Excalidraw MCP Server

Instructions

Implementation Reference

• src/index.js:480-491 (handler)

  The handler function for the 'group_elements' tool. It parses the input arguments using ElementIdsSchema, generates a unique groupId, stores the elementIds in sceneState.groups Map, and returns a JSON response with the groupId and elementIds.

  case 'group_elements': {
    const params = ElementIdsSchema.parse(args);
    const { elementIds } = params;
    
    const groupId = generateId();
    sceneState.groups.set(groupId, elementIds);
    
    const result = { groupId, elementIds };
    return {
      content: [{ type: 'text', text: JSON.stringify(result, null, 2) }]
    };
  }

• src/index.js:52-54 (schema)

  Zod schema used for input validation in the group_elements handler (and others). Defines required elementIds as array of strings.

  const ElementIdsSchema = z.object({
    elementIds: z.array(z.string())
  });

• src/index.js:184-196 (schema)

  Input schema definition for the group_elements tool in the MCP server capabilities declaration.

  group_elements: {
    description: 'Group multiple elements together',
    inputSchema: {
      type: 'object',
      properties: {
        elementIds: { 
          type: 'array',
          items: { type: 'string' }
        }
      },
      required: ['elementIds']
    }
  },

• src/index.js:753-764 (registration)

  Tool registration in the ListToolsRequestHandler response, listing the group_elements tool with its schema.

  name: 'group_elements',
  description: 'Group multiple elements together',
  inputSchema: {
    type: 'object',
    properties: {
      elementIds: { 
        type: 'array',
        items: { type: 'string' }
      }
    },
    required: ['elementIds']
  }