unity-mcp/unity-mcp-skill/references/workflows.md

Unity-MCP Workflow Patterns

Common workflows and patterns for effective Unity-MCP usage.

Table of Contents

• Setup & Verification
• Scene Creation Workflows
• Script Development Workflows
• Asset Management Workflows
• Testing Workflows
• Debugging Workflows
• Batch Operations

---

Setup & Verification

Initial Connection Verification

# 1. Check editor state
# Read mcpforunity://editor/state

# 2. Verify ready_for_tools == true
# If false, wait for recommended_retry_after_ms

# 3. Check active scene
# Read mcpforunity://editor/state → active_scene

# 4. List available instances (multi-instance)
# Read mcpforunity://instances

Before Any Operation

# Quick readiness check pattern:
editor_state = read_resource("mcpforunity://editor/state")

if not editor_state["ready_for_tools"]:
    # Check blocking_reasons
    # Wait recommended_retry_after_ms
    pass

if editor_state["is_compiling"]:
    # Wait for compilation to complete
    pass

---

Scene Creation Workflows

Create Complete Scene from Scratch

# 1. Create new scene
manage_scene(action="create", name="GameLevel", path="Assets/Scenes/")

# 2. Batch create environment objects
batch_execute(commands=[
    {"tool": "manage_gameobject", "params": {
        "action": "create", "name": "Ground", "primitive_type": "Plane",
        "position": [0, 0, 0], "scale": [10, 1, 10]
    }},
    {"tool": "manage_gameobject", "params": {
        "action": "create", "name": "Light", "primitive_type": "Cube"
    }},
    {"tool": "manage_gameobject", "params": {
        "action": "create", "name": "Player", "primitive_type": "Capsule",
        "position": [0, 1, 0]
    }}
])

# 3. Add light component (delete cube mesh, add light)
manage_components(action="remove", target="Light", component_type="MeshRenderer")
manage_components(action="remove", target="Light", component_type="MeshFilter")
manage_components(action="remove", target="Light", component_type="BoxCollider")
manage_components(action="add", target="Light", component_type="Light")
manage_components(action="set_property", target="Light", component_type="Light",
    property="type", value="Directional")

# 4. Set up camera
manage_gameobject(action="modify", target="Main Camera", position=[0, 5, -10],
    rotation=[30, 0, 0])

# 5. Verify with screenshot
manage_scene(action="screenshot")

# 6. Save scene
manage_scene(action="save")

Populate Scene with Grid of Objects

# Create 5x5 grid of cubes using batch
commands = []
for x in range(5):
    for z in range(5):
        commands.append({
            "tool": "manage_gameobject",
            "params": {
                "action": "create",
                "name": f"Cube_{x}_{z}",
                "primitive_type": "Cube",
                "position": [x * 2, 0, z * 2]
            }
        })

# Execute in batches of 25
batch_execute(commands=commands[:25], parallel=True)

Clone and Arrange Objects

# Find template object
result = find_gameobjects(search_term="Template", search_method="by_name")
template_id = result["ids"][0]

# Duplicate in a line
for i in range(10):
    manage_gameobject(
        action="duplicate",
        target=template_id,
        new_name=f"Instance_{i}",
        offset=[i * 2, 0, 0]
    )

---

Script Development Workflows

Create New Script and Attach

# 1. Create script
create_script(
    path="Assets/Scripts/EnemyAI.cs",
    contents='''using UnityEngine;

public class EnemyAI : MonoBehaviour
{
    public float speed = 5f;
    public Transform target;
    
    void Update()
    {
        if (target != null)
        {
            Vector3 direction = (target.position - transform.position).normalized;
            transform.position += direction * speed * Time.deltaTime;
        }
    }
}'''
)

# 2. CRITICAL: Refresh and compile
refresh_unity(mode="force", scope="scripts", compile="request", wait_for_ready=True)

# 3. Check for errors
console = read_console(types=["error"], count=10)
if console["messages"]:
    # Handle compilation errors
    print("Compilation errors:", console["messages"])
else:
    # 4. Attach to GameObject
    manage_gameobject(action="modify", target="Enemy", components_to_add=["EnemyAI"])
    
    # 5. Set component properties
    manage_components(
        action="set_property",
        target="Enemy",
        component_type="EnemyAI",
        properties={
            "speed": 10.0
        }
    )

Edit Existing Script Safely

# 1. Get current SHA
sha_info = get_sha(uri="mcpforunity://path/Assets/Scripts/PlayerController.cs")

# 2. Find the method to edit
matches = find_in_file(
    uri="mcpforunity://path/Assets/Scripts/PlayerController.cs",
    pattern="void Update\\(\\)"
)

