What is LittleJS-AI CLAUDE.md?

Project instructions for building playable games with LittleJS, a JavaScript game engine, using Claude as the coding assistant.

Use them to start or extend LittleJS games, choose the standard project structure, split game code into modules, and plan the next development step.

They keep game work focused on a playable core, organized into the expected example folders and files, with small iterative changes.

How KilledByAPixel/LittleJS-AI configures Claude Code

Reuse

Borrowing it

Nothing to install: this file belongs to KilledByAPixel/LittleJS-AI. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/KilledByAPixel/LittleJS-AI/main/CLAUDE.md

Clone the repo

git clone --depth 1 https://github.com/KilledByAPixel/LittleJS-AI

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/killedbyapixel/littlejs-ai/claude-md/github.svg)](https://agentmods.dev/instructions/killedbyapixel/littlejs-ai/claude-md)

Your own site

<a href="https://agentmods.dev/instructions/killedbyapixel/littlejs-ai/claude-md"><img src="https://agentmods.dev/badge/instructions/killedbyapixel/littlejs-ai/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/killedbyapixel/littlejs-ai/claude-md"><img src="https://agentmods.dev/badge/instructions/killedbyapixel/littlejs-ai/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 4 This file is loaded in full into every session.

When invoked 4 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00004	$0.00004
Opus 5.5	$0.00002	$0.00002
Sonnet 5.5	$0.00001	$0.00001
Haiku 4.5	$0.00000	$0.00000

Measured 2mo ago against content hash 918b1c905593, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

LittleJS-AI CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

LittleJS-AI AGENTS.md — 100% identical, 314 lines differ

CLAUDE.md · 1 lines

What it actually says

@AGENTS.md

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

2mo ago Changed · -227 lines · -3,662 tokens per session 918b1c905593
2mo ago First seen · 228 lines · 3,666 tokens per session scan A 69f97e351548

Subscribe to this mod's changes

LittleJS-AI CLAUDE.md is an instructions file published in the GitHub repository KilledByAPixel/LittleJS-AI (85 stars, last pushed 3d ago), licensed MIT. It adds 4 tokens to every session, about $0.0000 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Building agents Game development ai ai-agents chatgpt game-engine littlejs

LittleJS-AI CLAUDE.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
LittleJS-AI CLAUDE.mdKilledByAPixel/LittleJS-AI	Instructions file	85	3d ago	MIT	A	4	Claude Code
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

LittleJS-AI: Instructions file for Claude Code