Microsoft Teams API
Microsoft Teams integrates through Microsoft Graph, a public REST API covering teams, channels, chat messages, presence, meetings, and change notifications. Access is self-serve with OAuth 2.0 via Entra ID, though throttling is aggressive and some per-app caps cannot be raised.
Frequently asked questions
Microsoft Teams scores A on the API Report Card. Microsoft Teams integrates through Microsoft Graph, a public REST API covering teams, channels, chat messages, presence, meetings, and change notifications. Access is self-serve with OAuth 2.0 via Entra ID, though throttling is aggressive and some per-app caps cannot be raised.
Microsoft Teams has a workable official integration path. Most engineering teams can build against it directly. Open API: self-serve, documented, with SDKs
Microsoft Teams is Microsoft's unified communications and collaboration platform combining persistent chat, video meetings, voice/PSTN calling (Teams Phone), file collaboration via SharePoint/OneDrive, and an app/extension ecosystem.
Horizontal Enterprise Collaboration / Unified Communications (UCaaS). 1:1 and group chat, channel-based team conversations, threaded replies. Video meetings, webinars, town halls, and PSTN calling via Teams Phone. File co-authoring on Word/Excel/PowerPoint backed by SharePoint/OneDrive.
9/10. Microsoft has publicly cited 320M+ monthly active users (FY23 disclosure) and Teams is the default collaboration suite for the majority of Fortune 500 organizations.
Tenants, users, groups, teams, channels (standard/private/shared), and membership graph. Chat messages, channel messages, reactions, mentions, attachments, and read receipts. Online meetings, meeting attendance reports, call records (CDRs), and PSTN usage.
Launched in March 2017 as Microsoft's Slack response and rebuilt on a new Electron-free WebView2/React-based client ('new Teams') that became GA in 2023-2024, delivering significantly faster startup and lower memory usage.
Aggressive throttling - e.g., ~4 req/sec/app per team, 1 req/sec for chat/channel POSTs - that cannot be raised. Inconsistent 429s even with exponential backoff respecting documented limits. Full sourced list under Sources below.
Common alternatives include Slack, Zoom (Workplace / Team Chat), Google Chat / Google Workspace, Cisco Webex, Mattermost, RingCentral (Glip / MVP). Graded alternatives appear under "More from the report card" below.
Grades measure one thing: can a customer's engineering team get their own data out programmatically? We check six things (whether a real API exists, how access is gated, data coverage, auth quality, docs and developer experience, and stability) and roll them into a letter grade. Grades get re-verified, and they only move on evidence.