Welcome to Astrocal
The scheduling API built for AI agents and developers.
Astrocal is an API-first scheduling platform. Add calendar booking to any application with a few API calls, or let AI agents schedule meetings via MCP.
Quick Links
- Quickstart: Book your first meeting in 5 minutes
- Authentication: Set up API access
- MCP Integration: Connect AI agents to Astrocal
- React SDK: React provider, hooks, and widget component
- Embeddable Widget: Drop-in booking widget for any website
- Webhooks: Real-time booking event notifications
- Payments: Collect payments via Stripe Connect
- Rate Limits: Usage quotas and 429 handling
- Errors: Error codes and handling reference
- API Reference: Full endpoint documentation
Packages
Astrocal provides three npm packages depending on your integration approach:
| Package | Description | Links |
|---|---|---|
@astrocal/mcp-server | MCP server for AI agents | npm · GitHub |
@astrocal/react | React SDK with provider, hooks, and widget component | npm · GitHub |
@astrocal/widget | Embeddable booking widget (vanilla JS) | npm · GitHub |
How It Works
- Create an organization: Your tenant in Astrocal
- Define event types: Meeting templates with duration, availability rules, and buffer times
- Connect your calendar: Astrocal supports Google Calendar, Outlook/Microsoft 365, and CalDAV — reads busy times and writes new events
- Accept bookings: Via the REST API or MCP server
Key Concepts
Event Types are templates for bookable meetings. Each has a duration, availability rules (weekly recurring windows), optional buffer time between meetings, and optional booking caps to limit how many bookings can be made per period.
Availability Rules define when an event type can be booked. They're weekly recurring windows (e.g., Monday 9am-5pm) in a specific timezone.
Bookings are confirmed meetings. When created, Astrocal checks availability, prevents double-booking, and automatically creates events in all connected calendars.
MCP Server lets AI agents check availability and book meetings using the Model Context Protocol. It wraps the same REST API that developers use directly.
Embeddable Widget is a drop-in booking UI for any website. One script tag gives you a full calendar, time slot picker, and booking form, with Shadow DOM isolation and CSS theming.
Webhooks notify your server in real-time when bookings are created, cancelled, or rescheduled. Set up endpoints and verify signatures with HMAC-SHA256. See the Webhooks guide.
Payments let you charge for bookings via Stripe Connect. Set a price on any event type and collect payment before confirming the booking. See the Payments guide.
Rate Limits protect the API with per-minute and daily quotas based on your plan tier. Monitor usage via response headers and the usage endpoint. See the Rate Limits guide.
Cancel & Reschedule endpoints let invitees manage their own bookings using a cancel token, or developers can manage bookings with an API key. See the Bookings guide.
Error Handling follows a consistent JSON format with machine-readable error codes. See the Errors guide for the complete reference.