startup_mode) {
-    char tmp_cmd[20] = {0};
-    sprintf(tmp_cmd, "sensorCfgStart %d", startup_mode);
+    char tmp_cmd[20];  // "sensorCfgStart " (15) + "0/1" (1) + null = 17
+    buf_append_printf(tmp_cmd, sizeof(tmp_cmd), 0, "sensorCfgStart %d", startup_mode);
     cmd_ = std::string(tmp_cmd);
   }
   uint8_t on_message(std::string &message) override;
@@ -142,8 +142,8 @@ class SensitivityCommand : public Command {
   SensitivityCommand(uint8_t sensitivity) : sensitivity_(sensitivity) {
     if (sensitivity > 9)
       sensitivity_ = sensitivity = 9;
-    char tmp_cmd[20] = {0};
-    sprintf(tmp_cmd, "setSensitivity %d", sensitivity);
+    char tmp_cmd[20];  // "setSensitivity " (15) + "0-9" (1) + null = 17
+    buf_append_printf(tmp_cmd, sizeof(tmp_cmd), 0, "setSensitivity %d", sensitivity);
     cmd_ = std::string(tmp_cmd);
   };
   uint8_t on_message(std::string &message) override;

esphome/components/dsmr/__init__.py

@@ -25,29 +25,13 @@ dsmr_ns = cg.esphome_ns.namespace("esphome::dsmr")
 Dsmr = dsmr_ns.class_("Dsmr", cg.Component, uart.UARTDevice)
 
 
-def _validate_key(value):
-    value = cv.string_strict(value)
-    parts = [value[i : i + 2] for i in range(0, len(value), 2)]
-    if len(parts) != 16:
-        raise cv.Invalid("Decryption key must consist of 16 hexadecimal numbers")
-    parts_int = []
-    if any(len(part) != 2 for part in parts):
-        raise cv.Invalid("Decryption key must be format XX")
-    for part in parts:
-        try:
-            parts_int.append(int(part, 16))
-        except ValueError:
-            # pylint: disable=raise-missing-from
-            raise cv.Invalid("Decryption key must be hex values from 00 to FF")
-
-    return "".join(f"{part:02X}" for part in parts_int)
-
-
 CONFIG_SCHEMA = cv.All(
     cv.Schema(
         {
             cv.GenerateID(): cv.declare_id(Dsmr),
-            cv.Optional(CONF_DECRYPTION_KEY): _validate_key,
+            cv.Optional(CONF_DECRYPTION_KEY): lambda value: cv.bind_key(
+                value, name="Decryption key"
+            ),
             cv.Optional(CONF_CRC_CHECK, default=True): cv.boolean,
             cv.Optional(CONF_GAS_MBUS_ID, default=1): cv.int_,
             cv.Optional(CONF_WATER_MBUS_ID, default=2): cv.int_,

esphome/components/dsmr/dsmr.cpp

@@ -1,4 +1,5 @@
 #include "dsmr.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #include <AES.h>
@@ -294,8 +295,8 @@ void Dsmr::dump_config() {
   DSMR_TEXT_SENSOR_LIST(DSMR_LOG_TEXT_SENSOR, )
 }
 
-void Dsmr::set_decryption_key(const std::string &decryption_key) {
-  if (decryption_key.empty()) {
+void Dsmr::set_decryption_key(const char *decryption_key) {
+  if (decryption_key == nullptr || decryption_key[0] == '\0') {
     ESP_LOGI(TAG, "Disabling decryption");
     this->decryption_key_.clear();
     if (this->crypt_telegram_ != nullptr) {
@@ -305,21 +306,15 @@ void Dsmr::set_decryption_key(const std::string &decryption_key) {
     return;
   }
 
-  if (decryption_key.length() != 32) {
-    ESP_LOGE(TAG, "Error, decryption key must be 32 character long");
+  if (!parse_hex(decryption_key, this->decryption_key_, 16)) {
+    ESP_LOGE(TAG, "Error, decryption key must be 32 hex characters");
+    this->decryption_key_.clear();
     return;
   }
-  this->decryption_key_.clear();
 
   ESP_LOGI(TAG, "Decryption key is set");
   // Verbose level prints decryption key
-  ESP_LOGV(TAG, "Using decryption key: %s", decryption_key.c_str());
-
-  char temp[3] = {0};
-  for (int i = 0; i < 16; i++) {
-    strncpy(temp, &(decryption_key.c_str()[i * 2]), 2);
-    this->decryption_key_.push_back(std::strtoul(temp, nullptr, 16));
-  }
+  ESP_LOGV(TAG, "Using decryption key: %s", decryption_key);
 
   if (this->crypt_telegram_ == nullptr) {
     this->crypt_telegram_ = new uint8_t[this->max_telegram_len_];  // NOLINT

esphome/components/dsmr/dsmr.h

@@ -63,7 +63,7 @@ class Dsmr : public Component, public uart::UARTDevice {
 
   void dump_config() override;
 
-  void set_decryption_key(const std::string &decryption_key);
+  void set_decryption_key(const char *decryption_key);
   void set_max_telegram_length(size_t length) { this->max_telegram_len_ = length; }
   void set_request_pin(GPIOPin *request_pin) { this->request_pin_ = request_pin; }
   void set_request_interval(uint32_t interval) { this->request_interval_ = interval; }

esphome/components/esp32/__init__.py

@@ -34,6 +34,7 @@ from esphome.const import (
     KEY_CORE,
     KEY_FRAMEWORK_VERSION,
     KEY_NAME,
+    KEY_NATIVE_IDF,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_ESP32,
@@ -53,6 +54,7 @@ from .const import (  # noqa
     KEY_COMPONENTS,
     KEY_ESP32,
     KEY_EXTRA_BUILD_FILES,
+    KEY_FLASH_SIZE,
     KEY_PATH,
     KEY_REF,
     KEY_REPO,
@@ -199,6 +201,7 @@ def set_core_data(config):
     )
 
     CORE.data[KEY_ESP32][KEY_BOARD] = config[CONF_BOARD]
+    CORE.data[KEY_ESP32][KEY_FLASH_SIZE] = config[CONF_FLASH_SIZE]
     CORE.data[KEY_ESP32][KEY_VARIANT] = variant
     CORE.data[KEY_ESP32][KEY_EXTRA_BUILD_FILES] = {}
 
@@ -962,12 +965,54 @@ async def _add_yaml_idf_components(components: list[ConfigType]):
 
 
 async def to_code(config):
-    cg.add_platformio_option("board", config[CONF_BOARD])
-    cg.add_platformio_option("board_upload.flash_size", config[CONF_FLASH_SIZE])
-    cg.add_platformio_option(
-        "board_upload.maximum_size",
-        int(config[CONF_FLASH_SIZE].removesuffix("MB")) * 1024 * 1024,
-    )
+    framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
+    conf = config[CONF_FRAMEWORK]
+
+    # Check if using native ESP-IDF build (--native-idf)
+    use_platformio = not CORE.data.get(KEY_NATIVE_IDF, False)
+    if use_platformio:
+        # Clear IDF environment variables to avoid conflicts with PlatformIO's ESP-IDF
+        # but keep them when using --native-idf for native ESP-IDF builds
+        for clean_var in ("IDF_PATH", "IDF_TOOLS_PATH"):
+            os.environ.pop(clean_var, None)
+
+        cg.add_platformio_option("lib_ldf_mode", "off")
+        cg.add_platformio_option("lib_compat_mode", "strict")
+        cg.add_platformio_option("platform", conf[CONF_PLATFORM_VERSION])
+        cg.add_platformio_option("board", config[CONF_BOARD])
+        cg.add_platformio_option("board_upload.flash_size", config[CONF_FLASH_SIZE])
+        cg.add_platformio_option(
+            "board_upload.maximum_size",
+            int(config[CONF_FLASH_SIZE].removesuffix("MB")) * 1024 * 1024,
+        )
+
+        if CONF_SOURCE in conf:
+            cg.add_platformio_option("platform_packages", [conf[CONF_SOURCE]])
+
+        add_extra_script(
+            "pre",
+            "pre_build.py",
+            Path(__file__).parent / "pre_build.py.script",
+        )
+
+        add_extra_script(
+            "post",
+            "post_build.py",
+            Path(__file__).parent / "post_build.py.script",
+        )
+
+        # In testing mode, add IRAM fix script to allow linking grouped component tests
+        # Similar to ESP8266's approach but for ESP-IDF
+        if CORE.testing_mode:
+            cg.add_build_flag("-DESPHOME_TESTING_MODE")
+            add_extra_script(
+                "pre",
+                "iram_fix.py",
+                Path(__file__).parent / "iram_fix.py.script",
+            )
+    else:
+        cg.add_build_flag("-Wno-error=format")
+
     cg.set_cpp_standard("gnu++20")
     cg.add_build_flag("-DUSE_ESP32")
     cg.add_build_flag("-Wl,-z,noexecstack")
@@ -977,79 +1022,49 @@ async def to_code(config):
     cg.add_define("ESPHOME_VARIANT", VARIANT_FRIENDLY[variant])
     cg.add_define(ThreadModel.MULTI_ATOMICS)
 
-    cg.add_platformio_option("lib_ldf_mode", "off")
-    cg.add_platformio_option("lib_compat_mode", "strict")
-
-    framework_ver: cv.Version = CORE.data[KEY_CORE][KEY_FRAMEWORK_VERSION]
-
-    conf = config[CONF_FRAMEWORK]
-    cg.add_platformio_option("platform", conf[CONF_PLATFORM_VERSION])
-    if CONF_SOURCE in conf:
-        cg.add_platformio_option("platform_packages", [conf[CONF_SOURCE]])
-
     if conf[CONF_ADVANCED][CONF_IGNORE_EFUSE_CUSTOM_MAC]:
         cg.add_define("USE_ESP32_IGNORE_EFUSE_CUSTOM_MAC")
 
-    for clean_var in ("IDF_PATH", "IDF_TOOLS_PATH"):
-        os.environ.pop(clean_var, None)
-
     # Set the location of the IDF component manager cache
     os.environ["IDF_COMPONENT_CACHE_PATH"] = str(
         CORE.relative_internal_path(".espressif")
     )
 
-    add_extra_script(
-        "pre",
-        "pre_build.py",
-        Path(__file__).parent / "pre_build.py.script",
-    )
-
-    add_extra_script(
-        "post",
-        "post_build.py",
-        Path(__file__).parent / "post_build.py.script",
-    )
-
-    # In testing mode, add IRAM fix script to allow linking grouped component tests
-    # Similar to ESP8266's approach but for ESP-IDF
-    if CORE.testing_mode:
-        cg.add_build_flag("-DESPHOME_TESTING_MODE")
-        add_extra_script(
-            "pre",
-            "iram_fix.py",
-            Path(__file__).parent / "iram_fix.py.script",
-        )
-
     if conf[CONF_TYPE] == FRAMEWORK_ESP_IDF:
-        cg.add_platformio_option("framework", "espidf")
         cg.add_build_flag("-DUSE_ESP_IDF")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ESP_IDF")
+        if use_platformio:
+            cg.add_platformio_option("framework", "espidf")
     else:
-        cg.add_platformio_option("framework", "arduino, espidf")
         cg.add_build_flag("-DUSE_ARDUINO")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ARDUINO")
+        if use_platformio:
+            cg.add_platformio_option("framework", "arduino, espidf")
+
+            # Add IDF framework source for Arduino builds to ensure it uses the same version as
+            # the ESP-IDF framework
+            if (idf_ver := ARDUINO_IDF_VERSION_LOOKUP.get(framework_ver)) is not None:
+                cg.add_platformio_option(
+                    "platform_packages",
+                    [_format_framework_espidf_version(idf_ver, None)],
+                )
+
+            # ESP32-S2 Arduino: Disable USB Serial on boot to avoid TinyUSB dependency
+            if get_esp32_variant() == VARIANT_ESP32S2:
+                cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=1")
+                cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=0")
+                cg.add_build_flag("-DARDUINO_USB_CDC_ON_BOOT=0")
+
         cg.add_define(
             "USE_ARDUINO_VERSION_CODE",
             cg.RawExpression(
                 f"VERSION_CODE({framework_ver.major}, {framework_ver.minor}, {framework_ver.patch})"
             ),
         )
+
         add_idf_sdkconfig_option("CONFIG_MBEDTLS_PSK_MODES", True)
         add_idf_sdkconfig_option("CONFIG_MBEDTLS_CERTIFICATE_BUNDLE", True)
 
