HomeAssistant-API v6.0 Changelog

Breaking Changes

A lot has changed in this version. A lot went into modernising and standardizing the interfaces of the clients.
As such, many of the previous paradigms have changed. If you run into any bugs or issues, please let us know.

Minimum Python version raised to 3.11

Python 3.9 and 3.10 are no longer supported.

Client classes restructured

The old Client class (which combined sync and async via a use_async flag) has been removed. There are now four distinct client classes:

Async client methods no longer have the async_ prefix — e.g. async_get_states() is now just get_states() on AsyncClient.

Models split into Base/Sync/Async variants

Domain, Entity, Group, Service, and Event now have three variants each:

• Base* — plain data, no client reference
• * (e.g. Domain) — sync, bound to Client
• Async* (e.g. AsyncDomain) — async, bound to AsyncClient

Processing module rewritten

The decorator-based @Processing.processor(mimetype) registry has been replaced with simple dict-based MIME dispatch and separate sync/async entry points. Custom processor registration and the decode_bytes parameter have been removed.

Build system moved from Poetry to uv + hatchling

poetry.lock is removed. The project now uses uv for dependency management and hatchling as the build backend.

Type checker changed from mypy to zuban

New Features

WebSocket API support (sync & async)

Full WebSocket client implementation for both sync (WebsocketClient) and async (AsyncWebsocketClient) with support for:

• Config entries — get, disable, enable, ignore flow, subentries, subscribe
• Entity registry — list, get, update, remove entries
• Events — subscribe, fire, and listen
• Services — trigger with full domain/service routing
• Templates — render and subscribe to template updates

Entity registry models

New models: EntityRegistryEntry, EntityRegistryEntryExtended, EntityRegistryUpdateResult.

Configurable WebSocket max message size

WS clients accept a max_size parameter (default 16 MB) to handle large responses like full entity registry lists.

Improvements

• Unified method signatures across all four client classes for consistency
• Expanded ruff lint rules to ALL (from just E, F, W)
• Test coverage at 100%
• Modernized type annotations throughout
• Response content is now read lazily, eliminating internal _buffer access hacks
• Migrated HTTP/async/WebSocket transport from requests/aiohttp/websockets to niquests
• Cassette-based testing via nimax — tests replay pre-recorded HTTP cassettes and no longer require a running Home Assistant instance
• CI simplified: dropped Docker Compose, pytest runs directly against cassettes