How to use the s&box CLI agent skill: install and examples

What the skill lets the agent do

The skill gives an agent access to a command-line tool for s&box, a Source 2 engine. The tool is described as agent-native and has 79+ commands across 14 groups. The agent can create and edit project files such as .scene, .prefab, .vmat, .sound, Input.config and Collision.config, generate C# component and UI code, and query what objects and assets a scene uses.

Most commands work directly on the project's JSON files, so s&box does not need to be running for them to work.

• Project management: create projects, set project config, add or remove packages, and validate
• Scene and prefab editing: add, remove, clone and modify objects and components
• Materials, sounds, input and collision configs
• C# code generation for components, GameResources, editor menus, classes and Razor UI panels
• Asset reference queries and structural diffs between scenes or prefabs

Install the skill from this page

Download the skill ZIP from this page and unzip it into one of two places. For a personal setup, use ~/.claude/skills/. For a single project, use the .claude/skills/ folder inside that project.

If you use the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.

• Personal install: unzip into ~/.claude/skills/
• Project install: unzip into the .claude/skills/ folder of your project
• Claude apps: Settings → Capabilities → Skills, then upload the skill

Install the command-line tool

The skill calls a Python command-line tool, so the tool must be installed as well. The skill's install command pulls it from the HKUDS/CLI-Anything GitHub repository. You need Python 3.10 or newer.

• Requires Python 3.10+
• The install step downloads from GitHub, so it needs network access

Set up s&box and your project

If s&box is installed through Steam, the tool auto-detects it. If you installed it somewhere else, set SBOX_PATH to that installation directory. The source notes that SBOX_PATH is needed for some commands such as editor launch, while most commands work without it.

The tool finds the project from the current folder's .sbproj file if you do not pass --project. Pass --json when an agent is running commands, because the source says to always do so for agent use.

• s&box installed via Steam: auto-detected
• Custom install: set SBOX_PATH to the installation directory
• Project location: auto-detected from .sbproj in the current directory, or pass --project PATH

Trigger the skill with natural requests

You do not need to type commands yourself. Describe the task in plain language while you are working in an s&box project, and the agent can choose the matching commands. Name the thing you want changed, such as a scene, a tag, a component or a validation check.

Be specific about the file or the goal. Requests like 'check my s&box project for broken asset references' or 'make every object tagged tower sit 100 units higher in gameplay.scene' give the agent enough to act on.

• Check my s&box project for broken asset references and duplicate GUIDs
• Find every object in scenes/gameplay.scene that has a rigidbody and the tower tag
• Scaffold a PlayerController component with OnUpdate and OnFixedUpdate methods
• Show me every asset that scene references

Examples of what the agent can run

Validation is a good first task. The project validate command checks for broken asset references, duplicate GUIDs and malformed Input.config, and it can skip input or GUID checks when you pass the flags.

Bulk edits are where the skill saves the most repetitive work. A bulk-modify command applies the same change to every object matching a query, such as all objects with a given tag.

Code generation creates starter files, such as a component with [Property] fields or a networked component with RPC stubs.

• Validate: project validate checks asset references, GUIDs and Input.config
• Query: scene query filters by component, tag, name pattern or bounds
• Bulk change: scene bulk-modify with a tag filter, position change and enable flag
• Scaffold: codegen component with properties or networked RPC methods
• Compare: scene diff reports added, removed and modified GameObjects between two scenes

Safety notes: scripts and network

This skill runs scripts and uses the network. The install step fetches the tool from GitHub, and the tool runs as a command-line program on your machine. Review the skill files and the repository before installing if you need to verify what runs.

The commands edit your project files directly. The source does not say how direct file edits interact with a scene that is open in the s&box editor at the same time, so avoid editing the same scene in the editor while an agent changes it. Keep your project under version control so you can review and undo changes.

• Runs scripts on your machine and uses the network during install
• Edits .scene, .prefab and other project files in place
• Do not edit the same scene in the editor while the agent works on it, because the source does not say how conflicts are handled
• Use version control and review diffs before committing

Tips for better results

Ask the agent to validate before and after larger changes, so that broken references show up early. Ask for a scene diff when you want to confirm exactly what changed.

Keep requests tied to real names, tags and GUIDs in your project. The commands use names such as Enemy, tags such as tower, and object GUIDs, so the more precise the request, the fewer wrong edits.

• Run project validate before and after large edits
• Use scene diff to check what changed between versions
• Use the tag filters in bulk-modify to limit which objects change
• Keep the project in version control