Universal MCP Server

Instructions

Implementation Reference

• src/index.ts:119-136 (schema)

  Input schema for the 'write_file' tool defining required 'key' and 'content' string parameters.

  {
    name: 'write_file',
    description: 'Write content to a file',
    inputSchema: {
      type: 'object',
      properties: {
        key: {
          type: 'string',
          description: 'The file key/name',
        },
        content: {
          type: 'string',
          description: 'The content to write',
        },
      },
      required: ['key', 'content'],
    },
  },

• src/index.ts:176-198 (handler)

  Handler for 'write_file' tool: extracts arguments, logs request, invokes storage.write(), and returns JSON success response.

  case 'write_file': {
    const { key, content } = args as { key: string; content: string };
    
    logger.info('Tool request received', { 
      operation: 'tool:write',
      toolName: 'write_file',
      key,
      requestId 
    });
  
    await storage.write(key, content, requestId);
  
    return {
      content: [{
        type: 'text',
        text: JSON.stringify({
          success: true,
          message: `File '${key}' written successfully`,
          key
        }, null, 2)
      }]
    };
  }

• src/storage.ts:86-128 (helper)

  FileStorage.write() method: acquires lock, handles versioning and metadata, performs fs.writeFile to persist data as JSON.

  async write(key: string, content: string, requestId: string): Promise<void> {
    const releaseLock = await this.acquireLock(key);
    const filePath = this.getFilePath(key);
  
    try {
      logger.debug('Writing file', { operation: 'write', key, filePath, requestId });
  
      let currentVersion = 0;
      let createdAt = new Date().toISOString();
      
      try {
        const existing = await fs.readFile(filePath, 'utf-8');
        const existingItem: StorageItem = JSON.parse(existing);
        currentVersion = existingItem.metadata.version;
        createdAt = existingItem.metadata.createdAt;
      } catch {
        // ファイルが存在しない場合は新規作成
      }
  
      const item: StorageItem = {
        content,
        metadata: {
          createdAt,
          updatedAt: new Date().toISOString(),
          version: currentVersion + 1
        }
      };
  
      await fs.writeFile(filePath, JSON.stringify(item, null, 2), 'utf-8');
      
      logger.info('File written successfully', { 
        operation: 'write', 
        key, 
        version: item.metadata.version,
        requestId 
      });
    } catch (error) {
      logger.error('Failed to write file', error as Error, { operation: 'write', key, requestId });
      throw error;
    } finally {
      releaseLock();
    }
  }

• src/index-multimode.ts:128-145 (schema)

  Identical input schema for 'write_file' tool in the multi-mode server entry point.

  {
    name: 'write_file',
    description: 'Write content to a file',
    inputSchema: {
      type: 'object',
      properties: {
        key: {
          type: 'string',
          description: 'The file key/name',
        },
        content: {
          type: 'string',
          description: 'The content to write',
        },
      },
      required: ['key', 'content'],
    },
  },

• src/index-multimode.ts:185-207 (handler)

  Handler for 'write_file' tool in multi-mode server: identical to src/index.ts implementation.

  case 'write_file': {
    const { key, content } = args as { key: string; content: string };
    
    logger.info('Tool request received', { 
      operation: 'tool:write',
      toolName: 'write_file',
      key,
      requestId 
    });
  
    await storage.write(key, content, requestId);
  
    return {
      content: [{
        type: 'text',
        text: JSON.stringify({
          success: true,
          message: `File '${key}' written successfully`,
          key
        }, null, 2)
      }]
    };
  }