PyGithub MCP Server

Instructions

Args:
    params: Parameters for listing comments including:
        - owner: Repository owner (user or organization)
        - repo: Repository name
        - issue_number: Issue number
        - since: Filter by date (optional)
        - page: Page number (optional)
        - per_page: Results per page (optional)

Returns:
    List of comments from GitHub API

Implementation Reference

• src/pygithub_mcp_server/tools/issues/tools.py:239-275 (handler)

  MCP tool handler for list_issue_comments. Validates input using ListIssueCommentsParams, calls the operations function, formats JSON response, handles errors.

  @tool()
  def list_issue_comments(params: ListIssueCommentsParams) -> dict:
      """List comments on an issue.
      
      Args:
          params: Parameters for listing comments including:
              - owner: Repository owner (user or organization)
              - repo: Repository name
              - issue_number: Issue number
              - since: Filter by date (optional)
              - page: Page number (optional)
              - per_page: Results per page (optional)
      
      Returns:
          List of comments from GitHub API
      """
      try:
          logger.debug(f"list_issue_comments called with params: {params}")
          # Pass the Pydantic model directly to the operation
          result = issues.list_issue_comments(params)
          logger.debug(f"Got result: {result}")
          return {"content": [{"type": "text", "text": json.dumps(result, indent=2)}]}
      except GitHubError as e:
          logger.error(f"GitHub error: {e}")
          return {
              "content": [{"type": "error", "text": format_github_error(e)}],
              "is_error": True
          }
      except Exception as e:
          logger.error(f"Unexpected error: {e}")
          logger.error(traceback.format_exc())
          error_msg = str(e) if str(e) else "An unexpected error occurred"
          return {
              "content": [{"type": "error", "text": f"Internal server error: {error_msg}"}],
              "is_error": True
          }

• src/pygithub_mcp_server/schemas/issues.py:228-299 (schema)

  Pydantic schema ListIssueCommentsParams for input validation. Inherits from RepositoryRef (owner/repo), adds issue_number, since, page, per_page with validators.

  class ListIssueCommentsParams(RepositoryRef):
      """Parameters for listing comments on an issue."""
  
      model_config = ConfigDict(strict=True)
      
      issue_number: int = Field(..., description="Issue number to list comments for")
      since: Optional[datetime] = Field(
          None, 
          description="Filter by date (ISO 8601 format with timezone: YYYY-MM-DDThh:mm:ssZ)"
      )
      page: Optional[int] = Field(
          None, 
          description="Page number for pagination (1-based)"
      )
      per_page: Optional[int] = Field(
          None, 
          description="Results per page (max 100)"
      )
      
      @field_validator('page')
      @classmethod
      def validate_page(cls, v):
          """Validate that page is a positive integer."""
          if v is not None and v < 1:
              raise ValueError("Page number must be a positive integer")
          return v
      
      @field_validator('per_page')
      @classmethod
      def validate_per_page(cls, v):
          """Validate that per_page is a positive integer <= 100."""
          if v is not None:
              if v < 1:
                  raise ValueError("Results per page must be a positive integer")
              if v > 100:
                  raise ValueError("Results per page cannot exceed 100")
          return v
      
      @field_validator('since', mode='before')
      @classmethod
      def validate_since(cls, v):
          """Convert string dates to datetime objects.
          
          Accepts:
          - ISO 8601 format strings with timezone (e.g., "2020-01-01T00:00:00Z")
          - ISO 8601 format strings with timezone without colon (e.g., "2020-01-01T12:30:45-0500")
          - ISO 8601 format strings with short timezone (e.g., "2020-01-01T12:30:45+05")
          - ISO 8601 format strings with single digit timezone (e.g., "2020-01-01T12:30:45-5")
          - datetime objects
          
          Returns:
          - datetime object
          
          Raises:
          - ValueError: If the string cannot be converted to a valid datetime object
          """
          if isinstance(v, str):
              # Basic validation - must have 'T' and some form of timezone indicator
              if not ('T' in v and ('+' in v or 'Z' in v or '-' in v.split('T')[1])):
                  raise ValueError(
                      f"Invalid ISO format datetime: {v}. "
                      f"Must include date, time with 'T' separator, and timezone."
                  )
              
              try:
                  # Try to convert using our flexible converter
                  return convert_iso_string_to_datetime(v)
              except ValueError as e:
                  # Only raise if conversion actually fails
                  raise ValueError(f"Invalid ISO format datetime: {v}. {str(e)}")
          return v

• src/pygithub_mcp_server/tools/issues/tools.py:439-463 (registration)

  Registration function that includes list_issue_comments in the issue_tools list and calls register_tools to register with MCP server using function name as tool name.

  def register(mcp: FastMCP) -> None:
      """Register all issue tools with the MCP server.
      
      Args:
          mcp: The MCP server instance
      """
      from pygithub_mcp_server.tools import register_tools
      
      # List of all issue tools to register
      issue_tools = [
          create_issue,
          list_issues,
          get_issue,
          update_issue,
          add_issue_comment,
          list_issue_comments,
          update_issue_comment,
          delete_issue_comment,
          add_issue_labels,
          remove_issue_label,
      ]
      
      register_tools(mcp, issue_tools)
      logger.debug(f"Registered {len(issue_tools)} issue tools")

• src/pygithub_mcp_server/operations/issues.py:271-308 (helper)

  Core implementation: fetches issue comments using PyGithub, handles pagination, converts to dicts using convert_issue_comment.

  def list_issue_comments(params: ListIssueCommentsParams) -> List[Dict[str, Any]]:
      """List comments on an issue.
  
      Args:
          params: Validated parameters for listing comments
  
      Returns:
          List of comments from GitHub API
  
      Raises:
          GitHubError: If the API request fails
      """
      try:
          client = GitHubClient.get_instance()
          repository = client.get_repo(f"{params.owner}/{params.repo}")
          issue = repository.get_issue(params.issue_number)
  
          # Build kwargs for get_comments
          kwargs = {}
          if params.since is not None:
              logger.debug(f"Using UTC since parameter: {params.since.isoformat()}")
              kwargs["since"] = params.since
  
          # Get paginated comments with only provided parameters
          paginated_comments = issue.get_comments(**kwargs)
          
          # Use our pagination utility for consistent pagination handling
          comments = get_paginated_items(paginated_comments, params.page, params.per_page)
  
          logger.debug(f"Retrieved {len(comments)} comments")
  
          # Convert each comment to our schema
          converted_comments = [convert_issue_comment(comment) for comment in comments]
          return converted_comments
  
      except GithubException as e:
          raise GitHubClient.get_instance()._handle_github_exception(e)