connect

Instructions

Uses configuration from environment variables:
- MSSQL_HOST: Server hostname or IP
- MSSQL_USER: Username
- MSSQL_PASSWORD: Password
- MSSQL_DATABASE: Database name
- MSSQL_PORT: Port (default: 1433)

Returns:
    Connection status and details including host, database, and timestamp.

Implementation Reference

• src/mssql_mcp/server.py:119-148 (handler)

  The handler function for the 'connect' MCP tool. It calls get_connection_manager() to establish the database connection and returns status and details.

  @mcp.tool()
  def connect() -> dict[str, Any]:
      """Establish connection to the SQL Server database.
  
      Uses configuration from environment variables:
      - MSSQL_HOST: Server hostname or IP
      - MSSQL_USER: Username
      - MSSQL_PASSWORD: Password
      - MSSQL_DATABASE: Database name
      - MSSQL_PORT: Port (default: 1433)
  
      Returns:
          Connection status and details including host, database, and timestamp.
      """
      try:
          manager = get_connection_manager()
          info = manager.connect()
  
          return {
              "status": "connected",
              "host": info.host,
              "database": info.database,
              "connected_at": info.connected_at.isoformat(),
          }
      except ConnectionError as e:
          return {"status": "error", "error": str(e)}
      except Exception as e:
          logger.error(f"Unexpected error during connect: {e}")
          return {"status": "error", "error": f"Unexpected error: {e}"}

• src/mssql_mcp/server.py:119-148 (registration)

  The @mcp.tool() decorator registers the 'connect' function as an MCP tool on the FastMCP instance.

  @mcp.tool()
  def connect() -> dict[str, Any]:
      """Establish connection to the SQL Server database.
  
      Uses configuration from environment variables:
      - MSSQL_HOST: Server hostname or IP
      - MSSQL_USER: Username
      - MSSQL_PASSWORD: Password
      - MSSQL_DATABASE: Database name
      - MSSQL_PORT: Port (default: 1433)
  
      Returns:
          Connection status and details including host, database, and timestamp.
      """
      try:
          manager = get_connection_manager()
          info = manager.connect()
  
          return {
              "status": "connected",
              "host": info.host,
              "database": info.database,
              "connected_at": info.connected_at.isoformat(),
          }
      except ConnectionError as e:
          return {"status": "error", "error": str(e)}
      except Exception as e:
          logger.error(f"Unexpected error during connect: {e}")
          return {"status": "error", "error": f"Unexpected error: {e}"}

• src/mssql_mcp/server.py:31-42 (helper)

  Helper function that provides the global ConnectionManager instance, lazily initialized from MSSQLConfig.

  def get_connection_manager() -> ConnectionManager:
      """Get or create the global connection manager.
  
      Returns:
          ConnectionManager instance configured from environment variables
      """
      global _connection_manager
      if _connection_manager is None:
          config = MSSQLConfig()
          _connection_manager = ConnectionManager(config)
      return _connection_manager

• src/mssql_mcp/connection.py:59-102 (helper)

  Core helper method in ConnectionManager that performs the actual database connection using pymssql.connect.

  def connect(self, name: str = "default") -> ConnectionInfo:
      """Establish a connection to the SQL Server.
  
      Args:
          name: Connection name for reference
  
      Returns:
          ConnectionInfo with connection details
  
      Raises:
          ConnectionError: If connection fails
      """
      if name in self._connections and self._connections[name].is_active:
          logger.info(f"Reusing existing connection '{name}'")
          return self._connections[name]
  
      try:
          logger.info(f"Connecting to {self._config.host}/{self._config.database}")
  
          self._connection = pymssql.connect(
              server=self._config.host,
              user=self._config.user,
              password=self._config.password,
              database=self._config.database,
              port=self._config.port,
              login_timeout=self._config.timeout,
              timeout=self._config.query_timeout,
          )
  
          info = ConnectionInfo(
              name=name,
              host=self._config.host,
              database=self._config.database,
              connected_at=datetime.now(),
              is_active=True,
          )
          self._connections[name] = info
  
          logger.info(f"Connected successfully to {self._config.database}")
          return info
  
      except pymssql.Error as e:
          logger.error(f"Connection failed: {e}")
          raise ConnectionError(f"Failed to connect to {self._config.host}: {e}") from e