From 8dd1aec60672f26d1ec2a2d16a576752bde14e64 Mon Sep 17 00:00:00 2001
From: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>
Date: Wed, 21 Jan 2026 17:17:11 -0500
Subject: [PATCH 1/9] [esp32] Add warning for experimental 400MHz on ESP32-P4
 (#13433)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
---
 esphome/components/esp32/__init__.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/esphome/components/esp32/__init__.py b/esphome/components/esp32/__init__.py
index 07446ab046..e23a70a373 100644
--- a/esphome/components/esp32/__init__.py
+++ b/esphome/components/esp32/__init__.py
@@ -182,6 +182,12 @@ def set_core_data(config):
             path=[CONF_CPU_FREQUENCY],
         )
 
+    if variant == VARIANT_ESP32P4 and cpu_frequency == "400MHZ":
+        _LOGGER.warning(
+            "400MHz on ESP32-P4 is experimental and may not boot. "
+            "Consider using 360MHz instead. See https://github.com/esphome/esphome/issues/13425"
+        )
+
     CORE.data[KEY_ESP32] = {}
     CORE.data[KEY_CORE][KEY_TARGET_PLATFORM] = PLATFORM_ESP32
     conf = config[CONF_FRAMEWORK]

From ebf589560d88844dfd0c2bb56376124d18fba59e Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 21 Jan 2026 14:03:49 -1000
Subject: [PATCH 2/9] [wifi] Fix bk72xx manual_ip preventing API connection
 (#13426)

---
 esphome/components/wifi/wifi_component_libretiny.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/esphome/components/wifi/wifi_component_libretiny.cpp b/esphome/components/wifi/wifi_component_libretiny.cpp
index 162ed4e835..cc9f4ec193 100644
--- a/esphome/components/wifi/wifi_component_libretiny.cpp
+++ b/esphome/components/wifi/wifi_component_libretiny.cpp
@@ -460,13 +460,15 @@ void WiFiComponent::wifi_process_event_(LTWiFiEvent *event) {
         listener->on_wifi_connect_state(StringRef(it.ssid, it.ssid_len), it.bssid);
       }
 #endif
-      // For static IP configurations, GOT_IP event may not fire, so notify IP listeners here
-#if defined(USE_WIFI_IP_STATE_LISTENERS) && defined(USE_WIFI_MANUAL_IP)
+      // For static IP configurations, GOT_IP event may not fire, so set connected state here
+#ifdef USE_WIFI_MANUAL_IP
       if (const WiFiAP *config = this->get_selected_sta_(); config && config->get_manual_ip().has_value()) {
         s_sta_state = LTWiFiSTAState::CONNECTED;
+#ifdef USE_WIFI_IP_STATE_LISTENERS
         for (auto *listener : this->ip_state_listeners_) {
           listener->on_ip_state(this->wifi_sta_ip_addresses(), this->get_dns_address(0), this->get_dns_address(1));
         }
+#endif
       }
 #endif
       break;

From ce5ec7a78f3cc5be9871e8dd09c6b8c042d289d8 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 21 Jan 2026 14:04:07 -1000
Subject: [PATCH 3/9] [spi] Fix display init failure by marking displays as
 write-only for half-duplex mode (#13431)

---
 esphome/components/epaper_spi/display.py       | 2 +-
 esphome/components/ili9xxx/display.py          | 2 +-
 esphome/components/max7219/display.py          | 2 +-
 esphome/components/max7219digit/display.py     | 2 +-
 esphome/components/mipi_rgb/display.py         | 2 +-
 esphome/components/mipi_spi/display.py         | 4 +---
 esphome/components/pcd8544/display.py          | 2 +-
 esphome/components/qspi_dbi/display.py         | 2 +-
 esphome/components/spi/__init__.py             | 7 ++++++-
 esphome/components/spi/spi_esp_idf.cpp         | 5 ++++-
 esphome/components/ssd1306_spi/display.py      | 2 +-
 esphome/components/ssd1322_spi/display.py      | 2 +-
 esphome/components/ssd1325_spi/display.py      | 2 +-
 esphome/components/ssd1327_spi/display.py      | 2 +-
 esphome/components/ssd1331_spi/display.py      | 2 +-
 esphome/components/ssd1351_spi/display.py      | 2 +-
 esphome/components/st7567_spi/display.py       | 2 +-
 esphome/components/st7701s/display.py          | 2 +-
 esphome/components/st7735/display.py           | 2 +-
 esphome/components/st7789v/display.py          | 2 +-
 esphome/components/st7920/display.py           | 2 +-
 esphome/components/waveshare_epaper/display.py | 2 +-
 22 files changed, 30 insertions(+), 24 deletions(-)

diff --git a/esphome/components/epaper_spi/display.py b/esphome/components/epaper_spi/display.py
index a77e291237..8cc7b2663c 100644
--- a/esphome/components/epaper_spi/display.py
+++ b/esphome/components/epaper_spi/display.py
@@ -190,7 +190,7 @@ async def to_code(config):
     # Rotation is handled by setting the transform
     display_config = {k: v for k, v in config.items() if k != CONF_ROTATION}
     await display.register_display(var, display_config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ili9xxx/display.py b/esphome/components/ili9xxx/display.py
index 9588bccd55..bfb2300f4f 100644
--- a/esphome/components/ili9xxx/display.py
+++ b/esphome/components/ili9xxx/display.py
@@ -223,7 +223,7 @@ async def to_code(config):
     var = cg.Pvariable(config[CONF_ID], rhs)
 
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
     if init_sequences := config.get(CONF_INIT_SEQUENCE):
diff --git a/esphome/components/max7219/display.py b/esphome/components/max7219/display.py
index c9d10f3c45..a434125148 100644
--- a/esphome/components/max7219/display.py
+++ b/esphome/components/max7219/display.py
@@ -29,7 +29,7 @@ CONFIG_SCHEMA = (
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
     await display.register_display(var, config)
 
     cg.add(var.set_num_chips(config[CONF_NUM_CHIPS]))
diff --git a/esphome/components/max7219digit/display.py b/esphome/components/max7219digit/display.py
index fef121ff10..e6d53efc5d 100644
--- a/esphome/components/max7219digit/display.py
+++ b/esphome/components/max7219digit/display.py
@@ -86,7 +86,7 @@ CONFIG_SCHEMA = (
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
     await display.register_display(var, config)
 
     cg.add(var.set_num_chips(config[CONF_NUM_CHIPS]))
diff --git a/esphome/components/mipi_rgb/display.py b/esphome/components/mipi_rgb/display.py
index 96e167b2e6..084fe6de14 100644
--- a/esphome/components/mipi_rgb/display.py
+++ b/esphome/components/mipi_rgb/display.py
@@ -260,7 +260,7 @@ async def to_code(config):
         cg.add(var.set_enable_pins(enable))
 
     if CONF_SPI_ID in config:
-        await spi.register_spi_device(var, config)
+        await spi.register_spi_device(var, config, write_only=True)
         sequence, madctl = model.get_sequence(config)
         cg.add(var.set_init_sequence(sequence))
         cg.add(var.set_madctl(madctl))
diff --git a/esphome/components/mipi_spi/display.py b/esphome/components/mipi_spi/display.py
index 69bf133c68..8dccfa3a92 100644
--- a/esphome/components/mipi_spi/display.py
+++ b/esphome/components/mipi_spi/display.py
@@ -443,6 +443,4 @@ async def to_code(config):
         )
         cg.add(var.set_writer(lambda_))
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
-    # Displays are write-only, set the SPI device to write-only as well
-    cg.add(var.set_write_only(True))
+    await spi.register_spi_device(var, config, write_only=True)
diff --git a/esphome/components/pcd8544/display.py b/esphome/components/pcd8544/display.py
index 2c24b133da..9d993c2105 100644
--- a/esphome/components/pcd8544/display.py
+++ b/esphome/components/pcd8544/display.py
@@ -44,7 +44,7 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
 
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/qspi_dbi/display.py b/esphome/components/qspi_dbi/display.py
index e4440c9b81..48d1f6d12e 100644
--- a/esphome/components/qspi_dbi/display.py
+++ b/esphome/components/qspi_dbi/display.py
@@ -161,7 +161,7 @@ CONFIG_SCHEMA = cv.All(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     chip = DriverChip.chips[config[CONF_MODEL]]
     if chip.initsequence:
diff --git a/esphome/components/spi/__init__.py b/esphome/components/spi/__init__.py
index e890567abf..931882be8d 100644
--- a/esphome/components/spi/__init__.py
+++ b/esphome/components/spi/__init__.py
@@ -39,6 +39,7 @@ from esphome.const import (
 )
 from esphome.core import CORE, CoroPriority, coroutine_with_priority
 import esphome.final_validate as fv
+from esphome.types import ConfigType
 
 CODEOWNERS = ["@esphome/core", "@clydebarrow"]
 spi_ns = cg.esphome_ns.namespace("spi")
@@ -448,9 +449,13 @@ def spi_device_schema(
     )
 
