upnext

One queue over every audio source — including the ones you don't control.

A library your product imports so that whatever is driving — a model, a person clicking, a script — can control audio without knowing whether the sound is coming from Spotify, a browser tab, a podcast feed, or a file on disk.

const runtime = new Runtime({ adapters: [spotify, browser, local, nowPlaying] });

runtime.enqueue(NOW_PLAYING_URI);                         // the podcast already
                                                          // playing in their browser
runtime.enqueue('spotify:track:1OWBh1eVxUdA1Z6UA8r4nh');  // then a Spotify track
runtime.enqueue('https://example.com/episode.mp3');       // then a file on the web
runtime.enqueue('something calmer after those');          // then whatever you decide, later

await runtime.play();

Four sources, one list, in order. The first one is playing inside an app you do not own — and the queue waits for it to finish before taking over.

What you get

Add audio to your product without marrying one service. Write against one queue; swap or add backends later. An entry describes what to play, not where from, so it can bind to whichever source is available at the moment it plays.

Join what someone is already listening to instead of talking over it. The machine's current playback — a YouTube tab, a podcast in Safari, VLC — can be a queue entry like any other. Your track starts when theirs ends.

Know what you can do before you try it. runtime.can('seek') answers for the backend that is actually loaded. No silent no-ops, no discovering at 2am that one source quietly ignored a command.

Keep playing when a source fails. If a backend cannot load an entry, the same description is handed to the next one that can. A queue does not stop because one service is down.

Survive a restart. serialize() / restore() — and a queue saved on a machine with Spotify reopens on one without it, then plays from somewhere else.

What ships today

What each one can actually do

The point of the capability model is that these differ, and say so:

... View full README on GitHub