doublebash/outlook-mcp

How doublebash/outlook-mcp works

Outlook MCP Server exposes Microsoft 365 operations as MCP tools: a client invokes a named tool, the Worker dispatches it to a domain handler, and handlers use Microsoft Graph to read or mutate mailbox data. Authentication stores encrypted Microsoft tokens in Cloudflare KV and supplies access tokens to Graph requests. The graph preserves the documented mail, calendar, contacts, tasks, files, Teams meeting, and settings capabilities. Several domain handlers were not excerpted, so their internal behavior is not expanded beyond documented capabilities and indexed imports.

Main entry points: graph.ts Graph client · tools/index.ts Tool dispatch · calendar.ts Calendar tools · src/index.ts Worker entry

Components 21

MCP runtime

Worker entry src/index.ts
Tool dispatch src/tools/index.ts
Shared tool utilities src/tools/_shared.ts
Graph data sanitizers src/sanitize.ts

Identity and Graph

OAuth token store src/auth.ts
Graph client src/graph.ts

Mail

Email tools src/tools/email.ts
Email attachments src/tools/attachments.ts
Email composition helpers src/email-helpers.ts
Signature handling src/signature.ts

Outlook data

Calendar tools src/tools/calendar.ts
Calendar helpers src/calendar-helpers.ts
Contact tools src/tools/contacts.ts
Task tools src/tools/tasks.ts
Mailbox settings src/tools/mailbox.ts

Files and meetings

OneDrive tools src/tools/files.ts
Teams meeting tools src/tools/meetings.ts
Transcript helpers src/transcript-helpers.ts

Other components

MCP client
Microsoft Graph
Cloudflare KV

Connections 35

MCP client → Worker entry: calls MCP README.md
Worker entry → Tool dispatch: dispatches tools src/index.ts
Tool dispatch → Email tools: routes calls src/tools/index.ts
Tool dispatch → Email attachments: routes calls src/tools/index.ts
Tool dispatch → Calendar tools: routes calls src/tools/index.ts
Tool dispatch → Contact tools: routes calls src/tools/index.ts
Tool dispatch → Task tools: routes calls src/tools/index.ts
Tool dispatch → Mailbox settings: routes calls src/tools/index.ts
Tool dispatch → OneDrive tools: routes calls src/tools/index.ts
Tool dispatch → Teams meeting tools: routes calls src/tools/index.ts
Worker entry → OAuth token store: uses OAuth src/index.ts
Worker entry → Graph client: uses Graph client src/index.ts
OAuth token store → Cloudflare KV: stores tokens src/auth.ts
Graph client → OAuth token store: gets access token src/graph.ts
Graph client → Microsoft Graph: sends Graph requests src/graph.ts
Email tools → Graph client: reads and writes src/tools/email.ts
Email attachments → Graph client: reads and writes src/tools/attachments.ts
Calendar tools → Graph client: reads and writes src/tools/calendar.ts
Contact tools → Graph client: reads and writes src/tools/contacts.ts
Task tools → Graph client: reads and writes src/tools/tasks.ts
Mailbox settings → Graph client: reads and writes src/tools/mailbox.ts
OneDrive tools → Graph client: reads and writes src/tools/files.ts
Teams meeting tools → Graph client: reads and writes src/tools/meetings.ts
Email tools → Email composition helpers: builds messages src/tools/email.ts
Email tools → Signature handling: adds signatures src/tools/email.ts
Calendar tools → Calendar helpers: builds recurrence src/tools/calendar.ts
Calendar tools → Signature handling: adds signatures src/tools/calendar.ts
Email composition helpers → Graph client: fetches OneDrive bytes src/email-helpers.ts
Signature handling → Email composition helpers: sanitizes HTML src/signature.ts
Teams meeting tools → Transcript helpers: uses transcript helpers src/tools/meetings.ts
Task tools → Graph data sanitizers: formats task lists src/tools/tasks.ts
OneDrive tools → Graph data sanitizers: formats file lists src/tools/files.ts
Contact tools → Graph data sanitizers: formats contacts src/tools/contacts.ts
Calendar tools → Graph data sanitizers: formats events src/tools/calendar.ts
Tool dispatch → Shared tool utilities: uses shared schemas

Drawn by GitDiagram on November 14, 2026 from the repository's file tree, README and source files. Read as Markdown ·