For complex input (multi-line strings, code), save the JSON to a file and use:
unity-mcp-cli run-tool gameobject-component-modify --input-file args.json
Or pipe via stdin (recommended):
unity-mcp-cli run-tool gameobject-component-modify --input-file - <<'EOF'
{"param": "value"}
EOF

Troubleshooting

If unity-mcp-cli is not found, either install it globally (npm install -g unity-mcp-cli) or use npx unity-mcp-cli instead. Read the /unity-initial-setup skill for detailed installation instructions.

Input

Name	Type	Required	Description
`gameObjectRef`	`any`	Yes	Find GameObject in opened Prefab or in the active Scene.
`componentRef`	`any`	Yes	Component reference. Used to find a Component at GameObject.
`componentDiff`	`any`	Yes	The component data to apply. Should contain 'fields' and/or 'props' with the values to modify.
Only include the fields/properties you want to change.
Any unknown or invalid fields and properties will be reported in the response.

Input JSON Schema

{
  "type": "object",
  "properties": {
    "gameObjectRef": {
      "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Runtime.Data.GameObjectRef"
    },
    "componentRef": {
      "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Runtime.Data.ComponentRef"
    },
    "componentDiff": {
      "$ref": "#/$defs/com.IvanMurzak.ReflectorNet.Model.SerializedMember"
    }
  },
  "$defs": {
    "System.Type": {
      "type": "string"
    },
    "com.IvanMurzak.Unity.MCP.Runtime.Data.GameObjectRef": {
      "type": "object",
      "properties": {
        "instanceID": {
          "type": "integer",
          "description": "instanceID of the UnityEngine.Object. If it is '0' and 'path', 'name', 'assetPath' and 'assetGuid' is not provided, empty or null, then it will be used as 'null'. Priority: 1 (Recommended)"
        },
        "path": {
          "type": "string",
          "description": "Path of a GameObject in the hierarchy Sample 'character/hand/finger/particle'. Priority: 2."
        },
        "name": {
          "type": "string",
          "description": "Name of a GameObject in hierarchy. Priority: 3."
        },
        "assetType": {
          "$ref": "#/$defs/System.Type",
          "description": "Type of the asset."
        },
        "assetPath": {
          "type": "string",
          "description": "Path to the asset within the project. Starts with 'Assets/'"
        },
        "assetGuid": {
          "type": "string",
          "description": "Unique identifier for the asset."
        }
      },
      "required": [
        "instanceID"
      ],
      "description": "Find GameObject in opened Prefab or in the active Scene."
    },
    "com.IvanMurzak.Unity.MCP.Runtime.Data.ComponentRef": {
      "type": "object",
      "properties": {
        "index": {
          "type": "integer",
          "description": "Component 'index' attached to a gameObject. The first index is '0' and that is usually Transform or RectTransform. Priority: 2. Default value is -1."
        },
        "typeName": {
          "type": "string",
          "description": "Component type full name. Sample 'UnityEngine.Transform'. If the gameObject has two components of the same type, the output component is unpredictable. Priority: 3. Default value is null."
        },
        "instanceID": {
          "type": "integer",
          "description": "instanceID of the UnityEngine.Object. If this is '0', then it will be used as 'null'."
        }
      },
      "required": [
        "index",
        "instanceID"
      ],
      "description": "Component reference. Used to find a Component at GameObject."
    },
    "com.IvanMurzak.ReflectorNet.Model.SerializedMemberList": {
      "type": "array",
      "items": {
        "$ref": "#/$defs/com.IvanMurzak.ReflectorNet.Model.SerializedMember"
      }
    },
    "com.IvanMurzak.ReflectorNet.Model.SerializedMember": {
      "type": "object",
      "properties": {
        "typeName": {
          "type": "string",
          "description": "Full type name. Eg: 'System.String', 'System.Int32', 'UnityEngine.Vector3', etc."
        },
        "name": {
          "type": "string",
          "description": "Object name."
        },
        "value": {
          "description": "Value of the object, serialized as a non stringified JSON element. Can be null if the value is not set. Can be default value if the value is an empty object or array json."
        },
        "fields": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/com.IvanMurzak.ReflectorNet.Model.SerializedMember",
            "description": "Nested field value."
          },
          "description": "Fields of the object, serialized as a list of 'SerializedMember'."
        },
        "props": {
          "type": "array",
          "items": {
            "$ref": "#/$defs/com.IvanMurzak.ReflectorNet.Model.SerializedMember",
            "description": "Nested property value."
          },
          "description": "Properties of the object, serialized as a list of 'SerializedMember'."
        }
      },
      "required": [
        "typeName"
      ],
      "additionalProperties": false
    }
  },
  "required": [
    "gameObjectRef",
    "componentRef",
    "componentDiff"
  ]
}

Output

Output JSON Schema

{
  "type": "object",
  "properties": {
    "result": {
      "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Editor.API.Tool_GameObject+ModifyComponentResponse"
    }
  },
  "$defs": {
    "com.IvanMurzak.Unity.MCP.Runtime.Data.ComponentRef": {
      "type": "object",
      "properties": {
        "index": {
          "type": "integer",
          "description": "Component 'index' attached to a gameObject. The first index is '0' and that is usually Transform or RectTransform. Priority: 2. Default value is -1."
        },
        "typeName": {
          "type": "string",
          "description": "Component type full name. Sample 'UnityEngine.Transform'. If the gameObject has two components of the same type, the output component is unpredictable. Priority: 3. Default value is null."
        },
        "instanceID": {
          "type": "integer",
          "description": "instanceID of the UnityEngine.Object. If this is '0', then it will be used as 'null'."
        }
      },
      "required": [
        "index",
        "instanceID"
      ],
      "description": "Component reference. Used to find a Component at GameObject."
    },
    "com.IvanMurzak.Unity.MCP.Runtime.Data.ComponentDataShallow": {
      "type": "object",
      "properties": {
        "instanceID": {
          "type": "integer"
        },
        "typeName": {
          "type": "string"
        },
        "isEnabled": {
          "type": "string",
          "enum": [
            "False",
            "True",
            "NA"
          ]
        }
      },
      "required": [
        "instanceID",
        "isEnabled"
      ]
    },
    "System.String[]": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "com.IvanMurzak.Unity.MCP.Editor.API.Tool_GameObject+ModifyComponentResponse": {
      "type": "object",
      "properties": {
        "Success": {
          "type": "boolean",
          "description": "Whether the modification was successful."
        },
        "Reference": {
          "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Runtime.Data.ComponentRef",
          "description": "Reference to the modified component."
        },
        "Index": {
          "type": "integer",
          "description": "Index of the component in the GameObject's component list."
        },
        "Component": {
          "$ref": "#/$defs/com.IvanMurzak.Unity.MCP.Runtime.Data.ComponentDataShallow",
          "description": "Updated component information after modification."
        },
        "Logs": {
          "$ref": "#/$defs/System.String[]",
          "description": "Log of modifications made and any warnings/errors encountered."
        }
      },
      "required": [
        "Success",
        "Index"
      ]
    }
  },
  "required": [
    "result"
  ]
}

gameobject-component-modify

GameObject / Component / Modify

How to Call