SwingBy Web

A browser build of SwingBy, an orbital-mechanics puzzle game, hosted at swingby.magnussaurbier.de. You pilot a spacecraft through a miniature solar system using only gravity, an initial velocity, and boost/brake — see docs/GAME.md for the full picture.

Quick start

npm install
npm run dev -w @swingby/web      # dev server on localhost:5173
npm test                          # all tests, all packages
npm run typecheck
npm run lint                      # prettier --check
npm run build -w @swingby/web
npm run size                      # bundle budget gate, fails over 250 KB gzipped

Getting context for a task

Read this file, then follow the table below — open only what your task's trigger matches. Each docs/ file ends by naming the exact source files it describes, which is where to go next. Full process (including when to split work across subsessions) is in AGENTS.md.

Doc	Read this when...
docs/GAME.md	your task touches gameplay, mechanics, level content, package layout, or general repo conventions
docs/INTERFACES.md	you need the exact shape of a type/function/API contract, or which module owns a given file
docs/PHYSICS.md	you're touching gravity, integration, boost/brake math, bounds, or prediction — the physics core in full mathematical detail, every equation cited to a file:line
docs/INFRA.md	you're touching the API, the database, deployment, or hosting
infra/DEPLOY.md	you're actually running the deploy steps, not just reading about the architecture
infra/AUTOMATION.md	you need to know what's automated in CI vs. still manual

packages/core/src/types.ts and constants.ts are the shared type/constant contract read by both packages — read them before writing code against anything in docs/INTERFACES.md.

notes/archive/ holds working logs and specs for finished work. Not force-read — open it only when tracing a specific past decision (grep a feature name).

Standing constraints (apply regardless of task)

• Bundle budget: under 250 KB gzipped, gated by npm run size.
• packages/core is zero-dependency and runs in both the browser and Node — that's what makes server-side replay verification possible.
• Never use Math.pow in the physics path — see docs/GAME.md §4.
• Touch is first-class, not a desktop afterthought — this is a phone-playable game.
• Branch per task (feat/<slug> / fix/<slug>), push early and often — see AGENTS.md.