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Your First Prompt

You've installed the package and connected a client. Here's what to actually say.

Prerequisites​

  • Install is complete
  • The MCP for Unity status panel reads Connected
  • Your scene is open in the Unity Editor (any scene will do — even an empty one)

The prompt​

In your MCP client (Claude Desktop, Cursor, etc.), say:

Create a red, blue, and yellow cube in the current scene, spaced one unit apart on the X axis.

The assistant should:

  1. Call manage_scene (or find_gameobjects) to inspect the active scene
  2. Call manage_gameobject three times to create cubes
  3. Call manage_material to create or assign colored materials
  4. Call manage_components to attach the material to each cube's MeshRenderer

Total round trip is usually 5–15 seconds depending on your network and the client.

What you should see in Unity​

Three cubes appear in the Hierarchy panel. Switch to the Scene view to see them laid out. If the materials are correct, they'll render red, blue, and yellow.

If the cubes appear but materials are missing (gray), your project may be using URP/HDRP — the LLM should detect this from manage_graphics but sometimes guesses Standard. Tell it explicitly: "This project uses URP, please use the URP/Lit shader."

Stretching it​

Try escalating prompts in the same session:

Add a directional light if there isn't one, and a perspective camera positioned at (0, 2, -5) looking at the cubes.

Write a C# script that makes the red cube oscillate up and down by 0.5 units, attach it to the red cube, and enter Play mode.

Run all tests in EditMode and report which ones fail.

Each of these uses a different tool group — core for objects/scripts, core again for editor mode control, testing for test runs (you may need to activate the testing group first; see Tool Groups).

When something goes wrong​

  • "I couldn't find any Unity instance" — the server isn't reachable. Check the status panel.
  • "Multiple Unity instances detected" — you have more than one Editor open. See Multi-Instance Routing.
  • Tool calls succeed but nothing happens in the scene — your client may be in dry-run mode, or you might have hit an MCP visibility toggle for the relevant tool. Ask the assistant to call manage_tools action list_groups.