Fantastical MCP

An MCP server that gives AI assistants read/write access to your Fantastical calendar on macOS.

What it does

fantastical-mcp reads calendar events directly from Fantastical's local SQLite database and creates events via Fantastical's x-fantastical3:// URL scheme. No TCC permissions, no API keys, no network access -- it works entirely offline using the data Fantastical already stores on your Mac.

• Read -- Query events by date range, calendar, or full-text search

• Recurring events -- Series are expanded into per-occurrence results with timezone-aware rule evaluation and de-duplication of moved occurrences

• Write -- Create events using Fantastical's natural language parser

• Navigate -- Open Fantastical to a specific date

Installation

Prerequisites

• macOS

• Fantastical installed with at least one calendar

• An MCP client, such as Claude Desktop or Claude Code

• uv Python package manager: brew install uv

Install via uvx (Any MCP Client)

Fantastical MCP is published on PyPI and can be run directly with uvx:

uvx fantastical-mcp

Configure your MCP client to use uvx with fantastical-mcp as the argument.

Claude Desktop

Option 1: One-Click Install (Recommended)

1. Download the latest .mcpb file from the releases page

2. Double-click the file

3. Done!

Option 2: Manual Config

1. Go to Claude → Settings → Developer → Edit Config

2. Add the Fantastical server:

{
  "mcpServers": {
    "fantastical": {
      "command": "uvx",
      "args": ["fantastical-mcp"]
    }
  }
}

3. Save and restart Claude Desktop

Claude Code

claude mcp add-json fantastical '{"command":"uvx","args":["fantastical-mcp"]}'

To make it available globally (across all projects), add -s user:

claude mcp add-json -s user fantastical '{"command":"uvx","args":["fantastical-mcp"]}'

Verify it's working

After installation:

• If using Claude Desktop, you should see "Fantastical MCP" in the "Search and tools" list

• Try asking: "What's on my calendar today?"

Sample Usage

• "What's on my calendar today?"

• "Do I have any meetings on Thursday?"

• "Create a lunch meeting with Sarah tomorrow at noon at The Italian Place"

• "When am I free this Wednesday afternoon?"

• "Show me all events from my Work calendar this week"

• "Do I have any pending event invitations?"

Tips

• Create a project in Claude with custom instructions that explain how you organise your calendars. Tell Claude which calendars to prioritise and how you like events formatted.

• Pair with a task management MCP server (like things-mcp) so Claude can cross-reference your tasks and calendar, block time for deep work, or create todos from upcoming meetings.

• Use get_availability to quickly find free slots: "When am I free for a 90-minute block this week?"

Local Development

git clone https://github.com/jaydenk/fantastical-mcp.git
cd fantastical-mcp
uv venv && uv pip install -e ".[test]"

See docs/configuration.md for environment variables, calendar exclusion, and transport options.

Available tools

See docs/tools.md for parameters, types, defaults, and example output.

Troubleshooting

If it's not working:

1. Make sure Fantastical is installed and has been opened at least once

   • The Fantastical database needs to exist for the server to read events

2. Claude Desktop can't find uvx

   • Install uv globally with Homebrew (brew install uv)

   • Alternative: Use the full path to uvx in your config. Find it with which uvx (typically /Users/USERNAME/.local/bin/uvx)

3. "Database not found" errors

   • Fantastical stores its database at ~/Library/Group Containers/group.com.flexibits.fantastical2.mac/. Ensure this path exists and is accessible.

4. System calendars cluttering results

   • Set FANTASTICAL_EXCLUDED_CALENDARS to hide calendars like Weather or Openings. See docs/configuration.md for details.

Limitations

• No update or delete -- Fantastical's URL scheme only supports event creation. Modification and deletion require EventKit, which needs TCC permissions.

• macOS only -- Relies on Fantastical's macOS database location and the open command.

• Read-only database access -- The database is opened in ?mode=ro to prevent any risk of corruption.

• Blob format dependency -- The NSKeyedArchiver serialisation format is an internal detail of Fantastical and could change between versions. An FTS fallback path mitigates this.

Documentation

• Tool reference -- Detailed parameters and example output for every tool

• Configuration guide -- Environment variables, transport options, calendar exclusion

• How it works -- Technical architecture and design decisions

• Development guide -- Project structure, testing, and contributing

Licence

MIT