agentmods.dev

unity

Rules for the Unity game engine's MCP server, covering how an AI assistant should edit scenes and prefabs, which are reusable game-object templates.

In plain words
What is it for?
Use them when creating or changing Unity scenes, prefabs, objects, visual elements, shaders, or player input.
Why use it?
They help preserve Unity's editing workflow, including saving changes, keeping edits undoable, and avoiding incorrect file operations.

Cursor rule

33 4mo ago A scan 224 tokens original MIT archived
View the source file nurture-tech/unity-mcp-server
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 rules/nurture-tech/unity-mcp-server/unity
Clone the repo
git clone --depth 1 https://github.com/nurture-tech/unity-mcp-server
Per session 224 This file is loaded in full into every session.
When invoked 224 The same file — it is already loaded in full.
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 $0.00224 $0.00224
Opus 5 $0.00112 $0.00112
Sonnet 5 $0.00045 $0.00045
Haiku 4.5 $0.00022 $0.00022

Measured yesterday against content hash ff67642a2985, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

unity 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 yesterday.

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.

rules/cursor/unity.mdc · 24 lines

What it actually says

  • When editing an existing scene or prefab, open it first.

  • After creating a new scene, open it.

  • After creating or changing objects in a scene or prefab, focus on the objects that were created or changed.

  • After making a change to a scene or prefab that you want to keep, save it.

  • After editing a prefab, exit isolation mode before continuing to work on the scene.

  • Don't use generic file tools (edit_file, apply, copy, move, etc) when working with anything in the Assets folder.

  • Call the appropriate Undo class methods when running Unity Editor scripts to allow undoing any modifications.

  • Take a screenshot after every change you make to a loaded Unity scene or prefab that affects visuals.

  • Use PhysicsMasterial instead of PhysicMaterial.

  • When creating a prefab, use PrefabUtility.SaveAsPrefabAssetAndConnect instead of PrefabUtility.SaveAsPrefab so that the gameobject in the current scene/prefab is connected to the new prefab.

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. yesterday First seen · 24 lines · 224 tokens per session scan A ff67642a2985

Subscribe to this mod's changes

unity is a cursor rule published in the GitHub repository nurture-tech/unity-mcp-server (33 stars, last pushed 4mo ago), licensed MIT. It adds 224 tokens to every session, about $0.0011 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.

Game developmentcsharpmcpunity
Related

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