How do I install Ms Calendar?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Ms Calendar need an API key?

The publisher lists these environment variables: MICROSOFT_CLIENT_ID.

What transport does Ms Calendar use?

Ms Calendar runs locally over stdio.

When was Ms Calendar last checked?

Last checked 2026-11-08. Microsoft Calendar (Outlook Calendar) MCP server for managing events via Microsoft Graph.

Ms Calendar MCP server

Power your agent

Add this server

The publisher's own command. Not a PlugMCP endpoint.

Add to Cursor Add to VS Code Run on PlugMCP

Host a copy with our keys and logs.

Local command

npx -y [email protected]

Credentials from the publisher

MICROSOFT_CLIENT_ID — Entra ID application (client) ID for the public client app used to sign in. Run `npx -y ms-calendar-mcp login` once to cache a refresh token.

Claude Code has no install link for a local command. Copy the command below and run it in a terminal.

shClaude Code

1MICROSOFT_CLIENT_ID=<value> claude mcp add io.github.0xka13b-ms-calendar-mcp -- npx -y ms-calendar-mcp@1.0.1

Run in a terminal.

jsonClaude Desktop

1{2  "mcpServers": {3    "io.github.0xka13b-ms-calendar-mcp": {4      "command": "npx",5      "args": [6        "-y",7        "[email protected]"8      ],9      "env": {10        "MICROSOFT_CLIENT_ID": "<value>"11      }12    }13  }14}

claude_desktop_config.json

Local · npmPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
Version: 1.0.1
API key

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

Each server speaks the real MCP protocol and runs over either transport:

stdio — for local MCP clients that launch the server as a subprocess (Claude Desktop, IDEs, the MCP Inspector).
Streamable HTTP — for remote/hosted use, with the Microsoft Graph access token supplied per request via Authorization: Bearer.

Servers

Server	npm package (and binary)	Tools
Calendar	`ms-calendar-mcp`	9
Contacts	`ms-contacts-mcp`	7
OneDrive	`ms-onedrive-mcp`	9
Outlook	`microsoft-outlook-mcp`	14
SharePoint	`ms-sharepoint-mcp`	23

All tools are thin wrappers over the Microsoft Graph v1.0 API.

Layout

microsoft-mcp/
├── apps/                       # one MCP server per Microsoft 365 product
│   ├── calendar/
│   ├── contacts/
│   ├── onedrive/
│   ├── outlook/
│   └── sharepoint/
│       └── src/
│           ├── tools.ts        # declarative tool definitions (schema + handler)
│           └── index.ts        # run({ name, version }, tools)
└── packages/                   # shared building blocks
    ├── core/                   # MCP server bootstrap + dual transport (stdio / HTTP)
    ├── graph/                  # Microsoft Graph HTTP client
    ├── validation/             # id / path / query sanitizers
    └── logger/                 # structured JSON logging (stderr-only — stdio-safe)

A server is just a list of tools handed to run():

// apps/calendar/src/index.ts
import { run } from "@microsoft-mcp/core";
import { tools } from "./tools.js";

void run({ name: "microsoft-calendar", version: "1.0.0", title: "Microsoft Calendar" }, tools);

// a single tool
defineTool({
  name: "get_event",
  description: "Get a single calendar event by ID.",
  inputSchema: { event_id: z.string().describe("Event ID") },
  confirmationPolicy: "never",
  handler: ({ graph }, { event_id }) => {
    validateId(event_id, "event_id");
    return graph.request("GET", `/me/events/${event_id}`);
  },
});

confirmationPolicy ("always" for mutating/destructive tools, "never" for read-only) is surfaced to clients as MCP readOnlyHint / destructiveHint annotations.

Requirements

Node.js >= 20
pnpm 10 (corepack enable)

Setup

pnpm install
pnpm build        # build all servers (turbo) -> apps/*/dist/index.js
pnpm check-types  # typecheck everything

Tests & CI

pnpm test            # run the vitest suite once
pnpm test:watch      # watch mode
pnpm test:coverage   # run with a v8 coverage report (-> coverage/)

Tests live next to the code as *.test.ts and run on TypeScript source directly (no build step). The shared packages/* are covered by unit and integration tests — including a full Streamable-HTTP round-trip against a live server — and CI enforces a coverage floor on them. Each apps/* server ships an invariant suite that locks its tool surface (unique snake_case names, valid schemas and confirmation policies).

Every push and pull request to master runs CI: typecheck → build → tests with coverage. The coverage badge is regenerated from the run.

Authentication

You sign in once with your Microsoft account; the server then caches a refresh token and acquires access tokens silently from then on — no pasting, no 1-hour expiry. Sign-in uses your own Microsoft Entra ID app registration (free) so the servers act on your behalf.

