Calendly MCP Server

A Model Context Protocol (MCP) server for integrating with the Calendly API. This server provides tools to interact with Calendly's scheduling platform, allowing you to retrieve user information, list events, manage invitees, cancel events, and schedule meetings directly via the new Scheduling API.

Features

Core Calendly Integration

• User Information: Get current authenticated user details

• Event Management: List, retrieve, and cancel scheduled events

• Invitee Management: List and manage event invitees

• Organization: List organization memberships

NEW: Scheduling API Integration

• Direct Meeting Scheduling: Book meetings programmatically without redirects

• Event Type Discovery: List available event types for scheduling

• Real-Time Availability: Check available time slots for any event type

• Complete Booking Flow: End-to-end scheduling with calendar sync and notifications

• Location Support: Zoom, Google Meet, Teams, physical locations, and custom options

Related MCP server: Google-Calendar Universal MCP

Installation

Option 1: NPX (Recommended)

Run directly without installation:

npx calendly-mcp-server

Option 2: Manual Installation

1. Clone this repository:

git clone https://github.com/meAmitPatil/calendly-mcp-server.git
cd calendly-mcp-server

2. Install dependencies:

npm install

3. Build the project:

npm run build

Configuration

Authentication

This server supports two authentication methods:

Option 1: Personal Access Token (PAT)

For internal applications or personal use:

1. Get your Personal Access Token from your Calendly Integrations page

2. Select API and webhooks → Get a token now

3. Set the environment variable:

export CALENDLY_API_KEY="your_personal_access_token_here"

Option 2: OAuth 2.0

For public applications that multiple users will use:

1. Create a developer account at developer.calendly.com

2. Create an OAuth application to get your client credentials

3. Set the environment variables:

export CALENDLY_CLIENT_ID="your_client_id_here"
export CALENDLY_CLIENT_SECRET="your_client_secret_here"

4. Optionally, if you already have tokens:

export CALENDLY_ACCESS_TOKEN="your_access_token_here"
export CALENDLY_REFRESH_TOKEN="your_refresh_token_here"

Optional User Context (Recommended)

For better performance and automatic defaults, you can set user-specific URIs:

export CALENDLY_USER_URI="https://api.calendly.com/users/your_user_id"
export CALENDLY_ORGANIZATION_URI="https://api.calendly.com/organizations/your_org_id"

These can be obtained by running get_current_user after authentication. When set, the server will automatically use these as defaults for API calls that require user context.

MCP Configuration

Add the server to your MCP client configuration (e.g., Claude Desktop):

Option 1: Using NPX (Recommended)

For Personal Access Token:

{
  "mcpServers": {
    "calendly": {
      "command": "npx",
      "args": ["calendly-mcp-server"],
      "env": {
        "CALENDLY_API_KEY": "your_personal_access_token_here",
        "CALENDLY_USER_URI": "https://api.calendly.com/users/your_user_id",
        "CALENDLY_ORGANIZATION_URI": "https://api.calendly.com/organizations/your_org_id"
      }
    }
  }
}

For OAuth 2.0:

{
  "mcpServers": {
    "calendly": {
      "command": "npx",
      "args": ["calendly-mcp-server"],
      "env": {
        "CALENDLY_CLIENT_ID": "your_client_id_here",
        "CALENDLY_CLIENT_SECRET": "your_client_secret_here",
        "CALENDLY_ACCESS_TOKEN": "your_access_token_here",
        "CALENDLY_REFRESH_TOKEN": "your_refresh_token_here",
        "CALENDLY_USER_URI": "https://api.calendly.com/users/your_user_id",
        "CALENDLY_ORGANIZATION_URI": "https://api.calendly.com/organizations/your_org_id"
      }
    }
  }
}

Option 2: Using Local Installation

For Personal Access Token:

{
  "mcpServers": {
    "calendly": {
      "command": "node",
      "args": ["path/to/calendly-mcp-server/dist/index.js"],
      "env": {
        "CALENDLY_API_KEY": "your_personal_access_token_here",
        "CALENDLY_USER_URI": "https://api.calendly.com/users/your_user_id",
        "CALENDLY_ORGANIZATION_URI": "https://api.calendly.com/organizations/your_org_id"
      }
    }
  }
}