-        # Add IDF framework source for Arduino builds to ensure it uses the same version as
-        # the ESP-IDF framework
-        if (idf_ver := ARDUINO_IDF_VERSION_LOOKUP.get(framework_ver)) is not None:
-            cg.add_platformio_option(
-                "platform_packages", [_format_framework_espidf_version(idf_ver, None)]
-            )
-
-        # ESP32-S2 Arduino: Disable USB Serial on boot to avoid TinyUSB dependency
-        if get_esp32_variant() == VARIANT_ESP32S2:
-            cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=1")
-            cg.add_build_unflag("-DARDUINO_USB_CDC_ON_BOOT=0")
-            cg.add_build_flag("-DARDUINO_USB_CDC_ON_BOOT=0")
-
     cg.add_build_flag("-Wno-nonnull-compare")
 
     add_idf_sdkconfig_option(f"CONFIG_IDF_TARGET_{variant}", True)
@@ -1196,7 +1211,8 @@ async def to_code(config):
             "CONFIG_VFS_SUPPORT_DIR", not advanced[CONF_DISABLE_VFS_SUPPORT_DIR]
         )
 
-    cg.add_platformio_option("board_build.partitions", "partitions.csv")
+    if use_platformio:
+        cg.add_platformio_option("board_build.partitions", "partitions.csv")
     if CONF_PARTITIONS in config:
         add_extra_build_file(
             "partitions.csv", CORE.relative_config_path(config[CONF_PARTITIONS])
@@ -1361,19 +1377,16 @@ def copy_files():
     _write_idf_component_yml()
 
     if "partitions.csv" not in CORE.data[KEY_ESP32][KEY_EXTRA_BUILD_FILES]:
+        flash_size = CORE.data[KEY_ESP32][KEY_FLASH_SIZE]
         if CORE.using_arduino:
             write_file_if_changed(
                 CORE.relative_build_path("partitions.csv"),
-                get_arduino_partition_csv(
-                    CORE.platformio_options.get("board_upload.flash_size")
-                ),
+                get_arduino_partition_csv(flash_size),
             )
         else:
             write_file_if_changed(
                 CORE.relative_build_path("partitions.csv"),
-                get_idf_partition_csv(
-                    CORE.platformio_options.get("board_upload.flash_size")
-                ),
+                get_idf_partition_csv(flash_size),
             )
     # IDF build scripts look for version string to put in the build.
     # However, if the build path does not have an initialized git repo,

esphome/components/esp32/const.py

@@ -2,6 +2,7 @@ import esphome.codegen as cg
 
 KEY_ESP32 = "esp32"
 KEY_BOARD = "board"
+KEY_FLASH_SIZE = "flash_size"
 KEY_VARIANT = "variant"
 KEY_SDKCONFIG_OPTIONS = "sdkconfig_options"
 KEY_COMPONENTS = "components"

esphome/components/esp32/preferences.cpp

@@ -181,7 +181,8 @@ class ESP32Preferences : public ESPPreferences {
     if (actual_len != to_save.len) {
       return true;
     }
-    auto stored_data = std::make_unique<uint8_t[]>(actual_len);
+    // Most preferences are small, use stack buffer with heap fallback for large ones
+    SmallBufferWithHeapFallback<256> stored_data(actual_len);
     err = nvs_get_blob(nvs_handle, key_str, stored_data.get(), &actual_len);
     if (err != 0) {
       ESP_LOGV(TAG, "nvs_get_blob('%s') failed: %s", key_str, esp_err_to_name(err));

esphome/components/esp32_ble/ble_uuid.h

@@ -46,6 +46,8 @@ class ESPBTUUID {
 
   esp_bt_uuid_t get_uuid() const;
 
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use to_str() instead. Removed in 2026.8.0", "2026.2.0")
   std::string to_string() const;
   const char *to_str(std::span<char, UUID_STR_LEN> output) const;
 

esphome/components/esp32_ble_client/ble_client_base.cpp

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

esphome/components/esp32_ble_client/ble_client_base.h

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

esphome/components/esp32_ble_tracker/esp32_ble_tracker.cpp

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

esphome/components/esp32_ble_tracker/esp32_ble_tracker.h

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

esphome/components/event/__init__.py

@@ -90,9 +90,7 @@ async def setup_event_core_(var, config, *, event_types: list[str]):
 
     for conf in config.get(CONF_ON_EVENT, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(
-            trigger, [(cg.std_string, "event_type")], conf
-        )
+        await automation.build_automation(trigger, [(cg.StringRef, "event_type")], conf)
 
     cg.add(var.set_event_types(event_types))
 

esphome/components/event/automation.h

@@ -14,10 +14,10 @@ template<typename... Ts> class TriggerEventAction : public Action<Ts...>, public
   void play(const Ts &...x) override { this->parent_->trigger(this->event_type_.value(x...)); }
 };
 
-class EventTrigger : public Trigger<std::string> {
+class EventTrigger : public Trigger<StringRef> {
  public:
   EventTrigger(Event *event) {
-    event->add_on_event_callback([this](const std::string &event_type) { this->trigger(event_type); });
+    event->add_on_event_callback([this](StringRef event_type) { this->trigger(event_type); });
   }
 };
 

esphome/components/event/event.cpp

@@ -23,7 +23,7 @@ void Event::trigger(const std::string &event_type) {
   }
   this->last_event_type_ = found;
   ESP_LOGD(TAG, "'%s' >> '%s'", this->get_name().c_str(), this->last_event_type_);
-  this->event_callback_.call(event_type);
+  this->event_callback_.call(StringRef(found));
 #if defined(USE_EVENT) && defined(USE_CONTROLLER_REGISTRY)
   ControllerRegistry::notify_event(this);
 #endif
@@ -45,7 +45,7 @@ void Event::set_event_types(const std::vector<const char *> &event_types) {
   this->last_event_type_ = nullptr;  // Reset when types change
 }
 
-void Event::add_on_event_callback(std::function<void(const std::string &event_type)> &&callback) {
+void Event::add_on_event_callback(std::function<void(StringRef event_type)> &&callback) {
   this->event_callback_.add(std::move(callback));
 }
 

esphome/components/event/event.h

@@ -70,10 +70,10 @@ class Event : public EntityBase, public EntityBase_DeviceClass {
   /// Check if an event has been triggered.
   bool has_event() const { return this->last_event_type_ != nullptr; }
 
-  void add_on_event_callback(std::function<void(const std::string &event_type)> &&callback);
+  void add_on_event_callback(std::function<void(StringRef event_type)> &&callback);
 
  protected:
-  LazyCallbackManager<void(const std::string &event_type)> event_callback_;
+  LazyCallbackManager<void(StringRef event_type)> event_callback_;
   FixedVector<const char *> types_;
 
  private:

esphome/components/ezo_pmp/ezo_pmp.cpp

@@ -318,90 +318,93 @@ void EzoPMP::send_next_command_() {
   switch (this->next_command_) {
     // Read Commands
     case EZO_PMP_COMMAND_READ_DOSING:  // Page 54
-      command_buffer_length = sprintf((char *) command_buffer, "D,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "D,?");
       break;
 
     case EZO_PMP_COMMAND_READ_SINGLE_REPORT:  // Single Report (page 53)
-      command_buffer_length = sprintf((char *) command_buffer, "R");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "R");
       break;
 
     case EZO_PMP_COMMAND_READ_MAX_FLOW_RATE:
-      command_buffer_length = sprintf((char *) command_buffer, "DC,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "DC,?");
       break;
 
     case EZO_PMP_COMMAND_READ_PAUSE_STATUS:
-      command_buffer_length = sprintf((char *) command_buffer, "P,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "P,?");
       break;
 
     case EZO_PMP_COMMAND_READ_TOTAL_VOLUME_DOSED:
-      command_buffer_length = sprintf((char *) command_buffer, "TV,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "TV,?");
       break;
 
     case EZO_PMP_COMMAND_READ_ABSOLUTE_TOTAL_VOLUME_DOSED:
-      command_buffer_length = sprintf((char *) command_buffer, "ATV,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "ATV,?");
       break;
 
     case EZO_PMP_COMMAND_READ_CALIBRATION_STATUS:
-      command_buffer_length = sprintf((char *) command_buffer, "Cal,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Cal,?");
       break;
 
     case EZO_PMP_COMMAND_READ_PUMP_VOLTAGE:
-      command_buffer_length = sprintf((char *) command_buffer, "PV,?");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "PV,?");
       break;
 
       // Non-Read Commands
 
     case EZO_PMP_COMMAND_FIND:  // Find (page 52)
-      command_buffer_length = sprintf((char *) command_buffer, "Find");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Find");
       wait_time_for_command = 60000;  // This command will block all updates for a minute
       break;
 
     case EZO_PMP_COMMAND_DOSE_CONTINUOUSLY:  // Continuous Dispensing (page 54)
-      command_buffer_length = sprintf((char *) command_buffer, "D,*");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "D,*");
       break;
 
     case EZO_PMP_COMMAND_CLEAR_TOTAL_VOLUME_DOSED:  // Clear Total Volume Dosed (page 64)
-      command_buffer_length = sprintf((char *) command_buffer, "Clear");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Clear");
       break;
 
     case EZO_PMP_COMMAND_CLEAR_CALIBRATION:  // Clear Calibration (page 65)
-      command_buffer_length = sprintf((char *) command_buffer, "Cal,clear");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "Cal,clear");
       break;
 
     case EZO_PMP_COMMAND_PAUSE_DOSING:  // Pause (page 61)
-      command_buffer_length = sprintf((char *) command_buffer, "P");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "P");
       break;
 
     case EZO_PMP_COMMAND_STOP_DOSING:  // Stop (page 62)
-      command_buffer_length = sprintf((char *) command_buffer, "X");
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "X");
       break;
 
