Google Calendar MCP for Claude Code

A local MCP server that gives Claude Code full Google Calendar access — including reminders, which the official Anthropic MCP does not support.

What is an MCP?

MCP (Model Context Protocol) is an open standard created by Anthropic that lets Claude connect to external tools and services. Think of it as a plugin system: instead of Claude only working with text, MCPs let it interact with the real world — your calendar, files, databases, APIs, etc.

This MCP acts as a bridge between Claude Code and the Google Calendar API, giving Claude the ability to create and manage events directly from your conversations.

What this MCP adds over the official one

| Feature | Official MCP | This MCP | |---|---|---| | Create events | ✅ | ✅ | | Delete events | ✅ | ✅ | | List calendars | ✅ | ✅ | | Set reminders | ❌ | ✅ | | Update reminders | ❌ | ✅ |

Requirements

Python 3.8+
A Google account (Gmail)
Claude Code installed

Installation

Step 1 — Clone the repo

git clone https://github.com/YOUR_USERNAME/gcal-mcp.git
cd gcal-mcp

Step 2 — Install Python dependencies

pip3 install -r requirements.txt

Step 3 — Create your Google Cloud credentials

You need to create your own credentials. This is free and takes about 5 minutes.

Go to console.cloud.google.com and log in with your Gmail account
Create a new project (e.g. "Claude Calendar")
Go to APIs & Services → Library, search for Google Calendar API and enable it
Go to APIs & Services → Credentials → Create Credentials → OAuth client ID
When asked "What data will you be accessing?" → select User data
Fill in the OAuth consent screen:
- App name: anything you like (e.g. Claude MCP)
- User support email: your Gmail
- Developer contact email: your Gmail
- Skip the Scopes step
Application type: Desktop app → click Create
Download the JSON file and save it as credentials.json inside the gcal-mcp folder
Go back to APIs & Services → OAuth consent screen → Test users → click + Add users → add your Gmail address

Step 4 — Register the MCP in Claude Code

claude mcp add --scope user gcal-extended -- python3 /absolute/path/to/server.py

Replace /absolute/path/to/server.py with the real path on your machine. For example:

claude mcp add --scope user gcal-extended -- python3 /Users/yourname/gcal-mcp/server.py

Step 5 — Restart Claude Code

After restarting, the first time Claude uses the MCP a browser window will open asking you to authorize access to your Google Calendar. Click Allow. This only happens once — your token is saved locally in token.json.

Usage

Once set up, just talk to Claude naturally:

"Add a swimming session to my Gym calendar this Saturday at 2pm, 1 hour long, with reminders 3 days before, 1 day before, and the morning of."

Claude will call the MCP and create the event with all reminders included.

Available tools

| Tool | What it does | |---|---| | create_event | Creates an event with optional reminders | | update_event | Updates an existing event (including reminders) | | list_calendars | Lists all your calendars and their IDs | | delete_event | Deletes an event |

Reminders format

Reminders are passed as a list of minutes before the event start. Examples:

| Value | Meaning | |---|---| | 4320 | 3 days before | | 2880 | 2 days before | | 1440 | 1 day before | | 480 | 8 hours before | | 120 | 2 hours before |

Security

credentials.json and token.json are in .gitignore — they will never be committed
Your credentials stay entirely on your local machine
The MCP only requests the minimum required scope: https://www.googleapis.com/auth/calendar

License

MIT — free to use, modify, and share.

MCP Servers