Microsoft Teams

Teams is accessed through Microsoft Graph API — there's no standalone Teams API. This means agents must navigate Azure AD app registration, Graph permissions, and the broader Microsoft 365 ecosystem to interact with Teams. The Teams-specific Graph endpoints cover team/channel management, channel messages, chat messages, and meeting management. The Bot Framework enables agents to build interactive bots within Teams. For agents already in the Microsoft ecosystem, Graph integration is powerful: cross-product access to calendar, files, mail, and Teams from a single API. For agents outside the Microsoft ecosystem, the integration overhead is significant. The permission model distinguishes between delegated (user context) and application (daemon/agent context) permissions — agents typically need application permissions, which require admin consent.

Authentication requires Azure AD (Entra ID) app registration. Application permissions (for daemon/agent access without user context) require admin consent for the tenant. Common permissions needed: TeamSettings.ReadWrite.All, ChannelMessage.Send, Chat.ReadWrite.All, Group.ReadWrite.All. Token acquisition uses MSAL (Microsoft Authentication Library) or direct OAuth 2.0 client_credentials flow. Access tokens expire in ~1 hour. Certificate-based auth is supported and recommended for production agents. The permission model is the most complex among communication platforms — some operations require delegated permissions only, creating scenarios where application-level agents can't perform certain actions. Multi-tenant app registration adds further complexity. For agents, the auth setup is the primary barrier to entry.

Documentation is extensive at learn.microsoft.com/graph but navigating the Teams-specific content within the larger Graph documentation requires familiarity with the Microsoft docs structure. Graph Explorer (developer.microsoft.com/graph/graph-explorer) provides interactive API testing. Teams-specific quick starts and tutorials exist. The Bot Framework documentation is separate and substantial. SDKs (Microsoft Graph SDK) are available for .NET, JavaScript, Python, Java, Go, and PHP. The documentation's main weakness: conceptual complexity is inherent — agents must understand Azure AD, Graph, and Teams concepts simultaneously. For enterprise-focused agents, the documentation depth is a strength. For agents from non-Microsoft backgrounds, the learning curve is steep.

Teams resources are accessed via Microsoft Graph at graph.microsoft.com/v1.0/teams/{team-id}/channels, /chats, /messages. Channel message creation supports rich text with HTML and adaptive card attachments. The change notifications (webhooks) API provides real-time event subscriptions for message creation and team membership changes — subscriptions require renewal every 60 minutes (max). The API supports batch requests via /$batch endpoint, enabling agents to bundle multiple operations. Pagination uses @odata.nextLink URLs. The data model is relational: teams contain channels, channels contain messages, messages contain replies. Chat API covers 1:1 and group chats. Meeting scheduling goes through the calendar API. The API surface is powerful but requires Graph fluency.

Graph API errors return JSON with error.code and error.message fields. Throttling is aggressive: 429 Too Many Requests with Retry-After header. Teams-specific rate limits include message sending limits per channel per app. The throttling documentation provides general patterns but specific per-endpoint limits aren't always published — agents must handle 429s defensively. Change notification subscriptions can fail silently if the notification URL becomes unreachable — agents must monitor subscription health. Token acquisition errors from Azure AD include descriptive AADSTS error codes. Batch request errors are per-operation within the batch response. The Graph API generally handles errors well but the Teams-specific constraints (message rate limits, subscription renewal requirements) add operational complexity.