       // Non-Read commands with parameters
 
     case EZO_PMP_COMMAND_DOSE_VOLUME:  // Volume Dispensing (page 55)
-      command_buffer_length = sprintf((char *) command_buffer, "D,%0.1f", this->next_command_volume_);
+      command_buffer_length =
+          snprintf((char *) command_buffer, sizeof(command_buffer), "D,%0.1f", this->next_command_volume_);
       break;
 
     case EZO_PMP_COMMAND_DOSE_VOLUME_OVER_TIME:  // Dose over time (page 56)
-      command_buffer_length =
-          sprintf((char *) command_buffer, "D,%0.1f,%i", this->next_command_volume_, this->next_command_duration_);
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "D,%0.1f,%i",
+                                       this->next_command_volume_, this->next_command_duration_);
       break;
 
     case EZO_PMP_COMMAND_DOSE_WITH_CONSTANT_FLOW_RATE:  // Constant Flow Rate (page 57)
-      command_buffer_length =
-          sprintf((char *) command_buffer, "DC,%0.1f,%i", this->next_command_volume_, this->next_command_duration_);
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "DC,%0.1f,%i",
+                                       this->next_command_volume_, this->next_command_duration_);
       break;
 
     case EZO_PMP_COMMAND_SET_CALIBRATION_VOLUME:  // Set Calibration Volume (page 65)
-      command_buffer_length = sprintf((char *) command_buffer, "Cal,%0.2f", this->next_command_volume_);
+      command_buffer_length =
+          snprintf((char *) command_buffer, sizeof(command_buffer), "Cal,%0.2f", this->next_command_volume_);
       break;
 
     case EZO_PMP_COMMAND_CHANGE_I2C_ADDRESS:  // Change I2C Address (page 73)
-      command_buffer_length = sprintf((char *) command_buffer, "I2C,%i", this->next_command_duration_);
+      command_buffer_length =
+          snprintf((char *) command_buffer, sizeof(command_buffer), "I2C,%i", this->next_command_duration_);
       break;
 
     case EZO_PMP_COMMAND_EXEC_ARBITRARY_COMMAND_ADDRESS:  // Run an arbitrary command
-      command_buffer_length = sprintf((char *) command_buffer, this->arbitrary_command_, this->next_command_duration_);
+      command_buffer_length = snprintf((char *) command_buffer, sizeof(command_buffer), "%s", this->arbitrary_command_);
       ESP_LOGI(TAG, "Sending arbitrary command: %s", (char *) command_buffer);
       break;
 

esphome/components/fan/__init__.py

@@ -77,7 +77,7 @@ FanSpeedSetTrigger = fan_ns.class_(
     "FanSpeedSetTrigger", automation.Trigger.template(cg.int_)
 )
 FanPresetSetTrigger = fan_ns.class_(
-    "FanPresetSetTrigger", automation.Trigger.template(cg.std_string)
+    "FanPresetSetTrigger", automation.Trigger.template(cg.StringRef)
 )
 
 FanIsOnCondition = fan_ns.class_("FanIsOnCondition", automation.Condition.template())
@@ -287,7 +287,7 @@ async def setup_fan_core_(var, config):
         await automation.build_automation(trigger, [(cg.int_, "x")], conf)
     for conf in config.get(CONF_ON_PRESET_SET, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
+        await automation.build_automation(trigger, [(cg.StringRef, "x")], conf)
 
 
 async def register_fan(var, config):

esphome/components/fan/automation.h

@@ -208,7 +208,7 @@ class FanSpeedSetTrigger : public Trigger<int> {
   int last_speed_;
 };
 
-class FanPresetSetTrigger : public Trigger<std::string> {
+class FanPresetSetTrigger : public Trigger<StringRef> {
  public:
   FanPresetSetTrigger(Fan *state) {
     state->add_on_state_callback([this, state]() {
@@ -216,7 +216,7 @@ class FanPresetSetTrigger : public Trigger<std::string> {
       auto should_trigger = preset_mode != this->last_preset_mode_;
       this->last_preset_mode_ = preset_mode;
       if (should_trigger) {
-        this->trigger(std::string(preset_mode));
+        this->trigger(preset_mode);
       }
     });
     this->last_preset_mode_ = state->get_preset_mode();

esphome/components/json/__init__.py

@@ -1,6 +1,6 @@
 import esphome.codegen as cg
 import esphome.config_validation as cv
-from esphome.core import CoroPriority, coroutine_with_priority
+from esphome.core import CORE, CoroPriority, coroutine_with_priority
 
 CODEOWNERS = ["@esphome/core"]
 json_ns = cg.esphome_ns.namespace("json")
@@ -12,6 +12,11 @@ CONFIG_SCHEMA = cv.All(
 
 @coroutine_with_priority(CoroPriority.BUS)
 async def to_code(config):
-    cg.add_library("bblanchon/ArduinoJson", "7.4.2")
+    if CORE.is_esp32:
+        from esphome.components.esp32 import add_idf_component
+
+        add_idf_component(name="bblanchon/arduinojson", ref="7.4.2")
+    else:
+        cg.add_library("bblanchon/ArduinoJson", "7.4.2")
     cg.add_define("USE_JSON")
     cg.add_global(json_ns.using)

esphome/components/libretiny/__init__.py

@@ -382,4 +382,11 @@ async def component_to_code(config):
             "custom_options.sys_config#h", _BK7231N_SYS_CONFIG_OPTIONS
         )
 
+    # Disable LWIP statistics to save RAM - not needed in production
+    # Must explicitly disable all sub-stats to avoid redefinition warnings
+    cg.add_platformio_option(
+        "custom_options.lwip",
+        ["LWIP_STATS=0", "MEM_STATS=0", "MEMP_STATS=0"],
+    )
+
     await cg.register_component(var, config)

esphome/components/libretiny/preferences.cpp

@@ -166,8 +166,8 @@ class LibreTinyPreferences : public ESPPreferences {
       return true;
     }
 
-    // Allocate buffer on heap to avoid stack allocation for large data
-    auto stored_data = std::make_unique<uint8_t[]>(kv.value_len);
+    // Most preferences are small, use stack buffer with heap fallback for large ones
+    SmallBufferWithHeapFallback<256> stored_data(kv.value_len);
     fdb_blob_make(&this->blob, stored_data.get(), kv.value_len);
     size_t actual_len = fdb_kv_get_blob(db, key_str, &this->blob);
     if (actual_len != kv.value_len) {

esphome/components/lightwaverf/lightwaverf.cpp

@@ -1,3 +1,4 @@
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #ifdef USE_ESP8266
@@ -44,13 +45,16 @@ void LightWaveRF::send_rx(const std::vector<uint8_t> &msg, uint8_t repeats, bool
 }
 
 void LightWaveRF::print_msg_(uint8_t *msg, uint8_t len) {
-  char buffer[65];
+#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_DEBUG
+  char buffer[65];  // max 10 entries * 6 chars + null
   ESP_LOGD(TAG, " Received code (len:%i): ", len);
 
+  size_t pos = 0;
   for (int i = 0; i < len; i++) {
-    sprintf(&buffer[i * 6], "0x%02x, ", msg[i]);
+    pos = buf_append_printf(buffer, sizeof(buffer), pos, "0x%02x, ", msg[i]);
   }
   ESP_LOGD(TAG, "[%s]", buffer);
+#endif
 }
 
 void LightWaveRF::dump_config() {

esphome/components/lock/lock.cpp

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

esphome/components/lock/lock.h

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

esphome/components/logger/logger.cpp

@@ -1,8 +1,5 @@
 #include "logger.h"
 #include <cinttypes>
-#ifdef USE_ESPHOME_TASK_LOG_BUFFER
-#include <memory>  // For unique_ptr
-#endif
 
 #include "esphome/core/application.h"
 #include "esphome/core/hal.h"
@@ -199,7 +196,8 @@ inline uint8_t Logger::level_for(const char *tag) {
 
 Logger::Logger(uint32_t baud_rate, size_t tx_buffer_size) : baud_rate_(baud_rate), tx_buffer_size_(tx_buffer_size) {
   // add 1 to buffer size for null terminator
-  this->tx_buffer_ = new char[this->tx_buffer_size_ + 1];  // NOLINT
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->tx_buffer_ = new char[this->tx_buffer_size_ + 1];
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)
   this->main_task_ = xTaskGetCurrentTaskHandle();
 #elif defined(USE_ZEPHYR)
@@ -212,11 +210,14 @@ Logger::Logger(uint32_t baud_rate, size_t tx_buffer_size) : baud_rate_(baud_rate
 void Logger::init_log_buffer(size_t total_buffer_size) {
 #ifdef USE_HOST
   // Host uses slot count instead of byte size
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBufferHost>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBufferHost(total_buffer_size);
 #elif defined(USE_ESP32)
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBuffer>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBuffer(total_buffer_size);
 #elif defined(USE_LIBRETINY)
-  this->log_buffer_ = esphome::make_unique<logger::TaskLogBufferLibreTiny>(total_buffer_size);
+  // NOLINTNEXTLINE(cppcoreguidelines-owning-memory) - allocated once, never freed
+  this->log_buffer_ = new logger::TaskLogBufferLibreTiny(total_buffer_size);
 #endif
 
 #if defined(USE_ESP32) || defined(USE_LIBRETINY)

esphome/components/logger/logger.h

@@ -412,11 +412,11 @@ class Logger : public Component {
 #endif
 #ifdef USE_ESPHOME_TASK_LOG_BUFFER
 #ifdef USE_HOST
-  std::unique_ptr<logger::TaskLogBufferHost> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBufferHost *log_buffer_{nullptr};  // Allocated once, never freed
 #elif defined(USE_ESP32)
-  std::unique_ptr<logger::TaskLogBuffer> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBuffer *log_buffer_{nullptr};  // Allocated once, never freed
 #elif defined(USE_LIBRETINY)
-  std::unique_ptr<logger::TaskLogBufferLibreTiny> log_buffer_;  // Will be initialized with init_log_buffer
+  logger::TaskLogBufferLibreTiny *log_buffer_{nullptr};  // Allocated once, never freed
 #endif
 #endif
 

esphome/components/mapping/mapping.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
+#include <cinttypes>
 #include <map>
 #include <string>
 
@@ -43,8 +44,17 @@ template<typename K, typename V> class Mapping {
       esph_log_e(TAG, "Key '%p' not found in mapping", key);
     } else if constexpr (std::is_same_v<K, std::string>) {
       esph_log_e(TAG, "Key '%s' not found in mapping", key.c_str());
+    } else if constexpr (std::is_integral_v<K>) {
+      char buf[24];  // enough for 64-bit integer
+      if constexpr (std::is_unsigned_v<K>) {
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRIu64, static_cast<uint64_t>(key));
+      } else {
+        buf_append_printf(buf, sizeof(buf), 0, "%" PRId64, static_cast<int64_t>(key));
+      }
+      esph_log_e(TAG, "Key '%s' not found in mapping", buf);
     } else {
-      esph_log_e(TAG, "Key '%s' not found in mapping", to_string(key).c_str());
+      // All supported key types are handled above - this should never be reached
+      static_assert(sizeof(K) == 0, "Unsupported key type for Mapping error logging");
     }
     return {};
   }

esphome/components/mdns/mdns_esp32.cpp

@@ -24,13 +24,14 @@ static void register_esp32(MDNSComponent *comp, StaticVector<MDNSService, MDNS_S
   mdns_instance_name_set(hostname);
 
   for (const auto &service : services) {
-    auto txt_records = std::make_unique<mdns_txt_item_t[]>(service.txt_records.size());
+    // Stack buffer for up to 16 txt records, heap fallback for more
+    SmallBufferWithHeapFallback<16, mdns_txt_item_t> txt_records(service.txt_records.size());
     for (size_t i = 0; i < service.txt_records.size(); i++) {
       const auto &record = service.txt_records[i];
       // key and value are either compile-time string literals in flash or pointers to dynamic_txt_values_
       // Both remain valid for the lifetime of this function, and ESP-IDF makes internal copies
-      txt_records[i].key = MDNS_STR_ARG(record.key);
-      txt_records[i].value = MDNS_STR_ARG(record.value);
+      txt_records.get()[i].key = MDNS_STR_ARG(record.key);
+      txt_records.get()[i].value = MDNS_STR_ARG(record.value);
     }
     uint16_t port = const_cast<TemplatableValue<uint16_t> &>(service.port).value();
     err = mdns_service_add(nullptr, MDNS_STR_ARG(service.service_type), MDNS_STR_ARG(service.proto), port,

esphome/components/mipi_spi/mipi_spi.h

@@ -224,12 +224,9 @@ class MipiSpi : public display::Display,
                     this->madctl_ & MADCTL_BGR ? "BGR" : "RGB", DISPLAYPIXEL * 8, IS_BIG_ENDIAN ? "Big" : "Little");
     if (this->brightness_.has_value())
       esph_log_config(TAG, "  Brightness: %u", this->brightness_.value());
-    if (this->cs_ != nullptr)
-      esph_log_config(TAG, "  CS Pin: %s", this->cs_->dump_summary().c_str());
-    if (this->reset_pin_ != nullptr)
-      esph_log_config(TAG, "  Reset Pin: %s", this->reset_pin_->dump_summary().c_str());
-    if (this->dc_pin_ != nullptr)
-      esph_log_config(TAG, "  DC Pin: %s", this->dc_pin_->dump_summary().c_str());
+    log_pin(TAG, "  CS Pin: ", this->cs_);
+    log_pin(TAG, "  Reset Pin: ", this->reset_pin_);
+    log_pin(TAG, "  DC Pin: ", this->dc_pin_);
     esph_log_config(TAG,
                     "  SPI Mode: %d\n"
                     "  SPI Data rate: %dMHz\n"

esphome/components/mipi_spi/models/adafruit.py

@@ -26,5 +26,3 @@ ST7789V.extend(
     reset_pin=40,
     invert_colors=True,
 )
-
-models = {}

esphome/components/mipi_spi/models/amoled.py

@@ -105,6 +105,3 @@ CO5300 = DriverChip(
         (WCE, 0x00),
     ),
 )
-
-
-models = {}

esphome/components/mipi_spi/models/cyd.py

@@ -1,10 +1,45 @@
-from .ili import ILI9341
+from .ili import ILI9341, ILI9342, ST7789V
 
