vrc-udon-unity-mcp

vrc-udon-unity-mcp is a skill for Codex from sechiro/VRCUdonSkills-for-Codex. It costs 96 tokens per session (800 once invoked), scanned A, original, MIT.

A skill for using Unity MCP as an editor-support tool in VRChat UdonSharp projects built with Unity 2022.3.22f1. Unity MCP connects an agent to editor information such as scenes and prefabs.

In plain words
What is it for?
It helps inspect or assist with Unity scenes, prefabs, builders, packages, and editor settings, and document the setup in the project.
Why use it?
It separates editor inspection and assistance from the runtime code that runs inside a VRChat world.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions Codex; $skill-name invocation.

Good fit It helps inspect or assist with Unity scenes, prefabs, builders, packages, and editor settings, and document the setup in the project.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp
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.

Any agent
npx skills add sechiro/VRCUdonSkills-for-Codex --skill vrc-udon-unity-mcp
Clone the repo
git clone --depth 1 https://github.com/sechiro/VRCUdonSkills-for-Codex

Made for: Codex.

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.

agentmods badge for vrc-udon-unity-mcp

README.md
[![agentmods](https://agentmods.dev/badge/skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp/github.svg)](https://agentmods.dev/skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp)
Your own site
<a href="https://agentmods.dev/skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp"><img src="https://agentmods.dev/badge/skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp/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.

agentmods 80×15 button for vrc-udon-unity-mcp

Your own site · 80×15
<a href="https://agentmods.dev/skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp"><img src="https://agentmods.dev/badge/skills/sechiro/vrcudonskills-for-codex/vrc-udon-unity-mcp.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 96 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 800 The whole file, excluding the scripts and references it only reads on demand.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00096 $0.00800
Opus 5 $0.00048 $0.00400
Sonnet 5 $0.00019 $0.00160
Haiku 4.5 $0.00010 $0.00080

Measured 11d ago against content hash ed9cb966710b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

vrc-udon-unity-mcp 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 11d 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.

skills/vrc-udon-unity-mcp/SKILL.md · 57 lines

What it actually says

VRC Udon Unity MCP

役割

Unity 2022.3.22f1 を使う VRChat UdonSharp 案件で、unity-mcp を Editor 支援として安全に扱う。Scene、Prefab、Builder、Package、Editor 状態の確認や補助操作に使い、Runtime の設計責務とは分離する。

この Skill を使う場面

  • プロジェクトが CoplayDev/unity-mcp を導入している
  • Unity Editor 上の Scene / Prefab / Builder 状態を Codex から読みたい
  • Builder First の補助として Editor 側の状態確認や操作支援を使いたい
  • Unity 2022.3.22f1 前提で、導入方法と利用範囲も文書化したい

この Skill を使わない場面

  • unity-mcp を導入していない
  • Runtime 実装や UdonSharp コードだけで完結する
  • モジュール構造だけ整理したい

前提

  • Unity バージョンは 2022.3.22f1
  • unity-mcp は Runtime 依存ではなく Editor 支援ツールとして扱う
  • Scene / Prefab / Builder / Editor 設定の読解と補助に使う
  • 接続先は導入先プロジェクト直下の .mcp.json に書く
  • 実装や仕様の正本は project-owned 文書とコード側に残す

進め方

  1. references/unity-mcp-install-and-scope.md を読む。
  2. references/unity-mcp-usage-rules.md を読む。
  3. Unity が 2022.3.22f1 であることを確認する。
  4. 導入先プロジェクト直下に .mcp.json を置き、接続先を書く。
  5. 導入先の docs/ENVIRONMENT_SETUP.mddocs/SYSTEM_SPEC.md に、導入方法と利用範囲を書く。
  6. Scene / Prefab / Builder の確認補助に使う。
  7. Unity MCP で得た結果は Builder、コード、project-owned 文書へ反映して再現可能にする。

併用ガイド

  • 文書と環境再現は $vrc-udon-project-docs
  • モジュール構造は $vrc-udon-core-module
  • UI と操作導線は $vrc-udon-ui-menu
  • networking 文書は $vrc-udon-networking-rules

注意点

  • unity-mcp を Runtime 依存として扱わない
  • Unity Editor 上で見えた状態を、そのままワールド実行時の保証とみなさない
  • .mcp.json の接続先は project root に置き、案件ごとに管理する
  • 導入方法、利用範囲、無効化条件を project-owned 文書へ残す
  • Unity バージョン差がある前提で扱う
Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 11d ago First seen · 57 lines · 96 tokens per session scan A ed9cb966710b

Subscribe to this mod's changes

vrc-udon-unity-mcp is a skill published in the GitHub repository sechiro/VRCUdonSkills-for-Codex (58 stars, last pushed 4mo ago), licensed MIT. It adds 96 tokens to every session and 800 once invoked, about $0.0005 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.

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