Receipts ======== Receipts are used to publish which events in a room the user or their devices have interacted with. For example, which events the user has read. For efficiency this is done as "up to" markers, i.e. marking a particular event as, say, ``read`` indicates the user has read all events *up to* that event. Client-Server API ----------------- Clients will receive receipts in the following format:: { "type": "m.receipt", "room_id": , "content": { : { : { : { "ts": , ... }, ... } }, ... } } For example:: { "type": "m.receipt", "room_id": "!KpjVgQyZpzBwvMBsnT:matrix.org", "content": { "$1435641916114394fHBLK:matrix.org": { "read": { "@erikj:jki.re": { "ts": 1436451550453 }, ... } }, ... } } For efficiency, receipts are batched into one event per room. In the initialSync and v2 sync APIs the receipts are listed in a seperate top level ``receipts`` key. Each ``user_id``, ``receipt_type`` pair must be associated with only a single ``event_id``. New receipts that come down the event streams are deltas. Deltas update existing mappings, clobbering based on ``user_id``, ``receipt_type`` pairs. A client can update the markers for its user by issuing a request:: POST /_matrix/client/v2_alpha/rooms//receipt/read/ Where the contents of the ``POST`` will be included in the content sent to other users. The server will automatically set the ``ts`` field. Server-Server API ----------------- Receipts are sent across federation as EDUs with type ``m.receipt``. The format of the EDUs are:: { : { : { : { } }, ... }, ... } These are always sent as deltas to previously sent reciepts.