 ILI9341.extend(
+    # ESP32-2432S028 CYD board with Micro USB, has ILI9341 controller
     "ESP32-2432S028",
     data_rate="40MHz",
-    cs_pin=15,
-    dc_pin=2,
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
 )
 
-models = {}
+ST7789V.extend(
+    # ESP32-2432S028 CYD board with USB C + Micro USB, has ST7789V controller
+    "ESP32-2432S028-7789",
+    data_rate="40MHz",
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
+)
+
+# fmt: off
+
+ILI9342.extend(
+    # ESP32-2432S028 CYD board with USB C + Micro USB, has ILI9342 controller
+    "ESP32-2432S028-9342",
+    data_rate="40MHz",
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
+    initsequence=(
+        (0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02),  # Power Control A
+        (0xCF, 0x00, 0xC1, 0x30),  # Power Control B
+        (0xE8, 0x85, 0x00, 0x78),  # Driver timing control A
+        (0xEA, 0x00, 0x00),  # Driver timing control B
+        (0xED, 0x64, 0x03, 0x12, 0x81),  # Power on sequence control
+        (0xF7, 0x20),  # Pump ratio control
+        (0xC0, 0x23),  # Power Control 1
+        (0xC1, 0x10),  # Power Control 2
+        (0xC5, 0x3E, 0x28),  # VCOM Control 1
+        (0xC7, 0x86),  # VCOM Control 2
+        (0xB1, 0x00, 0x1B),  # Frame Rate Control
+        (0xB6, 0x0A, 0xA2, 0x27, 0x00),  # Display Function Control
+        (0xF2, 0x00),  # Enable 3G
+        (0x26, 0x01),  # Gamma Set
+        (0xE0, 0x00, 0x0C, 0x11, 0x04, 0x11, 0x08, 0x37, 0x89, 0x4C, 0x06, 0x0C, 0x0A, 0x2E, 0x34, 0x0F),  # Positive Gamma Correction
+        (0xE1, 0x00, 0x0B, 0x11, 0x05, 0x13, 0x09, 0x33, 0x67, 0x48, 0x07, 0x0E, 0x0B, 0x23, 0x33, 0x0F),  # Negative Gamma Correction
+    )
+)

esphome/components/mipi_spi/models/ili.py

@@ -148,6 +148,34 @@ ILI9341 = DriverChip(
         ),
     ),
 )
+
+# fmt: off
+
+ILI9342 = DriverChip(
+    "ILI9342",
+    width=320,
+    height=240,
+    mirror_x=True,
+    initsequence=(
+        (0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02),  # Power Control A
+        (0xCF, 0x00, 0xC1, 0x30),  # Power Control B
+        (0xE8, 0x85, 0x00, 0x78),  # Driver timing control A
+        (0xEA, 0x00, 0x00),  # Driver timing control B
+        (0xED, 0x64, 0x03, 0x12, 0x81),  # Power on sequence control
+        (0xF7, 0x20),  # Pump ratio control
+        (0xC0, 0x23),  # Power Control 1
+        (0xC1, 0x10),  # Power Control 2
+        (0xC5, 0x3E, 0x28),  # VCOM Control 1
+        (0xC7, 0x86),  # VCOM Control 2
+        (0xB1, 0x00, 0x1B),  # Frame Rate Control
+        (0xB6, 0x0A, 0xA2, 0x27, 0x00),  # Display Function Control
+        (0xF2, 0x00),  # Enable 3G
+        (0x26, 0x01),  # Gamma Set
+        (0xE0, 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98, 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x00),  # Positive Gamma
+        (0xE1, 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00),  # Negative Gamma
+    ),
+)
+
 # M5Stack Core2 uses ILI9341 chip - mirror_x disabled for correct orientation
 ILI9341.extend(
     "M5CORE2",
@@ -758,5 +786,3 @@ ST7796.extend(
     dc_pin=0,
     invert_colors=True,
 )
-
-models = {}

esphome/components/mipi_spi/models/jc.py

@@ -588,5 +588,3 @@ DriverChip(
         (0x29, 0x00),
     ),
 )
-
-models = {}

esphome/components/mipi_spi/models/lanbon.py

@@ -11,5 +11,3 @@ ST7789V.extend(
     dc_pin=21,
     reset_pin=18,
 )
-
-models = {}

esphome/components/mipi_spi/models/lilygo.py

@@ -56,5 +56,3 @@ ST7796.extend(
     backlight_pin=48,
     invert_colors=True,
 )
-
-models = {}

esphome/components/mqtt/mqtt_client.cpp

@@ -5,6 +5,7 @@
 #include <utility>
 #include "esphome/components/network/util.h"
 #include "esphome/core/application.h"
+#include "esphome/core/entity_base.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/version.h"
@@ -66,10 +67,13 @@ void MQTTClientComponent::setup() {
         "esphome/discover", [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); },
         2);
 
-    std::string topic = "esphome/ping/";
-    topic.append(App.get_name());
+    // Format topic on stack - subscribe() copies it
+    // "esphome/ping/" (13) + name (ESPHOME_DEVICE_NAME_MAX_LEN) + null (1)
+    constexpr size_t ping_topic_buffer_size = 13 + ESPHOME_DEVICE_NAME_MAX_LEN + 1;
+    char ping_topic[ping_topic_buffer_size];
+    buf_append_printf(ping_topic, sizeof(ping_topic), 0, "esphome/ping/%s", App.get_name().c_str());
     this->subscribe(
-        topic, [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); }, 2);
+        ping_topic, [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); }, 2);
   }
 
   if (this->enable_on_boot_) {
@@ -81,8 +85,11 @@ void MQTTClientComponent::send_device_info_() {
   if (!this->is_connected() or !this->is_discovery_ip_enabled()) {
     return;
   }
-  std::string topic = "esphome/discover/";
-  topic.append(App.get_name());
+  // Format topic on stack to avoid heap allocation
+  // "esphome/discover/" (17) + name (ESPHOME_DEVICE_NAME_MAX_LEN) + null (1)
+  constexpr size_t topic_buffer_size = 17 + ESPHOME_DEVICE_NAME_MAX_LEN + 1;
+  char topic[topic_buffer_size];
+  buf_append_printf(topic, sizeof(topic), 0, "esphome/discover/%s", App.get_name().c_str());
 
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   this->publish_json(
@@ -396,6 +403,12 @@ void MQTTClientComponent::loop() {
 
         this->last_connected_ = now;
         this->resubscribe_subscriptions_();
+
+        // Process pending resends for all MQTT components centrally
+        // This is more efficient than each component polling in its own loop
+        for (MQTTComponent *component : this->children_) {
+          component->process_resend();
+        }
       }
       break;
   }
@@ -500,39 +513,49 @@ bool MQTTClientComponent::publish(const std::string &topic, const std::string &p
 
 bool MQTTClientComponent::publish(const std::string &topic, const char *payload, size_t payload_length, uint8_t qos,
                                   bool retain) {
-  return publish({.topic = topic, .payload = std::string(payload, payload_length), .qos = qos, .retain = retain});
+  return this->publish(topic.c_str(), payload, payload_length, qos, retain);
 }
 
 bool MQTTClientComponent::publish(const MQTTMessage &message) {
+  return this->publish(message.topic.c_str(), message.payload.c_str(), message.payload.length(), message.qos,
+                       message.retain);
+}
+bool MQTTClientComponent::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos,
+                                       bool retain) {
+  return this->publish_json(topic.c_str(), f, qos, retain);
+}
+
+bool MQTTClientComponent::publish(const char *topic, const char *payload, size_t payload_length, uint8_t qos,
+                                  bool retain) {
   if (!this->is_connected()) {
-    // critical components will re-transmit their messages
     return false;
   }
-  bool logging_topic = this->log_message_.topic == message.topic;
-  bool ret = this->mqtt_backend_.publish(message);
+  size_t topic_len = strlen(topic);
+  bool logging_topic = (topic_len == this->log_message_.topic.size()) &&
+                       (memcmp(this->log_message_.topic.c_str(), topic, topic_len) == 0);
+  bool ret = this->mqtt_backend_.publish(topic, payload, payload_length, qos, retain);
   delay(0);
   if (!ret && !logging_topic && this->is_connected()) {
     delay(0);
-    ret = this->mqtt_backend_.publish(message);
+    ret = this->mqtt_backend_.publish(topic, payload, payload_length, qos, retain);
     delay(0);
   }
 
   if (!logging_topic) {
     if (ret) {
-      ESP_LOGV(TAG, "Publish(topic='%s' payload='%s' retain=%d qos=%d)", message.topic.c_str(), message.payload.c_str(),
-               message.retain, message.qos);
+      ESP_LOGV(TAG, "Publish(topic='%s' retain=%d qos=%d)", topic, retain, qos);
+      ESP_LOGVV(TAG, "Publish payload (len=%u): '%.*s'", payload_length, static_cast<int>(payload_length), payload);
     } else {
-      ESP_LOGV(TAG, "Publish failed for topic='%s' (len=%u). Will retry", message.topic.c_str(),
-               message.payload.length());
+      ESP_LOGV(TAG, "Publish failed for topic='%s' (len=%u). Will retry", topic, payload_length);
       this->status_momentary_warning("publish", 1000);
     }
   }
   return ret != 0;
 }
-bool MQTTClientComponent::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos,
-                                       bool retain) {
+
+bool MQTTClientComponent::publish_json(const char *topic, const json::json_build_t &f, uint8_t qos, bool retain) {
   std::string message = json::build_json(f);
-  return this->publish(topic, message, qos, retain);
+  return this->publish(topic, message.c_str(), message.length(), qos, retain);
 }
 
 void MQTTClientComponent::enable() {
@@ -610,18 +633,10 @@ static bool topic_match(const char *message, const char *subscription) {
 }
 
 void MQTTClientComponent::on_message(const std::string &topic, const std::string &payload) {
-#ifdef USE_ESP8266
-  // on ESP8266, this is called in lwIP/AsyncTCP task; some components do not like running
-  // from a different task.
-  this->defer([this, topic, payload]() {
-#endif
-    for (auto &subscription : this->subscriptions_) {
-      if (topic_match(topic.c_str(), subscription.topic.c_str()))
-        subscription.callback(topic, payload);
-    }
-#ifdef USE_ESP8266
-  });
-#endif
+  for (auto &subscription : this->subscriptions_) {
+    if (topic_match(topic.c_str(), subscription.topic.c_str()))
+      subscription.callback(topic, payload);
+  }
 }
 
 // Setters

esphome/components/mqtt/mqtt_client.h

@@ -229,6 +229,9 @@ class MQTTClientComponent : public Component
   bool publish(const std::string &topic, const char *payload, size_t payload_length, uint8_t qos = 0,
                bool retain = false);
 