# 3. Apply structured edit
script_apply_edits(
    name="PlayerController",
    path="Assets/Scripts",
    edits=[{
        "op": "replace_method",
        "methodName": "Update",
        "replacement": '''void Update()
    {
        float h = Input.GetAxis("Horizontal");
        float v = Input.GetAxis("Vertical");
        transform.Translate(new Vector3(h, 0, v) * speed * Time.deltaTime);
    }'''
    }]
)

# 4. Validate
validate_script(
    uri="mcpforunity://path/Assets/Scripts/PlayerController.cs",
    level="standard"
)

# 5. Refresh
refresh_unity(mode="force", scope="scripts", compile="request", wait_for_ready=True)

# 6. Check console
read_console(types=["error"], count=10)

Add Method to Existing Class

script_apply_edits(
    name="GameManager",
    path="Assets/Scripts",
    edits=[
        {
            "op": "insert_method",
            "afterMethod": "Start",
            "code": '''
    public void ResetGame()
    {
        SceneManager.LoadScene(SceneManager.GetActiveScene().name);
    }'''
        },
        {
            "op": "anchor_insert",
            "anchor": "using UnityEngine;",
            "position": "after",
            "text": "\nusing UnityEngine.SceneManagement;"
        }
    ]
)

---

Asset Management Workflows

Create and Apply Material

# 1. Create material
manage_material(
    action="create",
    material_path="Assets/Materials/PlayerMaterial.mat",
    shader="Standard",
    properties={
        "_Color": [0.2, 0.5, 1.0, 1.0],
        "_Metallic": 0.5,
        "_Glossiness": 0.8
    }
)

# 2. Assign to renderer
manage_material(
    action="assign_material_to_renderer",
    target="Player",
    material_path="Assets/Materials/PlayerMaterial.mat",
    slot=0
)

# 3. Verify visually
manage_scene(action="screenshot")

Create Procedural Texture

# 1. Create base texture
manage_texture(
    action="create",
    path="Assets/Textures/Checkerboard.png",
    width=256,
    height=256,
    fill_color=[255, 255, 255, 255]
)

# 2. Apply checkerboard pattern
manage_texture(
    action="apply_pattern",
    path="Assets/Textures/Checkerboard.png",
    pattern="checkerboard",
    palette=[[0, 0, 0, 255], [255, 255, 255, 255]],
    pattern_size=32
)

# 3. Create material with texture
manage_material(
    action="create",
    material_path="Assets/Materials/CheckerMaterial.mat",
    shader="Standard"
)

# 4. Assign texture to material (via manage_material set_material_shader_property)

Organize Assets into Folders

# 1. Create folder structure
batch_execute(commands=[
    {"tool": "manage_asset", "params": {"action": "create_folder", "path": "Assets/Prefabs"}},
    {"tool": "manage_asset", "params": {"action": "create_folder", "path": "Assets/Materials"}},
    {"tool": "manage_asset", "params": {"action": "create_folder", "path": "Assets/Scripts"}},
    {"tool": "manage_asset", "params": {"action": "create_folder", "path": "Assets/Textures"}}
])

# 2. Move existing assets
manage_asset(action="move", path="Assets/MyMaterial.mat", destination="Assets/Materials/MyMaterial.mat")
manage_asset(action="move", path="Assets/MyScript.cs", destination="Assets/Scripts/MyScript.cs")

Search and Process Assets

# Find all prefabs
result = manage_asset(
    action="search",
    path="Assets",
    search_pattern="*.prefab",
    page_size=50,
    generate_preview=False
)

# Process each prefab
for asset in result["assets"]:
    prefab_path = asset["path"]
    # Get prefab info
    info = manage_prefabs(action="get_info", prefab_path=prefab_path)
    print(f"Prefab: {prefab_path}, Children: {info['childCount']}")

---

Testing Workflows

Run Specific Tests

# 1. List available tests
# Read mcpforunity://tests/EditMode

# 2. Run specific tests
result = run_tests(
    mode="EditMode",
    test_names=["MyTests.TestPlayerMovement", "MyTests.TestEnemySpawn"],
    include_failed_tests=True
)
job_id = result["job_id"]

# 3. Wait for results
final_result = get_test_job(
    job_id=job_id,
    wait_timeout=60,
    include_failed_tests=True
)

# 4. Check results
if final_result["status"] == "complete":
    for test in final_result.get("failed_tests", []):
        print(f"FAILED: {test['name']}: {test['message']}")

Run Tests by Category

# Run all unit tests
result = run_tests(
    mode="EditMode",
    category_names=["Unit"],
    include_failed_tests=True
)

# Poll until complete
while True:
    status = get_test_job(job_id=result["job_id"], wait_timeout=30)
    if status["status"] in ["complete", "failed"]:
        break

