# Gol · Astro Lab

> An interactive astronomy simulation engine: the celestial sphere from any place and time, in a browser tab, on a phone, in a VR headset or on a full-dome projector. Made by Kaalshodh.

Gol is driven by a small line-based scripting language (`.gol`). An assistant writes a script, the person runs it in the app, and the sky does what the script says: switch views, toggle overlays, jump in time, move the observer, caption each step. The app runs the script on the person's own device. There is no account, no API key and no server call.

## How to drive Gol

- Write a `.gol` script, one command per line, and reply with it in a single ```gol fenced code block with no prose around it. The person shares or pastes your reply into the app and it runs.
- Or compose a share link: `https://gol.kaalshodh.com/app#~scene=<slug>&…`. The link keys are listed in the reference.
- The reference is the only authority. Every command you use must appear in it; unknown commands are skipped.
- With the desktop app (or a dev server) running, Gol serves MCP at `http://localhost:5173/mcp`: tools to read the state, run and validate scripts, query the sky, search the catalog, take a screenshot, render frame-accurate PNG sequences to disk (render_frames) and build share links, plus the reference as a resource. The app's "Connect your AI" panel has the client config.

## Reference

- [Scripting reference](https://gol.kaalshodh.com/skill.md): grammar, the full command catalog, overlay tokens, worked examples and a QA checklist. Read it before writing a script.
- [Scripting guide](https://gol.kaalshodh.com/scripting): the same reference rendered for people.
- [Manual](https://gol.kaalshodh.com/manual): what the app shows and how its views, scenes and time controls work.
- [Curriculum](https://gol.kaalshodh.com/curriculum): the concept graph the built-in lessons follow, in dependency order.
- [Spherics](https://gol.kaalshodh.com/spherics): the spherical-trigonometry demos.

## Companions

- [Kaalshodh](https://kaalshodh.com): precision Indian-calendar astronomy. Its MCP server answers exact dates, positions and events; use it for the numbers a lesson quotes.
- [Mandal](https://mandal.kaalshodh.com): the Sun–Earth–Moon orrery. Same script language, its own command catalog.