unity-game-player

A skill for autonomously playing games made with Unity, a game-development engine, while the game runs in the Unity Editor.

In plain words
What is it for?
It helps enter Play Mode, read live state through C# scripts, control gameplay for set periods, and repeat actions using trajectory and timing calculations.
Why use it?
It gives the agent a repeatable loop for observing the current game state, calculating actions, sending input, and checking what happened.

Skill for Claude CodeCodex

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 skills/signal-loop/unitycodemcpserver/unity-game-player
Any agent
npx skills add Signal-Loop/UnityCodeMCPServer --skill unity-game-player
Clone the repo
git clone --depth 1 https://github.com/Signal-Loop/UnityCodeMCPServer

Made for: Claude Code, Codex.

Per session 118 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,422 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 $0.00118 $0.02422
Opus 5 $0.00059 $0.01211
Sonnet 5 $0.00024 $0.00484
Haiku 4.5 $0.00012 $0.00242

Measured 2d ago against content hash 62543ea30a1a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

unity-game-player 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.

.agents/skills/unity-game-player/SKILL.md · 244 lines

How it starts

The opening of the file, as written. The whole thing — 244 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Unity Game Player

Skill for AI agents that play Unity games autonomously in the Editor via MCP tools.

Table of Contents

  1. Prerequisites
  2. Available Tools
  3. Core Loop Overview
  4. Phase 0 — INIT
  5. Phases 1+2 — SENSE + COMPUTE
  6. Phase 3 — ACT
  7. Phase 4 — REPEAT
  8. Critical Rules
  9. Common Pitfalls

For detailed tool API parameters and trajectory math patterns, see:


1. Prerequisites

  • Unity Editor must be running and the project open.
  • Read executing-csharp-scripts-in-unity-editor skill - it is critical to properly play Unity games in the Editor.
  • The game scene must be loaded.
  • Call enter_play_mode once before starting the loop. This enters Play Mode with Time.timeScale = 0 (paused).
  • All subsequent gameplay is driven by play_unity_game, which temporarily sets timeScale = 1 for the requested duration, then re-pauses.

2. Available Tools

The executing-csharp-scripts-in-unity-editor skill is essential to properly execute C# scripts in the Unity Editor. It must be read before using the execute_csharp_script_in_unity_editor tool.

Tool Purpose
enter_play_mode Enter Play Mode (paused). Call once at start.
play_unity_game Unpause for N ms, simulate inputs, capture console logs.
execute_csharp_script_in_unity_editor Run C# in the Editor to query/modify scene state. Read executing-csharp-scripts-in-unity-editor skill before use.
read_unity_console_logs Read recent console entries (use sparingly — prefer logs from tool output).
exit_play_mode Leave Play Mode. Call only when done.
get_unity_info Query Unity version, project path, scene list.

Read the full file on GitHub · 244 lines

Files

What ships with it

2 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. 2d ago First seen · 244 lines · 118 tokens per session scan A 62543ea30a1a

Subscribe to this mod's changes

unity-game-player is a skill published in the GitHub repository Signal-Loop/UnityCodeMCPServer (19 stars, last pushed 1mo ago), licensed MIT. It adds 118 tokens to every session and 2,422 once invoked, about $0.0006 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.

Related

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console-get-logs

Retrieve Unity Editor logs from the MCP plugin's LogCollector, optionally filtered by log type or time window. Useful for debugging and monitoring Editor activity.

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assets-prefab-save

Save the currently opened prefab edit stage back to its prefab asset without exiting the stage. Pair with 'assets-prefab-open' to enter the edit mode first.

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