For OAuth 2.0:

{
  "mcpServers": {
    "calendly": {
      "command": "node",
      "args": ["path/to/calendly-mcp-server/dist/index.js"],
      "env": {
        "CALENDLY_CLIENT_ID": "your_client_id_here",
        "CALENDLY_CLIENT_SECRET": "your_client_secret_here",
        "CALENDLY_ACCESS_TOKEN": "your_access_token_here",
        "CALENDLY_REFRESH_TOKEN": "your_refresh_token_here",
        "CALENDLY_USER_URI": "https://api.calendly.com/users/your_user_id",
        "CALENDLY_ORGANIZATION_URI": "https://api.calendly.com/organizations/your_org_id"
      }
    }
  }
}

Available Tools (12 Total)

All tools work seamlessly through Claude Desktop or any MCP client

OAuth 2.0 Tools

get_oauth_url

Generate OAuth authorization URL for user authentication.

Parameters:

• redirect_uri (required): The redirect URI for your OAuth application

• state (optional): Optional state parameter for security

exchange_code_for_tokens

Exchange authorization code for access and refresh tokens.

Parameters:

• code (required): The authorization code from OAuth callback

• redirect_uri (required): The redirect URI used in authorization

refresh_access_token

Refresh access token using refresh token.

Parameters:

• refresh_token (required): The refresh token to use

API Tools

get_current_user

Get information about the currently authenticated user.

list_events

List scheduled events with optional filtering.

Parameters:

• user_uri (optional): URI of the user whose events to list (uses CALENDLY_USER_URI if not provided)

• organization_uri (optional): URI of the organization to filter events

• status (optional): Filter by status ("active" or "canceled")

• max_start_time (optional): Maximum start time (ISO 8601 format)

• min_start_time (optional): Minimum start time (ISO 8601 format)

• count (optional): Number of events to return (default 20, max 100)

get_event

Get details of a specific event.

Parameters:

• event_uuid (required): UUID of the event to retrieve

list_event_invitees

List invitees for a specific event.

Parameters:

• event_uuid (required): UUID of the event

• status (optional): Filter by status ("active" or "canceled")

• email (optional): Filter by email address

• count (optional): Number of invitees to return (default 20, max 100)

cancel_event

Cancel a specific event.

Parameters:

• event_uuid (required): UUID of the event to cancel

• reason (optional): Reason for cancellation

list_organization_memberships

List organization memberships for the authenticated user.

Parameters:

• user_uri (optional): URI of the user (uses CALENDLY_USER_URI if not provided)

• organization_uri (optional): URI of the organization

• email (optional): Filter by email

• count (optional): Number of memberships to return (default 20, max 100)

Scheduling API Tools

list_event_types

List available event types for scheduling meetings.

Parameters:

• user (optional): URI of the user whose event types to list

• organization (optional): URI of the organization to filter event types

• count (optional): Number of event types to return (default 20, max 100)

get_event_type_availability

Get available time slots for a specific event type.

Parameters:

• event_type (required): URI of the event type to check availability for

• start_time (optional): Start time for availability window (ISO 8601 format)

• end_time (optional): End time for availability window (ISO 8601 format)

schedule_event

Schedule a meeting by creating an invitee for a specific event type and time.

Requirements: Paid Calendly plan (Standard or higher)

Parameters:

• event_type (required): URI of the event type to schedule

• start_time (required): Start time for the event (ISO 8601 UTC format)

• invitee_email (required): Email address of the invitee

• invitee_timezone (required): Timezone of the invitee (e.g., America/New_York)

• invitee_name (optional): Full name of the invitee

• invitee_first_name (optional): First name of the invitee

• invitee_last_name (optional): Last name of the invitee

• invitee_phone (optional): Phone number for SMS reminders (E.164 format)

• location_kind (optional): Meeting location type (zoom_conference, google_conference, physical, etc.)

