Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add instructions/ivanmurzak/ai-game-dev-plugin/agents-mdgit clone --depth 1 https://github.com/IvanMurzak/ai-game-dev-pluginWhat 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 | $0.00837 | $0.00837 |
| Opus 5 | $0.00418 | $0.00418 |
| Sonnet 5 | $0.00167 | $0.00167 |
| Haiku 4.5 | $0.00084 | $0.00084 |
Grade A, and why
ai-game-dev-plugin AGENTS.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 2d 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.
How it starts
The opening of the file, as written. The whole thing — 70 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md
Custom instructions for AI coding agents (Codex CLI reads this natively; other agents read it as extra context) working inside this repository.
What this repo is
ai-game-dev-plugin is a marketplace of game-dev plugins/skills for AI coding agents —
Unreal, Unity & Godot, one plugin each. Every plugin ships a single skill (a runbook) that
teaches the agent to drive that engine's official npm CLI (unreal-mcp-cli, unity-mcp-cli,
godot-cli) so the agent can take a user from nothing to a running editor connected to
ai-game.dev — creating the project, installing the engine plugin, logging
in, and opening the editor, automatically.
It targets both Claude Code and Codex CLI from one source tree.
Layout
.claude-plugin/marketplace.json # Claude Code marketplace catalog
.agents/plugins/marketplace.json # Codex marketplace catalog
.agents/skills/<engine>-game-dev/SKILL.md# Codex repo-native skills (GENERATED — do not hand-edit)
plugins/<engine>/
.claude-plugin/plugin.json # Claude Code plugin manifest
.codex-plugin/plugin.json # Codex plugin manifest
skills/<engine>-game-dev/SKILL.md # CANONICAL runbook (shared by both agents' plugins)
README.md # per-plugin readme (agent-neutral)
scripts/sync-skills.mjs # regenerates .agents/skills/ from the canonical skills
<engine> is one of unreal, unity, godot.
Single source of truth for the skill bodies
- The canonical runbook for each engine is
plugins/<engine>/skills/<engine>-game-dev/SKILL.md. Both plugin manifests (.claude-plugin/plugin.jsonand.codex-plugin/plugin.json) reference the plugin's own./skills/directory, so the two agent bundles share that one file — no second copy. - The repo-native Codex discovery copies under
.agents/skills/are generated from the canonical files byscripts/sync-skills.mjs. Never hand-edit.agents/skills/. - After editing any canonical
SKILL.md, run:
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.
- 2d ago First seen · 70 lines · 837 tokens per session scan A 6f0d2b5e9691
ai-game-dev-plugin AGENTS.md is an instructions file published in the GitHub repository IvanMurzak/ai-game-dev-plugin (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 837 tokens to every session, about $0.0042 per session on Opus 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 2026-08-31.
Other instructions, from other repositories
cocos-extensions AGENTS.md
Instructions for hhhh124hhhh/cocos-extensions, covering cocos mcp stack — agent 安装指南, 1. 这套东西由什么组成, 2. 前置条件, 3. 一键安装（推荐 agent 直接跑） and 4. 手动安装（无脚本时）.
godot-mcp AGENTS.md
Instructions for sandraschi/godot-mcp, covering agents.md — godot-mcp context, essential paths, module registration, key dependencies and conventions.
godot-mcp CLAUDE.md
Instructions for sandraschi/godot-mcp, covering godot-mcp — claude code guide, standards and key files.
godot-mcp copilot-instructions.md
Instructions for sandraschi/godot-mcp: You have access to a Godot 4 game engine control server with 49 tools across 10 domains: engine control, asset import/export, game building, fleet coordination, itch.io shipping, Steam publishing, animation, particles, HTML5 export, and cross-server MCP bridging.
unity-code-style-guide AGENTS.md
Instructions for krogh-jacobsen/unity-code-style-guide, covering agents.md — unity 6 c, project setup — edit this block, never do these — they corrupt the project, deprecated in unity 6 and if you read nothing else.
unity-cli-skill CLAUDE.md
Instructions for niqibiao/unity-cli-skill: Project instructions are maintained in and imported from @AGENTS.md.