REST API
Build into apps, backends, and pipelines. Predictable JSON responses with OpenAPI docs and copy-paste examples.
Browse API docs → Ask the sky a question —
from your app or your AI assistant.
Moon phases, planetary positions, charts, and sky events — as clean JSON for your app, or as tools your AI assistant can call. One account. One credit pool.
Free tier · no credit card · first call in ~5 minutes
Two ways in
Same sky data. Pick how you connect.
Works with Claude, ChatGPT, Perplexity, Cursor, VS Code, and AI apps you build yourself.
Hosted MCP
Connect your AI — Claude, ChatGPT, Cursor, or your own stack. OAuth or API key at
mcp.astronomycore.com.
Free to start
Welcome credits on signup. Upgrade when you need more volume or packages — no sales call.
See pricing →See it in action
Ask the sky a question — from code or your AI assistant.
Call REST from your code, or let any MCP-compatible assistant discover and invoke sky tools at runtime — hosted chat apps, Cursor, VS Code, or your own AI stack.
~120ms
median response
69+
REST endpoints
41
MCP tools
Your AI assistant · tonight's moon
Packages
Packages · One API key.
Add-on bundles unlock specialized modules — same labels on pricing and dashboard.
FAQ
Common questions
What is the difference between REST and MCP?
REST is direct HTTPS from your code. MCP is a hosted tool server that AI assistants discover at runtime. Same sky data, same credits, same API key.
Can I use MCP with my own AI, not just ChatGPT or Claude?
Yes. Connect via OAuth in hosted assistants, or add mcp.astronomycore.com to Cursor, VS Code, or any MCP-compatible client with your API key.
Do I need a credit card for the free tier?
No. Sign up with email or Google, verify your email, and use welcome credits on the Free tier.
Can I read the docs before signing up?
Yes. API reference, OpenAPI spec, and connect guides are public. You only need an account to generate an API key.
Ready to ask the sky?
Free API key in minutes. Same access for REST and MCP.
No credit card · cancel anytime