 
-async def register_spi_device(var, config):
+async def register_spi_device(
+    var: cg.Pvariable, config: ConfigType, write_only: bool = False
+) -> None:
     parent = await cg.get_variable(config[CONF_SPI_ID])
     cg.add(var.set_spi_parent(parent))
+    if write_only:
+        cg.add(var.set_write_only(True))
     if cs_pin := config.get(CONF_CS_PIN):
         pin = await cg.gpio_pin_expression(cs_pin)
         cg.add(var.set_cs_pin(pin))
diff --git a/esphome/components/spi/spi_esp_idf.cpp b/esphome/components/spi/spi_esp_idf.cpp
index a1837fa58d..107b6a3f1a 100644
--- a/esphome/components/spi/spi_esp_idf.cpp
+++ b/esphome/components/spi/spi_esp_idf.cpp
@@ -195,8 +195,11 @@ class SPIDelegateHw : public SPIDelegate {
     config.post_cb = nullptr;
     if (this->bit_order_ == BIT_ORDER_LSB_FIRST)
       config.flags |= SPI_DEVICE_BIT_LSBFIRST;
-    if (this->write_only_)
+    if (this->write_only_) {
       config.flags |= SPI_DEVICE_HALFDUPLEX | SPI_DEVICE_NO_DUMMY;
+      ESP_LOGD(TAG, "SPI device with CS pin %d using half-duplex mode (write-only)",
+               Utility::get_pin_no(this->cs_pin_));
+    }
     esp_err_t const err = spi_bus_add_device(this->channel_, &config, &this->handle_);
     if (err != ESP_OK) {
       ESP_LOGE(TAG, "Add device failed - err %X", err);
diff --git a/esphome/components/ssd1306_spi/display.py b/esphome/components/ssd1306_spi/display.py
index 4af41073d4..26953b4f39 100644
--- a/esphome/components/ssd1306_spi/display.py
+++ b/esphome/components/ssd1306_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1306_base.setup_ssd1306(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1322_spi/display.py b/esphome/components/ssd1322_spi/display.py
index 849e71abee..3d01caf874 100644
--- a/esphome/components/ssd1322_spi/display.py
+++ b/esphome/components/ssd1322_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1322_base.setup_ssd1322(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1325_spi/display.py b/esphome/components/ssd1325_spi/display.py
index e18db33c68..dbb9a14ac2 100644
--- a/esphome/components/ssd1325_spi/display.py
+++ b/esphome/components/ssd1325_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1325_base.setup_ssd1325(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1327_spi/display.py b/esphome/components/ssd1327_spi/display.py
index b622c098ec..f052764a91 100644
--- a/esphome/components/ssd1327_spi/display.py
+++ b/esphome/components/ssd1327_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1327_base.setup_ssd1327(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1331_spi/display.py b/esphome/components/ssd1331_spi/display.py
index 50895b3175..c16780302f 100644
--- a/esphome/components/ssd1331_spi/display.py
+++ b/esphome/components/ssd1331_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1331_base.setup_ssd1331(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/ssd1351_spi/display.py b/esphome/components/ssd1351_spi/display.py
index bd7033c3d4..2a6e984029 100644
--- a/esphome/components/ssd1351_spi/display.py
+++ b/esphome/components/ssd1351_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await ssd1351_base.setup_ssd1351(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/st7567_spi/display.py b/esphome/components/st7567_spi/display.py
index 305aa35024..02cd2c105c 100644
--- a/esphome/components/st7567_spi/display.py
+++ b/esphome/components/st7567_spi/display.py
@@ -32,7 +32,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await st7567_base.setup_st7567(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/st7701s/display.py b/esphome/components/st7701s/display.py
index 3078158d25..a8b12dfa28 100644
--- a/esphome/components/st7701s/display.py
+++ b/esphome/components/st7701s/display.py
@@ -173,7 +173,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     sequence = []
     for seq in config[CONF_INIT_SEQUENCE]:
diff --git a/esphome/components/st7735/display.py b/esphome/components/st7735/display.py
index 2761214315..9dc69f27ff 100644
--- a/esphome/components/st7735/display.py
+++ b/esphome/components/st7735/display.py
@@ -99,7 +99,7 @@ async def to_code(config):
         config[CONF_INVERT_COLORS],
     )
     await setup_st7735(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))
diff --git a/esphome/components/st7789v/display.py b/esphome/components/st7789v/display.py
index 8259eacf2d..c9f4199616 100644
--- a/esphome/components/st7789v/display.py
+++ b/esphome/components/st7789v/display.py
@@ -177,7 +177,7 @@ FINAL_VALIDATE_SCHEMA = spi.final_validate_device_schema(
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     cg.add(var.set_model_str(config[CONF_MODEL]))
 
diff --git a/esphome/components/st7920/display.py b/esphome/components/st7920/display.py
index de7b2247dd..ef33fac6c6 100644
--- a/esphome/components/st7920/display.py
+++ b/esphome/components/st7920/display.py
@@ -28,7 +28,7 @@ CONFIG_SCHEMA = (
 
 async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     if CONF_LAMBDA in config:
         lambda_ = await cg.process_lambda(
diff --git a/esphome/components/waveshare_epaper/display.py b/esphome/components/waveshare_epaper/display.py
index cea0b2be5e..5db7a1fc3d 100644
--- a/esphome/components/waveshare_epaper/display.py
+++ b/esphome/components/waveshare_epaper/display.py
@@ -239,7 +239,7 @@ async def to_code(config):
         raise NotImplementedError()
 
     await display.register_display(var, config)
-    await spi.register_spi_device(var, config)
+    await spi.register_spi_device(var, config, write_only=True)
 
     dc = await cg.gpio_pin_expression(config[CONF_DC_PIN])
     cg.add(var.set_dc_pin(dc))

From 19c1d3aee70133d9e59564791c522bdac5b6c29b Mon Sep 17 00:00:00 2001
From: Jonathan Swoboda <154711427+swoboda1337@users.noreply.github.com>
Date: Wed, 21 Jan 2026 20:41:59 -0500
Subject: [PATCH 4/9] [esp32] Bump Arduino to 3.3.6, platform to 55.03.36
 (#13438)

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
---
 .clang-tidy.hash                     |  2 +-
 esphome/components/esp32/__init__.py | 23 +++++++++++++++--------
 esphome/core/defines.h               |  2 +-
 platformio.ini                       |  6 +++---
 4 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/.clang-tidy.hash b/.clang-tidy.hash
index 0204b50264..0a272d21ba 100644
--- a/.clang-tidy.hash
+++ b/.clang-tidy.hash
@@ -1 +1 @@
-c0335c9688ce9defb4a7d4446b93460547e22df055668bacd7d963c770f0c65f
+15dc295268b2dcf75942f42759b3ddec64eba89f75525698eb39c95a7f4b14ce
diff --git a/esphome/components/esp32/__init__.py b/esphome/components/esp32/__init__.py
index e23a70a373..da49fdc070 100644
--- a/esphome/components/esp32/__init__.py
+++ b/esphome/components/esp32/__init__.py
@@ -348,7 +348,12 @@ def add_extra_build_file(filename: str, path: Path) -> bool:
 def _format_framework_arduino_version(ver: cv.Version) -> str:
     # format the given arduino (https://github.com/espressif/arduino-esp32/releases) version to
     # a PIO pioarduino/framework-arduinoespressif32 value
-    return f"pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/{str(ver)}/esp32-{str(ver)}.zip"
+    # 3.3.6+ changed filename from esp32-{ver}.zip to esp32-core-{ver}.tar.xz
+    if ver >= cv.Version(3, 3, 6):
+        filename = f"esp32-core-{ver}.tar.xz"
+    else:
+        filename = f"esp32-{ver}.zip"
+    return f"pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/{ver}/{filename}"
 
 
 def _format_framework_espidf_version(ver: cv.Version, release: str) -> str:
@@ -383,11 +388,12 @@ def _is_framework_url(source: str) -> bool:
 # The default/recommended arduino framework version
 #  - https://github.com/espressif/arduino-esp32/releases
 ARDUINO_FRAMEWORK_VERSION_LOOKUP = {
-    "recommended": cv.Version(3, 3, 5),
-    "latest": cv.Version(3, 3, 5),
-    "dev": cv.Version(3, 3, 5),
+    "recommended": cv.Version(3, 3, 6),
+    "latest": cv.Version(3, 3, 6),
+    "dev": cv.Version(3, 3, 6),
 }
 ARDUINO_PLATFORM_VERSION_LOOKUP = {
+    cv.Version(3, 3, 6): cv.Version(55, 3, 36),
     cv.Version(3, 3, 5): cv.Version(55, 3, 35),
     cv.Version(3, 3, 4): cv.Version(55, 3, 31, "2"),
     cv.Version(3, 3, 3): cv.Version(55, 3, 31, "2"),
@@ -405,6 +411,7 @@ ARDUINO_PLATFORM_VERSION_LOOKUP = {
 # These versions correspond to pioarduino/esp-idf releases
 # See: https://github.com/pioarduino/esp-idf/releases
 ARDUINO_IDF_VERSION_LOOKUP = {
+    cv.Version(3, 3, 6): cv.Version(5, 5, 2),
     cv.Version(3, 3, 5): cv.Version(5, 5, 2),
     cv.Version(3, 3, 4): cv.Version(5, 5, 1),
     cv.Version(3, 3, 3): cv.Version(5, 5, 1),
@@ -427,7 +434,7 @@ ESP_IDF_FRAMEWORK_VERSION_LOOKUP = {
     "dev": cv.Version(5, 5, 2),
 }
 ESP_IDF_PLATFORM_VERSION_LOOKUP = {
-    cv.Version(5, 5, 2): cv.Version(55, 3, 35),
+    cv.Version(5, 5, 2): cv.Version(55, 3, 36),
     cv.Version(5, 5, 1): cv.Version(55, 3, 31, "2"),
     cv.Version(5, 5, 0): cv.Version(55, 3, 31, "2"),
     cv.Version(5, 4, 3): cv.Version(55, 3, 32),
@@ -444,9 +451,9 @@ ESP_IDF_PLATFORM_VERSION_LOOKUP = {
 # The platform-espressif32 version
 #  - https://github.com/pioarduino/platform-espressif32/releases
 PLATFORM_VERSION_LOOKUP = {
-    "recommended": cv.Version(55, 3, 35),
-    "latest": cv.Version(55, 3, 35),
-    "dev": cv.Version(55, 3, 35),
+    "recommended": cv.Version(55, 3, 36),
+    "latest": cv.Version(55, 3, 36),
+    "dev": cv.Version(55, 3, 36),
 }
 
 
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index c229d1df7d..7c13823fba 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -234,7 +234,7 @@
 #define USB_HOST_MAX_REQUESTS 16
 
 #ifdef USE_ARDUINO
-#define USE_ARDUINO_VERSION_CODE VERSION_CODE(3, 3, 5)
+#define USE_ARDUINO_VERSION_CODE VERSION_CODE(3, 3, 6)
 #define USE_ETHERNET
 #define USE_ETHERNET_KSZ8081
 #define USE_ETHERNET_MANUAL_IP
diff --git a/platformio.ini b/platformio.ini
index b109284933..e9a588e4fd 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -133,9 +133,9 @@ extra_scripts = post:esphome/components/esp8266/post_build.py.script
 ; This are common settings for the ESP32 (all variants) using Arduino.
 [common:esp32-arduino]
 extends = common:arduino
-platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.35/platform-espressif32.zip
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.36/platform-espressif32.zip
 platform_packages =
-    pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/3.3.5/esp32-3.3.5.zip
+    pioarduino/framework-arduinoespressif32@https://github.com/espressif/arduino-esp32/releases/download/3.3.6/esp32-core-3.3.6.tar.xz
 
 framework = arduino, espidf  ; Arduino as an ESP-IDF component
 lib_deps =
@@ -168,7 +168,7 @@ extra_scripts = post:esphome/components/esp32/post_build.py.script
 ; This are common settings for the ESP32 (all variants) using IDF.
 [common:esp32-idf]
 extends = common:idf
-platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.35/platform-espressif32.zip
+platform = https://github.com/pioarduino/platform-espressif32/releases/download/55.03.36/platform-espressif32.zip
 platform_packages =
     pioarduino/framework-espidf@https://github.com/pioarduino/esp-idf/releases/download/v5.5.2/esp-idf-v5.5.2.tar.xz
 

