Astrocal

Name: Astrocal
Author: astrocal-dev

by astrocal-devversion 0.1.6i★ –iComputer or cloud

Registry namedev.astrocal/mcp-server

Install

Overview

Description from the maker (original English)

AI-native scheduling: check availability, book meetings, cancel and reschedule via MCP

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Computer or cloud
Transport: stdio, Streamable HTTP
Category: Other
You need to fill in: ASTROCAL_API_KEY

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on the maker’s server: what you ask it goes through their server.
You fill in yourself: ASTROCAL_API_KEY, ASTROCAL_API_URL, ASTROCAL_DEFAULT_EVENT_TYPE_ID

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Runs in the cloudNothing to install; it connects over the internet
npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Works in Claude on the web, desktop and mobile:

Open Settings → Connectors
Press Add custom connector
Paste the address below and press Add
If it asks you to sign in, sign in with the maker

https://api.astrocal.dev/mcp

Or run it on your computer

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

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

Run this in your terminal

claude mcp add --transport http astrocal https://api.astrocal.dev/mcp

Or run it on your computer

claude mcp add astrocal --env ASTROCAL_API_KEY=your-value --env ASTROCAL_API_URL=your-value --env ASTROCAL_DEFAULT_EVENT_TYPE_ID=your-value -- npx -y @astrocal/mcp-server

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "astrocal": {
      "url": "https://api.astrocal.dev/mcp"
    }
  }
}

Or run it on your computer

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

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

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "astrocal": {
      "type": "http",
      "url": "https://api.astrocal.dev/mcp"
    }
  }
}

Or run it on your computer

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "astrocal": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@astrocal/mcp-server"
      ],
      "env": {
        "ASTROCAL_API_KEY": "your-value",
        "ASTROCAL_API_URL": "your-value",
        "ASTROCAL_DEFAULT_EVENT_TYPE_ID": "your-value"
      }
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

ChatGPT connects only to servers on the internet:

Open ChatGPT on the web → Settings → Connectors (Apps)
Press Create or Add (some plans need Developer mode under Advanced first)
Paste the address below, give it a name and save
If it asks you to sign in, sign in with the maker

https://api.astrocal.dev/mcp

Menu names can differ slightly by plan and over time.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

ASTROCAL_API_KEY secret required env
Your Astrocal API key (create one at https://astrocal.dev/dashboard/connect)
ASTROCAL_API_URL env
Custom API base URL (defaults to https://api.astrocal.dev)
ASTROCAL_DEFAULT_EVENT_TYPE_ID env
Default event type ID when not specified in tool calls

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

We have not read this server’s tool list yet; we check endpoints in rotation.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified against the domain astrocal.dev (the registry checks domain ownership)
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
… Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
… Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
… Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint

Compared with others in Otheri

More stars than 0% of the other 32484 servers in this category
Published to the registry more recently than 14% of the other 32484 servers in this category
Basic checks equal to or better than 100% of the other 32484 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Astrocal safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

You need to fill in: ASTROCAL_API_KEY

Does it run on my computer or in the cloud?

Either way works: install it on your computer or connect to the cloud version.

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.1.6) reached the registry 4 months ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.

What can I use instead?

In the same category: Spec Driven Development, Remote Desktop Commander, Recta

Alternatives

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README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

@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 ac_test_* keys. No emails sent, no calendar events created, no charges made.

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 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

Variable	Required	Description
`ASTROCAL_API_KEY`	Yes	Your Astrocal API key (get one free)
`ASTROCAL_API_URL`	No	API base URL (default: `https://api.astrocal.dev`)
`ASTROCAL_DEFAULT_EVENT_TYPE_ID`	No	Default event type ID — your agent won't need to specify it on every call

Available Tools

`check_availability`

Check available time slots for booking.

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.

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 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.

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.

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.

`join_waitlist`

Join the waitlist when all slots are full.

event_type_id (string, required) — Event type to join the waitlist for
name (string, required) — Full name
email (string, required) — Email address
preferred_times (string, optional) — Preferred time ranges or notes

`check_waitlist`

Check your position on a waitlist.

waitlist_entry_id (string, required) — Waitlist entry ID returned from join_waitlist

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. 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."

Part of the Astrocal Platform

This MCP server is one of several ways to integrate with Astrocal:

[REST API](https://www.astrocal.dev/docs/api-reference) — Full scheduling API with OpenAPI 3.1 spec
[React SDK](https://www.npmjs.com/package/@astrocal/react) (@astrocal/react) — Typed hooks, provider, and booking widget for React apps
[Embeddable Widget](https://www.npmjs.com/package/@astrocal/widget) (@astrocal/widget) — Drop-in booking UI for any website
[Dashboard](https://www.astrocal.dev/dashboard) — Manage event types, bookings, team members, and billing
[Webhooks](https://www.astrocal.dev/docs/guides/webhooks) — Real-time notifications for booking events

Create a free account to get started.

License

MIT

Astrocal

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

Or run it on your computer

Or run it on your computer

Or run it on your computer

Or run it on your computer

Values you fill in

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Otheri

Common questions

Alternatives

Spec Driven Development

Remote Desktop Commander

Recta

README from the maker

@astrocal/mcp-server

Why Astrocal for AI Agents?

Quick Start

Claude Desktop

Other MCP Clients

Environment Variables

Available Tools

check_availability

create_booking

cancel_booking

reschedule_booking

list_bookings

list_event_types

join_waitlist

check_waitlist

Example Conversation

Part of the Astrocal Platform

Links

License

`check_availability`

`create_booking`

`cancel_booking`

`reschedule_booking`

`list_bookings`

`list_event_types`

`join_waitlist`

`check_waitlist`