MCP-MongoDB-MySQL-Server

Instructions

Implementation Reference

• src/index.ts:876-928 (handler)

  The main handler function for the connect_mongodb tool. Processes input arguments to establish a MongoDB connection, supporting URL, workspace .env, or env vars. Closes prior connections and uses MongoClient.

  private async handleConnectMongoDB(args: any) {
    let config: MongoDBConfig | null = null;
  
    // 优先使用URL
    if (args.url) {
      config = this.parseMongoConnectionUrl(args.url);
    }
    // 其次使用工作区配置
    else if (args.workspace) {
      this.currentWorkspace = args.workspace;
      config = await this.loadMongoWorkspaceConfig(args.workspace);
    }
    // 最后使用单独的参数
    else if (args.database) {
      config = {
        uri: process.env.MONGODB_URI || 'mongodb://localhost:27017',
        database: args.database
      };
    }
  
    if (!config) {
      throw new McpError(
        ErrorCode.InvalidParams,
        'No valid MongoDB configuration provided. Please provide either a URL, workspace path, or database name.'
      );
    }
  
    // 关闭现有连接
    if (this.mongoClient) {
      await this.mongoClient.close();
      this.mongoClient = null;
      this.mongoDB = null;
    }
  
    this.mongoConfig = config;
  
    try {
      await this.ensureMongoConnection();
      return {
        content: [
          {
            type: 'text',
            text: `Successfully connected to MongoDB database ${config.database}`
          }
        ]
      };
    } catch (error) {
      throw new McpError(
        ErrorCode.InternalError,
        `Failed to connect to MongoDB: ${getErrorMessage(error)}`
      );
    }
  }

• src/index.ts:234-258 (registration)

  Registers the connect_mongodb tool in the server's tool list for ListTools requests, defining its name, description, and input schema.

  {
    name: 'connect_mongodb',
    description: 'Connect to MongoDB database using URL or config',
    inputSchema: {
      type: 'object',
      properties: {
        url: {
          type: 'string',
          description: 'MongoDB URL (mongodb://user:pass@host:port/db)',
          optional: true
        },
        workspace: {
          type: 'string',
          description: 'Project workspace path',
          optional: true
        },
        database: { 
          type: 'string', 
          description: 'MongoDB database name',
          optional: true 
        }
      },
      // No required fields - will try different connection methods
    },
  },

• src/index.ts:552-553 (registration)

  Dispatcher switch case that routes connect_mongodb tool calls to the handleConnectMongoDB handler.

  case 'connect_mongodb':
    return await this.handleConnectMongoDB(request.params.arguments);

• src/index.ts:27-31 (schema)

  TypeScript interface defining the MongoDB configuration structure used by the connect_mongodb tool.

  interface MongoDBConfig {
    uri: string;
    database: string;
    options?: any;
  }

• src/index.ts:175-203 (helper)

  Helper function to parse a MongoDB connection URL into a MongoDBConfig object.

  private parseMongoConnectionUrl(url: string): MongoDBConfig {
    try {
      const parsed = parseUrl(url);
      if (!parsed.hostname) {
        throw new McpError(
          ErrorCode.InvalidParams,
          'Invalid MongoDB connection URL'
        );
      }
  
      const database = parsed.pathname?.slice(1);
      if (!database) {
        throw new McpError(
          ErrorCode.InvalidParams,
          'Database name must be specified in MongoDB URL'
        );
      }
  
      return {
        uri: url,
        database: database
      };
    } catch (error) {
      throw new McpError(
        ErrorCode.InvalidParams,
        `Invalid MongoDB connection URL: ${getErrorMessage(error)}`
      );
    }
  }