Test-Driven Development Pattern

# 1. Write test first
create_script(
    path="Assets/Tests/Editor/PlayerTests.cs",
    contents='''using NUnit.Framework;
using UnityEngine;

public class PlayerTests
{
    [Test]
    public void TestPlayerStartsAtOrigin()
    {
        var player = new GameObject("TestPlayer");
        Assert.AreEqual(Vector3.zero, player.transform.position);
        Object.DestroyImmediate(player);
    }
}'''
)

# 2. Refresh
refresh_unity(mode="force", scope="scripts", compile="request", wait_for_ready=True)

# 3. Run test (expect pass for this simple test)
result = run_tests(mode="EditMode", test_names=["PlayerTests.TestPlayerStartsAtOrigin"])
get_test_job(job_id=result["job_id"], wait_timeout=30)

---

Debugging Workflows

Diagnose Compilation Errors

# 1. Check console for errors
errors = read_console(
    types=["error"],
    count=20,
    include_stacktrace=True,
    format="detailed"
)

# 2. For each error, find the file and line
for error in errors["messages"]:
    # Parse error message for file:line info
    # Use find_in_file to locate the problematic code
    pass

# 3. After fixing, refresh and check again
refresh_unity(mode="force", scope="scripts", compile="request", wait_for_ready=True)
read_console(types=["error"], count=10)

Investigate Missing References

# 1. Find the GameObject
result = find_gameobjects(search_term="Player", search_method="by_name")

# 2. Get all components
# Read mcpforunity://scene/gameobject/{id}/components

# 3. Check for null references in serialized fields
# Look for fields with null/missing values

# 4. Find the referenced object
result = find_gameobjects(search_term="Target", search_method="by_name")

# 5. Set the reference
manage_components(
    action="set_property",
    target="Player",
    component_type="PlayerController",
    property="target",
    value={"instanceID": result["ids"][0]}  # Reference by ID
)

Check Scene State

# 1. Get hierarchy
hierarchy = manage_scene(action="get_hierarchy", page_size=100, include_transform=True)

# 2. Find objects at unexpected positions
for item in hierarchy["data"]["items"]:
    if item.get("transform", {}).get("position", [0,0,0])[1] < -100:
        print(f"Object {item['name']} fell through floor!")

# 3. Visual verification
manage_scene(action="screenshot")

---

Batch Operations

Mass Property Update

# Find all enemies
enemies = find_gameobjects(search_term="Enemy", search_method="by_tag")

# Update health on all enemies
commands = []
for enemy_id in enemies["ids"]:
    commands.append({
        "tool": "manage_components",
        "params": {
            "action": "set_property",
            "target": enemy_id,
            "component_type": "EnemyHealth",
            "property": "maxHealth",
            "value": 100
        }
    })

# Execute in batches
for i in range(0, len(commands), 25):
    batch_execute(commands=commands[i:i+25], parallel=True)

Mass Object Creation with Variations

import random

commands = []
for i in range(20):
    commands.append({
        "tool": "manage_gameobject",
        "params": {
            "action": "create",
            "name": f"Tree_{i}",
            "primitive_type": "Capsule",
            "position": [random.uniform(-50, 50), 0, random.uniform(-50, 50)],
            "scale": [1, random.uniform(2, 5), 1]
        }
    })

batch_execute(commands=commands, parallel=True)

Cleanup Pattern

# Find all temporary objects
temps = find_gameobjects(search_term="Temp_", search_method="by_name")

# Delete in batch
commands = [
    {"tool": "manage_gameobject", "params": {"action": "delete", "target": id}}
    for id in temps["ids"]
]

batch_execute(commands=commands, fail_fast=False)

---

Error Recovery Patterns

Stale File Recovery

try:
    apply_text_edits(uri=script_uri, edits=[...], precondition_sha256=old_sha)
except Exception as e:
    if "stale_file" in str(e):
        # Re-fetch SHA
        new_sha = get_sha(uri=script_uri)
        # Retry with new SHA
        apply_text_edits(uri=script_uri, edits=[...], precondition_sha256=new_sha["sha256"])

Domain Reload Recovery

# After domain reload, connection may be lost
# Wait and retry pattern:
import time

max_retries = 5
for attempt in range(max_retries):
    try:
        editor_state = read_resource("mcpforunity://editor/state")
        if editor_state["ready_for_tools"]:
            break
    except:
        time.sleep(2 ** attempt)  # Exponential backoff

Compilation Block Recovery

# If tools fail due to compilation:
# 1. Check console for errors
errors = read_console(types=["error"], count=20)

# 2. Fix the script errors
# ... edit scripts ...

# 3. Force refresh
refresh_unity(mode="force", scope="scripts", compile="request", wait_for_ready=True)

# 4. Verify clean console
errors = read_console(types=["error"], count=5)
if not errors["messages"]:
    # Safe to proceed with tools
    pass