Astrocal MCP server

@astrocal/mcp-server

Give your AI agents the power to schedule meetings. The official Model Context Protocol server for Astrocal — the API-first scheduling platform built for developers and AI agents.

Works with Claude Desktop, Cursor, Windsurf, and any MCP-compatible client. Your AI assistant can check availability, book meetings, cancel, reschedule, and manage waitlists — all through natural conversation.

Get your API key | Documentation | API Reference

Why Astrocal for AI Agents?

• Purpose-built for AI — Not a Calendly bolt-on. Astrocal's scheduling API was designed from day one for programmatic and AI-agent access.
• 8 tools, zero config — Check availability, book, cancel, reschedule, list event types, manage waitlists. Everything an agent needs.
• Calendar sync built in — Connects to Google Calendar, Microsoft 365, and CalDAV. Your agent books against real availability.
• Payments included — Stripe Connect integration means your agent can book paid consultations, not just free meetings.
• Sandbox mode — Test with actest keys. No emails sent, no calendar events created, no charges made.

Quick Start

Claude Desktop

Add to your claudedesktopconfig.json:

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

Restart Claude Desktop and the scheduling tools will be available immediately.

Other MCP Clients

Install globally:

npm install -g @astrocal/mcp-server

Run:

ASTROCAL_API_KEY=ac_live_xxx astrocal-mcp

Environment Variables

Available Tools

check_availability

Check available time slots for booking.

• eventtypeid (string, optional) — Event type to check. Optional if ASTROCALDEFAULTEVENTTYPEID 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.

• eventtypeid (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 receives a cancellation email automatically.

• 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.

Shortened. The full README is on GitHub.