Todo Markdown MCP Server

Instructions

Implementation Reference

• src/todoManager.ts:121-151 (handler)

  Core handler function that implements the logic for adding a new todo item: generates ID, appends to list, formats markdown, and writes to file with error handling for permissions.

  async addTodo(request: AddTodoRequest): Promise<TodoItem> {
    const todos = (await this.listTodos()).todos;
  
    const newTodo: TodoItem = {
      id: randomUUID(),
      text: request.text.trim(),
      completed: false,
      createdAt: new Date(),
    };
  
    todos.push(newTodo);
  
    const markdown = this.formatTodoMarkdown(todos);
  
    try {
      await writeFile(this.todoFilePath, markdown, 'utf-8');
    } catch (error) {
      if (error instanceof Error && error.message.includes('EACCES')) {
        throw new Error(
          `Permission denied: Cannot write to ${this.todoFilePath}. Check file permissions or set TODO_FILE_PATH environment variable to a writable location.`
        );
      } else if (error instanceof Error && error.message.includes('EROFS')) {
        throw new Error(
          `Read-only file system: Cannot write to ${this.todoFilePath}. Set TODO_FILE_PATH environment variable to a writable location.`
        );
      }
      throw error;
    }
  
    return newTodo;
  }

• src/index.ts:49-63 (registration)

  Tool registration in ListToolsRequestHandler, defining name, description, and JSON input schema for 'add_todo'.

  {
    name: 'add_todo',
    description: 'Add a new todo item',
    inputSchema: {
      type: 'object',
      properties: {
        text: {
          type: 'string',
          description: 'The todo item text',
        },
      },
      required: ['text'],
      additionalProperties: false,
    },
  },

• src/index.ts:129-144 (handler)

  MCP CallToolRequest dispatch handler for 'add_todo': validates input, calls todoManager.addTodo, and formats success response.

  case 'add_todo': {
    const args = request.params.arguments as unknown as AddTodoRequest;
    if (!args?.text || typeof args.text !== 'string') {
      throw new Error('Text is required and must be a string');
    }
  
    const todo = await this.todoManager.addTodo(args);
    return {
      content: [
        {
          type: 'text',
          text: `Todo added successfully: ${JSON.stringify(todo, null, 2)}`,
        },
      ],
    };
  }

• src/types.ts:14-16 (schema)

  TypeScript interface used for type-checking the AddTodoRequest parameters in handlers.

  export interface AddTodoRequest {
    text: string;
  }