2.4 KiB
Fully read markers
The history for a given room may be split into three sections: messages the user has read (or indicated they aren't interested in them), messages the user might have read some but not others, and messages the user hasn't seen yet. The "fully read marker" (also known as a "read marker") marks the last event of the first section, whereas the user's read receipt marks the last event of the second section.
Events
The user's fully read marker is kept as an event in the room's account data. The event may be read to determine the user's current fully read marker location in the room, and just like other account data events the event will be pushed down the event stream when updated.
The fully read marker is kept under an m.fully_read event. If the
event does not exist on the user's account data, the fully read marker
should be considered to be the user's read receipt location.
{{% event event="m.fully_read" %}}
Client behaviour
The client cannot update fully read markers by directly modifying the
m.fully_read account data event. Instead, the client must make use of
the read markers API to change the values.
{{< changed-in v="1.4" >}} m.read.private receipts can now be sent from
/read_markers.
The read markers API can additionally update the user's read receipt
(m.read or m.read.private) location in the same operation as setting
the fully read marker location. This is because read receipts and read
markers are commonly updated at the same time, and therefore the client
might wish to save an extra HTTP call. Providing m.read and/or
m.read.private performs the same task as a request to
/receipt/{receiptType}/{eventId}.
{{% http-api spec="client-server" api="read_markers" %}}
Server behaviour
The server MUST prevent clients from setting m.fully_read directly in
room account data. The server must additionally ensure that it treats
the presence of m.read and m.read.private in the /read_markers
request the same as how it would for a request to
/receipt/{receiptType}/{eventId}.
Upon updating the m.fully_read event due to a request to
/read_markers, the server MUST send the updated account data event
through to the client via the event stream (eg: /sync), provided any
applicable filters are also satisfied.