MSC for allowing anyone to create widgets in private rooms

proposals/3144-allow-widgets-in-private-rooms.md

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+# MSC3144: Allow Widgets By Default in Private Rooms
+
+As it stands, the default power levels of matrix rooms only allow the room creator and those
+granted sufficient power level the ability to add widgets to the room. This includes starting
+group calls. This is desirable in a public room, but in a private room where participants are
+generally trusted, it hinders users trying to make group calls.
+
+## Proposal
+
+This MSC proposes allowing all users to edit room widgets, including placing and ending group calls,
+in the default room configuration.
+
+It proposes to accomplish this by changing the `private_chat` preset on `createRoom` to send the
+`m.room.power_levels` event with the `im.vector.modular.widgets` event at the `users_default` level
+(ie. normally 0).
+
+There are a couple of stubling blocks in doing so, listed below. This MSC hopes to elicit discussion
+on whether any other solutions exist to these issues or whether they are acceptable tradeoffs.
+
+## Potential issues
+
+1. This change would happen on server implementation without clients or users knowing anything had
+   changed, so it could surprise users who are used to the current configuration, leaving them with
+   a private room where others can add widgets unexpectedly.
+
+1. Room admins might later change the room to be a public room without realising that anyone can
+   edit widgets, resulting in an insecure configuration.
+
+## Alternatives
+
+We could instead make a separate preset that did this and migrate clients over to using it. This would
+require all clients to make changes though. We could instead make this behaviour dependent on the version
+in the API URL.
+
+Another option would be to have clients change this power level after creating a room, so the client
+could warn the user that this setting was being applied, or give the user a choice. However, this would
+mean that the behaviour of rooms would diverge depending on what client they were created with, which is
+probably far more confusing.
+
+Changing a room from private to public is harder to work around. Clients can add a warning for this case
+but even if this MSC made such a warning mandatory, older clients will still exist.
+
+## Security considerations
+
+None forseen other than those detailed in 'potential issues'.
+
+## Unstable prefix
+
+N/A