Office Outlook MCP server

office-outlook-mcp

MCP server for Outlook / Microsoft 365 — mail, folders, calendar, contacts and tasks, with confirm-gated sending.

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

own discretion.

How it authenticates

Outlook Web holds its access token in memory and sends it as Authorization: Bearer …. This server snapshots that header from your signed-in browser tab through the fetchproxy bridge, then talks to https://outlook.office.com/api/v2.0 with ordinary server-side requests.

The browser is needed only to mint the token (~25h), never to make a call. That is the whole design: no Azure app registration, no admin consent, and no browser on the request path.

Tokens are cached at ~/.office-outlook-mcp/token.json (0600), so a restart does not re-capture.

Install

npm i -g @chrischall/office-outlook-mcp

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

npm i -g @fetchproxy/cli

The first capture 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": {
      "outlook": {
        "type": "local",
        "command": ["npx", "-y", "@chrischall/office-outlook-mcp"]
      }
    }
  }
}

That one file serves opencode 2 and current opencode 1 — verified live on 2.0.11, 1.18.31 and 1.18.28, which all connect from it.

Two things worth knowing, both measured rather than assumed:

servers directly under mcp ("mcp": { "outlook": { … } }), and the temptation is to write both so either version finds one. Do not: given a sibling key beside servers, opencode 2 parses the file — it still shows up in opencode debug config — and then reports "No MCP servers configured". No error, no warning, every server silently gone.

• Never carry both config shapes in one file. Older opencode 1 wants the

(Configuration is invalid at …), so if you see that, switch that machine to the flat shape rather than combining them.

• An opencode 1 old enough to reject servers says so loudly

opencode 2 talks to a background service, so opencode reload before opencode mcp list after editing config.

Configuration

Everything is optional — with nothing set, the server captures from the browser.

Tools

Read — outlooklistfolders, outlooklistmessages, outlookgetmessage, outlooklistattachments, outlooklistevents, outlookgetevent, outlooklistcalendars, outlookgetprofile, outlookgetmailboxsettings, outlooklistcontacts, outlooklistpeople, outlooklist_tasks

Write (all require confirm: true) — outlooksendmail, outlookcreatedraft, outlookmarkread, outlookmovemessage, outlookcreateevent

Diagnostics — outlook_healthcheck

Shortened. The full README is on GitHub.