ESP32 Arduino builds now disable all Arduino libraries by default. ESPHome uses ESP-IDF APIs directly for WiFi, networking, and BLE, so most Arduino libraries were compiled and linked but never called. External components that use Arduino libraries must explicitly enable them via cg.add_library().
This is a breaking change for external components in ESPHome 2026.2.0 and later.
get_preference_hash() is deprecated. Use the new make_entity_preference<T>() method to create preference objects for storing entity state. This prepares for fixing preference hash collisions that cause entities to overwrite each other's stored data.
This is a breaking change for external components in ESPHome 2026.2.0 and later.
The set_retry, cancel_retry, and RetryResult APIs are deprecated. They will be removed in ESPHome 2026.8.0. Use set_timeout or set_interval instead.
This is a breaking change for external components in ESPHome 2026.2.0 and later.
WiFi and Logger components now use StaticVector for listener storage, eliminating heap allocation and STL overhead. External components that register listeners must now call request functions during code generation.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
The scheduler's std::string-based APIs (set_timeout, set_interval, set_retry, defer, and their cancel counterparts) are now deprecated. Use const char* string literals or uint32_t numeric IDs instead.
This deprecation affects ESPHome 2026.1.0 and later, with removal planned for 2026.7.0.
The App.get_compilation_time() method is deprecated in favor of new constexpr methods. The compilation_time field in the native API now updates on every compile.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
The callback signatures for text_sensor, text, and select components have been updated to reduce heap allocations. The select component callback signature has changed significantly.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
ESP8266 builds now exclude unused Serial objects and waveform/PWM code by default. External components using these features must explicitly enable them.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
The GPIOPin::dump_summary() virtual method now writes to a caller-provided buffer instead of returning std::string. This eliminates heap allocations during configuration dumps.
This is a breaking change for external components that implement custom GPIO pins in ESPHome 2026.1.0 and later.
The OTA component now uses a listener interface instead of std::function callbacks. The alarm control panel component has removed per-state callback methods in favor of a unified state callback.
This is a breaking change for external components in ESPHome 2026.1.0 and later.