server

Music Assistant pulls your streaming subscriptions and your local files into one library, then plays it on whatever speakers you already own. It is the bridge between where your music lives (a streaming service, a NAS full of FLAC files) and where you want it playing (Chromecast, Sonos, AirPlay, and similar targets). Free and Apache 2.0 licensed, running as an always-on service.

It expects a machine that stays on: a Raspberry Pi, a NAS, or an Intel NUC. Two install paths, and both bundle every system dependency the server needs. The Home Assistant add-on is the recommended route, and a Docker container is the other. Home Assistant itself is not required. The server runs standalone, it is just built to sit beside Home Assistant so your automations can control playback.

Free, with no tier to buy and nothing gated. This is for anyone whose music is scattered across services and hardware and who wants a single queue driving every speaker in the house. The Home Assistant crowd is the obvious audience, but you do not have to be in it.

The catch is that it inherits every streaming provider's restrictions. Services change APIs, break integrations, and some do not permit third-party playback at all, so support varies by provider and can regress without warning through no fault of the project. Confirm your specific service works before you rebuild your whole listening setup around it.