Open source
PlanAstro is built from within the amateur-astronomy and astrophotography community, for people who experiment, build and adapt their own equipment, and value the open exchange of methods and results. Source availability is one concrete sign of that: Astro Portal Core, the public repository, is the self-hosted core of the product — not a reduced "community edition" of it.
What is in the public repository
The gallery, the shareable target pages, render/color-curve variants and stacking progressions, optional plate solving, the observation planner, the local deep-sky catalogue, and the self-hosted Bortle/SQM light-pollution estimate. Everything the open-source project ships is also what a free hosted account gets, within the resource limits a free tier can fund — a self-hoster stores media on their own disk, while the free hosted tier stores metadata only, because storage has a real cost that only subscriptions fund.
Whatever enters the open-source code enters the free hosted tier, for good. No feature is ever removed from the public repository to be sold later.
License
GNU AGPL v3. The project also includes Stellarium Web Engine and its unmodified compact sky data, under its own license — see the repository's own documentation for the exact upstream revision.
Self-hosting
Requirements: Node.js 20.9 or newer.
git clone https://github.com/sqound/astro-portal-core.git
cd astro-portal-core
npm install
npm run dev
Then open http://localhost:8787. The repository starts with a synthetic sample target that demonstrates the gallery, variants, stacking progression, sky map and editor. Full installation, configuration and deployment instructions live in the repository's own docs/ — including a self-hosted Cloudflare tunnel setup, PostgreSQL as an alternative to SQLite, and a pre-publication privacy checklist.
Behavior, not just a license
Trust depends on more than a license: documented formats, complete exports, unchanged original files, reproducible calculations, explicit sources and their licenses, no hidden telemetry, no hostile paywall, and a practical route away from the hosted service if you ever want one. This site and the hosted service are held to the same standard as the public repository.