1. Register an Entra ID app (one time)

Azure Portal → Microsoft Entra ID → App registrations → New registration. Name it anything; pick the Supported account types that fit (single-tenant, multi-tenant, and/or personal accounts).
Authentication → Add a platform → Mobile and desktop applications → add redirect URI http://localhost, and set Allow public client flows to Yes (enables the --device-code fallback).
API permissions → Add a permission → Microsoft Graph → Delegated permissions → add the scopes for the servers you use (then Grant admin consent if your tenant requires it):

Server Delegated scopes
Calendar Calendars.ReadWrite
Contacts Contacts.ReadWrite
OneDrive Files.ReadWrite.All
Outlook Mail.ReadWrite, Mail.Send
SharePoint Sites.ReadWrite.All

All servers also use User.Read. (offline_access is requested automatically for refresh.)
Copy the Application (client) ID.

Server	Delegated scopes
Calendar	`Calendars.ReadWrite`
Contacts	`Contacts.ReadWrite`
OneDrive	`Files.ReadWrite.All`
Outlook	`Mail.ReadWrite`, `Mail.Send`
SharePoint	`Sites.ReadWrite.All`

2. Sign in (one time per machine)

Set MICROSOFT_CLIENT_ID, then run the server's login command. A browser opens; after you consent, the token is cached under ~/.config/microsoft-mcp/:

export MICROSOFT_CLIENT_ID=<your-client-id>

npx -y ms-calendar-mcp login           # opens the browser
npx -y ms-calendar-mcp login --device-code   # headless: shows a code to enter

From then on the server refreshes tokens automatically. Use a non-default tenant with MICROSOFT_TENANT_ID (default common).

Advanced: supply your own token

To bypass the built-in flow, supply a pre-acquired Graph token directly:

stdio: set MICROSOFT_ACCESS_TOKEN (takes precedence over the cached sign-in). Good for quick tests — mint one with az account get-access-token --resource https://graph.microsoft.com --query accessToken -o tsv.
HTTP: send Authorization: Bearer <token> on each POST /mcp request. Each request is stateless with its own token, so callers never share credentials — this is the model for hosted/remote deployments, which handle their own auth.

Running

stdio (e.g. Claude Desktop)

Each server is published to npm and runnable with npx — no clone or build. Sign in once first (npx -y ms-calendar-mcp login, see Authentication), then:

// claude_desktop_config.json
{
  "mcpServers": {
    "microsoft-calendar": {
      "command": "npx",
      "args": ["-y", "ms-calendar-mcp"],
      "env": { "MICROSOFT_CLIENT_ID": "<your-client-id>" }
    }
  }
}

Or point at a local build instead of npm:

{
  "command": "node",
  "args": ["/abs/path/microsoft-mcp/apps/calendar/dist/index.js"],
  "env": { "MICROSOFT_CLIENT_ID": "<your-client-id>" }
}

During development you can skip the build and run the TypeScript directly:

MICROSOFT_ACCESS_TOKEN=<token> pnpm --filter ms-calendar-mcp dev

Streamable HTTP

# build first, then:
PORT=3000 node apps/calendar/dist/index.js --http
# or, in dev:
pnpm --filter ms-calendar-mcp dev -- --http --port 3000

The server exposes POST /mcp (the MCP endpoint) and GET /healthz. Point any Streamable-HTTP MCP client at http://localhost:3000/mcp with an Authorization: Bearer header.

Transport selection

Resolved in this order: --stdio / --http flag → MCP_TRANSPORT=stdio|http → default stdio. HTTP port: --port <n> → PORT → 3000.

Environment variables

Variable	Used by	Description
`MICROSOFT_CLIENT_ID`	stdio	Entra ID app (client) ID for sign-in. Required for the `login` flow.
`MICROSOFT_TENANT_ID`	stdio	Tenant for sign-in: `common` (default), `organizations`, `consumers`, or a tenant ID.
`MICROSOFT_ACCESS_TOKEN`	stdio	Pre-acquired Graph token; overrides the cached sign-in when set.
`MICROSOFT_MCP_CACHE_DIR`	stdio	Override the token-cache directory (default `~/.config/microsoft-mcp`).
`MCP_TRANSPORT`	both	`stdio` (default) or `http`.
`PORT`	http	Listen port (default `3000`).
`MCP_HTTP_BODY_LIMIT`	http	Max request body size (default `50mb`) for base64 uploads.
`MCP_DEBUG`	both	Any non-empty value enables debug logs (to stderr).

Add this server

Host a copy with our keys and logs.

Server facts

Tools

Questions

How do I install Ms Calendar?

Does Ms Calendar need an API key?

What transport does Ms Calendar use?

When was Ms Calendar last checked?

Documentation

Servers

Layout

Requirements

Setup

Tests & CI

Authentication

1. Register an Entra ID app (one time)

2. Sign in (one time per machine)

Advanced: supply your own token

Running

stdio (e.g. Claude Desktop)

Streamable HTTP

Transport selection

Environment variables