execute_query

Instructions

Implementation Reference

• src/adx_mcp_server/server.py:200-221 (handler)

  The execute_query tool handler function. It takes a KQL query string, validates config, gets a Kusto client, executes the query, formats results, and returns a list of dictionaries.

  async def execute_query(query: str) -> List[Dict[str, Any]]:
      """Execute a KQL query against the configured ADX database."""
      logger.info("Executing KQL query", database=config.database, query_preview=query[:100])
  
      if not config.cluster_url or not config.database:
          logger.error("Missing ADX configuration")
          raise ValueError("Azure Data Explorer configuration is missing. Please set ADX_CLUSTER_URL and ADX_DATABASE environment variables.")
  
      try:
          client = get_kusto_client()
          result_set = client.execute(config.database, query)
          results = format_query_results(result_set)
          logger.info("Query executed successfully", row_count=len(results))
          return results
      except Exception as e:
          logger.error(
              "Query execution failed",
              error=str(e),
              exception_type=type(e).__name__,
              database=config.database
          )
          raise

• src/adx_mcp_server/server.py:199-199 (registration)

  The @mcp.tool decorator registers execute_query as an MCP tool with a description: 'Executes a Kusto Query Language (KQL) query against the configured Azure Data Explorer database and returns the results as a list of dictionaries.'

  @mcp.tool(description="Executes a Kusto Query Language (KQL) query against the configured Azure Data Explorer database and returns the results as a list of dictionaries.")

• src/adx_mcp_server/server.py:84-137 (helper)

  get_kusto_client() is a helper used by execute_query to create and configure a Kusto client with Azure credentials (WorkloadIdentityCredential or DefaultAzureCredential).

  def get_kusto_client() -> KustoClient:
      """
      Create and configure a Kusto client with appropriate Azure credentials.
  
      Prioritizes WorkloadIdentityCredential when running in AKS with workload identity,
      falls back to DefaultAzureCredential for other authentication methods.
  
      Returns:
          KustoClient: Configured Kusto client instance
      """
      tenant_id = os.environ.get('AZURE_TENANT_ID')
      client_id = os.environ.get('AZURE_CLIENT_ID')
      token_file_path = os.environ.get('ADX_TOKEN_FILE_PATH', '/var/run/secrets/azure/tokens/azure-identity-token')
  
      if tenant_id and client_id:
          logger.info(
              "Using WorkloadIdentityCredential",
              client_id=client_id,
              tenant_id=tenant_id,
              token_file_path=token_file_path
          )
          try:
              credential = WorkloadIdentityCredential(
                  tenant_id=tenant_id,
                  client_id=client_id,
                  token_file_path=token_file_path
              )
          except Exception as e:
              logger.warning(
                  "Failed to initialize WorkloadIdentityCredential, falling back",
                  error=str(e),
                  exception_type=type(e).__name__
              )
              credential = DefaultAzureCredential()
      else:
          logger.info("Using DefaultAzureCredential (missing WorkloadIdentity credentials)")
          credential = DefaultAzureCredential()
  
      try:
          kcsb = KustoConnectionStringBuilder.with_azure_token_credential(
              connection_string=config.cluster_url,
              credential=credential
          )
          client = KustoClient(kcsb)
          logger.debug("Kusto client initialized successfully", cluster_url=config.cluster_url)
          return client
      except Exception as e:
          logger.error(
              "Failed to create Kusto client",
              error=str(e),
              exception_type=type(e).__name__,
              cluster_url=config.cluster_url
          )
          raise

• src/adx_mcp_server/server.py:139-172 (helper)

  format_query_results() is a helper used by execute_query to format Kusto query results into a list of dictionaries with column names as keys.

  def format_query_results(result_set) -> List[Dict[str, Any]]:
      """
      Format Kusto query results into a list of dictionaries.
  
      Args:
          result_set: Raw result set from KustoClient
  
      Returns:
          List of dictionaries with column names as keys
      """
      if not result_set or not result_set.primary_results:
          logger.debug("Empty or null result set received")
          return []
  
      try:
          primary_result = result_set.primary_results[0]
          columns = [col.column_name for col in primary_result.columns]
  
          formatted_results = []
          for row in primary_result.rows:
              record = {}
              for i, value in enumerate(row):
                  record[columns[i]] = value
              formatted_results.append(record)
  
          logger.debug("Query results formatted", row_count=len(formatted_results), columns=columns)
          return formatted_results
      except Exception as e:
          logger.error(
              "Error formatting query results",
              error=str(e),
              exception_type=type(e).__name__
          )
          raise

• src/adx_mcp_server/server.py:176-197 (schema)

  validate_table_name() and validate_sample_size() are validation helpers used by other tools (not execute_query directly), but represent the schema validation pattern for the server's tools.

  def validate_table_name(table_name: str) -> str:
      """Validate a KQL table name to prevent injection attacks.
  
      Allows simple identifiers (my_table) and dot-qualified names (database.table).
      Rejects any characters that could enable KQL injection.
      """
      if not table_name or not table_name.strip():
          raise ValueError("Table name cannot be empty")
      table_name = table_name.strip()
      if not _TABLE_NAME_PATTERN.match(table_name):
          raise ValueError(
              f"Invalid table name: '{table_name}'. "
              "Table names must contain only letters, digits, underscores, "
              "and dots (for qualified names like 'database.table')."
          )
      return table_name
  
  def validate_sample_size(sample_size: int) -> int:
      """Validate sample_size is a positive integer."""
      if not isinstance(sample_size, int) or sample_size <= 0:
          raise ValueError(f"sample_size must be a positive integer, got: {sample_size}")
      return sample_size