From 645832a0708573c8763ee50b7fc5564fabb619ea Mon Sep 17 00:00:00 2001
From: Edward Firmo <94725493+edwardtfn@users.noreply.github.com>
Date: Thu, 22 Jan 2026 03:10:12 +0100
Subject: [PATCH 5/9] [nextion] Add configurable startup and queue timeout
 constants (#11098)

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@koston.org>
Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick+github@koston.org>
Co-authored-by: Keith Burzinski <kbx81x@gmail.com>
---
 esphome/components/nextion/base_component.py |  2 ++
 esphome/components/nextion/display.py        | 18 ++++++++++
 esphome/components/nextion/nextion.cpp       | 36 ++++++++++++--------
 esphome/components/nextion/nextion.h         | 29 ++++++++++++++--
 tests/components/nextion/common.yaml         |  2 ++
 5 files changed, 70 insertions(+), 17 deletions(-)

diff --git a/esphome/components/nextion/base_component.py b/esphome/components/nextion/base_component.py
index 392481e39a..86551cbe23 100644
--- a/esphome/components/nextion/base_component.py
+++ b/esphome/components/nextion/base_component.py
@@ -16,6 +16,7 @@ CONF_EXIT_REPARSE_ON_START = "exit_reparse_on_start"
 CONF_FONT_ID = "font_id"
 CONF_FOREGROUND_PRESSED_COLOR = "foreground_pressed_color"
 CONF_MAX_COMMANDS_PER_LOOP = "max_commands_per_loop"
+CONF_MAX_QUEUE_AGE = "max_queue_age"
 CONF_MAX_QUEUE_SIZE = "max_queue_size"
 CONF_ON_BUFFER_OVERFLOW = "on_buffer_overflow"
 CONF_ON_PAGE = "on_page"
@@ -25,6 +26,7 @@ CONF_ON_WAKE = "on_wake"
 CONF_PRECISION = "precision"
 CONF_SKIP_CONNECTION_HANDSHAKE = "skip_connection_handshake"
 CONF_START_UP_PAGE = "start_up_page"
+CONF_STARTUP_OVERRIDE_MS = "startup_override_ms"
 CONF_TFT_URL = "tft_url"
 CONF_TOUCH_SLEEP_TIMEOUT = "touch_sleep_timeout"
 CONF_VARIABLE_NAME = "variable_name"
diff --git a/esphome/components/nextion/display.py b/esphome/components/nextion/display.py
index 0b4ba3a171..ffc509fc64 100644
--- a/esphome/components/nextion/display.py
+++ b/esphome/components/nextion/display.py
@@ -23,6 +23,7 @@ from .base_component import (
     CONF_DUMP_DEVICE_INFO,
     CONF_EXIT_REPARSE_ON_START,
     CONF_MAX_COMMANDS_PER_LOOP,
+    CONF_MAX_QUEUE_AGE,
     CONF_MAX_QUEUE_SIZE,
     CONF_ON_BUFFER_OVERFLOW,
     CONF_ON_PAGE,
@@ -31,6 +32,7 @@ from .base_component import (
     CONF_ON_WAKE,
     CONF_SKIP_CONNECTION_HANDSHAKE,
     CONF_START_UP_PAGE,
+    CONF_STARTUP_OVERRIDE_MS,
     CONF_TFT_URL,
     CONF_TOUCH_SLEEP_TIMEOUT,
     CONF_WAKE_UP_PAGE,
@@ -65,6 +67,12 @@ CONFIG_SCHEMA = (
             ),
             cv.Optional(CONF_DUMP_DEVICE_INFO, default=False): cv.boolean,
             cv.Optional(CONF_EXIT_REPARSE_ON_START, default=False): cv.boolean,
+            cv.Optional(CONF_MAX_QUEUE_AGE, default="8000ms"): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(
+                    min=TimePeriod(milliseconds=0), max=TimePeriod(milliseconds=65535)
+                ),
+            ),
             cv.Optional(CONF_MAX_COMMANDS_PER_LOOP): cv.uint16_t,
             cv.Optional(CONF_MAX_QUEUE_SIZE): cv.positive_int,
             cv.Optional(CONF_ON_BUFFER_OVERFLOW): automation.validate_automation(
@@ -100,6 +108,12 @@ CONFIG_SCHEMA = (
                 }
             ),
             cv.Optional(CONF_SKIP_CONNECTION_HANDSHAKE, default=False): cv.boolean,
+            cv.Optional(CONF_STARTUP_OVERRIDE_MS, default="8000ms"): cv.All(
+                cv.positive_time_period_milliseconds,
+                cv.Range(
+                    min=TimePeriod(milliseconds=0), max=TimePeriod(milliseconds=65535)
+                ),
+            ),
             cv.Optional(CONF_START_UP_PAGE): cv.uint8_t,
             cv.Optional(CONF_TFT_URL): cv.url,
             cv.Optional(CONF_TOUCH_SLEEP_TIMEOUT): cv.Any(
@@ -138,6 +152,8 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await uart.register_uart_device(var, config)
 
+    cg.add(var.set_max_queue_age(config[CONF_MAX_QUEUE_AGE]))
+
     if max_queue_size := config.get(CONF_MAX_QUEUE_SIZE):
         cg.add_define("USE_NEXTION_MAX_QUEUE_SIZE")
         cg.add(var.set_max_queue_size(max_queue_size))
@@ -146,6 +162,8 @@ async def to_code(config):
         cg.add_define("USE_NEXTION_COMMAND_SPACING")
         cg.add(var.set_command_spacing(command_spacing.total_milliseconds))
 
+    cg.add(var.set_startup_override_ms(config[CONF_STARTUP_OVERRIDE_MS]))
+
     if CONF_BRIGHTNESS in config:
         cg.add(var.set_brightness(config[CONF_BRIGHTNESS]))
 
diff --git a/esphome/components/nextion/nextion.cpp b/esphome/components/nextion/nextion.cpp
index 354288e1a3..4bba33f961 100644
--- a/esphome/components/nextion/nextion.cpp
+++ b/esphome/components/nextion/nextion.cpp
@@ -152,21 +152,25 @@ void Nextion::dump_config() {
 #else  // USE_NEXTION_CONFIG_SKIP_CONNECTION_HANDSHAKE
   ESP_LOGCONFIG(TAG,
 #ifdef USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
-                "  Device Model:   %s\n"
-                "  FW Version:     %s\n"
-                "  Serial Number:  %s\n"
-                "  Flash Size:     %s\n"
+                "  Device Model: %s\n"
+                "  FW Version: %s\n"
+                "  Serial Number: %s\n"
+                "  Flash Size: %s\n"
+                "  Max queue age: %u ms\n"
+                "  Startup override: %u ms\n",
 #endif  // USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
 #ifdef USE_NEXTION_CONFIG_EXIT_REPARSE_ON_START
-                "  Exit reparse:   YES\n"
+                "  Exit reparse: YES\n"
 #endif  // USE_NEXTION_CONFIG_EXIT_REPARSE_ON_START
-                "  Wake On Touch:  %s\n"
-                "  Touch Timeout:  %" PRIu16,
+                "  Wake On Touch: %s\n"
+                "  Touch Timeout: %" PRIu16,
 #ifdef USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
                 this->device_model_.c_str(), this->firmware_version_.c_str(), this->serial_number_.c_str(),
-                this->flash_size_.c_str(),
+                this->flash_size_.c_str(), this->max_q_age_ms_,
+                this->startup_override_ms_
 #endif  // USE_NEXTION_CONFIG_DUMP_DEVICE_INFO
-                YESNO(this->connection_state_.auto_wake_on_touch_), this->touch_sleep_timeout_);
+                    YESNO(this->connection_state_.auto_wake_on_touch_),
+                this->touch_sleep_timeout_);
 #endif  // USE_NEXTION_CONFIG_SKIP_CONNECTION_HANDSHAKE
 
 #ifdef USE_NEXTION_MAX_COMMANDS_PER_LOOP
@@ -174,21 +178,21 @@ void Nextion::dump_config() {
 #endif  // USE_NEXTION_MAX_COMMANDS_PER_LOOP
 
   if (this->wake_up_page_ != 255) {
-    ESP_LOGCONFIG(TAG, "  Wake Up Page:   %u", this->wake_up_page_);
+    ESP_LOGCONFIG(TAG, "  Wake Up Page: %u", this->wake_up_page_);
   }
 
 #ifdef USE_NEXTION_CONF_START_UP_PAGE
   if (this->start_up_page_ != 255) {
-    ESP_LOGCONFIG(TAG, "  Start Up Page:  %u", this->start_up_page_);
+    ESP_LOGCONFIG(TAG, "  Start Up Page: %u", this->start_up_page_);
   }
 #endif  // USE_NEXTION_CONF_START_UP_PAGE
 
 #ifdef USE_NEXTION_COMMAND_SPACING
-  ESP_LOGCONFIG(TAG, "  Cmd spacing:      %u ms", this->command_pacer_.get_spacing());
+  ESP_LOGCONFIG(TAG, "  Cmd spacing: %u ms", this->command_pacer_.get_spacing());
 #endif  // USE_NEXTION_COMMAND_SPACING
 
 #ifdef USE_NEXTION_MAX_QUEUE_SIZE
-  ESP_LOGCONFIG(TAG, "  Max queue size:   %zu", this->max_queue_size_);
+  ESP_LOGCONFIG(TAG, "  Max queue size: %zu", this->max_queue_size_);
 #endif
 }
 
@@ -336,7 +340,8 @@ void Nextion::loop() {
     if (this->started_ms_ == 0)
       this->started_ms_ = App.get_loop_component_start_time();
 
