index

A project-wide description of a Unity 6.2 LTS game using C# 12, URP, the new Input System, UI Toolkit, Addressables, multiplayer networking, and Unity’s testing tools.

In plain words
What is it for?
Use it as the baseline when adding Unity features, choosing APIs, organizing systems, handling assets, building multiplayer code, or writing tests. It also sets expectations for modularity, performance, naming, documentation, and supported platforms.
Why use it?
It gives coding agents the project’s required technology choices and architectural expectations, reducing the chance that new code uses incompatible or outdated systems.

Cursor rule for Cursor

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/common-ka/ai-agent-unity-rules/index
Clone the repo
git clone --depth 1 https://github.com/Common-ka/ai-agent-unity-rules

Made for: Cursor.

Per session 392 This file is loaded in full into every session.
When invoked 392 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 $0.00392 $0.00392
Opus 5 $0.00196 $0.00196
Sonnet 5 $0.00078 $0.00078
Haiku 4.5 $0.00039 $0.00039

Measured 2d ago against content hash 5d997d3e22dd, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

index 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.

.cursor/index.mdc · 70 lines

What it actually says

Unity 6.2 Project Rules

Project Overview

This project uses Unity 6.2 (LTS 2025) with modern systems and architectural approaches.

Tech Stack

  • Unity Version: 6.2 LTS (2025)
  • C# Version: 12.0
  • Rendering Pipeline: URP (Universal Render Pipeline)
  • Input System: New Input System (InputSystem package)
  • UI Framework: UI Toolkit (not UGUI)
  • Asset Management: Addressables
  • Multiplayer: Netcode for GameObjects
  • Testing: Unity Test Framework

Architectural Principles

1. Modularity

  • Each system must be independent
  • Use ScriptableObject Architecture for configuration
  • Use dependency injection to wire up components

2. Performance

  • Object pooling for frequently instantiated objects
  • Addressables instead of Resources
  • ECS/DOTS for performance-critical systems
  • Burst Compiler where applicable

3. Maintainability

  • Strict naming conventions
  • XML documentation for public APIs
  • Unit tests for business logic
  • Prefabs for reusable objects

4. Code Style

  • Follow the Unity C# Style Guide
  • Use modern C# features (pattern matching, records, init-only properties)
  • async/await instead of coroutines where possible

Supported Platforms

  • Windows (Primary)
  • macOS
  • Linux
  • iOS
  • Android
  • WebGL (limited support)

Important Rules

ALWAYS:

  • New Input System
  • UI Toolkit
  • Addressables
  • [SerializeField] instead of public
  • XML documentation

NEVER:

  • Legacy Input
  • UGUI for new UI
  • Resources.Load
  • FindObjectOfType in Update
  • Magic numbers
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 · 70 lines · 392 tokens per session scan A 5d997d3e22dd

Subscribe to this mod's changes

index is a cursor rule published in the GitHub repository Common-ka/ai-agent-unity-rules (39 stars, last pushed 8mo ago), licensed MIT. It adds 392 tokens to every session, about $0.0020 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.