Mattermost WebSocket API

Real-time WebSocket event stream for Mattermost v4. Clients connect to /api/v4/websocket, authenticate via cookie, Authorization header, or an authentication_challenge action, and receive event envelopes (event, data, broadcast, seq) covering posts, channels, users, teams, reactions, typing, status, threads, plugins, and more. Client actions user_typing, get_statuses, and get_statuses_by_ids are supported over the same socket.