-    if (this->started_ms_ + this->startup_override_ms_ < App.get_loop_component_start_time()) {
+    if (this->startup_override_ms_ > 0 &&
+        this->started_ms_ + this->startup_override_ms_ < App.get_loop_component_start_time()) {
       ESP_LOGV(TAG, "Manual ready set");
       this->connection_state_.nextion_reports_is_setup_ = true;
     }
@@ -845,7 +850,8 @@ void Nextion::process_nextion_commands_() {
 
   const uint32_t ms = App.get_loop_component_start_time();
 
-  if (!this->nextion_queue_.empty() && this->nextion_queue_.front()->queue_time + this->max_q_age_ms_ < ms) {
+  if (this->max_q_age_ms_ > 0 && !this->nextion_queue_.empty() &&
+      this->nextion_queue_.front()->queue_time + this->max_q_age_ms_ < ms) {
     for (size_t i = 0; i < this->nextion_queue_.size(); i++) {
       NextionComponentBase *component = this->nextion_queue_[i]->component;
       if (this->nextion_queue_[i]->queue_time + this->max_q_age_ms_ < ms) {
diff --git a/esphome/components/nextion/nextion.h b/esphome/components/nextion/nextion.h
index 331e901578..c543e14bfe 100644
--- a/esphome/components/nextion/nextion.h
+++ b/esphome/components/nextion/nextion.h
@@ -1309,6 +1309,30 @@ class Nextion : public NextionBase, public PollingComponent, public uart::UARTDe
    */
   bool is_connected() { return this->connection_state_.is_connected_; }
 
+  /**
+   * @brief Set the maximum age for queue items
+   * @param age_ms Maximum age in milliseconds before queue items are removed
+   */
+  inline void set_max_queue_age(uint16_t age_ms) { this->max_q_age_ms_ = age_ms; }
+
+  /**
+   * @brief Get the maximum age for queue items
+   * @return Maximum age in milliseconds
+   */
+  inline uint16_t get_max_queue_age() const { return this->max_q_age_ms_; }
+
+  /**
+   * @brief Set the startup override timeout
+   * @param timeout_ms Time in milliseconds to wait before forcing setup complete
+   */
+  inline void set_startup_override_ms(uint16_t timeout_ms) { this->startup_override_ms_ = timeout_ms; }
+
+  /**
+   * @brief Get the startup override timeout
+   * @return Startup override timeout in milliseconds
+   */
+  inline uint16_t get_startup_override_ms() const { return this->startup_override_ms_; }
+
  protected:
 #ifdef USE_NEXTION_MAX_COMMANDS_PER_LOOP
   uint16_t max_commands_per_loop_{1000};
@@ -1479,9 +1503,10 @@ class Nextion : public NextionBase, public PollingComponent, public uart::UARTDe
   void reset_(bool reset_nextion = true);
 
   std::string command_data_;
-  const uint16_t startup_override_ms_ = 8000;
-  const uint16_t max_q_age_ms_ = 8000;
   uint32_t started_ms_ = 0;
+
+  uint16_t startup_override_ms_ = 8000;  ///< Timeout before forcing setup complete
+  uint16_t max_q_age_ms_ = 8000;         ///< Maximum age for queue items in ms
 };
 
 }  // namespace nextion
diff --git a/tests/components/nextion/common.yaml b/tests/components/nextion/common.yaml
index f5ee12a51c..48a7292f43 100644
--- a/tests/components/nextion/common.yaml
+++ b/tests/components/nextion/common.yaml
@@ -277,6 +277,8 @@ display:
     command_spacing: 5ms
     max_commands_per_loop: 20
     max_queue_size: 50
+    startup_override_ms: 10000ms  # Wait 10s for display ready
+    max_queue_age: 5000ms         # Remove queue items after 5s
     on_sleep:
       then:
         lambda: 'ESP_LOGD("display","Display went to sleep");'

From aa5092bdc272bf93bd7b675438608dda3f41b517 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 21 Jan 2026 18:35:43 -1000
Subject: [PATCH 6/9] [mqtt] Use stack buffers for discovery message formatting
 (#13216)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
---
 .../components/mqtt/custom_mqtt_device.cpp    |  2 +-
 esphome/components/mqtt/mqtt_client.cpp       | 12 ++++-
 esphome/components/mqtt/mqtt_component.cpp    | 49 +++++++++++++------
 esphome/components/mqtt/mqtt_fan.cpp          |  2 +-
 esphome/components/mqtt/mqtt_number.cpp       |  2 +-
 5 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/esphome/components/mqtt/custom_mqtt_device.cpp b/esphome/components/mqtt/custom_mqtt_device.cpp
index 7ff65bb42c..64521f5cf3 100644
--- a/esphome/components/mqtt/custom_mqtt_device.cpp
+++ b/esphome/components/mqtt/custom_mqtt_device.cpp
@@ -18,7 +18,7 @@ bool CustomMQTTDevice::publish(const std::string &topic, float value, int8_t num
 }
 bool CustomMQTTDevice::publish(const std::string &topic, int value) {
   char buffer[24];
-  int len = snprintf(buffer, sizeof(buffer), "%d", value);
+  size_t len = buf_append_printf(buffer, sizeof(buffer), 0, "%d", value);
   return global_mqtt_client->publish(topic, buffer, len);
 }
 bool CustomMQTTDevice::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos, bool retain) {
diff --git a/esphome/components/mqtt/mqtt_client.cpp b/esphome/components/mqtt/mqtt_client.cpp
index de79b61358..e7364f3406 100644
--- a/esphome/components/mqtt/mqtt_client.cpp
+++ b/esphome/components/mqtt/mqtt_client.cpp
@@ -98,7 +98,17 @@ void MQTTClientComponent::send_device_info_() {
         uint8_t index = 0;
         for (auto &ip : network::get_ip_addresses()) {
           if (ip.is_set()) {
-            root["ip" + (index == 0 ? "" : esphome::to_string(index))] = ip.str();
+            char key[8];  // "ip" + up to 3 digits + null
+            char ip_buf[network::IP_ADDRESS_BUFFER_SIZE];
+            if (index == 0) {
+              key[0] = 'i';
+              key[1] = 'p';
+              key[2] = '\0';
+            } else {
+              buf_append_printf(key, sizeof(key), 0, "ip%u", index);
+            }
+            ip.str_to(ip_buf);
+            root[key] = ip_buf;
             index++;
           }
         }
diff --git a/esphome/components/mqtt/mqtt_component.cpp b/esphome/components/mqtt/mqtt_component.cpp
index 2ba466af3b..cb8b92cad0 100644
--- a/esphome/components/mqtt/mqtt_component.cpp
+++ b/esphome/components/mqtt/mqtt_component.cpp
@@ -190,27 +190,37 @@ bool MQTTComponent::send_discovery_() {
         StringRef object_id = this->get_default_object_id_to_(object_id_buf);
         if (discovery_info.unique_id_generator == MQTT_MAC_ADDRESS_UNIQUE_ID_GENERATOR) {
           char friendly_name_hash[9];
-          snprintf(friendly_name_hash, sizeof(friendly_name_hash), "%08" PRIx32, fnv1_hash(this->friendly_name_()));
+          buf_append_printf(friendly_name_hash, sizeof(friendly_name_hash), 0, "%08" PRIx32,
+                            fnv1_hash(this->friendly_name_()));
           // Format: mac-component_type-hash (e.g. "aabbccddeeff-sensor-12345678")
           // MAC (12) + "-" (1) + domain (max 20) + "-" (1) + hash (8) + null (1) = 43
           char unique_id[MAC_ADDRESS_BUFFER_SIZE + ESPHOME_DOMAIN_MAX_LEN + 11];
           char mac_buf[MAC_ADDRESS_BUFFER_SIZE];
           get_mac_address_into_buffer(mac_buf);
-          snprintf(unique_id, sizeof(unique_id), "%s-%s-%s", mac_buf, this->component_type(), friendly_name_hash);
+          buf_append_printf(unique_id, sizeof(unique_id), 0, "%s-%s-%s", mac_buf, this->component_type(),
+                            friendly_name_hash);
           root[MQTT_UNIQUE_ID] = unique_id;
         } else {
           // default to almost-unique ID. It's a hack but the only way to get that
           // gorgeous device registry view.
-          root[MQTT_UNIQUE_ID] = "ESP" + std::string(this->component_type()) + object_id.c_str();
+          // "ESP" (3) + component_type (max 20) + object_id (max 128) + null
+          char unique_id_buf[3 + MQTT_COMPONENT_TYPE_MAX_LEN + OBJECT_ID_MAX_LEN + 1];
+          buf_append_printf(unique_id_buf, sizeof(unique_id_buf), 0, "ESP%s%s", this->component_type(),
+                            object_id.c_str());
+          root[MQTT_UNIQUE_ID] = unique_id_buf;
         }
 
         const std::string &node_name = App.get_name();
-        if (discovery_info.object_id_generator == MQTT_DEVICE_NAME_OBJECT_ID_GENERATOR)
-          root[MQTT_OBJECT_ID] = node_name + "_" + object_id.c_str();
+        if (discovery_info.object_id_generator == MQTT_DEVICE_NAME_OBJECT_ID_GENERATOR) {
+          // node_name (max 31) + "_" (1) + object_id (max 128) + null
+          char object_id_full[ESPHOME_DEVICE_NAME_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1];
+          buf_append_printf(object_id_full, sizeof(object_id_full), 0, "%s_%s", node_name.c_str(), object_id.c_str());
+          root[MQTT_OBJECT_ID] = object_id_full;
+        }
 
         const std::string &friendly_name_ref = App.get_friendly_name();
         const std::string &node_friendly_name = friendly_name_ref.empty() ? node_name : friendly_name_ref;
-        std::string node_area = App.get_area();
+        const char *node_area = App.get_area();
 