+  /// Publish directly without creating MQTTMessage (avoids heap allocation for topic)
+  bool publish(const char *topic, const char *payload, size_t payload_length, uint8_t qos = 0, bool retain = false);
+
   /** Construct and send a JSON MQTT message.
    *
    * @param topic The topic.
@@ -237,6 +240,9 @@ class MQTTClientComponent : public Component
    */
   bool publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos = 0, bool retain = false);
 
+  /// Publish JSON directly without heap allocation for topic
+  bool publish_json(const char *topic, const json::json_build_t &f, uint8_t qos = 0, bool retain = false);
+
   /// Setup the MQTT client, registering a bunch of callbacks and attempting to connect.
   void setup() override;
   void dump_config() override;

esphome/components/mqtt/mqtt_component.cpp

@@ -308,16 +308,12 @@ void MQTTComponent::call_setup() {
   }
 }
 
-void MQTTComponent::call_loop() {
-  if (this->is_internal())
+void MQTTComponent::process_resend() {
+  // Called by MQTTClientComponent when connected to process pending resends
+  // Note: is_internal() check not needed - internal components are never registered
+  if (!this->resend_state_)
     return;
 
-  this->loop();
-
-  if (!this->resend_state_ || !this->is_connected_()) {
-    return;
-  }
-
   this->resend_state_ = false;
   if (this->is_discovery_enabled()) {
     if (!this->send_discovery_()) {

esphome/components/mqtt/mqtt_component.h

@@ -81,8 +81,6 @@ class MQTTComponent : public Component {
   /// Override setup_ so that we can call send_discovery() when needed.
   void call_setup() override;
 
-  void call_loop() override;
-
   void call_dump_config() override;
 
   /// Send discovery info the Home Assistant, override this.
@@ -133,6 +131,9 @@ class MQTTComponent : public Component {
   /// Internal method for the MQTT client base to schedule a resend of the state on reconnect.
   void schedule_resend_state();
 
+  /// Process pending resend if needed (called by MQTTClientComponent)
+  void process_resend();
+
   /** Send a MQTT message.
    *
    * @param topic The topic.

esphome/components/network/ip_address.h

@@ -60,6 +60,8 @@ struct IPAddress {
   }
   IPAddress(const std::string &in_address) { inet_aton(in_address.c_str(), &ip_addr_); }
   IPAddress(const ip_addr_t *other_ip) { ip_addr_ = *other_ip; }
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use str_to() instead. Removed in 2026.8.0", "2026.2.0")
   std::string str() const {
     char buf[IP_ADDRESS_BUFFER_SIZE];
     this->str_to(buf);
@@ -147,6 +149,8 @@ struct IPAddress {
   bool is_ip4() const { return IP_IS_V4(&ip_addr_); }
   bool is_ip6() const { return IP_IS_V6(&ip_addr_); }
   bool is_multicast() const { return ip_addr_ismulticast(&ip_addr_); }
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use str_to() instead. Removed in 2026.8.0", "2026.2.0")
   std::string str() const {
     char buf[IP_ADDRESS_BUFFER_SIZE];
     this->str_to(buf);

esphome/components/pipsolar/output/pipsolar_output.cpp

@@ -8,7 +8,7 @@ namespace pipsolar {
 static const char *const TAG = "pipsolar.output";
 
 void PipsolarOutput::write_state(float state) {
-  char tmp[10];
+  char tmp[16];
   snprintf(tmp, sizeof(tmp), this->set_command_, state);
 
   if (std::find(this->possible_values_.begin(), this->possible_values_.end(), state) != this->possible_values_.end()) {

esphome/components/prometheus/prometheus_handler.h

@@ -41,12 +41,14 @@ class PrometheusHandler : public AsyncWebHandler, public Component {
   void add_label_name(EntityBase *obj, const std::string &value) { relabel_map_name_.insert({obj, value}); }
 
   bool canHandle(AsyncWebServerRequest *request) const override {
-    if (request->method() == HTTP_GET) {
-      if (request->url() == "/metrics")
-        return true;
-    }
-
-    return false;
+    if (request->method() != HTTP_GET)
+      return false;
+#ifdef USE_ESP32
+    char url_buf[AsyncWebServerRequest::URL_BUF_SIZE];
+    return request->url_to(url_buf) == "/metrics";
+#else
+    return request->url() == ESPHOME_F("/metrics");
+#endif
   }
 
   void handleRequest(AsyncWebServerRequest *req) override;

esphome/components/rf_bridge/rf_bridge.cpp

@@ -1,6 +1,7 @@
 #include "rf_bridge.h"
-#include "esphome/core/log.h"
 #include "esphome/core/application.h"
+#include "esphome/core/helpers.h"
+#include "esphome/core/log.h"
 #include <cinttypes>
 #include <cstring>
 
@@ -72,9 +73,9 @@ bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
 
       data.length = raw[2];
       data.protocol = raw[3];
-      char next_byte[3];
+      char next_byte[3];  // 2 hex chars + null
       for (uint8_t i = 0; i < data.length - 1; i++) {
-        sprintf(next_byte, "%02X", raw[4 + i]);
+        buf_append_printf(next_byte, sizeof(next_byte), 0, "%02X", raw[4 + i]);
         data.code += next_byte;
       }
 
@@ -90,10 +91,10 @@ bool RFBridgeComponent::parse_bridge_byte_(uint8_t byte) {
 
       uint8_t buckets = raw[2] << 1;
       std::string str;
-      char next_byte[3];
+      char next_byte[3];  // 2 hex chars + null
 
       for (uint32_t i = 0; i <= at; i++) {
-        sprintf(next_byte, "%02X", raw[i]);
+        buf_append_printf(next_byte, sizeof(next_byte), 0, "%02X", raw[i]);
         str += next_byte;
         if ((i > 3) && buckets) {
           buckets--;

esphome/components/select/__init__.py

@@ -33,7 +33,7 @@ SelectPtr = Select.operator("ptr")
 # Triggers
 SelectStateTrigger = select_ns.class_(
     "SelectStateTrigger",
-    automation.Trigger.template(cg.std_string, cg.size_t),
+    automation.Trigger.template(cg.StringRef, cg.size_t),
 )
 
 # Actions
@@ -100,7 +100,7 @@ async def setup_select_core_(var, config, *, options: list[str]):
     for conf in config.get(CONF_ON_VALUE, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(
-            trigger, [(cg.std_string, "x"), (cg.size_t, "i")], conf
+            trigger, [(cg.StringRef, "x"), (cg.size_t, "i")], conf
         )
 
     if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:

esphome/components/select/automation.h

@@ -6,11 +6,11 @@
 
 namespace esphome::select {
 
-class SelectStateTrigger : public Trigger<std::string, size_t> {
+class SelectStateTrigger : public Trigger<StringRef, size_t> {
  public:
   explicit SelectStateTrigger(Select *parent) : parent_(parent) {
     parent->add_on_state_callback(
-        [this](size_t index) { this->trigger(std::string(this->parent_->option_at(index)), index); });
+        [this](size_t index) { this->trigger(StringRef(this->parent_->option_at(index)), index); });
   }
 
  protected:

esphome/components/sensor/__init__.py

@@ -9,6 +9,7 @@ from esphome.const import (
     CONF_ABOVE,
     CONF_ACCURACY_DECIMALS,
     CONF_ALPHA,
+    CONF_BASELINE,
     CONF_BELOW,
     CONF_CALIBRATION,
     CONF_DEVICE_CLASS,
@@ -38,7 +39,6 @@ from esphome.const import (
     CONF_TIMEOUT,
     CONF_TO,
     CONF_TRIGGER_ID,
-    CONF_TYPE,
     CONF_UNIT_OF_MEASUREMENT,
     CONF_VALUE,
     CONF_WEB_SERVER,
@@ -107,7 +107,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
 from esphome.core.entity_helpers import entity_duplicate_validator, setup_entity
-from esphome.cpp_generator import MockObjClass
+from esphome.cpp_generator import MockObj, MockObjClass
 from esphome.util import Registry
 
 CODEOWNERS = ["@esphome/core"]
@@ -574,38 +574,56 @@ async def lambda_filter_to_code(config, filter_id):
     return automation.new_lambda_pvariable(filter_id, lambda_, StatelessLambdaFilter)
 
 
-DELTA_SCHEMA = cv.Schema(
-    {
-        cv.Required(CONF_VALUE): cv.positive_float,
-        cv.Optional(CONF_TYPE, default="absolute"): cv.one_of(
-            "absolute", "percentage", lower=True
-        ),
-    }
+def validate_delta_value(value):
+    if isinstance(value, str) and value.endswith("%"):
+        # Check it's a well-formed percentage, but return the string as-is
+        try:
+            cv.positive_float(value[:-1])
+            return value
+        except cv.Invalid as exc:
+            raise cv.Invalid("Malformed delta % value") from exc
+    return cv.positive_float(value)
+
+
+# This ideally would be done with `cv.maybe_simple_value` but it doesn't seem to respect the default for min_value.
+DELTA_SCHEMA = cv.Any(
+    cv.All(
+        {
+            # Ideally this would be 'default=float("inf")' but it doesn't translate well to C++
+            cv.Optional(CONF_MAX_VALUE): validate_delta_value,
+            cv.Optional(CONF_MIN_VALUE, default="0.0"): validate_delta_value,
+            cv.Optional(CONF_BASELINE): cv.templatable(cv.float_),
+        },
+        cv.has_at_least_one_key(CONF_MAX_VALUE, CONF_MIN_VALUE),
+    ),
+    validate_delta_value,
 )
 
 
-def validate_delta(config):
-    try:
-        value = cv.positive_float(config)
-        return DELTA_SCHEMA({CONF_VALUE: value, CONF_TYPE: "absolute"})
-    except cv.Invalid:
-        pass
-    try:
-        value = cv.percentage(config)
-        return DELTA_SCHEMA({CONF_VALUE: value, CONF_TYPE: "percentage"})
-    except cv.Invalid:
-        pass
-    raise cv.Invalid("Delta filter requires a positive number or percentage value.")
+def _get_delta(value):
+    if isinstance(value, str):
+        assert value.endswith("%")
+        return 0.0, float(value[:-1])
+    return value, 0.0
 
 
-@FILTER_REGISTRY.register("delta", DeltaFilter, cv.Any(DELTA_SCHEMA, validate_delta))
+@FILTER_REGISTRY.register("delta", DeltaFilter, DELTA_SCHEMA)
 async def delta_filter_to_code(config, filter_id):
-    percentage = config[CONF_TYPE] == "percentage"
-    return cg.new_Pvariable(
-        filter_id,
-        config[CONF_VALUE],
-        percentage,
-    )
+    # The config could be just the min_value, or it could be a dict.
+    max = MockObj("std::numeric_limits<float>::infinity()"), 0
+    if isinstance(config, dict):
+        min = _get_delta(config[CONF_MIN_VALUE])
+        if CONF_MAX_VALUE in config:
+            max = _get_delta(config[CONF_MAX_VALUE])
+    else:
+        min = _get_delta(config)
+    var = cg.new_Pvariable(filter_id, *min, *max)
+    if isinstance(config, dict) and (baseline_lambda := config.get(CONF_BASELINE)):
+        baseline = await cg.process_lambda(
+            baseline_lambda, [(float, "x")], return_type=float
+        )
+        cg.add(var.set_baseline(baseline))
+    return var
 
 
 @FILTER_REGISTRY.register("or", OrFilter, validate_filters)

esphome/components/sensor/filter.cpp

@@ -291,22 +291,27 @@ optional<float> ThrottleWithPriorityFilter::new_value(float value) {
 }
 
