ESPHome 2025.11.0 introduces memory optimizations to the Event entity class that reduce heap usage and store event type strings in flash. These changes affect external components implementing custom event devices.
ESPHome 2025.11.0 introduces a memory optimization to the Fan entity class that also changes how preset modes are ordered. This affects external components implementing custom fan devices and may change the display order of preset modes in Home Assistant.
ESPHome 2025.11.0 introduces memory optimizations to the Light entity class that reduce both heap and flash usage. These changes affect external components implementing custom light devices and effects.
ESPHome 2025.11.0 introduces significant optimizations to the Select entity class that reduce memory usage and improve performance. These changes affect external components that implement custom select entities.
The core automation framework (actions, triggers, and conditions) has been optimized to use const references instead of pass-by-value for parameter passing. This reduces memory allocations by 83% in the automation execution path.
This is a breaking change for external components with custom actions or conditions in ESPHome 2025.11.0 and later.
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