unity-prototype

A command that creates a playable Unity game prototype from a described mechanic. It writes basic C# scripts, builds a scene with game objects and physics settings, connects the camera, and checks the console for errors.

In plain words
What is it for?
Use it for prototypes with player controls, abilities, platforms, obstacles, triggers, scoring, win or lose rules, physics, and a camera that follows the player.
Why use it?
It turns a short gameplay idea into something you can run and test. This helps expose problems in movement, rules, collisions, camera behavior, and scene setup early.

Command for Claude Code

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 commands/xeldaralz/everything-claude-unity/unity-prototype
Clone the repo
git clone --depth 1 https://github.com/XeldarAlz/everything-claude-unity

Made for: Claude Code.

Per session 32 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 519 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 $0.00032 $0.00519
Opus 5 $0.00016 $0.00260
Sonnet 5 $0.00006 $0.00104
Haiku 4.5 $0.00003 $0.00052

Measured 2d ago against content hash 45cf4331dd68, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

unity-prototype 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.

.claude/commands/unity-prototype.md · 64 lines

How it starts

The opening of the file, as written. The whole thing — 64 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/unity-prototype — Rapid Prototype

Create a playable prototype of: $ARGUMENTS

Workflow

Use the unity-prototyper agent to deliver a complete, playable prototype.

Step 1: Decompose

Break the mechanic into:

  • Player systems (movement, abilities, input)
  • World elements (platforms, obstacles, triggers)
  • Game rules (win/lose, scoring)
  • Camera behavior

Step 2: Write Scripts

Create minimal, functional C# scripts:

  • Player controller with exposed [SerializeField] parameters
  • Game mechanics (physics, triggers, scoring)
  • Follow the prototype design principle: functional > clean

Step 3: Build Scene via MCP

Using batch_execute for speed:

  1. Create a new scene named Prototype_[MechanicName]
  2. Create all GameObjects (player, environment, obstacles, camera)
  3. Add and configure components (Rigidbody, Collider, Renderer)
  4. Set up physics layers and collision matrix
  5. Configure Cinemachine camera to follow player

Step 4: Verify

  • Check console via read_console for any errors
  • Report the complete prototype setup to the user

Step 5: Report

Tell the user:

  • Controls — what keys/buttons to use
  • Scripts created — file names and locations
  • Scene — name and how to open it
  • Tweakable values — which SerializeField parameters to adjust
  • Next steps — what to add for a fuller prototype

Step 6: Auto-Verify (Optional)

After the prototype is complete, offer to run the unity-verifier agent:

  • Quick review of all prototype scripts for critical issues
  • Auto-fix serialization safety, null checks, and performance pitfalls
  • Skip architecture concerns (prototypes prioritize speed over structure)

Suggest: "Prototype ready! Want me to run a quick verification pass?"

Design Rules

  • 10-minute target — if it takes longer, you're overbuilding
  • Placeholder visuals — colored primitives, no art needed
  • Everything tweakable — SerializeField with Headers
  • Single scene — no multi-scene for prototypes
  • No UI — use Debug.Log and Gizmos for feedback

Read the full file on GitHub · 64 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 · 64 lines · 32 tokens per session scan A 45cf4331dd68

Subscribe to this mod's changes

unity-prototype is a command published in the GitHub repository XeldarAlz/everything-claude-unity (21 stars, last pushed 4mo ago), licensed MIT. It adds 32 tokens to every session and 519 once invoked, about $0.0002 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 2026-08-30.