         JsonObject device_info = root[MQTT_DEVICE].to<JsonObject>();
         char mac[MAC_ADDRESS_BUFFER_SIZE];
@@ -221,18 +231,29 @@ bool MQTTComponent::send_discovery_() {
         device_info[MQTT_DEVICE_SW_VERSION] = ESPHOME_PROJECT_VERSION " (ESPHome " ESPHOME_VERSION ")";
         const char *model = std::strchr(ESPHOME_PROJECT_NAME, '.');
         device_info[MQTT_DEVICE_MODEL] = model == nullptr ? ESPHOME_BOARD : model + 1;
-        device_info[MQTT_DEVICE_MANUFACTURER] =
-            model == nullptr ? ESPHOME_PROJECT_NAME : std::string(ESPHOME_PROJECT_NAME, model - ESPHOME_PROJECT_NAME);
+        if (model == nullptr) {
+          device_info[MQTT_DEVICE_MANUFACTURER] = ESPHOME_PROJECT_NAME;
+        } else {
+          // Extract manufacturer (part before '.') using stack buffer to avoid heap allocation
+          // memcpy is used instead of strncpy since we know the exact length and strncpy
+          // would still require manual null-termination
+          char manufacturer[sizeof(ESPHOME_PROJECT_NAME)];
+          size_t len = model - ESPHOME_PROJECT_NAME;
+          memcpy(manufacturer, ESPHOME_PROJECT_NAME, len);
+          manufacturer[len] = '\0';
+          device_info[MQTT_DEVICE_MANUFACTURER] = manufacturer;
+        }
 #else
         static const char ver_fmt[] PROGMEM = ESPHOME_VERSION " (config hash 0x%08" PRIx32 ")";
+        // Buffer sized for format string expansion: ~4 bytes net growth from format specifier to 8 hex digits, plus
+        // safety margin
+        char version_buf[sizeof(ver_fmt) + 8];
 #ifdef USE_ESP8266
-        char fmt_buf[sizeof(ver_fmt)];
-        strcpy_P(fmt_buf, ver_fmt);
-        const char *fmt = fmt_buf;
+        snprintf_P(version_buf, sizeof(version_buf), ver_fmt, App.get_config_hash());
 #else
-        const char *fmt = ver_fmt;
+        snprintf(version_buf, sizeof(version_buf), ver_fmt, App.get_config_hash());
 #endif
-        device_info[MQTT_DEVICE_SW_VERSION] = str_sprintf(fmt, App.get_config_hash());
+        device_info[MQTT_DEVICE_SW_VERSION] = version_buf;
         device_info[MQTT_DEVICE_MODEL] = ESPHOME_BOARD;
 #if defined(USE_ESP8266) || defined(USE_ESP32)
         device_info[MQTT_DEVICE_MANUFACTURER] = "Espressif";
@@ -246,7 +267,7 @@ bool MQTTComponent::send_discovery_() {
         device_info[MQTT_DEVICE_MANUFACTURER] = "Host";
 #endif
 #endif
-        if (!node_area.empty()) {
+        if (node_area[0] != '\0') {
           device_info[MQTT_DEVICE_SUGGESTED_AREA] = node_area;
         }
 
diff --git a/esphome/components/mqtt/mqtt_fan.cpp b/esphome/components/mqtt/mqtt_fan.cpp
index a6f0503588..0909090023 100644
--- a/esphome/components/mqtt/mqtt_fan.cpp
+++ b/esphome/components/mqtt/mqtt_fan.cpp
@@ -175,7 +175,7 @@ bool MQTTFanComponent::publish_state() {
   auto traits = this->state_->get_traits();
   if (traits.supports_speed()) {
     char buf[12];
-    int len = snprintf(buf, sizeof(buf), "%d", this->state_->speed);
+    size_t len = buf_append_printf(buf, sizeof(buf), 0, "%d", this->state_->speed);
     bool success = this->publish(this->get_speed_level_state_topic(), buf, len);
     failed = failed || !success;
   }
diff --git a/esphome/components/mqtt/mqtt_number.cpp b/esphome/components/mqtt/mqtt_number.cpp
index 8342210ee4..471c0d1208 100644
--- a/esphome/components/mqtt/mqtt_number.cpp
+++ b/esphome/components/mqtt/mqtt_number.cpp
@@ -75,7 +75,7 @@ bool MQTTNumberComponent::send_initial_state() {
 }
 bool MQTTNumberComponent::publish_state(float value) {
   char buffer[64];
-  snprintf(buffer, sizeof(buffer), "%f", value);
+  buf_append_printf(buffer, sizeof(buffer), 0, "%f", value);
   return this->publish(this->get_state_topic_(), buffer);
 }
 

From 99aa83564e9e2961b2d771da3b8262ed6df01a7f Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 21 Jan 2026 18:35:59 -1000
Subject: [PATCH 7/9] [mqtt] Reduce heap allocations in hot paths (#13362)

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>
---
 .../mqtt/mqtt_alarm_control_panel.cpp         |   2 +-
 .../components/mqtt/mqtt_binary_sensor.cpp    |   2 +-
 esphome/components/mqtt/mqtt_component.cpp    | 101 ++++++++++++------
 esphome/components/mqtt/mqtt_component.h      |  69 ++++++++----
 esphome/components/mqtt/mqtt_cover.cpp        |   2 +-
 esphome/components/mqtt/mqtt_date.cpp         |   2 +-
 esphome/components/mqtt/mqtt_datetime.cpp     |   2 +-
 esphome/components/mqtt/mqtt_light.cpp        |   2 +-
 esphome/components/mqtt/mqtt_number.cpp       |   2 +-
 esphome/components/mqtt/mqtt_select.cpp       |   2 +-
 esphome/components/mqtt/mqtt_sensor.cpp       |   2 +-
 esphome/components/mqtt/mqtt_text.cpp         |   2 +-
 esphome/components/mqtt/mqtt_time.cpp         |   2 +-
 esphome/components/mqtt/mqtt_valve.cpp        |   2 +-
 esphome/core/automation.h                     |  57 ++++++++--
 15 files changed, 179 insertions(+), 72 deletions(-)

diff --git a/esphome/components/mqtt/mqtt_alarm_control_panel.cpp b/esphome/components/mqtt/mqtt_alarm_control_panel.cpp
index 6245d10882..715e6feed8 100644
--- a/esphome/components/mqtt/mqtt_alarm_control_panel.cpp
+++ b/esphome/components/mqtt/mqtt_alarm_control_panel.cpp
@@ -43,7 +43,7 @@ void MQTTAlarmControlPanelComponent::setup() {
 
 void MQTTAlarmControlPanelComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT alarm_control_panel '%s':", this->alarm_control_panel_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
   ESP_LOGCONFIG(TAG,
                 "  Supported Features: %" PRIu32 "\n"
                 "  Requires Code to Disarm: %s\n"
diff --git a/esphome/components/mqtt/mqtt_binary_sensor.cpp b/esphome/components/mqtt/mqtt_binary_sensor.cpp
index a37043406b..7cbb5dcc0e 100644
--- a/esphome/components/mqtt/mqtt_binary_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_binary_sensor.cpp
@@ -19,7 +19,7 @@ void MQTTBinarySensorComponent::setup() {
 
 void MQTTBinarySensorComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Binary Sensor '%s':", this->binary_sensor_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 MQTTBinarySensorComponent::MQTTBinarySensorComponent(binary_sensor::BinarySensor *binary_sensor)
     : binary_sensor_(binary_sensor) {
diff --git a/esphome/components/mqtt/mqtt_component.cpp b/esphome/components/mqtt/mqtt_component.cpp
index cb8b92cad0..7607a4e817 100644
--- a/esphome/components/mqtt/mqtt_component.cpp
+++ b/esphome/components/mqtt/mqtt_component.cpp
@@ -27,20 +27,23 @@ inline char *append_char(char *p, char c) {
 // Max lengths for stack-based topic building.
 // These limits are enforced at Python config validation time in mqtt/__init__.py
 // using cv.Length() validators for topic_prefix and discovery_prefix.
-// MQTT_COMPONENT_TYPE_MAX_LEN and MQTT_SUFFIX_MAX_LEN are defined in mqtt_component.h.
+// MQTT_COMPONENT_TYPE_MAX_LEN, MQTT_SUFFIX_MAX_LEN, and MQTT_DEFAULT_TOPIC_MAX_LEN are in mqtt_component.h.
 // ESPHOME_DEVICE_NAME_MAX_LEN and OBJECT_ID_MAX_LEN are defined in entity_base.h.
 // This ensures the stack buffers below are always large enough.
-static constexpr size_t TOPIC_PREFIX_MAX_LEN = 64;      // Validated in Python: cv.Length(max=64)
 static constexpr size_t DISCOVERY_PREFIX_MAX_LEN = 64;  // Validated in Python: cv.Length(max=64)
-
-// Stack buffer sizes - safe because all inputs are length-validated at config time
-// Format: prefix + "/" + type + "/" + object_id + "/" + suffix + null
-static constexpr size_t DEFAULT_TOPIC_MAX_LEN =
-    TOPIC_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1 + MQTT_SUFFIX_MAX_LEN + 1;
 // Format: prefix + "/" + type + "/" + name + "/" + object_id + "/config" + null
 static constexpr size_t DISCOVERY_TOPIC_MAX_LEN = DISCOVERY_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 +
                                                   ESPHOME_DEVICE_NAME_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 7 + 1;
 
+// Function implementation of LOG_MQTT_COMPONENT macro to reduce code size
+void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic) {
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  if (state_topic)
+    ESP_LOGCONFIG(tag, "  State Topic: '%s'", obj->get_state_topic_to_(buf).c_str());
+  if (command_topic)
+    ESP_LOGCONFIG(tag, "  Command Topic: '%s'", obj->get_command_topic_to_(buf).c_str());
+}
+
 void MQTTComponent::set_qos(uint8_t qos) { this->qos_ = qos; }
 
 void MQTTComponent::set_subscribe_qos(uint8_t qos) { this->subscribe_qos_ = qos; }
@@ -69,19 +72,18 @@ std::string MQTTComponent::get_discovery_topic_(const MQTTDiscoveryInfo &discove
   return std::string(buf, p - buf);
 }
 
-std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) const {
+StringRef MQTTComponent::get_default_topic_for_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf, const char *suffix,
+                                                   size_t suffix_len) const {
   const std::string &topic_prefix = global_mqtt_client->get_topic_prefix();
   if (topic_prefix.empty()) {
-    // If the topic_prefix is null, the default topic should be null
-    return "";
+    return StringRef();  // Empty topic_prefix means no default topic
   }
 
   const char *comp_type = this->component_type();
   char object_id_buf[OBJECT_ID_MAX_LEN];
   StringRef object_id = this->get_default_object_id_to_(object_id_buf);
 
