Unity Bridge

Interact with Unity Editor via file-based IPC. Always read params/{tool}.json before calling a tool to get accurate parameters.

Invocation

bridge.py is located in the same directory as this SKILL.md. Run from the Unity project root:

python3 <skill-dir>/bridge.py <tool-name> '<json-params>'

where <skill-dir> is the directory containing this file. Omit JSON when no parameters are needed.

Critical Rules

1. Pre-check: Unity Editor must be running. Verify via Temp/UnityBridge/heartbeat
2. Read params first: Always read params/{tool-name}.json before calling — do not guess parameters from memory
3. camelCase: JSON parameter keys must be camelCase. PascalCase keys are ignored
4. Serial execution: Only one tool call at a time. Concurrent calls are queued
5. Param source: JSON files under params/ are auto-generated from C# tool method signatures

Tool Index (65 tools)

Scene (7): scene-list-opened list opened scenes · scene-get-data get scene data · scene-open open scene · scene-create create scene · scene-save save scene · scene-set-active set active scene · scene-unload unload scene

GameObject (11): gameobject-find find · gameobject-create create · gameobject-destroy destroy · gameobject-modify modify properties · gameobject-duplicate duplicate · gameobject-set-parent set parent · gameobject-component-add add component · gameobject-component-destroy remove component · gameobject-component-get get component data · gameobject-component-list-all list components · gameobject-component-modify modify component

Assets (11): assets-find search assets · assets-find-built-in search built-in assets · assets-get-data get asset data · assets-modify modify asset · assets-copy copy · assets-move move · assets-delete delete · assets-refresh refresh AssetDatabase · assets-create-folder create folder · assets-material-create create material · assets-shader-list-all list shaders

Prefab (5): assets-prefab-open open for editing · assets-prefab-close close editing · assets-prefab-save save · assets-prefab-create create · assets-prefab-instantiate instantiate

Script (4): script-read read · script-update-or-create create/update · script-delete delete · script-execute execute C# code

Object (2): object-get-data get data · object-modify modify

Editor (4): editor-application-get-state editor state · editor-application-set-state set state · editor-selection-get get selection · editor-selection-set set selection

Reflection (2): reflection-method-find find methods · reflection-method-call call method

Screenshot (1): screenshot-capture capture Game view (Play Mode) or Scene view (Edit Mode) as PNG

Runtime (2): runtime-query query MonoBehaviour fields in Play Mode · runtime-invoke invoke public static methods in Play Mode

Console (1): console-get-logs get logs

Profiler (5): profiler-snapshot performance snapshot · profiler-gc-alloc GC allocations · profiler-hotpath hot paths · profiler-frame-hierarchy frame hierarchy · profiler-stream multi-frame sampling

Package (4): package-list installed packages · package-search search packages · package-add install · package-remove uninstall

LightProbe (5): lightprobe-bake bake · lightprobe-clear clear · lightprobe-analyze analyze lighting · lightprobe-configure-lights configure lights · lightprobe-generate-grid generate grid

Tests (1): tests-run run tests

Script Recompilation

`script-update-or-create` and `script-delete` trigger Unity recompilation (30-60s). During recompilation the heartbeat expires and subsequent tool calls will be rejected.

Workflow:

1. Call script-update-or-create or script-delete
2. Immediately pause all subsequent bridge calls
3. Notify user: "Script modified, Unity is recompiling. Please let me know when compilation is complete."
4. Wait for user confirmation before resuming operations

Similarly, any operation that triggers AssetDatabase.Refresh() with pending script changes may cause recompilation.

MCP Server

For Cursor/Copilot/Windsurf and other MCP clients, see docs/SETUP.md.

Error Handling

• heartbeat not found: Unity Editor is not running or Bridge is not installed
• heartbeat stale: Editor may be compiling or frozen
• timeout: Operation timed out (default 30s)
• tool not found: Check tool name spelling against the index above
• parameter error: Read params/{tool}.json to verify correct parameter names and types