The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond.
Universal scaffold for game-dev agents and commands
This repo is an operating system for AI-assisted game projects. It gives you reusable commands, role-based agents, shared rules, and workflow hooks, while keeping Unity, Unreal, Godot, and web instructions isolated from one another. The same scaffold is adapted for multiple assistants through dedicated client folders and registries.
Builders who want one coordinated game-development workflow across multiple AI assistants and engines.
You can start, review, and ship game work with the same commands and standards across different agents instead of rebuilding your process each time.
What it does
Multi-harness adapters
Adapter folders for Claude Code, Codex, Cursor, OpenCode, Kiro, Grok Build, and Kilo point each client at the same shared source of truth.
Role-based agents
The `agents/` folder contains many specialist markdown agents such as gameplay programmer, level designer, QA lead, and reviewer roles.
Repeatable commands
The `commands/` folder provides chat commands like `/gdd`, `/full-game`, `/godot-setup`, and `/unity-build-fix`.
Shared rules and skills
The scaffold separates policy in `rules/` from execution patterns in `skills/`, with engine-specific sublayers where needed.
Engine isolation
Unity, Unreal, Godot, and web guidance live in separate rule layers so each engine can keep its own conventions.
Workflow safeguards
`npm run setup:hooks` installs pre-commit checks that keep generated artifacts and structure in sync.
How to get it
- 1Run
git clone https://github.com/MRCalderon3D/everything-game-dev-code.git cd everything-game-dev-code npm run setup:hooks
README
Everything Game Dev Code
A universal scaffold for AI-assisted game development.
Multi-engine. Multi-harness. One coordinated workflow.
Unity · Unreal Engine · Godot · HTML/JS — 2D and 3D, strict engine isolation, shared standards.
Not just a prompt collection — a structured operating system for game projects that combines:
- Rules for policy and standards
- Agents for role specialization
- Commands for repeatable entry points
- Skills for reusable execution patterns
- Contexts for phase-specific behavior
- Hooks for workflow automation
- Harness adapters for Claude, Codex, Cursor, OpenCode, Kiro, Grok Build, and Kilo (see docs/harness-support.md for what each one supports)
Quickstart
git clone https://github.com/MRCalderon3D/everything-game-dev-code.git
cd everything-game-dev-code
npm run setup:hooks
npm run setup:hooks wires the repo's pre-commit checks (structure sync + validation) so committed artifacts never drift; it needs Node.js 18+ and takes one second. Run npm run doctor at any time to diagnose your installation (environment, hooks, active engine profile, generated-artifact drift) with remediation hints.
Open the folder in your AI coding assistant (Claude Code, Cursor, Codex, OpenCode, Kiro, Grok Build, or Kilo). The scaffold is loaded from the assistant's adapter plus the shared AGENTS.md, rules/, commands/, agents/, and skills/ layers.
Then type commands in the chat:
| Command | What it does |
|---|---|
/plan | Outline your project before coding |
/gdd | Generate a Game Design Document |
/tdd | Apply test-driven development to the current task |
/scene-bootstrap | Scaffold a new scene |
/unity-setup | Bootstrap a Unity project with conventions |
/unity-build-fix | Diagnose and fix Unity build errors |
/godot-setup | Bootstrap a Godot project |
/unreal-setup | Bootstrap an Unreal project |
/web-setup | Bootstrap a web (HTML5) project, 2D canvas or 3D WebGL |
/generate-assets | Generate real assets — images, skyboxes, 3D models, SFX, music, voice, video — from text prompts |
/full-game | Orchestrate an entire game from scratch (experimental) |
You don't have to follow a specific order. Pick whatever command fits your current need — start a new project, generate a GDD for an existing one, run a QA review, or fix a build error.
Step-by-step guide
The guides/Dash & Collect/ folder contains a full tutorial that walks through building a game using the scaffold's commands, agents, skills, and contexts across all project phases.
Example projects
The samples/ folder contains thirteen complete HTML games built with the /full-game command in a single pass each (PirateInvaders, Tetris2DMutation, LosRenacidos, pacmanAI, harness-comparison variants, PrismDefense3D — the first 3D sample, built on Three.js against the web 3D rules, plus its CC0-textured Visuals variant and its AssetsGen variant where every model, texture, skybox, sound, and the intro cinematic were generated through the /generate-assets layer, and NebulaLance — a 2.5D R-Type-style shoot-'em-up whose ship, enemies, boss, nebula, audio, and image-to-video menu cinematic are all AI-generated), plus a writeup comparing how different AI harnesses performed on the same brief. For real projects, we recommend going step by step.
Goals
- Keep shared game-development standards engine-neutral.
- Let Unity, Unreal, Godot, and the web layer each extend the base cleanly without contaminating one another.
- Support real production work across design, engineering, content, QA, release, and live ops.
- Turn repeated solutions into reusable skills and structured workflows.
- Make the repository portable across multiple coding assistants and harnesses.
Repository Model
This scaffold is organized in layers:
rules/— what good looks likeagents/— who does the workcommands/— how work startsskills/— how work is executed wellcontexts/— how priorities shift by phasehooks/— how workflow safeguards are enforcedmanifests/— how subsets are installed by profile, plus the engine layer registry (engines.json), the harness adapter registry (harnesses.json), and the generative asset provider registry (asset-providers.json)schemas/— JSON validation for manifests, hooks, and pluginsscripts/— generators, validators, and diagnostics (new:engine,doctor,sync:*)docs/templates/— structured templates for GDD, TDD, QA plans, and other deliverablesdocs/orchestration/— agent routing, role handoffs, and workflow sequencestests/— how the scaffold verifies itself- harness adapters — how different AI clients consume the same source of truth
Engine Isolation Policy
The repository is intentionally split into:
rules/common/rules/unity/rules/unreal/rules/godot/rules/web/
And equivalent skill / command / review layers where needed.
