Developer Reference

REST and WebSocket APIs

Your server exposes a REST API under /api/ and a WebSocket API at /api/websocket. Authenticate with a long-lived access token created from your user profile page.

Built on open source

ProjectX42 is a fork of Home Assistant, distributed under the Apache License 2.0. The architecture — integrations, entities, services, the event bus — is unchanged, so upstream developer material remains technically accurate for anyone extending ProjectX42, even though the branding and hosted services differ.

ProjectX42 is an independent project and is not affiliated with, endorsed by, or sponsored by Home Assistant, Nabu Casa, or the Open Home Foundation.

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