Astrocal
About Astrocal

Scheduling infrastructure for the AI-native era

Every AI agent needs to book meetings. Every SaaS product needs scheduling. Astrocal is the API and MCP server that makes both possible — whitelabel, usage-based, and ready in five minutes.

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120+features shipped
89PRDs completed
8MCP tools for AI agents
$0to get started

The scheduling market is broken

per month for Cronofy's scheduling API

Enterprise scheduling APIs price out indie developers and early-stage startups. API access shouldn't require a five-figure annual contract.

API calls to book a meeting via MCP

Check availability, pick a slot, create a booking. Astrocal's MCP server handles the full lifecycle — including cancellations, rescheduling, and waitlists — so your agent never leaves the protocol.

Cal.com paused its hosted API access

The open-source alternative told developers to self-host. That's not an API product — it's a deployment project. Developers need hosted infrastructure, not another repo to maintain.

What we're building

API-first

A complete REST API with OpenAPI 3.1 spec, cursor pagination, webhooks, and predictable error codes. Everything you need to build scheduling into your product.

MCP-native

A purpose-built MCP server with 8 scheduling tools. Any AI agent — Claude, GPT, Cursor, or your own — can check availability, book, cancel, reschedule, and manage waitlists without leaving the protocol.

Whitelabel

Embeddable widget, custom CSS properties, removable branding. Your customers see your brand, not ours. Scheduling as invisible infrastructure.

The market opportunity

📈

$470M+ market

The appointment scheduling software market is projected to exceed $470M. AI agent tooling is the fastest-growing segment, and no incumbent owns the developer layer.

🤖

10–50K AI developers

The MCP ecosystem is exploding. Thousands of developers are building AI agents that need real-world capabilities — scheduling is one of the most requested.

💰

Pricing gap

Cronofy starts at $819/month. Calendly's API is locked to enterprise. Cal.com's hosted API is paused. There's no scheduling API that starts free and scales with usage.

Why Astrocal wins

🥇

Deepest MCP integration

8 purpose-built tools covering the full booking lifecycle: availability, booking, cancellation, rescheduling, and waitlists. Published on npm. AI agents can manage scheduling end-to-end — no custom integration needed.

⚡

Five-minute setup

Sign up, create an event type, connect your calendar, get an API key. From zero to live bookings in under five minutes. No deployment, no infrastructure to manage.

🏗️

Infrastructure, not a tool

Calendly is a tool people use. Astrocal is infrastructure developers embed. We're the Stripe of scheduling — invisible to the end user, indispensable to the builder.

📊

Usage-based pricing

Free tier with full API access. Paid plans scale by booking volume, not seats. No per-user fees, no enterprise-only API access, no surprises.

MCP-Native

Let AI agents book meetings.

Astrocal ships an MCP server out of the box. Any AI agent that speaks MCP can check availability, create bookings, and manage schedules. No custom integration code required.

  • Claude
  • GPT-4
  • Any MCP-compatible agent
MCP Server docs
Terminal
# Install and run the MCP server
npx @astrocal/mcp-server

# Agent calls available via MCP
> list_event_types
> get_available_slots  slug="discovery" date="2025-03-20"
> create_booking  slug="discovery" start="2025-03-20T10:00:00Z"
  name="Jane Doe" email="jane@example.com"

Frequently asked questions

Astrocal is an API-first scheduling platform built for developers and AI agents. It provides a REST API, embeddable widget, and MCP server for programmatic booking — all hosted, so there's nothing to deploy.
Developers building scheduling into SaaS products, AI agent builders who need their agents to book meetings, and teams that want a scheduling API without enterprise pricing.
Usage-based SaaS pricing. A generous free tier gets developers started, and paid plans scale by booking volume. No per-seat fees and no enterprise-only features.
Model Context Protocol (MCP) is the open standard that lets AI agents use external tools. Astrocal's MCP server means any compatible AI agent can check availability and create bookings natively — no custom API integration required.
MVP. The core API, dashboard, MCP server, and widget are built and functional. We're focused on developer adoption and iterating on feedback before scaling.
Calendly is a scheduling tool for end-users. Astrocal is scheduling infrastructure for developers. Full API access on every plan, native MCP support, whitelabel embedding, and usage-based pricing instead of per-seat fees.
Cal.com paused hosted API access — developers must self-host. Cronofy's API starts at $819/month. Astrocal offers a hosted API with a free tier, MCP support, and an embeddable widget that neither competitor provides at this price point.
Yes. The free plan includes full API access, Google Calendar sync, the embeddable widget, MCP server access, and 10 bookings per month. No credit card required, no time limit.

See it in action

Full API access from day one. Set up in five minutes, no credit card required.

Get started freeRead the docs