Shared documents should describe intent, ownership, and quality bars. Engine-specific files should describe implementation conventions inside that engine only.
AI Asset Generation (optional)
The scaffold ships an optional engine-neutral asset generation layer. It is an upgrade, not a dependency: the default asset workflow is unchanged, and AI generation only activates when a provider API key is present in the environment.
Without a key (default). Use the scaffold's built-in tooling exactly as always:
the engine placeholder commands (/unity-placeholders, /godot-placeholders,
/web-placeholders) and the procedural / Canvas / WebAudio pipelines. A game built
entirely on placeholders is a complete, valid result — nothing about the workflow
requires an API.
With a key (FAL_KEY for the default fal.ai provider). /generate-assets becomes
available to upgrade placeholders to real content from text prompts:
- Generate placeholders first so every asset has a stable name and path.
- Run
/generate-assetsto produce images and textures, equirectangular skyboxes, 3D models (GLB/OBJ), sound effects, music, voice lines, and intro/cinematic video — dropped onto those same names and paths (zero code changes). - Import through the active engine layer and review with the matching pass command (
/art-2d-pass,/art-3d-pass,/audio-pass).
Resolution order, quality, and cost. For images and skyboxes the scaffold prefers a
free harness-native generator (e.g. Codex $imagegen) when the running harness has one,
then the paid API, then placeholders; 3D/audio/video only have the API or placeholder
paths. Quality vs price is the user's dial: every capability has budget / balanced /
premium tiers (--quality, default balanced) — a full asset pass runs roughly
$2-3 / $5-7 / $10+ respectively. Because the API costs money, generation also asks before
spending: every run prints a cost estimate, and scripts/generate-assets.js refuses runs
at or above a configurable threshold (confirmOverUsd) without explicit confirmation.
Autonomous flows like /full-game keep placeholders as the default and ask once — tier
and spend — before generating.
Capability-to-model routing lives in manifests/asset-providers.json (default provider: fal.ai — one pay-per-use key covers every modality). scripts/generate-assets.js performs the generation and writes a .provenance.json sidecar (provider, model, prompt, seed, request id) per run; assets without provenance are treated as unlicensed content. The key is read only from the FAL_KEY environment variable and is never committed (.env files are gitignored). Governance rules — the optional-capability, resolution-order, and cost-confirmation policy — live in rules/common/asset-pipeline.md. For a worked end-to-end example see the samples/PrismDefense3DAssetsGen variant.
Intended Use Cases
- New game project setup
- Multi-engine studio workflows
- Internal AI workflow standardization
- GDD and technical design maintenance
- QA and release readiness reviews
- Plugin / content / tooling governance
- Cross-discipline planning and orchestration
Supported Harnesses
- Claude Code
- Codex
- Cursor
- OpenCode
- Kiro
- Grok Build
- Kilo
Each harness adapter points back to the same shared scaffold rather than becoming a second source of truth.
MCP servers
The scaffold curates a set of MCP servers (browser playtesting, AI asset generation, Blender/DCC control, and more) in mcp-configs/mcp-servers.json, with ready-to-use, harness-native configs generated into mcp-configs/generated/. MCP is vendor-neutral, so they work with any MCP-capable client. See docs/mcp-setup.md for per-harness install and a Blender end-to-end walkthrough.
Codex usage
Codex should start from AGENTS.md and .codex/README.md. Slash-style commands such as /plan, /gdd, and /unity-review map to commands/<name>.md; if the Codex client does not execute slash commands natively, type the command name in chat and ask Codex to run the matching scaffold command.
For raster-first asset work in Codex, use $imagegen alongside the shared art pipeline skills. Good fits include concept sheets, sprite source art, UI mockups, marketing key art, painted backgrounds, and bitmap edits; keep vector/code-native asset work in the normal repo workflows. If a generated image becomes a real project asset, move the selected file from $CODEX_HOME/generated_images/... into the workspace and keep the scaffold's naming and folder conventions.
Current Status
The scaffold is intentionally modular. Different blocks may be added or replaced over time, but the repository should always preserve:
- flat agent and command structures
- layered rules
- grouped skills
- engine isolation
- harness portability
Principles
- Design before implementation
- Explicit ownership over implicit assumptions
- Testability over cleverness
- Documentation that supports execution
- Measured performance and release readiness
- Accessibility, QA, and compliance as first-class requirements
License
This repository is provided under the MIT License unless you replace it with your studio’s internal licensing policy.
Files in the repo
- .agents
- .claude
- .claude-plugin
- .codex
- .cursor
- .githooks
- .github
- .grok
- .kilo
- .kiro
- .opencode
- agents
- commands
- contexts
- docs
- examples
- guides
- hooks
- manifests
- mcp-configs
- plugins
- rules
- samples
- schemas
- scripts
- skills
- tests
- .env.example
- .gitattributes
- .gitignore
- .markdownlint.json
- .mcp.json
- .prettierrc
- AGENTS.md
- CHANGELOG.md
- CLAUDE.md
- CONTRIBUTING.md
- install.ps1
- install.sh
- LICENSE
- package-lock.json
- package.json
- README.md
- SECURITY.md
- STRUCTURE-TREE.txt
- TROUBLESHOOTING.md
- VERSION
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