murrkit
The AI 2D Game Creation Tool
An autonomous AI agent that designs, builds, playtests and polishes 2-D browser games for you — in Phaser 3 + TypeScript. Describe a game in plain language; murrkit generates the sprite art, writes the code, plays the game headlessly, and iterates until it’s actually fun.
Free & open source — MIT licensed.
From a Sentence to a Playable Game
Most “AI game makers” stop at a snippet of code. murrkit goes all the way: it owns the full loop — concept, art, code, testing and polish — and it doesn’t declare a game finished until an AI vision-check agrees it looks and plays right. The result is a real, hot-reloadable Phaser 3 project you can open, edit and ship.
How murrkit Works
Six autonomous stages, looping until the game meets the bar.
Imagine
Expands a vague prompt into a full technical design — controls, physics, level progression and AI behaviour.
Generate
Produces sprite sheets, tilesets and UI art through the Kitty image API.
Write
The “captain” writes clean TypeScript scenes with hot-reload as it goes.
Playtest
Playwright drives the game headlessly with real keyboard/mouse input and captures state snapshots.
Vision-gate
AI vision compares the result to references and blocks completion until it passes.
Iterate
Failing verdicts automatically re-invoke the captain — murrkit fixes its own work.
See It In Action
Cat Volleyball — fast 2-D beach volleyball with battling cats, fireball spikes and online 2-player — was built entirely with murrkit. Every sprite, every arena and every line of gameplay code came out of this pipeline.
Play Cat VolleyballWhy murrkit
Fully Autonomous
Design → art → code → test → polish runs end-to-end. You approve the plan; murrkit does the rest.
Vision-Verified
AI looks at every change and refuses to finish until the game actually meets the reference.
Real Phaser Project
Outputs a hot-reloadable Phaser 3 + TypeScript project — open it, tweak it, ship it.
Self-Playtesting
Headless Playwright runs drive the game like a player and feed results back into the loop.
Budget-Aware
A spend cap keeps image generation on a leash — set BUDGET_LIMIT_USD and relax.
Open Source
MIT licensed and on GitHub. Read it, fork it, extend it, contribute back.
Download murrkit
Get the full studio for Windows. The page is free to browse — a quick, free sign-in is required only to start the download (anti-abuse). After install, a short Setup screen connects Claude Code and your Kitty token, then you’re building games.
Sign in to download Free account required · Windows 64-bitPrefer to run from source? Clone it on GitHub — see the setup below.
Getting Started
Two things to connect, then you’re generating games.
1. Install Claude Code
murrkit uses the Claude Code CLI as its brain (you provide your own Anthropic subscription or API key). Install it globally and make sure it’s on your PATH:
npm install -g @anthropic-ai/claude-code
claude --version2. Get your Kitty App token
The art is generated through the Kitty image API. Open your Druid Cat dashboard, top up credits, and copy your Kitty App token (it looks like kitty_…). Paste it into murrkit’s Setup screen, or into .env as KITTY_APP_TOKEN. Images cost roughly $0.04–$0.16 each.
3. Build a game
Launch murrkit, type your game idea into Chat, review the captain’s design document and reply “APPROVE”. From there it generates assets, writes code, playtests and iterates — automatically.
Running from source
Requirements: the Claude Code CLI (the AI brain — required), Python 3.13 + uv and Node 20 LTS (on Windows, avoid Node 22.19.0 — a known readlink regression). Then:
git clone https://github.com/DruidCat237/murrkit.git
cd murrkit
uv sync
cd frontend && npm install && cd ..
cd phaser_game && npm install && npx playwright install chromium && cd ..
cp .env.example .env # add your tokens
# run the three services (separate terminals)
uv run uvicorn backend.main:app --port 8001
cd frontend && npm run dev # http://localhost:3001
cd phaser_game && npm run dev # http://localhost:5173| Requirement | Required | Where to get it |
|---|---|---|
| Claude Code CLI | Required | npm i -g @anthropic-ai/claude-code |
KITTY_APP_TOKEN | Required | Your Druid Cat dashboard |
DEEPSEEK_API_KEY | Optional | platform.deepseek.com |
GEMINI_API_KEY | Optional | aistudio.google.com |
ELEVENLABS_API_KEY | Optional | elevenlabs.io |
BUDGET_LIMIT_USD | Optional | Spend cap (default 80) |
Under the Hood
Proudly Open Source
murrkit is MIT licensed and developed in the open. Inspect how the agent loop works, file issues, request features or send a pull request — it’s all on GitHub.
DruidCat237/murrkit