Codex Game Studio

Codex Game Studio is a workspace-local Codex template for building games with a full studio workflow, first-class Web Browser game support, and Codex-native agents.

Clone this repository as the starting point for each game project, then open that project folder in Codex. The active template surfaces are the repo-local .codex/skills and .codex/agents directories, with browser-game routing provided by the installed Codex Game Studio plugin.

What Is Included

• 131 Codex skills under .codex/skills.
• 54 Codex-native agent TOMLs under .codex/agents.
• Studio workflow docs, rules, templates, and agent memory under .codex/.
• Repo-local Codex hook routing in .codex/hooks.json and hook scripts in .codex/hooks/.
• Engine-family coverage for Godot, Unity, Unreal, and Web Browser.
• Web Browser specialist agents plus mirrored Phaser, Three.js, and React Three Fiber library skills. Browser umbrella skills come from the Codex Game Studio plugin and are not duplicated in this repository.
• A reusable skill testing framework in Codex Skill Testing Framework/.
• Repeatable sync and validation scripts in scripts/.
• Source inventories in sources/.

Skill Sources

• Studio workflow skills: 73 Codex-native skills with normal names such as prototype, test-setup, skill-test, and team-ui.
• React Three Fiber skills: 11 skills using r3f-* names.
• Phaser official skills: 28 skills using phaser-* names.
• Three.js game skills: 19 skills using the upstream threejs-* names.

The studio workflow skills are maintained directly in this template. Browser entrypoint skills such as game-studio, web-game-foundations, phaser-2d-game, three-webgl-game, react-three-fiber-game, game-ui-frontend, web-3d-asset-pipeline, sprite-pipeline, and game-playtest are supplied by the installed Codex Game Studio plugin, so this repository does not keep local copies of them. The browser-library mirrors can be regenerated from upstream clones with the sync script.

Validate

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\validate-skills.ps1

Expected result:

Validated 131 Codex skills and 54 Codex agents

Regenerate Browser Skills

The source clones are expected at ..\work\upstreams when working from this local workspace.

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\sync-codex-workspace.ps1

This regenerates the R3F, Phaser, and Three.js skill mirrors, then validates the workspace. It does not regenerate agents or duplicate browser-game plugin skills.

How To Use This Template

Use this repository as a per-project Codex workspace template. Do not copy these skills or agents into your global ~/.codex folder for normal project use. Codex should be opened from the game project root so it can read the repo-local .codex/ directory.

New Game Project

Clone this template as the starting folder for a new game:

cd E:\YourGameProjects
git clone https://github.com/onemanking/codex-game-studio.git my-new-game
cd my-new-game

If this clone will become your own game repository, point origin at your own GitHub repo before pushing project work:

git remote set-url origin https://github.com/<your-user>/<your-game-repo>.git

Then open my-new-game in Codex. The active Codex surfaces are:

AGENTS.md
.codex/config.toml
.codex/hooks.json
.codex/agents/
.codex/skills/

Validate the workspace after cloning:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\validate-skills.ps1

The validator also rejects SKILL.md files with a UTF-8 byte-order mark (BOM). Codex requires the opening --- delimiter to be the first bytes in each skill file; a BOM makes an otherwise valid YAML frontmatter fail to load.

Start the studio flow in Codex with:

/start

For browser-game projects, route through the installed Codex Game Studio plugin first, then use this template's agents and mirrored deep library skills as needed:

/game-studio
/web-game-foundations

Existing Game Project

If you already have a game repository, copy the Codex workspace surface into that project:

Copy-Item -Recurse E:\CodexUtility\codex-game-studio\.codex E:\YourExistingGame\.codex
Copy-Item -Recurse E:\CodexUtility\codex-game-studio\scripts E:\YourExistingGame\scripts
Copy-Item E:\CodexUtility\codex-game-studio\AGENTS.md E:\YourExistingGame\AGENTS.md

If the existing project already has AGENTS.md, merge the instructions instead of overwriting the file. Keep any project-specific rules that already describe the real game codebase. If the existing project already has a scripts/ directory, copy or merge at least scripts/validate-skills.ps1 because the repo-local hooks use it for Codex skill and agent validation.

After copying, open E:\YourExistingGame in Codex and run:

powershell -NoProfile -ExecutionPolicy Bypass -File .\scripts\validate-skills.ps1

If the project already received an older copy of this template, remove legacy UTF-8 BOM markers before restarting Codex:

powershell -NoProfile -ExecutionPolicy Bypass -File E:\CodexUtility\codex-game-studio\scripts\repair-skill-encoding.ps1 -RepoRoot E:\YourExistingGame

What Codex Actually Uses

Codex uses the repo-local .codex/skills, .codex/agents, hooks, and AGENTS.md from the project folder you open, plus installed Codex plugin skills. The vendor/upstream-skills directory is not the active runtime surface; it is kept as a source snapshot for traceability and future regeneration of mirrored browser-library skills.

No legacy assistant-specific workspace directory or instruction file is required for this template.