How can we "like" or add other reactions to someone else's channel message or comment via the Graph API?
How can we "like" or add other reactions to someone else's channel message or comment via the Graph API?
I've not done this myself, but it certainly looks possible. You need to reply to the message, as per https://docs.microsoft.com/en-us/graph/api/channel-post-messagereply?view=graph-rest-1.0&tabs=http and notice that it has a "reactions" collection. That would be populated with a chatMessageReaction type, as per https://docs.microsoft.com/en-us/graph/api/resources/chatmessagereaction?view=graph-rest-beta
Note of warning: chatMessageReaction is a beta type though, so just be aware you need to call the beta endpoint, and it has a risk to use in production code as things might change.
Update: We reached out to MS Support and received the following info: "The API to reply to a message using a POST /replies request is solemnly for issuing a reply to a message, and not to edit the status of the parent message itself. Moreover, the "update chatMessage" API which is a PATCH /messages and which is the only API to edit a parent message only supports updating the policyViolation property of a chatMessage. Essentially, there is currently no documented API / already-present API examples on how to add a reaction, making this purely unsupported."