MSC3868: Room contribution

Follow the progress of the PR here.

Many projects and communities have a room on Matrix nowadays and many may wish to show their friends how to support them. The goal, would be to have something only visible to room & space members and to provide something easier to manage & display than putting links into the room topic or announcing them periodically.

Proposal

This proposal implements a new m.room.contribute state event. This state event contains a “uri” parameter that may link to a git repo or any kind of URI and a “text” parameter that may contain the text of the button directing to the support link. There may be multiple “uri” and “text” parameters, each adding a different button containing a different link. Alternatively to the “uri” parameter, a “copy” one can be specified and will tell clients to copy the value in the clipboard. Another, optional, “badge_uri” parameter may be specified and only may contain a MXC URI to a image media. When specified, the image, or badge, is displayed in place of the text, the text becoming the alt property of said image. An example of this event would look like this:

{
  "links": [
    {
      "uri": "https://git.me/contribute",
      "text": "Contribute code!"
    },
    {
      "uri": "https://translate.me/contribute",
      "text": "Translate the project!"
    },
    {
      "uri": "mailto:team@verygoodproje.ct",
      "text": "Get in touch!"
    },
    {
      "text": "Donation IBAN",
      "copy": "CH5604835012345678009"
    },
    {
      "uri": "https://liberapay.com/foo",
      "text": "Support us on LiberaPay",
      "badge_uri": "mxc://jae.fi/5d718eb34d05c8b6b1304e2a106aa800400476a6"
    }
  ]
}

Potential issues

The authors aren’t aware of any potential issues being raised.

Alternatives

Historically, that sort of advertisement is either taken care of by adding the said URIs to the room topic or periodically sending an announcement in the channel. However room topic is public information when the room has m.room.join_rules other than invite.

Security considerations

State events are currently not encrypted which could leak some data.

Unstable prefix

Unstable implementations should use the state event type of eu.dn0.msc3868.rev1.room.contribute

Dependencies

The authors believe this MSC could benefit from MSC3414: Encrypted State Events while not considering it as a blocker. Given the use of MXC URIs to display badges, the implementation of MSC3468: MXC to Hashes would benefit the current MSC while, again, not blocking its implementation.