---
name: littlejs-api
description: Use when you need the exact signature, parameter order, defaults, or existence of a LittleJS engine symbol — e.g. drawTile arguments, the ParticleEmitter constructor, Timer or Sound methods, EngineObject properties, tile/TileInfo helpers. Look the symbol up instead of guessing from memory; LittleJS argument orders are easy to get subtly wrong.
---

# littlejs-api

The curated LittleJS API reference ships with this plugin at:

`${CLAUDE_SKILL_DIR}/../../reference.md`

It is ~2300 lines / 180KB — do **NOT** read the whole file into context. Grep it for the symbol you need and read only the surrounding lines:

- Look up one symbol: grep for the symbol name (e.g. `ParticleEmitter`, `drawTile`, `tileCollisionTest`) and read ~20 lines around the first hit — entries are one-line signatures with a trailing `//` comment, grouped in sections.
- Broader area (e.g. "what sound functions exist?"): grep for the section heading (`## LittleJS` lists them all — `Drawing System`, `Audio System`, `Input System`, `Object System`, `Tile Layer System`, `Particle System`, `3D Math`, `3D Rendering`, `3D Levels`, `Tweakables`, `Level Editor`, `Post Processing`, `Box2D Physics`, ...) and skim that section only. The 3D Rendering section alone is ~600 lines, so inside it grep for the symbol rather than reading it through.
- Renamed or removed symbols: check the `## Deprecated` section at the end.
- The reference links to `EDITOR.md` (customizing the level editors). It is bundled with the **custom-level-editor** skill, at `${CLAUDE_SKILL_DIR}/../custom-level-editor/EDITOR.md` — use that skill for anything about level editors.
- If a symbol is NOT in the reference, verify against the engine build itself before concluding it exists: grep `${CLAUDE_SKILL_DIR}/../../dist/littlejs.js` for it. Trust the engine source over memory.

For engine *conventions and pitfalls* (argument-order traps, per-frame vs per-second units, naming rules), use the **littlejs-conventions** skill instead — this skill is only for exact API lookup.