Fastmail Calendar MCP Server
An MCP (Model Context Protocol) server that enables AI assistants to interact with Fastmail Calendar via CalDAV. This allows AI to view, create, modify, and delete calendar events in your Fastmail account.
Features
- List Calendars: View all calendars in your Fastmail account
- List Events: Retrieve events from a specific calendar within a date range
- Create Events: Add new calendar events with details like title, description, location, and time
- Update Events: Modify existing calendar events
- Delete Events: Remove calendar events
Configuration
This MCP server requires the following configuration:
- username: Your Fastmail email address (e.g.,
user@fastmail.com) - appPassword: A Fastmail app password (16 characters)
Creating a Fastmail App Password
- Log in to Fastmail
- Go to Settings → Privacy & Security → Integrations
- Click New app password
- Select permissions (ensure "Calendars" is included)
- Click Generate password
- Copy the generated password (16 characters)
Installation
Via Smithery
smithery install fastmail-calendar-mcp --client claude --config '{"username":"your-email@fastmail.com","appPassword":"your-app-password"}'
Manual Installation for Claude Desktop
Add to your Claude Desktop config file (~/.config/claude/claude_desktop_config.json):
{
"mcpServers": {
"fastmail-calendar": {
"command": "npx",
"args": [
"-y",
"fastmail-calendar-mcp"
],
"env": {
"FASTMAIL_USERNAME": "your-email@fastmail.com",
"FASTMAIL_APP_PASSWORD": "your-app-password"
}
}
}
}
For Cursor IDE
Add to ~/.cursor/mcp.json:
{
"mcpServers": {
"fastmail-calendar": {
"command": "node",
"args": ["/path/to/fastmail-calendar-mcp/dist/index.js"],
"env": {
"FASTMAIL_USERNAME": "your-email@fastmail.com",
"FASTMAIL_APP_PASSWORD": "your-app-password"
}
}
}
}
Development
Setup
npm install
npm run build
Running Locally
export FASTMAIL_USERNAME="your-email@fastmail.com"
export FASTMAIL_APP_PASSWORD="your-app-password"
npm start
Development Mode
npm run dev
This will watch for changes and automatically rebuild.
Deploying to Smithery
- Push this repository to GitHub
- Go to smithery.ai
- Click Deploy
- Select your GitHub repository
- Smithery will automatically detect the TypeScript MCP project and deploy it
Available Tools
list_calendars
Lists all calendars in your Fastmail account.
Returns: Array of calendar objects with displayName, url, description, and timezone.
list_events
Lists events from a specific calendar within a date range.
Parameters:
calendarUrl(required): The URL of the calendarstartDate(required): Start date in ISO format (e.g., "2024-01-01")endDate(required): End date in ISO format (e.g., "2024-12-31")
Returns: Array of event objects with url, etag, and data (iCalendar format).
create_event
Creates a new calendar event.
Parameters:
calendarUrl(required): The calendar URL where the event will be createdsummary(required): Event titlestartDate(required): Event start date/time in ISO formatendDate(required): Event end date/time in ISO formatdescription(optional): Event descriptionlocation(optional): Event location
Returns: Success message with the created event URL.
update_event
Updates an existing calendar event.
Parameters:
eventUrl(required): The URL of the event to updatesummary(optional): New event titledescription(optional): New event descriptionstartDate(optional): New start date/time in ISO formatendDate(optional): New end date/time in ISO formatlocation(optional): New event location
Returns: Success message.
delete_event
Deletes a calendar event.
Parameters:
eventUrl(required): The URL of the event to deleteetag(required): The etag of the event (obtained fromlist_events)
Returns: Success message.
Example Usage
Once installed, you can ask your AI assistant:
- "List my Fastmail calendars"
- "Show me my calendar events for next week"
- "Create a meeting on December 15th at 2 PM titled 'Team Sync'"
- "Update the 'Team Sync' event to include a Zoom link in the description"
- "Delete the event with URL [event-url]"
Security Notes
- Never commit your Fastmail app password to version control
- Use environment variables or secure secret management
- App passwords are safer than your main Fastmail password
- You can revoke app passwords at any time from Fastmail settings
License
MIT