MSC3395: Synthetic appservice events

[Half-Shot]

Rendered

Initial implementation for Synapse here
Initial implementation for the matrix-bot-sdk here

[Half-Shot]

I'm not a fan of the name, happy to for something better. Mainly to distinguish that these aren't "real" events.

[Half-Shot]

These 4 were chosen for their simplicity / needs for my projects, but happy to consider more

[ShadowJonathan]

I think this is reasonable and good as-is.

This also potentially opens up the door for tight modded homeserver <-> modded appservice integration via this method with the prospect of homeservers allowing custom synthetic events to be sent over this "channel", which is exciting.

[ShadowJonathan]

Bikeshed: What about introducing a synthetic namespace where these events are listed instead? I assume this'd be helpful if it were introduced for all users, i think an additional "exclude" (by regex) key could be useful in the future then to exclude the likes of bridged users (to reduce noise)

[Half-Shot]

So the plan atm is to have the m.synthetic_events key sit under the user namespaces, which organically excludes users we don't care about and only include users we do care about.

If you did want all users, you could do a .*. If you wanted all users except bridges, I'd imagine you'd have a regex that negatively matches the bridge users?

There might be scope for a exclusionary namespace eventually for ease of configuration, but definitely out of scope for this MSC

[Half-Shot]

Noting that @Yoric had some interest in being able to intercept reports from users into services, so perhaps the ideal flow is that appservices are sent reports via this mechanism.

[Half-Shot]

Media creation / deletion would be a good one too.

[turt2live]

@Half-Shot what sort of review are you looking for on this? It's made it onto the SCT board, but without context.

[turt2live]

oob conversation has lead to a realization of not being sure why this is on the board - removing.