astronomy mcp server for ChatGPT

io.github.cyanheads/astronomy-mcp-server

Offline observational astronomy: positions, rise/set, moon phases, eclipses, and seasons.

client:ChatGPT transport:streamable-http runtime:npm tools:7

Install astronomy mcp server in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://astronomy.caseyjhand.com/mcp

Custom connectors are a paid-plan feature and take a remote URL only. ChatGPT cannot run a packaged server locally. ChatGPT docs