Remote iCloud calendar MCP Server

Remote MCP server so Claude Code (or any MCP-compatible client) can manage calendar events directly you can deploy at https://horizon.prefect.io/.

Works with

• Claude Code / Claude Desktop / Claude.ai
• ChatGpt
• Anything that supports Oauth MCP servers

Environment Variables

Variable	Required	Default	Description
ICLOUD_USERNAME	Yes	—	iCloud account email address
ICLOUD_PASSWORD	Yes	—	iCloud app-specific password
ICLOUD_CALENDAR	No	Alex Plugg	Name of the target iCloud calendar

Credentials are stored encrypted in secrets.env via SOPS + Age and loaded automatically by direnv.

ICS Import (CLI)

Import an ICS file directly into iCloud:

uv run python main.py SchemaICAL.ics
# or, if inside the devenv shell:
import SchemaICAL.ics

Options:

usage: main.py [-h] [--username USERNAME] [--password PASSWORD] [--calendar CALENDAR] ics_file

positional arguments:
  ics_file                    Path to the ICS file to import

options:
  -u, --username USERNAME     iCloud username (falls back to ICLOUD_USERNAME)
  -p, --password PASSWORD     iCloud app-specific password (falls back to ICLOUD_PASSWORD)
  -c, --calendar CALENDAR     Target calendar name (default: Alex Plugg)

MCP Server

server.py is a FastMCP server that exposes CRUD operations on iCloud calendar events.

Tools

Tool	Description
list_events	List events in a date range (defaults to current month)
get_event	Fetch a single event by UID
create_event	Create a new event with title, time, description, and location
update_event	Update any fields of an existing event by UID
delete_event	Delete an event by UID

Installation — Claude Code (user-level)

Register the server globally so it is available in every project:

claude mcp add --scope user icloud-calendar \
  uv -- run fastmcp run /home/kog/repos/ics-icloud-import/server.py

The server reads ICLOUD_USERNAME, ICLOUD_PASSWORD, and ICLOUD_CALENDAR from the environment. These are already available in any shell that loads this repo's direnv config.

Installation — Claude Desktop (macOS / Windows)

Add the following to your Claude Desktop config file:

• macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
• Windows: %APPDATA%\Claude\claude_desktop_config.json

{
  "mcpServers": {
    "icloud-calendar": {
      "command": "uv",
      "args": [
        "run",
        "--project", "/path/to/ics-icloud-import",
        "fastmcp", "run", "/path/to/ics-icloud-import/server.py"
      ],
      "env": {
        "ICLOUD_USERNAME": "your@icloud.com",
        "ICLOUD_PASSWORD": "xxxx-xxxx-xxxx-xxxx",
        "ICLOUD_CALENDAR": "My Calendar"
      }
    }
  }
}

Replace /path/to/ics-icloud-import with the actual path to this repository.

Running the server manually

uv run fastmcp run server.py