• location_details (optional): Location details (required for physical meetings)

• event_guests (optional): Array of additional email addresses (max 10)

• questions_and_answers (optional): Array of question/answer pairs

• utm_source, utm_campaign, utm_medium (optional): UTM tracking parameters

Usage Examples

Once configured with your MCP client, you can use these tools:

Live Demo

Here's the MCP server in action with Claude Desktop:

Example: User asks "Show me my Calendly events" and gets formatted event details including date, time, duration, location, and invitee information.

OAuth Flow Examples:

# Generate OAuth URL
get_oauth_url redirect_uri="https://myapp.com/auth/callback"

# Exchange code for tokens (after user authorizes)
exchange_code_for_tokens code="AUTHORIZATION_CODE" redirect_uri="https://myapp.com/auth/callback"

# Refresh access token
refresh_access_token refresh_token="REFRESH_TOKEN"

API Examples:

# Get current user information
get_current_user

# List recent events
list_events count=10

# Get specific event details
get_event event_uuid="EVENT_UUID_HERE"

# List invitees for an event
list_event_invitees event_uuid="EVENT_UUID_HERE"

# Cancel an event
cancel_event event_uuid="EVENT_UUID_HERE" reason="Meeting no longer needed"

Scheduling API Examples:

# List available event types
list_event_types

# Check availability for a specific event type
get_event_type_availability event_type="https://api.calendly.com/event_types/AAAAAAAAAAAAAAAA"

# Schedule a meeting (requires paid plan)
schedule_event event_type="https://api.calendly.com/event_types/AAAAAAAAAAAAAAAA" start_time="2025-10-21T19:00:00Z" invitee_email="client@company.com" invitee_name="John Smith" invitee_timezone="America/New_York" location_kind="zoom_conference"

🎯 Claude Desktop Examples:

# Natural language commands that work in Claude Desktop:
"Show me my event types"
"Check availability for my 30-minute consultation next week"
"Schedule a meeting with john@company.com for tomorrow at 2 PM"
"Book a client onboarding call for Friday"

API Limitations

• Scheduling API: Requires paid Calendly plan (Standard or higher)

• Event Rescheduling: Not supported via API (only cancellation)

• Event Type Creation: Cannot create new event types via API

• Rate Limits: Standard Calendly API rate limits apply

Troubleshooting

NPX Issues

• "command not found: npx": Install Node.js 18+ which includes npx

• NPX downloads every time: This is normal behavior; NPX caches packages for faster subsequent runs

• Permission errors: Ensure you have write access to npm cache directory (npm config get cache)

• Network issues: Use npx --offline calendly-mcp-server to use cached version

Authentication Issues

• "No authentication token available": Set CALENDLY_API_KEY environment variable

• 400 errors on list_events: Set CALENDLY_USER_URI environment variable or provide user_uri parameter

• Permission errors: Ensure API key has correct permissions

Scheduling API Issues

• 403 Forbidden on schedule_event: Requires paid Calendly plan (Standard or higher)

• 400 Bad Request: Check that event_type URI is valid and start_time is in correct UTC format

• Invalid time slot: Use get_event_type_availability to verify the time slot is available

General Issues

• TypeScript errors: Ensure Node.js version 18+ is installed

• Module not found: Run npm run build if using local installation

Development

Quick Start for Development

# Test with NPX (recommended for users)
npx calendly-mcp-server

# Test with MCP Inspector
npx @modelcontextprotocol/inspector npx calendly-mcp-server

# Clone for development
git clone <repository-url>
cd calendly-mcp-server
npm install
npm run build

Scripts

• npm run build: Build the TypeScript code

• npm run dev: Run in development mode with auto-reload

• npm start: Run the built server

Project Structure

src/
├── index.ts          # Main server implementation
├── types.ts          # TypeScript type definitions (if needed)
└── utils.ts          # Utility functions (if needed)

Contributing

1. Fork the repository

2. Create a feature branch

3. Make your changes

4. Test thoroughly

5. Submit a pull request

License

MIT License - see LICENSE file for details.

Support

For issues with this MCP server, please create an issue in the repository. For Calendly API documentation, visit the Calendly Developer Portal.