MCP server for the Astrocal scheduling API. Lets AI agents check availability, book meetings, cancel, reschedule, and list bookings via the Model Context Protocol.

Quick Start

Claude Desktop

Add to your claude_desktop_config.json:

{
  "mcpServers": {
    "astrocal": {
      "command": "npx",
      "args": ["-y", "@astrocal/mcp-server"],
      "env": {
        "ASTROCAL_API_KEY": "ac_live_xxxxxxxxxxxxx"
      }
    }
  }
}

Restart Claude Desktop and the tools will be available.

Other MCP Clients

Install globally:

npm install -g @astrocal/mcp-server

Run:

ASTROCAL_API_KEY=ac_live_xxx astrocal-mcp

Environment Variables

Variable	Required	Description
`ASTROCAL_API_KEY`	Yes	Your Astrocal API key (get from the dashboard)
`ASTROCAL_API_URL`	No	API base URL (default: `https://api.astrocal.dev`)
`ASTROCAL_DEFAULT_EVENT_TYPE_ID`	No	Default event type ID — skips needing to pass it to every tool call

Available Tools

`check_availability`

Check available time slots for booking a meeting.

Input:

event_type_id (string, optional) — Event type to check. Optional if ASTROCAL_DEFAULT_EVENT_TYPE_ID is set.
start_date (string, required) — Start date in ISO 8601 format (e.g., 2026-03-15)
end_date (string, required) — End date in ISO 8601 format (e.g., 2026-03-22)
timezone (string, optional) — IANA timezone (e.g., America/New_York). Defaults to UTC.

`create_booking`

Book a meeting at a specific time.

Input:

event_type_id (string, optional) — Event type to book. Optional if default is set.
start_time (string, required) — ISO 8601 datetime (e.g., 2026-03-15T14:00:00Z)
invitee_name (string, required) — Full name of the person booking
invitee_email (string, required) — Email address for calendar invitation
invitee_timezone (string, optional) — IANA timezone. Defaults to UTC.
notes (string, optional) — Meeting notes (max 1000 characters)

`cancel_booking`

Cancel an existing booking. The invitee will be notified via email.

Input:

booking_id (string, required) — ID of the booking to cancel
reason (string, optional) — Cancellation reason (max 500 characters)

`reschedule_booking`

Reschedule a booking to a new time. Check availability first.

Input:

booking_id (string, required) — ID of the booking to reschedule
new_start_time (string, required) — New time in ISO 8601 format
reason (string, optional) — Reason for rescheduling (max 500 characters)

`list_bookings`

List bookings with optional filters.

Input:

status (string, optional) — Filter: confirmed, cancelled, or pending_payment
limit (number, optional) — Max results (default: 10, max: 100)
event_type_id (string, optional) — Filter by event type

`list_event_types`

List available event types that can be booked. No input required.

Example Conversation

User: "What meetings can I book?"

Agent: calls list_event_types — "You have two event types: a 30-minute consultation (free) and a 1-hour strategy session ($50)."

User: "Check if next Tuesday at 2pm is free for a consultation"

Agent: calls check_availability — "Tuesday at 2pm is available."

User: "Book it for jane@example.com"

Agent: calls create_booking — "Done! Meeting confirmed for Tuesday, March 17 at 2:00 PM UTC with Jane Doe. A calendar invitation has been sent."

User: "Actually, move it to 3pm"

Agent: calls reschedule_booking — "Rescheduled to 3:00 PM. Jane has been notified."