-  char buf[DEFAULT_TOPIC_MAX_LEN];
-  char *p = buf;
+  char *p = buf.data();
 
   p = append_str(p, topic_prefix.data(), topic_prefix.size());
   p = append_char(p, '/');
@@ -89,21 +91,44 @@ std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) con
   p = append_char(p, '/');
   p = append_str(p, object_id.c_str(), object_id.size());
   p = append_char(p, '/');
-  p = append_str(p, suffix.data(), suffix.size());
+  p = append_str(p, suffix, suffix_len);
+  *p = '\0';
 
-  return std::string(buf, p - buf);
+  return StringRef(buf.data(), p - buf.data());
+}
+
+std::string MQTTComponent::get_default_topic_for_(const std::string &suffix) const {
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_default_topic_for_to_(buf, suffix.data(), suffix.size());
+  return std::string(ref.c_str(), ref.size());
+}
+
+StringRef MQTTComponent::get_state_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const {
+  if (this->custom_state_topic_.has_value()) {
+    // Returns ref to existing data for static/value, uses buf only for lambda case
+    return this->custom_state_topic_.ref_or_copy_to(buf.data(), buf.size());
+  }
+  return this->get_default_topic_for_to_(buf, "state", 5);
+}
+
+StringRef MQTTComponent::get_command_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const {
+  if (this->custom_command_topic_.has_value()) {
+    // Returns ref to existing data for static/value, uses buf only for lambda case
+    return this->custom_command_topic_.ref_or_copy_to(buf.data(), buf.size());
+  }
+  return this->get_default_topic_for_to_(buf, "command", 7);
 }
 
 std::string MQTTComponent::get_state_topic_() const {
-  if (this->custom_state_topic_.has_value())
-    return this->custom_state_topic_.value();
-  return this->get_default_topic_for_("state");
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_state_topic_to_(buf);
+  return std::string(ref.c_str(), ref.size());
 }
 
 std::string MQTTComponent::get_command_topic_() const {
-  if (this->custom_command_topic_.has_value())
-    return this->custom_command_topic_.value();
-  return this->get_default_topic_for_("command");
+  char buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+  StringRef ref = this->get_command_topic_to_(buf);
+  return std::string(ref.c_str(), ref.size());
 }
 
 bool MQTTComponent::publish(const std::string &topic, const std::string &payload) {
@@ -168,10 +193,14 @@ bool MQTTComponent::send_discovery_() {
             break;
         }
 
-        if (config.state_topic)
-          root[MQTT_STATE_TOPIC] = this->get_state_topic_();
-        if (config.command_topic)
-          root[MQTT_COMMAND_TOPIC] = this->get_command_topic_();
+        if (config.state_topic) {
+          char state_topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+          root[MQTT_STATE_TOPIC] = this->get_state_topic_to_(state_topic_buf);
+        }
+        if (config.command_topic) {
+          char command_topic_buf[MQTT_DEFAULT_TOPIC_MAX_LEN];
+          root[MQTT_COMMAND_TOPIC] = this->get_command_topic_to_(command_topic_buf);
+        }
         if (this->command_retain_)
           root[MQTT_COMMAND_RETAIN] = true;
 
@@ -309,7 +338,9 @@ void MQTTComponent::set_availability(std::string topic, std::string payload_avai
 }
 void MQTTComponent::disable_availability() { this->set_availability("", "", ""); }
 void MQTTComponent::call_setup() {
-  if (this->is_internal())
+  // Cache is_internal result once during setup - topics don't change after this
+  this->is_internal_ = this->compute_is_internal_();
+  if (this->is_internal_)
     return;
 
   this->setup();
@@ -361,26 +392,28 @@ StringRef MQTTComponent::get_default_object_id_to_(std::span<char, OBJECT_ID_MAX
 }
 StringRef MQTTComponent::get_icon_ref_() const { return this->get_entity()->get_icon_ref(); }
 bool MQTTComponent::is_disabled_by_default_() const { return this->get_entity()->is_disabled_by_default(); }
-bool MQTTComponent::is_internal() {
+bool MQTTComponent::compute_is_internal_() {
   if (this->custom_state_topic_.has_value()) {
-    // If the custom state_topic is null, return true as it is internal and should not publish
+    // If the custom state_topic is empty, return true as it is internal and should not publish
     // else, return false, as it is explicitly set to a topic, so it is not internal and should publish
-    return this->get_state_topic_().empty();
+    // Using is_empty() avoids heap allocation for non-lambda cases
+    return this->custom_state_topic_.is_empty();
   }
 
   if (this->custom_command_topic_.has_value()) {
-    // If the custom command_topic is null, return true as it is internal and should not publish
+    // If the custom command_topic is empty, return true as it is internal and should not publish
     // else, return false, as it is explicitly set to a topic, so it is not internal and should publish
-    return this->get_command_topic_().empty();
+    // Using is_empty() avoids heap allocation for non-lambda cases
+    return this->custom_command_topic_.is_empty();
   }
 
-  // No custom topics have been set
-  if (this->get_default_topic_for_("").empty()) {
-    // If the default topic prefix is null, then the component, by default, is internal and should not publish
+  // No custom topics have been set - check topic_prefix directly to avoid allocation
+  if (global_mqtt_client->get_topic_prefix().empty()) {
+    // If the default topic prefix is empty, then the component, by default, is internal and should not publish
     return true;
   }
 
-  // Use ESPHome's component internal state if topic_prefix is not null with no custom state_topic or command_topic
+  // Use ESPHome's component internal state if topic_prefix is not empty with no custom state_topic or command_topic
   return this->get_entity()->is_internal();
 }
 
diff --git a/esphome/components/mqtt/mqtt_component.h b/esphome/components/mqtt/mqtt_component.h
index dea91e3d5a..1a5e6db3af 100644
--- a/esphome/components/mqtt/mqtt_component.h
+++ b/esphome/components/mqtt/mqtt_component.h
@@ -20,17 +20,22 @@ struct SendDiscoveryConfig {
   bool command_topic{true};  ///< If the command topic should be included. Default to true.
 };
 
-// Max lengths for stack-based topic building (must match mqtt_component.cpp)
+// Max lengths for stack-based topic building.
+// These limits are enforced at Python config validation time in mqtt/__init__.py
+// using cv.Length() validators for topic_prefix and discovery_prefix.
+// This ensures the stack buffers are always large enough.
 static constexpr size_t MQTT_COMPONENT_TYPE_MAX_LEN = 20;
 static constexpr size_t MQTT_SUFFIX_MAX_LEN = 32;
+static constexpr size_t MQTT_TOPIC_PREFIX_MAX_LEN = 64;  // Validated in Python: cv.Length(max=64)
+// Stack buffer size - safe because all inputs are length-validated at config time
+// Format: prefix + "/" + type + "/" + object_id + "/" + suffix + null
+static constexpr size_t MQTT_DEFAULT_TOPIC_MAX_LEN =
+    MQTT_TOPIC_PREFIX_MAX_LEN + 1 + MQTT_COMPONENT_TYPE_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1 + MQTT_SUFFIX_MAX_LEN + 1;
 
-#define LOG_MQTT_COMPONENT(state_topic, command_topic) \
-  if (state_topic) { \
-    ESP_LOGCONFIG(TAG, "  State Topic: '%s'", this->get_state_topic_().c_str()); \
-  } \
-  if (command_topic) { \
-    ESP_LOGCONFIG(TAG, "  Command Topic: '%s'", this->get_command_topic_().c_str()); \
-  }
+class MQTTComponent;  // Forward declaration
+void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic);
+
+#define LOG_MQTT_COMPONENT(state_topic, command_topic) log_mqtt_component(TAG, this, state_topic, command_topic)
 
 // Macro to define component_type() with compile-time length verification
 // Usage: MQTT_COMPONENT_TYPE(MQTTSensorComponent, "sensor")
@@ -74,6 +79,8 @@ static constexpr size_t MQTT_SUFFIX_MAX_LEN = 32;
  * a clean separation.
  */
 class MQTTComponent : public Component {
+  friend void log_mqtt_component(const char *tag, MQTTComponent *obj, bool state_topic, bool command_topic);
+
  public:
   /// Constructs a MQTTComponent.
   explicit MQTTComponent();
@@ -88,7 +95,8 @@ class MQTTComponent : public Component {
 
   virtual bool send_initial_state() = 0;
 
-  virtual bool is_internal();
+  /// Returns cached is_internal result (computed once during setup).
+  bool is_internal() const { return this->is_internal_; }
 
   /// Set QOS for state messages.
   void set_qos(uint8_t qos);
@@ -179,7 +187,16 @@ class MQTTComponent : public Component {
   /// Helper method to get the discovery topic for this component.
   std::string get_discovery_topic_(const MQTTDiscoveryInfo &discovery_info) const;
 
-  /** Get this components state/command/... topic.
+  /** Get this components state/command/... topic into a buffer.
+   *
+   * @param buf The buffer to write to (must be exactly MQTT_DEFAULT_TOPIC_MAX_LEN).
+   * @param suffix The suffix/key such as "state" or "command".
+   * @return StringRef pointing to the buffer with the topic.
+   */
+  StringRef get_default_topic_for_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf, const char *suffix,
+                                      size_t suffix_len) const;
+
+  /** Get this components state/command/... topic (allocates std::string).
    *
    * @param suffix The suffix/key such as "state" or "command".
    * @return The full topic.
@@ -200,10 +217,20 @@ class MQTTComponent : public Component {
   /// Get whether the underlying Entity is disabled by default
   bool is_disabled_by_default_() const;
 
-  /// Get the MQTT topic that new states will be shared to.
+  /// Get the MQTT state topic into a buffer (no heap allocation for non-lambda custom topics).
+  /// @param buf Buffer of exactly MQTT_DEFAULT_TOPIC_MAX_LEN bytes.
+  /// @return StringRef pointing to the topic in the buffer.
+  StringRef get_state_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const;
+
+  /// Get the MQTT command topic into a buffer (no heap allocation for non-lambda custom topics).
+  /// @param buf Buffer of exactly MQTT_DEFAULT_TOPIC_MAX_LEN bytes.
+  /// @return StringRef pointing to the topic in the buffer.
+  StringRef get_command_topic_to_(std::span<char, MQTT_DEFAULT_TOPIC_MAX_LEN> buf) const;
+
+  /// Get the MQTT topic that new states will be shared to (allocates std::string).
   std::string get_state_topic_() const;
 
-  /// Get the MQTT topic for listening to commands.
+  /// Get the MQTT topic for listening to commands (allocates std::string).
   std::string get_command_topic_() const;
 
   bool is_connected_() const;
@@ -221,12 +248,18 @@ class MQTTComponent : public Component {
 
   std::unique_ptr<Availability> availability_;
 
