What is unity-ai-project-brain AGENTS.md?

A set of instructions for an AI agent working with Unity Project Brain, a read-only tool for understanding Unity projects and their file and scene relationships.

Reasoning about Unity code, scenes, prefabs, serialized references, asset identifiers, symbols, runtime evidence, and Git history before proposing changes.

It defines trusted sources and safety limits, reducing the risk of invented relationships or accidental changes to Unity files.

How orange91pku/unity-ai-project-brain configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to orange91pku/unity-ai-project-brain. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/orange91pku/unity-ai-project-brain/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/orange91pku/unity-ai-project-brain

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/orange91pku/unity-ai-project-brain/agents-md/github.svg)](https://agentmods.dev/instructions/orange91pku/unity-ai-project-brain/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/orange91pku/unity-ai-project-brain/agents-md"><img src="https://agentmods.dev/badge/instructions/orange91pku/unity-ai-project-brain/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/orange91pku/unity-ai-project-brain/agents-md"><img src="https://agentmods.dev/badge/instructions/orange91pku/unity-ai-project-brain/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 568 This file is loaded in full into every session.

When invoked 568 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00568	$0.00568
Opus 5.5	$0.00227	$0.00227
Sonnet 5.5	$0.00114	$0.00114
Haiku 4.5	$0.00057	$0.00057

Measured 2mo ago against content hash d9e29eca11a9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

unity-ai-project-brain 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 2mo 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.md · 67 lines

How it starts

The opening of the file, as written. The whole thing — 67 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AI agent guide

Mission

Unity Project Brain is a read-only context engine for Unity repositories. It joins code intelligence, Unity GUID/fileID identity, serialized scene and prefab relationships, optional Roslyn symbols, runtime evidence, and Git history so AI agents can reason about a project before proposing changes.

Safe boundary

Treat the configured Unity repository as private unless the operator says otherwise.
Do not commit local project configuration, indexes, databases, caches, credentials, or absolute machine paths.
Do not mutate Unity source through Project Brain. Mutation belongs in an external tool and its result must pass Unity verification.
Preserve unresolved and ambiguous relationships as explicit evidence; never invent a link to make an answer look complete.
Keep the Context API loopback-only and MCP read-only unless the operator deliberately changes that boundary.

Authoritative sources

Git working tree and commits: code content and history.
Unity .meta files: asset GUID identity.
Text-serialized .unity, .prefab, and .asset files: object, component, hierarchy, and serialized-reference identity.
Roslyn-compatible symbol catalogs: optional code symbol identity.
Attributed verification reports: acceptance evidence.
GitNexus: rebuildable code graph and semantic retrieval index.
Project Brain SQLite graph: rebuildable Unity identity and evidence index.

Entry points

src/cli.mjs: GitNexus orchestration and scoped MCP descriptors.
project_brain/unity_graph.py: Unity graph build, validate, and query.
project_brain/context_api.py: read-only CLI and loopback HTTP API.
project_brain/change_envelope.py: versioned change contracts.
schemas/: public interoperability contracts.
docs/ARCHITECTURE.md: system boundaries and data flow.
docs/GETTING_STARTED.md: reproducible setup.
docs/UPM_INSTALL.md: no-clone Unity package distribution.
Packages/com.heycici.project-brain/: read-only Unity Editor bridge.

Read the full file on GitHub · 67 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.

2mo ago First seen · 67 lines · 568 tokens per session scan A d9e29eca11a9

Subscribe to this mod's changes

unity-ai-project-brain AGENTS.md is an instructions file published in the GitHub repository orange91pku/unity-ai-project-brain (2 stars, last pushed 5d ago), licensed Apache-2.0. It adds 568 tokens to every session, about $0.0023 per session on Opus 5.5. 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.

ai-agents artificial-intelligence code-intelligence context-engine developer-tools game-development

unity-ai-project-brain AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
unity-ai-project-brain AGENTS.mdorange91pku/unity-ai-project-brain	Instructions file	2	5d ago	Apache-2.0	A	568	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

unity-ai-project-brain: Instructions file for Codex