Cal.com MCP Server

Exposes Cal.com scheduling tools to AI agents via the Model Context Protocol (MCP).

Tools Available

Tool	Description
list_event_types	List all available event types (meeting types)
get_availability	Get free/busy slots for a date range
create_booking	Create a new booking/appointment
cancel_booking	Cancel an existing booking
reschedule_booking	Move a booking to a new time slot
list_bookings	List bookings with status filters

Setup

1. Configure environment

cp .env.example .env
# Edit .env and set your CAL_API_KEY

2. Install dependencies

npm install

3. Run tests

npm test

4. Start the server

npm start
# Server will run at http://localhost:3000

Transport Options

Streamable HTTP (recommended for production)

POST http://localhost:3000/mcp
GET  http://localhost:3000/mcp

SSE (Server-Sent Events)

GET  http://localhost:3000/sse          # Open SSE stream
POST http://localhost:3000/sse-messages # Send messages

stdio (local testing)

TRANSPORT=stdio npm start

Connecting to Claude

Add to your MCP client config:

{
  "mcpServers": {
    "calcom": {
      "url": "http://localhost:3000/mcp",
      "transport": "streamable-http"
    }
  }
}

API Endpoints

• GET /health — Health check
• GET / — Server manifest (lists tools and capabilities)
• POST /mcp — MCP Streamable HTTP endpoint
• GET /sse — SSE connection
• POST /sse-messages — SSE message endpoint

Environment Variables

Variable	Description	Default
CAL_API_KEY	Cal.com API key (required)	—
CAL_API_BASE	Cal.com API base URL	https://api.cal.com/v1
PORT	HTTP server port	3000
TRANSPORT	http or stdio	http
LOG_LEVEL	debug, info, warn, error	info