matrix-spec-proposals/proposals/4320-rich-presence.md

MSC4320: Rich Presence

Context

Discord, a popular instant messenger, has a feature where alongside normal presence (ie online/away/busy/offline, status messages) there can be current activities. For example, music shows album art, song name, artist and current song progress, games show the map and such, etc.

Proposal

Data transport

JSON data will be sent over a websocket running on http://localhost:{TBD}/rpc. This will be easiest for native clients, web clients will require something running on the host. Clients will send data to the server via a PUT to /_matrix/client/v3/profile/{userId}/m.rpc with content explained in "data content". Servers should preform basic validation on m.rpc to ensure only the needed fields are included. After an activity is closed or a song is paused/stopped, aDELETE should be sent to _matrix/client/v3/profile/{userId}/m.rpc. Note that skipping a track should not delete the RPC, as long as there's music playing. In that event, the m.rpc field should just be updated.

Data federation

m.rpc data will be federated over a GET to /_matrix/client/v3/profile/{userId}/m.rpc, as per MSC4133.

Data content

All rich presence needs a type (can be "m.rpc.media" or "m.rpc.activity") within m.rpc. Each type has different requirements. m.rpc.media is for media and m.rpc.activity is for general activities (usually games). Required fields if type is m.rpc.media:

• artist containing the artist.
• album containing the album.
• track containing the track name.

Required fields if type is m.rpc.activity:

• name containing the activity name.

Optional fields if type is m.rpc.media:

• progress containing length with the length of the track in seconds.
  • time_complete is needed for clients to show the media progress. It should only be updated in the event of the timestamp not being able to be guessed by a client.
  • Both of these are highly recommended to be added.
• cover_art containing a MXC with the album art. Clients should hash the album art and re-use the MXC for album art matching that hash to avoid duplicating uploads.
• player containing the media player.
• streaming_link containing a link to the song on streaming services (i.e. Spotify, YouTube). Clients should warn the user before opening the link.

Optional fields if type is m.rpc.activity:

• image containing an MXC to show as an activity image. Clients should hash the image and re-use the MXC for album art matching that hash to avoid duplicating uploads.
• details containing details (i.e. current map, location, etc). If m.rpc is not present within a profile, clients can assume that the user either chose not to send RPC or doesn't have anything sending RPC right now.

Examples

Media:

{
	"avatar_url": "…", "displayname": "…",
	"m.rpc": {
	    "type": "m.rpc.media",
	    "progress"{
		"length": 204,
		"complete": 102,
	    },
	    "artist": "ari melody",
	    "album": "free2play",
	    "track": "FTL (Faster Than Light)",
	    "cover_art": "mxc://ip-logger.com/YS5tqBewwZ4HFF3hU9KT8OskREUmlPfM",
	    "player": "Spotify",
	    "streaming_link": "https://open.spotify.com/track/1zJWGrUJ7dy7wQuMSVbvCn"
	}
}

Games:

{
	"avatar_url": "…", "displayname": "…",
	"m.rpc": {
		"type": "m.rpc.activity",
		"name": "SuperTuxKart",
		"details": "Playing Oliver's Math Class as Xenia on Intermediate"
	}
}

Potential implementations

• Something using arRPC to pretend to be Discord to get info.
• A script mirroring the "now playing" feature on last.fm or ListenBrainz.
• A Visual Studio Code extension showing the open project, file, etc. Maybe even errors in the code!

Security considerations

This introduces a privacy risk, as not all users want to broadcast the current song or activity they're doing. Therefore, this feature must not be enabled by default on clients that support this MSC. Clients supporting this feature may notify the user in a non-intrusive way.

Alternatives

None considered.

Potential issues

Web clients need to run something on the host, decreasing portability. This can't really be solved.

Unstable prefix

While in development, clients implementing this MSC should use com.ip-logger.msc4320.rpc(.*) instead of m.rpc(.*).