Todo List MCP Server

Instructions

Implementation Reference

• src/handlers/toolHandlers.ts:62-92 (handler)

  The handleCreateTodo method implements the core logic for the create_todo tool: sanitizes and validates input using CreateTodoSchema, creates the todo via TodoService, and returns a success response.

  private async handleCreateTodo(request: CallToolRequest): Promise<CallToolResult> {
    try {
      const sanitizedArgs = sanitizeInput(request.params.arguments);
      const validatedRequest = validateData(CreateTodoSchema, sanitizedArgs);
      
      const todo = this.todoService.createTodo({
        ...validatedRequest,
        priority: validatedRequest.priority || "medium",
        tags: validatedRequest.tags || [],
      });
  
      return {
        content: [
          {
            type: "text",
            text: `✅ Todo criado com sucesso!\n\n${JSON.stringify(todo, null, 2)}`,
          },
        ],
      };
    } catch (error) {
      const errorResponse = createErrorResponse(error, "criar todo");
      return {
        content: [
          {
            type: "text",
            text: `❌ ${errorResponse.error}\n${errorResponse.details || ""}`,
          },
        ],
      };
    }
  }

• src/config/toolDefinitions.ts:2-35 (registration)

  Tool definition and registration in TOOL_DEFINITIONS array, including name, description, and inputSchema.

  {
    name: "create_todo",
    description: "Create a new todo item with validation",
    inputSchema: {
      type: "object",
      properties: {
        title: {
          type: "string",
          description: "Title of the todo (1-200 characters)",
          minLength: 1,
          maxLength: 200,
        },
        description: {
          type: "string",
          description: "Optional description (max 1000 characters)",
          maxLength: 1000,
        },
        priority: {
          type: "string",
          enum: ["low", "medium", "high"],
          description: "Priority level",
          default: "medium",
        },
        tags: {
          type: "array",
          items: { type: "string", minLength: 1, maxLength: 50 },
          maxItems: 10,
          description: "Tags for categorization",
          default: [],
        },
      },
      required: ["title"],
    },
  },

• src/schemas/todo.schemas.ts:19-24 (schema)

  Zod schema definition for CreateTodoSchema used in validation for create_todo input.

  export const CreateTodoSchema = z.object({
    title: NonEmptyStringSchema.max(200, 'Título não pode exceder 200 caracteres'),
    description: z.string().max(500, 'Descrição não pode exceder 500 caracteres').optional(),
    priority: z.enum(['low', 'medium', 'high']).default('medium'),
    tags: z.array(z.string().min(1).max(50)).max(10).default([])
  });

• src/services/todo.services.ts:151-168 (helper)

  TodoService.createTodo method that generates UUID, sets defaults, validates with CreateTodoSchema, stores the todo in an in-memory Map, and returns the new Todo object.

  createTodo(request: CreateTodoRequest): Todo {
    // Validar entrada
    const validatedRequest = validateData(CreateTodoSchema, request);
    
    const todo: Todo = {
      id: randomUUID(),
      title: validatedRequest.title,
      description: validatedRequest.description,
      completed: false,
      createdAt: new Date(),
      priority: validatedRequest.priority || 'medium',
      tags: validatedRequest.tags || []
    };
  
    this.todos.set(todo.id, todo);
    
    return todo;
  }