Taiga MCP Bridge

Instructions

Implementation Reference

• src/server.py:111-129 (handler)

  The handler function for the 'list_projects' MCP tool. It validates the session, retrieves the Taiga client wrapper, calls the Taiga API to list projects, and returns the list of projects.

  @mcp.tool("list_projects", description="Lists projects accessible to the user associated with the provided session_id.")
  def list_projects(session_id: str) -> List[Dict[str, Any]]:
      """Lists projects accessible by the authenticated user."""
      logger.info(f"Executing list_projects for session {session_id[:8]}...")
      taiga_client_wrapper = _get_authenticated_client(session_id) # Use wrapper variable name
      try:
          # Use pytaigaclient syntax: client.resource.method()
          projects = taiga_client_wrapper.api.projects.list()
          # Remove .to_dict() as pytaigaclient should return dicts
          # result = [p.to_dict() for p in projects]
          logger.info(
              f"list_projects successful for session {session_id[:8]}, found {len(projects)} projects.")
          return projects # Return directly
      except TaigaException as e:
          logger.error(f"Taiga API error listing projects: {e}", exc_info=False)
          raise e
      except Exception as e:
          logger.error(f"Unexpected error listing projects: {e}", exc_info=True)
          raise RuntimeError(f"Server error listing projects: {e}")

• src/server.py:39-52 (helper)

  Helper function used by list_projects (and other tools) to fetch and validate the authenticated TaigaClientWrapper from the session store.

  def _get_authenticated_client(session_id: str) -> TaigaClientWrapper:
      """
      Retrieves the authenticated TaigaClientWrapper for a given session ID.
      Raises PermissionError if the session is invalid or not found.
      """
      client = active_sessions.get(session_id)
      # Also check if the client object itself exists and is authenticated
      if not client or not client.is_authenticated:
          logger.warning(f"Invalid or expired session ID provided: {session_id}")
          # Raise PermissionError - FastMCP will map this to an appropriate error response
          raise PermissionError(
              f"Invalid or expired session ID: '{session_id}'. Please login again.")
      logger.debug(f"Retrieved valid client for session ID: {session_id}")
      return client

• src/taiga_client.py:15-80 (helper)

  The TaigaClientWrapper class provides the authenticated client instance used by list_projects to interact with the Taiga API, including login and is_authenticated check.

  class TaigaClientWrapper:
      """
      A wrapper around the pytaiga-client library to manage API instance
      and authentication state.
      """
  
      def __init__(self, host: str):
          if not host:
              raise ValueError("Taiga host URL cannot be empty.")
          # Store host, but initialize client later during login/token auth
          self.host = host
          # Use the new client type
          self.api: Optional[TaigaClient] = None
          logger.info(f"TaigaClientWrapper initialized for host: {self.host}")
  
      def login(self, username: str, password: str) -> bool:
          """
          Authenticates with the Taiga instance using username and password.
          Uses pytaigaclient.
          """
          try:
              logger.info(
                  f"Attempting login for user '{username}' on {self.host}")
              # Initialize the client here
              api_instance = TaigaClient(host=self.host)
              # Use the auth resource's login method
              api_instance.auth.login(username=username, password=password)
              self.api = api_instance
              logger.info(
                  f"Login successful for user '{username}'. Auth token acquired.")
              return True
          except TaigaException as e:
              logger.error(
                  f"Taiga login failed for user '{username}': {e}", exc_info=False)
              self.api = None
              raise e
          except Exception as e:
              logger.error(
                  f"An unexpected error occurred during login for user '{username}': {e}", exc_info=True)
              self.api = None
              # Wrap unexpected errors in TaigaException if needed, or re-raise
              raise TaigaException(f"Unexpected login error: {e}")
  
      # Add method for token authentication if needed by pytaigaclient
      # def set_token(self, token: str, token_type: str = "Bearer"):
      #     logger.info(f"Initializing TaigaClient with token on {self.host}")
      #     self.api = TaigaClient(host=self.host, auth_token=token, token_type=token_type)
      #     logger.info("TaigaClient initialized with token.")
  
      @property
      def is_authenticated(self) -> bool:
          """Checks if the client is currently authenticated (has an API instance with a token)."""
          # Check if api exists and has a token
          return self.api is not None and self.api.auth_token is not None
  
      def _ensure_authenticated(self):
          """Internal helper to check authentication before API calls."""
          if not self.is_authenticated:
              logger.error(
                  "Action required authentication, but client is not logged in.")
              # Use a standard exception type that FastMCP might handle better,
              # or a custom one if needed. PermissionError fits well.
              raise PermissionError(
                  "Client not authenticated. Please login first.")
  
  # No changes needed to _ensure_authenticated or is_authenticated property logic,