Mattermost

aid: mattermost
name: Mattermost
description: >-
  Mattermost is an open-source collaboration platform for technical teams
  that combines secure team messaging, workflow automation, voice/video
  calling, and integrations as a self-hosted Slack alternative. The
  Mattermost REST API exposes full programmatic control over users,
  teams, channels, posts, files, integrations, plugins, and webhooks.
type: Index
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
  - Messaging
  - Collaboration
  - Team Chat
  - Open Source
  - DevOps
  - Self-Hosted
url: https://raw.githubusercontent.com/api-evangelist/mattermost/refs/heads/main/apis.yml
created: '2026-05-11'
modified: '2026-05-29'
specificationVersion: '0.19'
apis:
  - aid: mattermost:rest-api
    name: Mattermost REST API
    description: >-
      REST API v4 for managing users, teams, channels, posts, threads,
      files, integrations, plugins, webhooks, slash commands, and
      OAuth applications. Authentication uses Personal Access Tokens
      or session tokens via Bearer authentication.
    humanURL: https://api.mattermost.com/
    baseURL: https://your-mattermost-server.com/api/v4
    tags:
      - Messaging
      - Users
      - Teams
      - Channels
      - Posts
      - Webhooks
      - Integrations
    properties:
      - type: Documentation
        url: https://api.mattermost.com/
      - type: APIReference
        url: https://developers.mattermost.com/integrate/reference/rest-api/
      - type: OpenAPI Source
        url: https://github.com/mattermost/mattermost-api-reference
      - type: Developer Guide
        url: https://developers.mattermost.com/contribute/more-info/server/rest-api/
  - aid: mattermost:websocket-api
    name: Mattermost WebSocket API
    description: >-
      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.
    humanURL: https://developers.mattermost.com/api-documentation
    baseURL: wss://your-mattermost-server.com/api/v4/websocket
    tags:
      - WebSocket
      - Events
      - Real-Time
      - Messaging
      - AsyncAPI
    properties:
      - type: Documentation
        url: https://developers.mattermost.com/api-documentation
      - type: AsyncAPI
        url: https://raw.githubusercontent.com/api-evangelist/mattermost/refs/heads/main/asyncapi/mattermost-asyncapi.yml
      - type: APIReference
        url: https://developers.mattermost.com/integrate/reference/rest-api/
common:
  - type: LinkedIn
    url: https://www.linkedin.com/company/mattermost
  - type: Website
    url: https://mattermost.com
  - type: Documentation
    url: https://docs.mattermost.com
  - type: Developer Portal
    url: https://developers.mattermost.com/
  - type: GitHubOrganization
    url: https://github.com/mattermost
  - type: SignUp
    url: https://mattermost.com/sign-up/
  - type: Pricing
    url: https://mattermost.com/pricing/
  - name: MCP Server
    url: https://github.com/mattermost/mmctl-mcp
    type: MCPServer
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com