 // DeltaFilter
-DeltaFilter::DeltaFilter(float delta, bool percentage_mode)
-    : delta_(delta), current_delta_(delta), last_value_(NAN), percentage_mode_(percentage_mode) {}
+DeltaFilter::DeltaFilter(float min_a0, float min_a1, float max_a0, float max_a1)
+    : min_a0_(min_a0), min_a1_(min_a1), max_a0_(max_a0), max_a1_(max_a1) {}
+
+void DeltaFilter::set_baseline(float (*fn)(float)) { this->baseline_ = fn; }
+
 optional<float> DeltaFilter::new_value(float value) {
-  if (std::isnan(value)) {
-    if (std::isnan(this->last_value_)) {
-      return {};
-    } else {
-      return this->last_value_ = value;
-    }
+  // Always yield the first value.
+  if (std::isnan(this->last_value_)) {
+    this->last_value_ = value;
+    return value;
   }
-  float diff = fabsf(value - this->last_value_);
-  if (std::isnan(this->last_value_) || (diff > 0.0f && diff >= this->current_delta_)) {
-    if (this->percentage_mode_) {
-      this->current_delta_ = fabsf(value * this->delta_);
-    }
-    return this->last_value_ = value;
+  // calculate min and max using the linear equation
+  float ref = this->baseline_(this->last_value_);
+  float min = fabsf(this->min_a0_ + ref * this->min_a1_);
+  float max = fabsf(this->max_a0_ + ref * this->max_a1_);
+  float delta = fabsf(value - ref);
+  // if there is no reference, e.g. for the first value, just accept this one,
+  // otherwise accept only if within range.
+  if (delta > min && delta <= max) {
+    this->last_value_ = value;
+    return value;
   }
   return {};
 }

esphome/components/sensor/filter.h

@@ -452,15 +452,21 @@ class HeartbeatFilter : public Filter, public Component {
 
 class DeltaFilter : public Filter {
  public:
-  explicit DeltaFilter(float delta, bool percentage_mode);
+  explicit DeltaFilter(float min_a0, float min_a1, float max_a0, float max_a1);
+
+  void set_baseline(float (*fn)(float));
 
   optional<float> new_value(float value) override;
 
  protected:
-  float delta_;
-  float current_delta_;
+  // These values represent linear equations for the min and max values but in practice only one of a0 and a1 will be
+  // non-zero Each limit is calculated as fabs(a0 + value * a1)
+
+  float min_a0_, min_a1_, max_a0_, max_a1_;
+  // default baseline is the previous value
+  float (*baseline_)(float) = [](float last_value) { return last_value; };
+
   float last_value_{NAN};
-  bool percentage_mode_;
 };
 
 class OrFilter : public Filter {

esphome/components/shtcx/shtcx.cpp

@@ -13,14 +13,14 @@ static const uint16_t SHTCX_COMMAND_READ_ID_REGISTER = 0xEFC8;
 static const uint16_t SHTCX_COMMAND_SOFT_RESET = 0x805D;
 static const uint16_t SHTCX_COMMAND_POLLING_H = 0x7866;
 
-inline const char *to_string(SHTCXType type) {
+static const LogString *shtcx_type_to_string(SHTCXType type) {
   switch (type) {
     case SHTCX_TYPE_SHTC3:
-      return "SHTC3";
+      return LOG_STR("SHTC3");
     case SHTCX_TYPE_SHTC1:
-      return "SHTC1";
+      return LOG_STR("SHTC1");
     default:
-      return "UNKNOWN";
+      return LOG_STR("UNKNOWN");
   }
 }
 
@@ -52,7 +52,7 @@ void SHTCXComponent::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "SHTCx:\n"
                 "  Model: %s (%04x)",
-                to_string(this->type_), this->sensor_id_);
+                LOG_STR_ARG(shtcx_type_to_string(this->type_)), this->sensor_id_);
   LOG_I2C_DEVICE(this);
   if (this->is_failed()) {
     ESP_LOGE(TAG, ESP_LOG_MSG_COMM_FAIL);

esphome/components/sim800l/sim800l.cpp

@@ -1,4 +1,5 @@
 #include "sim800l.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cstring>
 
@@ -50,8 +51,8 @@ void Sim800LComponent::update() {
   } else if (state_ == STATE_RECEIVED_SMS) {
     // Serial Buffer should have flushed.
     // Send cmd to delete received sms
-    char delete_cmd[20];
-    sprintf(delete_cmd, "AT+CMGD=%d", this->parse_index_);
+    char delete_cmd[20];  // "AT+CMGD=" (8) + uint8_t (max 3) + null = 12 <= 20
+    buf_append_printf(delete_cmd, sizeof(delete_cmd), 0, "AT+CMGD=%d", this->parse_index_);
     this->send_cmd_(delete_cmd);
     this->state_ = STATE_CHECK_SMS;
     this->expect_ack_ = true;

esphome/components/spi_led_strip/spi_led_strip.cpp

@@ -1,4 +1,5 @@
 #include "spi_led_strip.h"
+#include "esphome/core/helpers.h"
 
 namespace esphome {
 namespace spi_led_strip {
@@ -47,15 +48,14 @@ void SpiLedStrip::dump_config() {
 void SpiLedStrip::write_state(light::LightState *state) {
   if (this->is_failed())
     return;
-  if (ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE) {
-    char strbuf[49];
-    size_t len = std::min(this->buffer_size_, (size_t) (sizeof(strbuf) - 1) / 3);
-    memset(strbuf, 0, sizeof(strbuf));
-    for (size_t i = 0; i != len; i++) {
-      sprintf(strbuf + i * 3, "%02X ", this->buf_[i]);
-    }
+#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
+  {
+    char strbuf[49];  // format_hex_pretty_size(16) = 48, fits 16 bytes
+    size_t len = std::min(this->buffer_size_, (size_t) 16);
+    format_hex_pretty_to(strbuf, sizeof(strbuf), this->buf_, len, ' ');
     esph_log_v(TAG, "write_state: buf = %s", strbuf);
   }
+#endif
   this->enable();
   this->write_array(this->buf_, this->buffer_size_);
   this->disable();

esphome/components/sprinkler/sprinkler.cpp

@@ -43,13 +43,11 @@ SprinklerControllerSwitch::SprinklerControllerSwitch()
     : turn_on_trigger_(new Trigger<>()), turn_off_trigger_(new Trigger<>()) {}
 
 void SprinklerControllerSwitch::loop() {
-  if (!this->f_.has_value())
-    return;
+  // Loop is only enabled when f_ has a value (see setup())
   auto s = (*this->f_)();
-  if (!s.has_value())
-    return;
-
-  this->publish_state(*s);
+  if (s.has_value()) {
+    this->publish_state(*s);
+  }
 }
 
 void SprinklerControllerSwitch::write_state(bool state) {
@@ -74,7 +72,13 @@ float SprinklerControllerSwitch::get_setup_priority() const { return setup_prior
 Trigger<> *SprinklerControllerSwitch::get_turn_on_trigger() const { return this->turn_on_trigger_; }
 Trigger<> *SprinklerControllerSwitch::get_turn_off_trigger() const { return this->turn_off_trigger_; }
 
-void SprinklerControllerSwitch::setup() { this->state = this->get_initial_state_with_restore_mode().value_or(false); }
+void SprinklerControllerSwitch::setup() {
+  this->state = this->get_initial_state_with_restore_mode().value_or(false);
+  // Disable loop if no state lambda is set - nothing to poll
+  if (!this->f_.has_value()) {
+    this->disable_loop();
+  }
+}
 
 void SprinklerControllerSwitch::dump_config() { LOG_SWITCH("", "Sprinkler Switch", this); }
 
@@ -327,25 +331,32 @@ SprinklerValveOperator *SprinklerValveRunRequest::valve_operator() { return this
 
 SprinklerValveRunRequestOrigin SprinklerValveRunRequest::request_is_from() { return this->origin_; }
 
-Sprinkler::Sprinkler() {}
-Sprinkler::Sprinkler(const std::string &name) {
-  // The `name` is needed to set timers up, hence non-default constructor
-  // replaces `set_name()` method previously existed
-  this->name_ = name;
+Sprinkler::Sprinkler() : Sprinkler("") {}
+Sprinkler::Sprinkler(const char *name) : name_(name) {
+  // The `name` is stored for dump_config logging
   this->timer_.init(2);
-  this->timer_.push_back({this->name_ + "sm", false, 0, 0, std::bind(&Sprinkler::sm_timer_callback_, this)});
-  this->timer_.push_back({this->name_ + "vs", false, 0, 0, std::bind(&Sprinkler::valve_selection_callback_, this)});
+  // Timer names only need to be unique within this component instance
+  this->timer_.push_back({"sm", false, 0, 0, std::bind(&Sprinkler::sm_timer_callback_, this)});
+  this->timer_.push_back({"vs", false, 0, 0, std::bind(&Sprinkler::valve_selection_callback_, this)});
 }
 
-void Sprinkler::setup() { this->all_valves_off_(true); }
+void Sprinkler::setup() {
+  this->all_valves_off_(true);
+  // Start with loop disabled - nothing to do when idle
+  this->disable_loop();
+}
 
 void Sprinkler::loop() {
   for (auto &vo : this->valve_op_) {
     vo.loop();
   }
-  if (this->prev_req_.has_request() && this->prev_req_.has_valve_operator() &&
-      this->prev_req_.valve_operator()->state() == IDLE) {
-    this->prev_req_.reset();
+  if (this->prev_req_.has_request()) {
+    if (this->prev_req_.has_valve_operator() && this->prev_req_.valve_operator()->state() == IDLE) {
+      this->prev_req_.reset();
+    }
+  } else if (this->state_ == IDLE) {
+    // Nothing more to do - disable loop until next activation
+    this->disable_loop();
   }
 }
 
@@ -1333,6 +1344,8 @@ void Sprinkler::start_valve_(SprinklerValveRunRequest *req) {
   if (!this->is_a_valid_valve(req->valve())) {
     return;  // we can't do anything if the valve number isn't valid
   }
+  // Enable loop to monitor valve operator states
+  this->enable_loop();
   for (auto &vo : this->valve_op_) {  // find the first available SprinklerValveOperator, load it and start it up
     if (vo.state() == IDLE) {
       auto run_duration = req->run_duration() ? req->run_duration() : this->valve_run_duration_adjusted(req->valve());
@@ -1575,8 +1588,7 @@ const LogString *Sprinkler::state_as_str_(SprinklerState state) {
 
 void Sprinkler::start_timer_(const SprinklerTimerIndex timer_index) {
   if (this->timer_duration_(timer_index) > 0) {
-    // FixedVector ensures timer_ can't be resized, so .c_str() pointers remain valid
-    this->set_timeout(this->timer_[timer_index].name.c_str(), this->timer_duration_(timer_index),
+    this->set_timeout(this->timer_[timer_index].name, this->timer_duration_(timer_index),
                       this->timer_cbf_(timer_index));
     this->timer_[timer_index].start_time = millis();
     this->timer_[timer_index].active = true;
@@ -1587,7 +1599,7 @@ void Sprinkler::start_timer_(const SprinklerTimerIndex timer_index) {
 
 bool Sprinkler::cancel_timer_(const SprinklerTimerIndex timer_index) {
   this->timer_[timer_index].active = false;
-  return this->cancel_timeout(this->timer_[timer_index].name.c_str());
+  return this->cancel_timeout(this->timer_[timer_index].name);
 }
 
 bool Sprinkler::timer_active_(const SprinklerTimerIndex timer_index) { return this->timer_[timer_index].active; }
@@ -1618,7 +1630,7 @@ void Sprinkler::sm_timer_callback_() {
 }
 
 void Sprinkler::dump_config() {
-  ESP_LOGCONFIG(TAG, "Sprinkler Controller -- %s", this->name_.c_str());
+  ESP_LOGCONFIG(TAG, "Sprinkler Controller -- %s", this->name_);
   if (this->manual_selection_delay_.has_value()) {
     ESP_LOGCONFIG(TAG, "  Manual Selection Delay: %" PRIu32 " seconds", this->manual_selection_delay_.value_or(0));
   }

esphome/components/sprinkler/sprinkler.h

@@ -11,7 +11,7 @@
 
 namespace esphome::sprinkler {
 
-const std::string MIN_STR = "min";
+inline constexpr const char *MIN_STR = "min";
 
 enum SprinklerState : uint8_t {
   // NOTE: these states are used by both SprinklerValveOperator and Sprinkler (the controller)!
@@ -49,7 +49,7 @@ struct SprinklerQueueItem {
 };
 
 struct SprinklerTimer {
-  const std::string name;
+  const char *name;
   bool active;
   uint32_t time;
   uint32_t start_time;
@@ -176,7 +176,7 @@ class SprinklerValveRunRequest {
 class Sprinkler : public Component {
  public:
   Sprinkler();
-  Sprinkler(const std::string &name);
+  Sprinkler(const char *name);
   void setup() override;
   void loop() override;
   void dump_config() override;
@@ -504,7 +504,7 @@ class Sprinkler : public Component {
   uint32_t start_delay_{0};
   uint32_t stop_delay_{0};
 
