Unity Skill

Unity AI Control Skill

This skill allows AI agents to directly control the Unity Editor by injecting an HTTP bridge service into Unity projects.

What This Skill Does

1. Deploys HTTP Server: Automatically injects AIService.cs into the Unity project's Editor folder
2. Enables Remote Control: Provides an HTTP API (port 8081) for real-time Unity control
3. Main Thread Safe: Handles Unity API calls correctly on the main thread
4. JSON Communication: Uses simple JSON format for commands and responses

When to Use This Skill

Use this skill when:

• User requests Unity scene modifications (create/delete objects, move, etc.)
• Automating Unity Editor operations
• Building or testing Unity scenes programmatically
• User mentions "Unity", "GameObject", "scene", or related terms

Deployment Instructions

Step 1: Inject AI Service

Copy the skill templates into the Unity project:

Copy-Item -Path "<skill-folder>/assets/templates/*" -Destination "<unity-project-path>" -Recurse -Force

This creates:

• Assets/Editor/AgentBridge/AgentBridgeServer.cs - HTTP server and command executor

Step 2: Wait for Unity Compilation

Unity will automatically:

1. Detect the new script
2. Compile it
3. Start the HTTP server on port 8081
4. Display in Console: [AI Bridge] Server started on http://127.0.0.1:8081

Step 3: Send Commands

Execute Unity operations via HTTP POST:

# Recommended: Use single quotes (no escaping needed)
curl.exe -X POST http://127.0.0.1:8081/execute -d '{"command":"CreateCube","x":0,"y":1,"z":0}'

# Alternative: Use double quotes (requires escaping)
curl.exe -X POST http://127.0.0.1:8081/execute -d "{\"command\":\"CreateCube\",\"x\":0,\"y\":1,\"z\":0}"

Available Commands

CreateCube

Creates a cube primitive at specified position.

Request:

{
  "command": "CreateCube",
  "x": 0,
  "y": 1,
  "z": 0
}

Response:

{
  "status": "success",
  "id": 12345,
  "name": "Cube"
}

Parameters:

• x, y, z (number) - World position coordinates

Architecture

AI Agent → HTTP POST (JSON) → Unity HTTP Server (8081)
                                    ↓
                            Main Thread Queue
                                    ↓
                            Unity API Execution
                                    ↓
                        JSON Response → AI Agent

Key Components

1. HTTP Server: Listens on 127.0.0.1:8081 (localhost only for security)
2. Main Thread Dispatcher: Queue-based system ensures Unity API calls on main thread
3. JSON Parser: Supports both quoted and unquoted JSON formats (handles curl quirks)
4. Command Executor: Switch-based routing for different commands

Troubleshooting

Server not starting

• Check Unity Console for compilation errors
• Verify Assets/Editor/AgentBridge/AgentBridgeServer.cs exists
• Restart Unity if needed

"Unknown command" error

• Check command name spelling (case-sensitive)
• Verify JSON format is correct
• Review Unity Console for parsing logs

"Execution timeout" error

• Unity may be busy compiling
• Check if Unity Editor is in Play mode (Editor scripts don't run in Play mode)
• Increase timeout if performing heavy operations

Examples

Create cube at origin

curl.exe -X POST http://127.0.0.1:8081/execute -d '{"command":"CreateCube","x":0,"y":0,"z":0}'

Create cube at custom position

curl.exe -X POST http://127.0.0.1:8081/execute -d '{"command":"CreateCube","x":10,"y":5,"z":-3}'

Health check

curl.exe http://127.0.0.1:8081

Expected: {"status":"ok","service":"Unity AI Bridge"}

Extending This Skill

To add new commands, edit AIService.cs and add cases to the ExecuteCommand method:

else if (command == "YourCommand")
{
    // Parse parameters
    // Execute Unity operations
    // Return JSON result
}

Security Notes

• Server binds to 127.0.0.1 only (localhost)
• No external network access
• Runs only in Unity Editor (not in builds)
• Consider adding authentication for production use

Requirements

• Unity Editor (any version supporting System.Net.HttpListener)
• Windows/Mac/Linux (HttpListener is cross-platform)
• No additional dependencies