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.
The Socket class virtual methods getpeername() and getsockname() that returned std::string have been removed. The ClientInfo struct no longer contains std::string fields.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
Several string formatting helpers that returned std::string are now soft-deprecated in favor of stack-based alternatives. This prevents heap fragmentation on long-running ESP devices.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
Several entity component getters now return StringRef instead of const char* or std::string. This improves safety by eliminating null pointer crashes and provides a modern C++ API.
This is a breaking change for external components in ESPHome 2026.1.0 and later.
The USE_ESP_IDF C++ define and related Python APIs are deprecated. Since Arduino-ESP32 is built on ESP-IDF, all IDF APIs are available on ESP32 regardless of framework selection.
This is a breaking change for external components in ESPHome 2026.1.0 and later.