-  bool command_retain_{false};
-  bool retain_{true};
-  uint8_t qos_{0};
-  uint8_t subscribe_qos_{0};
-  bool discovery_enabled_{true};
-  bool resend_state_{false};
+  // Packed bitfields - QoS values are 0-2, bools are flags
+  uint8_t qos_ : 2 {0};
+  uint8_t subscribe_qos_ : 2 {0};
+  bool command_retain_ : 1 {false};
+  bool retain_ : 1 {true};
+  bool discovery_enabled_ : 1 {true};
+  bool resend_state_ : 1 {false};
+  bool is_internal_ : 1 {false};  ///< Cached result of compute_is_internal_(), set during setup
+
+  /// Compute is_internal status based on topics and entity state.
+  /// Called once during setup to cache the result.
+  bool compute_is_internal_();
 };
 
 }  // namespace esphome::mqtt
diff --git a/esphome/components/mqtt/mqtt_cover.cpp b/esphome/components/mqtt/mqtt_cover.cpp
index f2df6af236..493514c8fb 100644
--- a/esphome/components/mqtt/mqtt_cover.cpp
+++ b/esphome/components/mqtt/mqtt_cover.cpp
@@ -51,7 +51,7 @@ void MQTTCoverComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT cover '%s':", this->cover_->get_name().c_str());
   auto traits = this->cover_->get_traits();
   bool has_command_topic = traits.get_supports_position() || !traits.get_supports_tilt();
-  LOG_MQTT_COMPONENT(true, has_command_topic)
+  LOG_MQTT_COMPONENT(true, has_command_topic);
   if (traits.get_supports_position()) {
     ESP_LOGCONFIG(TAG,
                   "  Position State Topic: '%s'\n"
diff --git a/esphome/components/mqtt/mqtt_date.cpp b/esphome/components/mqtt/mqtt_date.cpp
index dba7c1a671..cbe4045486 100644
--- a/esphome/components/mqtt/mqtt_date.cpp
+++ b/esphome/components/mqtt/mqtt_date.cpp
@@ -36,7 +36,7 @@ void MQTTDateComponent::setup() {
 
 void MQTTDateComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Date '%s':", this->date_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTDateComponent, "date")
diff --git a/esphome/components/mqtt/mqtt_datetime.cpp b/esphome/components/mqtt/mqtt_datetime.cpp
index 5f1cf19b97..f7b4ef0685 100644
--- a/esphome/components/mqtt/mqtt_datetime.cpp
+++ b/esphome/components/mqtt/mqtt_datetime.cpp
@@ -47,7 +47,7 @@ void MQTTDateTimeComponent::setup() {
 
 void MQTTDateTimeComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT DateTime '%s':", this->datetime_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTDateTimeComponent, "datetime")
diff --git a/esphome/components/mqtt/mqtt_light.cpp b/esphome/components/mqtt/mqtt_light.cpp
index fac19f3210..e43cb63f4f 100644
--- a/esphome/components/mqtt/mqtt_light.cpp
+++ b/esphome/components/mqtt/mqtt_light.cpp
@@ -90,7 +90,7 @@ void MQTTJSONLightComponent::send_discovery(JsonObject root, mqtt::SendDiscovery
 bool MQTTJSONLightComponent::send_initial_state() { return this->publish_state_(); }
 void MQTTJSONLightComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Light '%s':", this->state_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 }  // namespace esphome::mqtt
diff --git a/esphome/components/mqtt/mqtt_number.cpp b/esphome/components/mqtt/mqtt_number.cpp
index 471c0d1208..a014096c5f 100644
--- a/esphome/components/mqtt/mqtt_number.cpp
+++ b/esphome/components/mqtt/mqtt_number.cpp
@@ -30,7 +30,7 @@ void MQTTNumberComponent::setup() {
 
 void MQTTNumberComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Number '%s':", this->number_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTNumberComponent, "number")
diff --git a/esphome/components/mqtt/mqtt_select.cpp b/esphome/components/mqtt/mqtt_select.cpp
index 03ab82312b..2d830998ec 100644
--- a/esphome/components/mqtt/mqtt_select.cpp
+++ b/esphome/components/mqtt/mqtt_select.cpp
@@ -25,7 +25,7 @@ void MQTTSelectComponent::setup() {
 
 void MQTTSelectComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Select '%s':", this->select_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTSelectComponent, "select")
diff --git a/esphome/components/mqtt/mqtt_sensor.cpp b/esphome/components/mqtt/mqtt_sensor.cpp
index c14c889d47..f136b82355 100644
--- a/esphome/components/mqtt/mqtt_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_sensor.cpp
@@ -28,7 +28,7 @@ void MQTTSensorComponent::dump_config() {
   if (this->get_expire_after() > 0) {
     ESP_LOGCONFIG(TAG, "  Expire After: %" PRIu32 "s", this->get_expire_after() / 1000);
   }
-  LOG_MQTT_COMPONENT(true, false)
+  LOG_MQTT_COMPONENT(true, false);
 }
 
 MQTT_COMPONENT_TYPE(MQTTSensorComponent, "sensor")
diff --git a/esphome/components/mqtt/mqtt_text.cpp b/esphome/components/mqtt/mqtt_text.cpp
index cee94965c6..fed9224b42 100644
--- a/esphome/components/mqtt/mqtt_text.cpp
+++ b/esphome/components/mqtt/mqtt_text.cpp
@@ -26,7 +26,7 @@ void MQTTTextComponent::setup() {
 
 void MQTTTextComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT text '%s':", this->text_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTTextComponent, "text")
diff --git a/esphome/components/mqtt/mqtt_time.cpp b/esphome/components/mqtt/mqtt_time.cpp
index b75325022a..8749c3b59e 100644
--- a/esphome/components/mqtt/mqtt_time.cpp
+++ b/esphome/components/mqtt/mqtt_time.cpp
@@ -36,7 +36,7 @@ void MQTTTimeComponent::setup() {
 
 void MQTTTimeComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT Time '%s':", this->time_->get_name().c_str());
-  LOG_MQTT_COMPONENT(true, true)
+  LOG_MQTT_COMPONENT(true, true);
 }
 
 MQTT_COMPONENT_TYPE(MQTTTimeComponent, "time")
diff --git a/esphome/components/mqtt/mqtt_valve.cpp b/esphome/components/mqtt/mqtt_valve.cpp
index 2faaace46b..8e66a69c6f 100644
--- a/esphome/components/mqtt/mqtt_valve.cpp
+++ b/esphome/components/mqtt/mqtt_valve.cpp
@@ -39,7 +39,7 @@ void MQTTValveComponent::dump_config() {
   ESP_LOGCONFIG(TAG, "MQTT valve '%s':", this->valve_->get_name().c_str());
   auto traits = this->valve_->get_traits();
   bool has_command_topic = traits.get_supports_position();
-  LOG_MQTT_COMPONENT(true, has_command_topic)
+  LOG_MQTT_COMPONENT(true, has_command_topic);
   if (traits.get_supports_position()) {
     ESP_LOGCONFIG(TAG,
                   "  Position State Topic: '%s'\n"
diff --git a/esphome/core/automation.h b/esphome/core/automation.h
index eac469d0fc..31a2fc06f4 100644
--- a/esphome/core/automation.h
+++ b/esphome/core/automation.h
@@ -4,6 +4,7 @@
 #include "esphome/core/defines.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/string_ref.h"
 #include <concepts>
 #include <functional>
 #include <utility>
@@ -190,15 +191,55 @@ template<typename T, typename... X> class TemplatableValue {
   /// Get the static string pointer (only valid if is_static_string() returns true)
   const char *get_static_string() const { return this->static_str_; }
 
- protected:
-  enum : uint8_t {
-    NONE,
-    VALUE,
-    LAMBDA,
-    STATELESS_LAMBDA,
-    STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
-  } type_;
+  /// Check if the string value is empty without allocating (for std::string specialization).
+  /// For NONE, returns true. For STATIC_STRING/VALUE, checks without allocation.
+  /// For LAMBDA/STATELESS_LAMBDA, must call value() which may allocate.
+  bool is_empty() const requires std::same_as<T, std::string> {
+    switch (this->type_) {
+      case NONE:
+        return true;
+      case STATIC_STRING:
+        return this->static_str_ == nullptr || this->static_str_[0] == '\0';
+      case VALUE:
+        return this->value_->empty();
+      default:  // LAMBDA/STATELESS_LAMBDA - must call value()
+        return this->value().empty();
+    }
+  }
 
+  /// Get a StringRef to the string value without heap allocation when possible.
+  /// For STATIC_STRING/VALUE, returns reference to existing data (no allocation).
+  /// For LAMBDA/STATELESS_LAMBDA, calls value(), copies to provided buffer, returns ref to buffer.
+  /// @param lambda_buf Buffer used only for lambda case (must remain valid while StringRef is used).
+  /// @param lambda_buf_size Size of the buffer.
+  /// @return StringRef pointing to the string data.
+  StringRef ref_or_copy_to(char *lambda_buf, size_t lambda_buf_size) const requires std::same_as<T, std::string> {
+    switch (this->type_) {
+      case NONE:
+        return StringRef();
+      case STATIC_STRING:
+        if (this->static_str_ == nullptr)
+          return StringRef();
+        return StringRef(this->static_str_, strlen(this->static_str_));
+      case VALUE:
+        return StringRef(this->value_->data(), this->value_->size());
+      default: {  // LAMBDA/STATELESS_LAMBDA - must call value() and copy
+        std::string result = this->value();
+        size_t copy_len = std::min(result.size(), lambda_buf_size - 1);
+        memcpy(lambda_buf, result.data(), copy_len);
+        lambda_buf[copy_len] = '\0';
+        return StringRef(lambda_buf, copy_len);
+      }
+    }
+  }
+
+ protected : enum : uint8_t {
+   NONE,
+   VALUE,
+   LAMBDA,
+   STATELESS_LAMBDA,
+   STATIC_STRING,  // For const char* when T is std::string - avoids heap allocation
+ } type_;
   // For std::string, use heap pointer to minimize union size (4 bytes vs 12+).
   // For other types, store value inline as before.
   using ValueStorage = std::conditional_t<USE_HEAP_STORAGE, T *, T>;