-  std::string name_;
+  const char *name_{""};
 
   /// Sprinkler controller state
   SprinklerState state_{IDLE};

esphome/components/statsd/statsd.cpp

@@ -114,14 +114,22 @@ void StatsdComponent::update() {
     // This implies you can't explicitly set a gauge to a negative number without first setting it to zero.
     if (val < 0) {
       if (this->prefix_) {
-        out.append(str_sprintf("%s.", this->prefix_));
+        out.append(this->prefix_);
+        out.append(".");
       }
-      out.append(str_sprintf("%s:0|g\n", s.name));
+      out.append(s.name);
+      out.append(":0|g\n");
     }
     if (this->prefix_) {
-      out.append(str_sprintf("%s.", this->prefix_));
+      out.append(this->prefix_);
+      out.append(".");
     }
-    out.append(str_sprintf("%s:%f|g\n", s.name, val));
+    out.append(s.name);
+    // Buffer for ":" + value + "|g\n".
+    // %f with -DBL_MAX can produce up to 321 chars, plus ":" and "|g\n" (4) + null = 326
+    char val_buf[330];
+    buf_append_printf(val_buf, sizeof(val_buf), 0, ":%f|g\n", val);
+    out.append(val_buf);
 
     if (out.length() > SEND_THRESHOLD) {
       this->send_(&out);

esphome/components/template/select/__init__.py

@@ -88,5 +88,5 @@ async def to_code(config):
 
     if CONF_SET_ACTION in config:
         await automation.build_automation(
-            var.get_set_trigger(), [(cg.std_string, "x")], config[CONF_SET_ACTION]
+            var.get_set_trigger(), [(cg.StringRef, "x")], config[CONF_SET_ACTION]
         )

esphome/components/template/select/template_select.cpp

@@ -41,7 +41,7 @@ void TemplateSelect::update() {
 }
 
 void TemplateSelect::control(size_t index) {
-  this->set_trigger_->trigger(std::string(this->option_at(index)));
+  this->set_trigger_->trigger(StringRef(this->option_at(index)));
 
   if (this->optimistic_)
     this->publish_state(index);

esphome/components/template/select/template_select.h

@@ -4,6 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/string_ref.h"
 #include "esphome/core/template_lambda.h"
 
 namespace esphome::template_ {
@@ -17,7 +18,7 @@ class TemplateSelect final : public select::Select, public PollingComponent {
   void dump_config() override;
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
-  Trigger<std::string> *get_set_trigger() const { return this->set_trigger_; }
+  Trigger<StringRef> *get_set_trigger() const { return this->set_trigger_; }
   void set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
   void set_initial_option_index(size_t initial_option_index) { this->initial_option_index_ = initial_option_index; }
   void set_restore_value(bool restore_value) { this->restore_value_ = restore_value; }
@@ -27,7 +28,7 @@ class TemplateSelect final : public select::Select, public PollingComponent {
   bool optimistic_ = false;
   size_t initial_option_index_{0};
   bool restore_value_ = false;
-  Trigger<std::string> *set_trigger_ = new Trigger<std::string>();
+  Trigger<StringRef> *set_trigger_ = new Trigger<StringRef>();
   TemplateLambda<std::string> f_;
 
   ESPPreferenceObject pref_;

esphome/components/voice_assistant/voice_assistant.h

@@ -81,6 +81,8 @@ struct Timer {
              this->id.c_str(), this->name.c_str(), this->total_seconds, this->seconds_left, YESNO(this->is_active));
     return buffer.data();
   }
+  // Remove before 2026.8.0
+  ESPDEPRECATED("Use to_str() instead. Removed in 2026.8.0", "2026.2.0")
   std::string to_string() const {
     char buffer[TO_STR_BUFFER_SIZE];
     return this->to_str(buffer);

esphome/components/web_server/ota/ota_web_server.cpp

@@ -32,8 +32,15 @@ class OTARequestHandler : public AsyncWebHandler {
   void handleUpload(AsyncWebServerRequest *request, const PlatformString &filename, size_t index, uint8_t *data,
                     size_t len, bool final) override;
   bool canHandle(AsyncWebServerRequest *request) const override {
-    // Check if this is an OTA update request
-    bool is_ota_request = request->url() == "/update" && request->method() == HTTP_POST;
+    if (request->method() != HTTP_POST)
+      return false;
+      // Check if this is an OTA update request
+#ifdef USE_ESP32
+    char url_buf[AsyncWebServerRequest::URL_BUF_SIZE];
+    bool is_ota_request = request->url_to(url_buf) == "/update";
+#else
+    bool is_ota_request = request->url() == ESPHOME_F("/update");
+#endif
 
 #if defined(USE_WEBSERVER_OTA_DISABLED) && defined(USE_CAPTIVE_PORTAL)
     // IMPORTANT: USE_WEBSERVER_OTA_DISABLED only disables OTA for the web_server component

esphome/components/web_server/web_server.cpp

@@ -2175,7 +2175,12 @@ std::string WebServer::update_json_(update::UpdateEntity *obj, JsonDetail start_
 #endif
 
 bool WebServer::canHandle(AsyncWebServerRequest *request) const {
+#ifdef USE_ESP32
+  char url_buf[AsyncWebServerRequest::URL_BUF_SIZE];
+  StringRef url = request->url_to(url_buf);
+#else
   const auto &url = request->url();
+#endif
   const auto method = request->method();
 
   // Static URL checks - use ESPHOME_F to keep strings in flash on ESP8266
@@ -2311,30 +2316,35 @@ bool WebServer::canHandle(AsyncWebServerRequest *request) const {
   return false;
 }
 void WebServer::handleRequest(AsyncWebServerRequest *request) {
+#ifdef USE_ESP32
+  char url_buf[AsyncWebServerRequest::URL_BUF_SIZE];
+  StringRef url = request->url_to(url_buf);
+#else
   const auto &url = request->url();
+#endif
 
   // Handle static routes first
-  if (url == "/") {
+  if (url == ESPHOME_F("/")) {
     this->handle_index_request(request);
     return;
   }
 
 #if !defined(USE_ESP32) && defined(USE_ARDUINO)
-  if (url == "/events") {
+  if (url == ESPHOME_F("/events")) {
     this->events_.add_new_client(this, request);
     return;
   }
 #endif
 
 #ifdef USE_WEBSERVER_CSS_INCLUDE
-  if (url == "/0.css") {
+  if (url == ESPHOME_F("/0.css")) {
     this->handle_css_request(request);
     return;
   }
 #endif
 
 #ifdef USE_WEBSERVER_JS_INCLUDE
-  if (url == "/0.js") {
+  if (url == ESPHOME_F("/0.js")) {
     this->handle_js_request(request);
     return;
   }

esphome/components/web_server_idf/web_server_idf.cpp

@@ -246,21 +246,16 @@ optional<std::string> AsyncWebServerRequest::get_header(const char *name) const
   return request_get_header(*this, name);
 }
 
-std::string AsyncWebServerRequest::url() const {
-  auto *query_start = strchr(this->req_->uri, '?');
-  std::string result;
-  if (query_start == nullptr) {
-    result = this->req_->uri;
-  } else {
-    result = std::string(this->req_->uri, query_start - this->req_->uri);
-  }
+StringRef AsyncWebServerRequest::url_to(std::span<char, URL_BUF_SIZE> buffer) const {
+  const char *uri = this->req_->uri;
+  const char *query_start = strchr(uri, '?');
+  size_t uri_len = query_start ? static_cast<size_t>(query_start - uri) : strlen(uri);
+  size_t copy_len = std::min(uri_len, URL_BUF_SIZE - 1);
+  memcpy(buffer.data(), uri, copy_len);
+  buffer[copy_len] = '\0';
   // Decode URL-encoded characters in-place (e.g., %20 -> space)
-  // This matches AsyncWebServer behavior on Arduino
-  if (!result.empty()) {
-    size_t new_len = url_decode(&result[0]);
-    result.resize(new_len);
-  }
-  return result;
+  size_t decoded_len = url_decode(buffer.data());
+  return StringRef(buffer.data(), decoded_len);
 }
 
 std::string AsyncWebServerRequest::host() const { return this->get_header("Host").value(); }
@@ -487,7 +482,7 @@ void AsyncEventSource::deferrable_send_state(void *source, const char *event_typ
 AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *request,
                                                    esphome::web_server_idf::AsyncEventSource *server,
                                                    esphome::web_server::WebServer *ws)
-    : server_(server), web_server_(ws), entities_iterator_(new esphome::web_server::ListEntitiesIterator(ws, server)) {
+    : server_(server), web_server_(ws), entities_iterator_(ws, server) {
   httpd_req_t *req = *request;
 
   httpd_resp_set_status(req, HTTPD_200);
@@ -531,12 +526,12 @@ AsyncEventSourceResponse::AsyncEventSourceResponse(const AsyncWebServerRequest *
   }
 #endif
 
-  this->entities_iterator_->begin(ws->include_internal_);
+  this->entities_iterator_.begin(ws->include_internal_);
 
   // just dump them all up-front and take advantage of the deferred queue
   //     on second thought that takes too long, but leaving the commented code here for debug purposes
-  // while(!this->entities_iterator_->completed()) {
-  //  this->entities_iterator_->advance();
+  // while(!this->entities_iterator_.completed()) {
+  //  this->entities_iterator_.advance();
   //}
 }
 
@@ -634,8 +629,8 @@ void AsyncEventSourceResponse::process_buffer_() {
 void AsyncEventSourceResponse::loop() {
   process_buffer_();
   process_deferred_queue_();
-  if (!this->entities_iterator_->completed())
-    this->entities_iterator_->advance();
+  if (!this->entities_iterator_.completed())
+    this->entities_iterator_.advance();
 }
 
 bool AsyncEventSourceResponse::try_send_nodefer(const char *message, const char *event, uint32_t id,
@@ -781,7 +776,7 @@ void AsyncEventSourceResponse::deferrable_send_state(void *source, const char *e
                                                      message_generator_t *message_generator) {
   // allow all json "details_all" to go through before publishing bare state events, this avoids unnamed entries showing
   // up in the web GUI and reduces event load during initial connect
-  if (!entities_iterator_->completed() && 0 != strcmp(event_type, "state_detail_all"))
+  if (!this->entities_iterator_.completed() && 0 != strcmp(event_type, "state_detail_all"))
     return;
 
   if (source == nullptr)

esphome/components/web_server_idf/web_server_idf.h

@@ -3,21 +3,26 @@
 
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
+#include "esphome/core/string_ref.h"
 #include <esp_http_server.h>
 
