sactivity

Spotify WebSocket Activity API Library

How it works

Sactivity has two exports, Sactivity and SpotifyClient.

Sactivity is a class that connects to Spotify for you.
1. It takes your Spotify authoirzation and uses it to generate a token for connecting to Spotify.
2. Then, it connects to one of multiple Spotify "dealers" that push notifications over a WebSocket.
3. It passes this socket to SpotifyClient, but you can also connect to Spotify on your own and pass it to SpotifyClient.
SpotifyClient handles everything after connecting to the WebSocket, which can still involve some required REST requests.
1. Waits to receive an initialization payload from Spotify, which includes a connection ID
2. Calls PUT https://api.spotify.com/v1/me/notifications/user?connection_id=${connectionID} to subscribe to activity on the account associated with the connection ID, and by relation, the authorization you provided.
3. Calls POST https://guc-spclient.spotify.com/track-playback/v1/devices and temporarily registers a fake Spotify Web Client that will receive notifications from Spotify.
4. Calls PUT https://guc-spclient.spotify.com/connect-state/v1/devices/hobs_${clientID} and subscribes to media player events.
5. SpotifyClient will now emit various events as the media presence changes.

Event Name	Description	Data Type
volume	Emitted whenever the volume has changed	number
playing	Emitted whenever music is playing again	void
stopped	Emitted whenever music is stopped	void
paused	Emitted whenever music is paused	void
resumed	Emitted whenever music is resumed	void
track	Emitted whenever a new track is playing	SpotifyTrack
options	Emitted whenever playback options have changed (shuffle, repeat, repeat-one)	PlaybackOptions
position	Emitted whenever the position in a song has changed. This includes at the start of a new track.	string
device	Emitted whenever the device that is playing music has changed.	SpotifyDevice
close	Emitted whenever the WebSocket has closed. This is a cue to reconnect after a set amount of time.	void

In the tests folder, you can find a working example.

Data types are declared here

Sactivity works off of cookies issued by Spotify upon login, which seem to persist for quite a while. Here's how to obtain the cookies needed:

Open Chrome
Open devtools
Go to the network inspector, and in the filter type "get_access_token"
Navigate to https://open.spotify.com in that tab
Click on the network request that shows up, then copy the entirety of the cookie header in the Request headers.