Is the S&box skill free?

Yes. The skill itself is free from gavogavogavo/claude-sbox. SkillProof publishes the install command and an independent test verdict at no cost.

What is the S&box SkillProof Score?

10.0/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 10/10, docs & honesty 5/5.

How do I install S&box?

Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.

Can I use S&box with Cursor, Copilot, Gemini CLI, Codex or other AI tools?

The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.

S&box

Blocks Unity muscle memory when writing s&box (Source 2 / Facepunch) C# components, Razor UI, and networking.

by gavogavogavo · gavogavogavo/claude-sbox

Tested · Works

Install — copy the command Download source ↗

Test report

Verdict: Tested · Works
Score: 10.0/10
Tested: Jul 14, 2026
Environment: Claude Code 2.x (agent harness)
Upstream re-checked: Jul 18, 2026 · 2797a66

Asked for a pickup component in both modes: baseline reflexively wrote MonoBehaviour/transform.position/Destroy(gameObject) Unity code, the skill produced correct Component/[Sync]/[Rpc.Broadcast]/IsProxy s&box code -- exactly the Unity-leakage failure the skill's own README warns about, reproduced live and then fixed.

Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works

Installs cleanly 5/5
Triggers reliably 5/5
Output vs. baseline 10/10
Docs & honesty 5/5

What S&box does

Routes s&box game-code requests to reference files for Component lifecycle, Razor UI, networking ([Sync]/RPCs), physics, and input, backed by a Unity-to-s&box translation table and a curated API schema. Triggers on any s&box, Facepunch engine, or Source 2 C# game project mention, and explicitly refuses to fire on Unity/Godot/Unreal code.

How to install S&box

git clone https://github.com/gavogavogavo/claude-sbox
cd claude-sbox
mkdir -p ~/.claude/skills
cp -r . ~/.claude/skills/sbox

Skills live in ~/.claude/skills/ (global) or .claude/skills/ (per-project). Restart Claude Code after installing.

Commands — how to trigger S&box

/sbox Blocks Unity muscle memory when writing s&box (Source 2 / Facepunch) C# components, Razor UI, and networking.

It also activates on plain-language prompts like these:

Building a game in s&box, how do I move the player around?
Writing Razor UI for my s&box HUD panel, need a PanelComponent
My s&box [Sync] property isn't replicating to clients

Frequently asked questions

Is the S&box skill free?: Yes. The skill itself is free from gavogavogavo/claude-sbox. SkillProof publishes the install command and an independent test verdict at no cost.
Does S&box work with Claude Code?: We tested it with Claude Code 2.x (agent harness) on Jul 14, 2026. Verdict: Tested · Works. Asked for a pickup component in both modes: baseline reflexively wrote MonoBehaviour/transform.position/Destroy(gameObject) Unity code, the skill produced correct Component/[Sync]/[Rpc.Broadcast]/IsProxy s&box code -- exactly the Unity-leakage failure the skill's own README warns about, reproduced live and then fixed.
What is the S&box SkillProof Score?: 10.0/10 — installs cleanly 5/5, triggers reliably 5/5, output vs. baseline 10/10, docs & honesty 5/5.
How do I install S&box?: Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
Can I use S&box with Cursor, Copilot, Gemini CLI, Codex or other AI tools?: The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.