 #include <atomic>
 #include <functional>
 #include <list>
 #include <map>
+#include <span>
 #include <string>
 #include <utility>
 #include <vector>
 
+#ifdef USE_WEBSERVER
+#include "esphome/components/web_server/list_entities.h"
+#endif
+
 namespace esphome {
 #ifdef USE_WEBSERVER
 namespace web_server {
 class WebServer;
-class ListEntitiesIterator;
 };  // namespace web_server
 #endif
 namespace web_server_idf {
@@ -107,7 +112,15 @@ class AsyncWebServerRequest {
   ~AsyncWebServerRequest();
 
   http_method method() const { return static_cast<http_method>(this->req_->method); }
-  std::string url() const;
+  static constexpr size_t URL_BUF_SIZE = CONFIG_HTTPD_MAX_URI_LEN + 1;  ///< Buffer size for url_to()
+  /// Write URL (without query string) to buffer, returns StringRef pointing to buffer.
+  /// URL is decoded (e.g., %20 -> space).
+  StringRef url_to(std::span<char, URL_BUF_SIZE> buffer) const;
+  /// Get URL as std::string. Prefer url_to() to avoid heap allocation.
+  std::string url() const {
+    char buffer[URL_BUF_SIZE];
+    return std::string(this->url_to(buffer));
+  }
   std::string host() const;
   // NOLINTNEXTLINE(readability-identifier-naming)
   size_t contentLength() const { return this->req_->content_len; }
@@ -284,7 +297,7 @@ class AsyncEventSourceResponse {
   std::atomic<int> fd_{};
   std::vector<DeferredEvent> deferred_queue_;
   esphome::web_server::WebServer *web_server_;
-  std::unique_ptr<esphome::web_server::ListEntitiesIterator> entities_iterator_;
+  esphome::web_server::ListEntitiesIterator entities_iterator_;
   std::string event_buffer_{""};
   size_t event_bytes_sent_;
   uint16_t consecutive_send_failures_{0};
@@ -303,7 +316,10 @@ class AsyncEventSource : public AsyncWebHandler {
 
   // NOLINTNEXTLINE(readability-identifier-naming)
   bool canHandle(AsyncWebServerRequest *request) const override {
-    return request->method() == HTTP_GET && request->url() == this->url_;
+    if (request->method() != HTTP_GET)
+      return false;
+    char url_buf[AsyncWebServerRequest::URL_BUF_SIZE];
+    return request->url_to(url_buf) == this->url_;
   }
   // NOLINTNEXTLINE(readability-identifier-naming)
   void handleRequest(AsyncWebServerRequest *request) override;

esphome/components/wifi/wifi_component_esp8266.cpp

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

esphome/components/wifi/wifi_component_esp_idf.cpp

@@ -827,16 +827,17 @@ void WiFiComponent::wifi_process_event_(IDFWiFiEvent *data) {
     }
 
     uint16_t number = it.number;
-    auto records = std::make_unique<wifi_ap_record_t[]>(number);
-    err = esp_wifi_scan_get_ap_records(&number, records.get());
-    if (err != ESP_OK) {
-      ESP_LOGW(TAG, "esp_wifi_scan_get_ap_records failed: %s", esp_err_to_name(err));
-      return;
-    }
-
     scan_result_.init(number);
-    for (int i = 0; i < number; i++) {
-      auto &record = records[i];
+
+    // Process one record at a time to avoid large buffer allocation
+    wifi_ap_record_t record;
+    for (uint16_t i = 0; i < number; i++) {
+      err = esp_wifi_scan_get_ap_record(&record);
+      if (err != ESP_OK) {
+        ESP_LOGW(TAG, "esp_wifi_scan_get_ap_record failed: %s", esp_err_to_name(err));
+        esp_wifi_clear_ap_list();  // Free remaining records not yet retrieved
+        break;
+      }
       bssid_t bssid;
       std::copy(record.bssid, record.bssid + 6, bssid.begin());
       std::string ssid(reinterpret_cast<const char *>(record.ssid));

esphome/components/wifi_info/text_sensor.py

@@ -79,13 +79,17 @@ async def setup_conf(config, key):
 
 async def to_code(config):
     # Request specific WiFi listeners based on which sensors are configured
+    # Each sensor needs its own listener slot - call request for EACH sensor
+
     # SSID and BSSID use WiFiConnectStateListener
-    if CONF_SSID in config or CONF_BSSID in config:
-        wifi.request_wifi_connect_state_listener()
+    for key in (CONF_SSID, CONF_BSSID):
+        if key in config:
+            wifi.request_wifi_connect_state_listener()
 
     # IP address and DNS use WiFiIPStateListener
-    if CONF_IP_ADDRESS in config or CONF_DNS_ADDRESS in config:
-        wifi.request_wifi_ip_state_listener()
+    for key in (CONF_IP_ADDRESS, CONF_DNS_ADDRESS):
+        if key in config:
+            wifi.request_wifi_ip_state_listener()
 
     # Scan results use WiFiScanResultsListener
     if CONF_SCAN_RESULTS in config:

esphome/components/wl_134/wl_134.cpp

@@ -1,4 +1,5 @@
 #include "wl_134.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #include <cinttypes>
@@ -78,8 +79,8 @@ Wl134Component::Rfid134Error Wl134Component::read_packet_() {
            reading.id, reading.country, reading.isData ? "true" : "false", reading.isAnimal ? "true" : "false",
            reading.reserved0, reading.reserved1);
 
-  char buf[20];
-  sprintf(buf, "%03d%012lld", reading.country, reading.id);
+  char buf[20];  // "%03d" (3) + "%012" PRId64 (12) + null = 16 max
+  buf_append_printf(buf, sizeof(buf), 0, "%03d%012" PRId64, reading.country, reading.id);
   this->publish_state(buf);
   if (this->do_reset_) {
     this->set_timeout(1000, [this]() { this->publish_state(""); });

esphome/components/x9c/x9c.cpp

@@ -6,7 +6,7 @@ namespace x9c {
 
 static const char *const TAG = "x9c.output";
 
-void X9cOutput::trim_value(int change_amount) {
+void X9cOutput::trim_value(int32_t change_amount) {
   if (change_amount == 0) {
     return;
   }
@@ -47,17 +47,17 @@ void X9cOutput::setup() {
 
   if (this->initial_value_ <= 0.50) {
     this->trim_value(-101);  // Set min value (beyond 0)
-    this->trim_value(static_cast<uint32_t>(roundf(this->initial_value_ * 100)));
+    this->trim_value(lroundf(this->initial_value_ * 100));
   } else {
     this->trim_value(101);  // Set max value (beyond 100)
-    this->trim_value(static_cast<uint32_t>(roundf(this->initial_value_ * 100) - 100));
+    this->trim_value(lroundf(this->initial_value_ * 100) - 100);
   }
   this->pot_value_ = this->initial_value_;
   this->write_state(this->initial_value_);
 }
 
 void X9cOutput::write_state(float state) {
-  this->trim_value(static_cast<uint32_t>(roundf((state - this->pot_value_) * 100)));
+  this->trim_value(lroundf((state - this->pot_value_) * 100));
   this->pot_value_ = state;
 }
 

esphome/components/x9c/x9c.h

@@ -18,7 +18,7 @@ class X9cOutput : public output::FloatOutput, public Component {
   void setup() override;
   void dump_config() override;
 
-  void trim_value(int change_amount);
+  void trim_value(int32_t change_amount);
 
  protected:
   void write_state(float state) override;

esphome/config_validation.py

@@ -1046,20 +1046,20 @@ def mac_address(value):
     return core.MACAddress(*parts_int)
 
 
-def bind_key(value):
+def bind_key(value, *, name="Bind key"):
     value = string_strict(value)
     parts = [value[i : i + 2] for i in range(0, len(value), 2)]
     if len(parts) != 16:
-        raise Invalid("Bind key must consist of 16 hexadecimal numbers")
+        raise Invalid(f"{name} must consist of 16 hexadecimal numbers")
     parts_int = []
     if any(len(part) != 2 for part in parts):
-        raise Invalid("Bind key must be format XX")
+        raise Invalid(f"{name} must be format XX")
     for part in parts:
         try:
             parts_int.append(int(part, 16))
         except ValueError:
             # pylint: disable=raise-missing-from
-            raise Invalid("Bind key must be hex values from 00 to FF")
+            raise Invalid(f"{name} must be hex values from 00 to FF")
 
     return "".join(f"{part:02X}" for part in parts_int)
 

esphome/const.py

@@ -1379,6 +1379,7 @@ KEY_FRAMEWORK_VERSION = "framework_version"
 KEY_NAME = "name"
 KEY_VARIANT = "variant"
 KEY_PAST_SAFE_MODE = "past_safe_mode"
+KEY_NATIVE_IDF = "native_idf"
 
 # Entity categories
 ENTITY_CATEGORY_NONE = ""

esphome/core/__init__.py

@@ -17,6 +17,7 @@ from esphome.const import (
     CONF_WEB_SERVER,
     CONF_WIFI,
     KEY_CORE,
+    KEY_NATIVE_IDF,
     KEY_TARGET_FRAMEWORK,
     KEY_TARGET_PLATFORM,
     PLATFORM_BK72XX,
@@ -763,6 +764,9 @@ class EsphomeCore:
 
     @property
     def firmware_bin(self) -> Path:
+        # Check if using native ESP-IDF build (--native-idf)
+        if self.data.get(KEY_NATIVE_IDF, False):
+            return self.relative_build_path("build", f"{self.name}.bin")
         if self.is_libretiny:
             return self.relative_pioenvs_path(self.name, "firmware.uf2")
         return self.relative_pioenvs_path(self.name, "firmware.bin")

esphome/core/component.cpp

@@ -47,18 +47,21 @@ struct ComponentPriorityOverride {
 };
 
 // Error messages for failed components
+// Using raw pointer instead of unique_ptr to avoid global constructor/destructor overhead
+// This is never freed as error messages persist for the lifetime of the device
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-std::unique_ptr<std::vector<ComponentErrorMessage>> component_error_messages;
+std::vector<ComponentErrorMessage> *component_error_messages = nullptr;
 // Setup priority overrides - freed after setup completes
+// Using raw pointer instead of unique_ptr to avoid global constructor/destructor overhead
 // NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
-std::unique_ptr<std::vector<ComponentPriorityOverride>> setup_priority_overrides;
+std::vector<ComponentPriorityOverride> *setup_priority_overrides = nullptr;
 
 // Helper to store error messages - reduces duplication between deprecated and new API
 // Remove before 2026.6.0 when deprecated const char* API is removed
 void store_component_error_message(const Component *component, const char *message, bool is_flash_ptr) {
   // Lazy allocate the error messages vector if needed
   if (!component_error_messages) {
-    component_error_messages = std::make_unique<std::vector<ComponentErrorMessage>>();
+    component_error_messages = new std::vector<ComponentErrorMessage>();
   }
   // Check if this component already has an error message
   for (auto &entry : *component_error_messages) {
@@ -467,7 +470,7 @@ float Component::get_actual_setup_priority() const {
 void Component::set_setup_priority(float priority) {
   // Lazy allocate the vector if needed
   if (!setup_priority_overrides) {
-    setup_priority_overrides = std::make_unique<std::vector<ComponentPriorityOverride>>();
+    setup_priority_overrides = new std::vector<ComponentPriorityOverride>();
     // Reserve some space to avoid reallocations (most configs have < 10 overrides)
     setup_priority_overrides->reserve(10);
   }
@@ -553,7 +556,8 @@ WarnIfComponentBlockingGuard::~WarnIfComponentBlockingGuard() {}
 
 void clear_setup_priority_overrides() {
   // Free the setup priority map completely
-  setup_priority_overrides.reset();
+  delete setup_priority_overrides;
+  setup_priority_overrides = nullptr;
 }
 
 }  // namespace esphome