Todo Markdown MCP Server

Instructions

Implementation Reference

• src/index.ts:146-162 (handler)

  The handler function for the 'update_todo' tool within the CallToolRequestSchema request handler. It validates the input arguments, calls the todoManager.updateTodo method, and formats the response.

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

• src/index.ts:64-86 (registration)

  Registration of the 'update_todo' tool in the ListToolsRequestSchema handler, including name, description, and input schema.

  {
    name: 'update_todo',
    description: 'Update an existing todo item',
    inputSchema: {
      type: 'object',
      properties: {
        id: {
          type: 'string',
          description: 'The todo item ID',
        },
        text: {
          type: 'string',
          description: 'New text for the todo item',
        },
        completed: {
          type: 'boolean',
          description: 'Whether the todo is completed',
        },
      },
      required: ['id'],
      additionalProperties: false,
    },
  },

• src/todoManager.ts:153-196 (helper)

  The core implementation of updating a todo item in the TodoManager class. Finds the todo by ID, applies updates to text and/or completed status, regenerates the markdown file, and saves it.

  async updateTodo(request: UpdateTodoRequest): Promise<TodoItem> {
    const todos = (await this.listTodos()).todos;
    const todoIndex = todos.findIndex((todo) => todo.id === request.id);
  
    if (todoIndex === -1) {
      throw new Error(`Todo with id ${request.id} not found`);
    }
  
    const todo = todos[todoIndex]!;
  
    if (request.text !== undefined) {
      todo.text = request.text.trim();
    }
  
    if (request.completed !== undefined) {
      todo.completed = request.completed;
      if (request.completed && !todo.completedAt) {
        todo.completedAt = new Date();
      } else if (!request.completed) {
        delete todo.completedAt;
      }
    }
  
    todos[todoIndex] = todo;
  
    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 todo;
  }

• src/types.ts:18-22 (schema)

  TypeScript type definition for the UpdateTodoRequest used for type-checking the tool arguments.

  export interface UpdateTodoRequest {
    id: string;
    text?: string;
    completed?: boolean;
  }