From a9ce3df04c9f4db4b0d66d461d6380c45b7354d6 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 21 Jan 2026 18:36:12 -1000
Subject: [PATCH 8/9] [esp8266] Use SmallBufferWithHeapFallback in preferences
 (#13397)

---
 esphome/components/esp8266/preferences.cpp | 25 ++++------------------
 1 file changed, 4 insertions(+), 21 deletions(-)

diff --git a/esphome/components/esp8266/preferences.cpp b/esphome/components/esp8266/preferences.cpp
index 47987b4a95..35d1cd07f7 100644
--- a/esphome/components/esp8266/preferences.cpp
+++ b/esphome/components/esp8266/preferences.cpp
@@ -12,7 +12,6 @@ extern "C" {
 #include "preferences.h"
 
 #include <cstring>
-#include <memory>
 
 namespace esphome::esp8266 {
 
@@ -143,16 +142,8 @@ class ESP8266PreferenceBackend : public ESPPreferenceBackend {
       return false;
 
     const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
-    uint32_t stack_buffer[PREF_BUFFER_WORDS];
-    std::unique_ptr<uint32_t[]> heap_buffer;
-    uint32_t *buffer;
-
-    if (buffer_size <= PREF_BUFFER_WORDS) {
-      buffer = stack_buffer;
-    } else {
-      heap_buffer = make_unique<uint32_t[]>(buffer_size);
-      buffer = heap_buffer.get();
-    }
+    SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
+    uint32_t *buffer = buffer_alloc.get();
     memset(buffer, 0, buffer_size * sizeof(uint32_t));
 
     memcpy(buffer, data, len);
@@ -167,16 +158,8 @@ class ESP8266PreferenceBackend : public ESPPreferenceBackend {
       return false;
 
     const size_t buffer_size = static_cast<size_t>(this->length_words) + 1;
-    uint32_t stack_buffer[PREF_BUFFER_WORDS];
-    std::unique_ptr<uint32_t[]> heap_buffer;
-    uint32_t *buffer;
-
-    if (buffer_size <= PREF_BUFFER_WORDS) {
-      buffer = stack_buffer;
-    } else {
-      heap_buffer = make_unique<uint32_t[]>(buffer_size);
-      buffer = heap_buffer.get();
-    }
+    SmallBufferWithHeapFallback<PREF_BUFFER_WORDS, uint32_t> buffer_alloc(buffer_size);
+    uint32_t *buffer = buffer_alloc.get();
 
     bool ret = this->in_flash ? load_from_flash(this->offset, buffer, buffer_size)
                               : load_from_rtc(this->offset, buffer, buffer_size);

From a1c4d5626857d8eecb656b8d588de99759090356 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 21 Jan 2026 18:37:13 -1000
Subject: [PATCH 9/9] [alarm_control_panel] Reduce heap allocations in
 arm/disarm methods (#13358)

---
 .../alarm_control_panel.cpp                   | 55 ++++++-------------
 .../alarm_control_panel/alarm_control_panel.h | 30 ++++++++--
 .../alarm_control_panel_call.cpp              |  6 +-
 .../alarm_control_panel_call.h                |  3 +-
 .../alarm_control_panel/automation.h          | 30 +---------
 5 files changed, 49 insertions(+), 75 deletions(-)

diff --git a/esphome/components/alarm_control_panel/alarm_control_panel.cpp b/esphome/components/alarm_control_panel/alarm_control_panel.cpp
index 248b5065ad..ab0a780cef 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel.cpp
+++ b/esphome/components/alarm_control_panel/alarm_control_panel.cpp
@@ -67,52 +67,29 @@ void AlarmControlPanel::add_on_ready_callback(std::function<void()> &&callback)
   this->ready_callback_.add(std::move(callback));
 }
 
-void AlarmControlPanel::arm_away(optional<std::string> code) {
+void AlarmControlPanel::arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(),
+                                       const char *code) {
   auto call = this->make_call();
-  call.arm_away();
-  if (code.has_value())
-    call.set_code(code.value());
+  (call.*arm_method)();
+  if (code != nullptr)
+    call.set_code(code);
   call.perform();
 }
 
-void AlarmControlPanel::arm_home(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_home();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
+void AlarmControlPanel::arm_away(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_away, code); }
+
+void AlarmControlPanel::arm_home(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_home, code); }
+
+void AlarmControlPanel::arm_night(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::arm_night, code); }
+
+void AlarmControlPanel::arm_vacation(const char *code) {
+  this->arm_with_code_(&AlarmControlPanelCall::arm_vacation, code);
 }
 
-void AlarmControlPanel::arm_night(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_night();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
+void AlarmControlPanel::arm_custom_bypass(const char *code) {
+  this->arm_with_code_(&AlarmControlPanelCall::arm_custom_bypass, code);
 }
 
-void AlarmControlPanel::arm_vacation(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_vacation();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
-
-void AlarmControlPanel::arm_custom_bypass(optional<std::string> code) {
-  auto call = this->make_call();
-  call.arm_custom_bypass();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
-
-void AlarmControlPanel::disarm(optional<std::string> code) {
-  auto call = this->make_call();
-  call.disarm();
-  if (code.has_value())
-    call.set_code(code.value());
-  call.perform();
-}
+void AlarmControlPanel::disarm(const char *code) { this->arm_with_code_(&AlarmControlPanelCall::disarm, code); }
 
 }  // namespace esphome::alarm_control_panel
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel.h b/esphome/components/alarm_control_panel/alarm_control_panel.h
index 340f15bcd6..e8dc197e26 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel.h
+++ b/esphome/components/alarm_control_panel/alarm_control_panel.h
@@ -76,37 +76,53 @@ class AlarmControlPanel : public EntityBase {
    *
    * @param code The code
    */
-  void arm_away(optional<std::string> code = nullopt);
+  void arm_away(const char *code = nullptr);
+  void arm_away(const optional<std::string> &code) {
+    this->arm_away(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in home mode
    *
    * @param code The code
    */
-  void arm_home(optional<std::string> code = nullopt);
+  void arm_home(const char *code = nullptr);
+  void arm_home(const optional<std::string> &code) {
+    this->arm_home(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in night mode
    *
    * @param code The code
    */
-  void arm_night(optional<std::string> code = nullopt);
+  void arm_night(const char *code = nullptr);
+  void arm_night(const optional<std::string> &code) {
+    this->arm_night(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in vacation mode
    *
    * @param code The code
    */
-  void arm_vacation(optional<std::string> code = nullopt);
+  void arm_vacation(const char *code = nullptr);
+  void arm_vacation(const optional<std::string> &code) {
+    this->arm_vacation(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** arm the alarm in custom bypass mode
    *
    * @param code The code
    */
-  void arm_custom_bypass(optional<std::string> code = nullopt);
+  void arm_custom_bypass(const char *code = nullptr);
+  void arm_custom_bypass(const optional<std::string> &code) {
+    this->arm_custom_bypass(code.has_value() ? code.value().c_str() : nullptr);
+  }
 
   /** disarm the alarm
    *
    * @param code The code
    */
-  void disarm(optional<std::string> code = nullopt);
+  void disarm(const char *code = nullptr);
+  void disarm(const optional<std::string> &code) { this->disarm(code.has_value() ? code.value().c_str() : nullptr); }
 
   /** Get the state
    *
@@ -118,6 +134,8 @@ class AlarmControlPanel : public EntityBase {
 
  protected:
   friend AlarmControlPanelCall;
+  // Helper to reduce code duplication for arm/disarm methods
+  void arm_with_code_(AlarmControlPanelCall &(AlarmControlPanelCall::*arm_method)(), const char *code);
   // in order to store last panel state in flash
   ESPPreferenceObject pref_;
   // current state
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp b/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp
index 5e98d58368..ba58ee3904 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp
+++ b/esphome/components/alarm_control_panel/alarm_control_panel_call.cpp
@@ -10,8 +10,10 @@ static const char *const TAG = "alarm_control_panel";
 
 AlarmControlPanelCall::AlarmControlPanelCall(AlarmControlPanel *parent) : parent_(parent) {}
 
-AlarmControlPanelCall &AlarmControlPanelCall::set_code(const std::string &code) {
-  this->code_ = code;
+AlarmControlPanelCall &AlarmControlPanelCall::set_code(const char *code) {
+  if (code != nullptr) {
+    this->code_ = std::string(code);
+  }
   return *this;
 }
 
diff --git a/esphome/components/alarm_control_panel/alarm_control_panel_call.h b/esphome/components/alarm_control_panel/alarm_control_panel_call.h
index cff00900dd..58764ea166 100644
--- a/esphome/components/alarm_control_panel/alarm_control_panel_call.h
+++ b/esphome/components/alarm_control_panel/alarm_control_panel_call.h
@@ -14,7 +14,8 @@ class AlarmControlPanelCall {
  public:
   AlarmControlPanelCall(AlarmControlPanel *parent);
 
-  AlarmControlPanelCall &set_code(const std::string &code);
+  AlarmControlPanelCall &set_code(const char *code);
+  AlarmControlPanelCall &set_code(const std::string &code) { return this->set_code(code.c_str()); }
   AlarmControlPanelCall &arm_away();
   AlarmControlPanelCall &arm_home();
   AlarmControlPanelCall &arm_night();
diff --git a/esphome/components/alarm_control_panel/automation.h b/esphome/components/alarm_control_panel/automation.h
index ce5ceadb47..4ff34de0d5 100644
--- a/esphome/components/alarm_control_panel/automation.h
+++ b/esphome/components/alarm_control_panel/automation.h
@@ -66,15 +66,7 @@ template<typename... Ts> class ArmAwayAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_away();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_away(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
@@ -86,15 +78,7 @@ template<typename... Ts> class ArmHomeAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_home();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_home(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;
@@ -106,15 +90,7 @@ template<typename... Ts> class ArmNightAction : public Action<Ts...> {
 
   TEMPLATABLE_VALUE(std::string, code)
 
-  void play(const Ts &...x) override {
-    auto call = this->alarm_control_panel_->make_call();
-    auto code = this->code_.optional_value(x...);
-    if (code.has_value()) {
-      call.set_code(code.value());
-    }
-    call.arm_night();
-    call.perform();
-  }
+  void play(const Ts &...x) override { this->alarm_control_panel_->arm_night(this->code_.optional_value(x...)); }
 
  protected:
   AlarmControlPanel *alarm_control_panel_;