io.github.chrischall/microsoft-teams-mcp

microsoft-teams-mcp

MCP server for Microsoft Teams — list your chats, teams and channels, and read whichever chat or channel is currently open, routed through your signed-in browser tab.

This project was developed and is maintained by AI (Claude Code). Use at your own discretion.

How it works — and its one real limitation

Teams Web's chat and message data lives only in a client-side cache fed by a WebSocket/registrar sync channel — there is no REST or GraphQL endpoint that returns it. So this server does not capture a token and make plain server-side requests the way an API-backed MCP would; instead every call routes through the fetchproxy browser bridge and reads the DOM your signed-in teams.cloud.microsoft tab has already rendered. teams.microsoft.com (the old host) is not supported.

That has one real consequence: this server can only read whichever chat or channel is currently displayed in your browser tab. The bridge can fetch and read — it cannot navigate a tab to a different conversation. teams_list_chats and teams_list_teams_and_channels always work (their sidebars are always rendered once that nav section is open); teams_get_open_chat_messages and teams_get_open_channel_posts read whatever conversation you have open. To read a different chat or channel, open it in the browser first.

The bridge is on the request path for every call here, not just once to mint a token — unlike an API-backed MCP, there is nothing to cache between calls.

Install

npm i -g @chrischall/microsoft-teams-mcp

Requires the Transporter Chrome extension and @fetchproxy/cli, on a matching major version:

npm i -g @fetchproxy/cli

The first call prints a 6-digit pair code to approve in the Transporter popup; the grant persists.

Install in opencode

opencode reads MCP servers from opencode.json (project) or ~/.config/opencode/opencode.json (global):

{
  "mcp": {
    "servers": {
      "teams": {
        "type": "local",
        "command": ["npx", "-y", "@chrischall/microsoft-teams-mcp"]
      }
    }
  }
}

Configuration

Everything is optional — this server needs no credentials of its own.

variable	purpose
TEAMS_WS_PORT	fetchproxy concentrator port. Defaults to 37149, the fleet-wide shared port.

Tools

• teams_list_chats — the Chat sidebar: title, last-message preview, last-activity time, and Teams' own conversation id for each chat.
• teams_get_open_chat_messages — the message thread of whichever chat is currently open: sender, ISO-8601 time, message id, and text.
• teams_list_teams_and_channels — the Teams-and-Channels sidebar (a DIFFERENT view from Chat): every team and channel the user belongs to, with each channel's parent team name.
• teams_get_open_channel_posts — the top-level posts of whichever channel is currently open: sender, subject (when present), prose time (not ISO-8601 — Teams doesn't expose one for these), message id, and text. Threaded replies under a post are not included.
• teams_get_activity — the Activity feed (the bell icon in the left nav): mentions, replies, reactions, and the like across every chat and channel, each with its title, message preview, prose time, and location (the team/channel or chat it happened in). Requires the Activity view open.
• teams_healthcheck — verifies the bridge can reach a signed-in tab.

All five data tools are read-only and take no arguments.

No Calendar tool here. Teams Web's Calendar renders inside an embedded outlook.office.com iframe, which the fetchproxy bridge (DOM reads only against the top-level tab, no iframe crossing) cannot reach — and isn't the right place for it anyway. Use office-outlook-mcp's outlook_list_events / outlook_get_event / outlook_list_calendars instead: real Outlook REST API calls via a captured token, with no "must have it open" limitation at all.

Things worth knowing

• No chat or channel selection. See "How it works" above — there is no id parameter on either "open" tool because there is no way to act on one. Ask the person to open the chat/channel they mean, or use the matching list tool to show them what's available.
• Chat and Teams-and-Channels are different nav sections. Reading channels needs the Teams-and-Channels view open in the browser (the "Teams" icon in the left rail, not "Chat") — if a channel tool returns nothing, that's usually why.
• Grouped messages still resolve a sender. Teams visually hides the sender name on consecutive messages from the same person, but the name stays in the DOM, so sender is populated on every row regardless.
• Quoted content concatenates. A chat message that quotes an earlier one, or a channel post whose body includes a reply preview, has that quoted text run together with the real content inside text — a limitation of bulk text extraction, not a bug.
• Multiple open Teams tabs race. The bridge reads whichever matching tab answers first ("first responsive"), not necessarily the one you meant. If results look like they're from the wrong chat/channel, close extra teams.cloud.microsoft tabs so only one remains.
• Scope grows quietly. If you see a read_dom_list name not in declared set error, the extension's approved scope is behind the server's declared one — this shouldn't happen in a released version, but if it does, revoke and re-pair teams-mcp in the Transporter popup.

Development

npm install
npm run build
npm test              # typecheck + suite
npm run test:coverage # CI's gate

This server depends on read_dom_list, a fetchproxy capability added alongside this repo — it needs @fetchproxy/protocol/@fetchproxy/server >= 3.1.0, the first published versions that include it (chrischall/fetchproxy#381).

License

MIT