unity-game-dev

A setup guide for using an AI coding assistant to create or open Unity game projects and connect them to ai-game.dev, an online service for AI-assisted game development.

In plain words
What is it for?
It helps create projects, install the Unity-MCP plugin, log in to ai-game.dev, and open a connected Unity Editor.
Why use it?
It removes the guesswork from installing the connection tools, signing in, and opening the correct Unity Editor in the required order.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/ivanmurzak/ai-game-dev-plugin/unity-game-dev
Any agent
npx skills add IvanMurzak/ai-game-dev-plugin --skill unity-game-dev
Clone the repo
git clone --depth 1 https://github.com/IvanMurzak/ai-game-dev-plugin

Made for: Claude Code, Codex.

Per session 58 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,787 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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.

ModelPer sessionOnce invoked
Fable 5 $0.00058 $0.01787
Opus 5 $0.00029 $0.00894
Sonnet 5 $0.00012 $0.00357
Haiku 4.5 $0.00006 $0.00179

Measured 2d ago against content hash e0f66354841c, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

unity-game-dev 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.

.agents/skills/unity-game-dev/SKILL.md · 161 lines

How it starts

The opening of the file, as written. The whole thing — 161 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Unity — AI Game Dev runbook

This skill teaches your AI coding assistant (Claude Code or Codex CLI) to drive Unity fully automatically through the unity-mcp-cli npm package. The goal: take the user from nothing to a running Unity Editor that is connected to ai-game.dev so the AI can build the game for them.

Every command runs via npx so nothing needs to be installed globally:

npx -y unity-mcp-cli@latest <command> [args]

Prerequisites (check first)

  • Node.js 18+node --version.
  • Unity Hub + a Unity Editor installed (e.g. Unity 6). create-project uses Unity Hub to scaffold and to resolve the editor version; the requested version must be installed.
  • A free ai-game.dev account — the login step authorizes the project against the cloud.
  • Windows / macOS / Linux with a real desktop session (the editor opens a window).

The automatic end-to-end sequence

Run these in order. Do not skip the ordering rule around close → login → open.

1. Create the project (fresh start only)

Skip this step if the user already has a project — go straight to step 2 pointing at it.

npx -y unity-mcp-cli@latest create-project "C:/Games/MyGame" --unity 6000.0.0f1
  • create-project <path> scaffolds a new Unity project at <path> via Unity Hub.
  • --unity <version> selects the installed editor version (must be installed in the Hub).

Verify: the <path> now contains Assets/, Packages/, and ProjectSettings/.

2. Install the Unity-MCP plugin

npx -y unity-mcp-cli@latest install-plugin "C:/Games/MyGame"

Patches Packages/manifest.json to add the Unity-MCP package so the editor can expose its tools to the cloud AI. Verify: Packages/manifest.json now references the AI Game Developer package.

3. Close the editor before logging in

npx -y unity-mcp-cli@latest close "C:/Games/MyGame"
# add --force if the editor won't exit cleanly

This ordering is critical. The editor must not be running when you log in, because it reads the auth token from the project's UserSettings only at startup. If it is already open it would run with a stale (or missing) token. Always close before login. Use --force only if a normal close fails.

Read the full file on GitHub · 161 lines

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.

  1. 2d ago First seen · 161 lines · 58 tokens per session scan A e0f66354841c

Subscribe to this mod's changes

unity-game-dev is a skill published in the GitHub repository IvanMurzak/ai-game-dev-plugin (2 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 58 tokens to every session and 1,787 once invoked, about $0.0003 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.