Skyjam API

The Skyjam service API is used by the Google Play Music application for Android. It is a JSON API that provides access to songs and playlists.

This is unofficial, and not otherwise documented by Google. Parts of this were originally posted at http://dpogue.ca/gmusic.html.

Authenticating

The service API uses Google's ClientLogin for authentication. This process is documented fairly thoroughly in [http://code.google.com/apis/accounts/docs/AuthForInstalledApps.html](Google's API documentation) and we can copy their sample requests exactly, aside from the value of the service parameter.

The service parameter value for Skyjam is sj

Using cURL, I was able to get an auth token with the following command:

curl -d accountType=GOOGLE \
     -d Email=jondoe@gmail.com \
     -d Passwd=north23AZ \
     -d service=sj \
     https://www.google.com/accounts/ClientLogin

The response should contain 3 values, SID, LSID, and Auth. We need the Auth token value for authenticating our API requests.

Making a request

According to the URIs from the Android client, the base for API requests is https://www.googleapis.com/sj/v1beta1/. All requests return JSON data, matching the definitions below.

When making a request, we need to include the Auth token as an HTTP header. Using cURL, that looks like this:

curl --header "Authorization: GoogleLogin auth=YOUR_AUTH_TOKEN" \
     https://www.googleapis.com/sj/v1beta1/tracks

If everything is successful, you should get back a JSON response containing all of the metadata for all of your tracks.

JSON Models

TrackFeed

This stores a (partial) list of tracks, and sometimes a token for requesting the rest of the list.

Key	Meaning
`nextPageToken`	A token which can be used to fetch the next page of tracks. This is only present if there are more than 5000 tracks in the library.
`data`	A TrackFeedData object.

TrackFeedData

This stores a list of tracks.

Key	Meaning
`items`	A JSON array of Track objects

Track

This model stores the metadata associated with a single track.

Key	Meaning
`album`	The album name
`albumArtRef`	A JSON array of AlbumArtRef objects
`albumArtist`	The name of the album artist
`albumId`	The internal ID of the album (only present if bought from the store?)
`artist`	The artist name
`beatsPerMinute`	The number of beats per minute
`comment`	A comment
`composer`	The composer name
`creationTimestamp`	A timestamp representing the track's creation on the server
`discNumber`	The disc number
`durationMillis`	The duration of the track in milliseconds
`estimatedSize`	The estimated size of the track (in bytes? kilobytes?)
`genre`	The genre
`deleted`	Boolean indicating whether the track has been deleted
`lastModifiedTimestamp`	Timestamp of the last modificaton
`playCount`	The number of times the track has been played
`rating`	The 1-5 rating (as a string, not an integer!)
`id`	The server ID of the track (also called RemoteID sometimes)
`storeId`	The ID of the track in the store (only present for store bought tracks)
`title`	The track title
`totalDiscCount`	The total number of discs
`trackNumber`	The track number
`trackType`	The type of track (certain values indicate it's a store bought track)
`year`	The year

PlaylistFeed

This stores a (partial) list of playlists, and sometimes a token for requesting the rest of the list.

Key	Meaning
`nextPageToken`	A token which can be used to fetch the next page of playlists.
`data`	A PlaylistFeedData object.

PlaylistFeedData

This stores a list of playlists.

Key	Meaning
`items`	A JSON array of Playlist objects

Playlist

This stores the information about a playlist.

Key	Meaning
`creationTimestamp`	The timestamp of when the playlist was created.
`deleted`	Boolean indicating whether the playlist has been deleted.
`lastModifiedTimestamp`	The timestamp of when the playlist was last modified.
`name`	The name of the playlist.
`id`	The server ID of the playlist.
`type`	`"USER_GENERATED"` or `"MAGIC"`

Requests

All POST requests must set the Content-Type to application/json!

Tracks

Get the list of tracks

GET https://www.googleapis.com/sj/v1beta1/tracks

Returns: TrackFeed

Get the rest of the tracks using the continuation token

POST https://www.googleapis.com/sj/v1beta1/trackfeed

Returns: TrackFeed

The body is a JSON object with the following key:

Key	Meaning
`start-token`	The value of the `nextPageToken` from the TrackFeed

Get a single track

GET https://www.googleapis.com/sj/v1beta1/tracks/<track ID>

Returns: Track

Playlists

Get a list of all playlists

GET https://www.googleapis.com/sj/v1beta1/playlists

Returns: PlaylistFeed

Get the rest of the playlists using the continuation token

POST https://www.googleapis.com/sj/v1beta1/playlistfeed