Physics and netcode SDK for authoritative-server multiplayer games. Jolt physics, hot reload, app-based world logic, Three.js client.

Demo: https://anentrypoint.github.io/spoint/

npx spoint
# or
npm install && npm start
# open http://localhost:3001              -> multiplayer (WebSocket to this server)
# open http://localhost:3001/?singleplayer -> in-browser server (runs the same server in a Worker)

There is one server. npm start runs a single node server.js on one port (worldDef.port, default 3001). Multiplayer is /; the in-browser / singleplayer mode is /?singleplayer on the same origin — the client (client/app.js) picks a WebSocket client vs an in-Worker BrowserServer from the query string, not a second port. Do not run a second node server.js on a different PORT for the same project: each process freezes its own node_modules/asset snapshot at boot, so two instances drift (the ":3001 and a script-default :8090 look different" trap). Dev/eval scripts that default to PORT=8090 just start that one server on another port; use one instance and /?singleplayer instead. The server refuses a second instance on an in-use port with a clear message.

node ./bin/create-app.js my-app

Or manually create apps/<name>/index.js:

export default {
  server: {
    setup(ctx) {
      ctx.state.counter = ctx.state.counter || 0
    },
    update(ctx, dt) {
      ctx.state.counter += dt
    },
    onInteract(ctx, player) { },
    onCollision(ctx, other) { }
  },
  client: {
    setup(engine) { },
    render(ctx) {
      return { custom: { mesh: 'box', color: 0xff0000, sx: 1, sy: 1, sz: 1 } }
    }
  }
}

export default {
  port: 3001,
  tickRate: 64,
  gravity: [0, -18, 0],
  movement: { maxSpeed: 14, sprintSpeed: 24, groundAccel: 300, airAccel: 30, friction: 5, stopSpeed: 1, jumpImpulse: 5.5 },
  player: { health: 100, capsuleRadius: 0.28, capsuleHalfHeight: 0.63, modelScale: 1.323, feetOffset: 0.212 },
  scene: { skyColor: 0x54c5eb, sunColor: 0xffffff, sunIntensity: 1.5, sunPosition: [21, 50, 20] },
  camera: { fov: 70, shoulderOffset: 0.35, zoomStages: [0, 1.5, 3, 5, 8], defaultZoomIndex: 2 },
  entities: [
    { id: 'env', model: './apps/maps/mymap.glb', position: [0, 0, 0], scale: [1, 1, 1], bodyType: 'static' },
    { id: 'game', position: [0, 0, 0], app: 'tps-game' }
  ],
  playerModel: './apps/tps-game/cleetus.vrm',
  spawnPoint: [0, 2, 0]
}

Press P to toggle editor mode:

• G / R / S — translate / rotate / scale gizmo
• F — focus camera on selected entity
• Del — delete selected entity
• Drag-and-drop .glb files to place models

Add ?singleplayer to the URL to run the same server inside a Web Worker (BrowserServer + src/sdk/WorkerEntry.js) instead of connecting to it over WebSocket — same origin, same code, no separate process. ?world=<name> selects the world (default tps-game); singleplayer-world.json is the last-resort fallback.

server.js                         Entry point
src/sdk/server.js                 Creates subsystems
src/sdk/TickHandler.js            Per-tick: movement → physics → collisions → apps → snapshot
src/physics/World.js              Jolt physics wrapper
src/netcode/PhysicsIntegration.js CharacterVirtual per player
src/apps/AppRuntime.js            Entity system, app lifecycle
client/app.js                     Three.js renderer, VRM loading, input loop
client/BrowserServer.js           Runs the server in a Web Worker for ?singleplayer (same origin)

npm run bots

Env vars: BOT_COUNT, BOT_DURATION, BOT_HZ, BOT_URL

MIT