List unread messages

Being able to tell which messages have been read is a feature in the Javascript Webex SDK, but this should be exposed in the REST API. Being able to tell which messages have been read and query unread messages allows for processing of unread messages by bots to e.g. tell you what you have missed.

Currently this is impossible to do with the existing API which blocks any features that wants to process unread messages, but forces developers to use Javascript SDK to get access to this feature, which is infeasible for codebases built in other languages e.g. Python.

Something like this would also be beneficial for allowing you to see who has read a particular message, allowing to implement similar 'Seen by' functionality currently in the Webex app.

This should work by having Seen events like in the Javascript SDK so that the last message seen by a user in a room can be tracked which would allow to fetch messages up to this last seen message. The result of this could then be exposed by REST endpoints.

Here is a related idea:

https://ciscocollabcustomer.ideas.aha.io/ideas/WXCUST-I-2635