Semantic Scholar MCP Server

Instructions

Get papers that cite a specific paper.

Args:
    paper_id: Paper ID to get citations for
    limit: Maximum number of results (default: 10, max: 1000)
    offset: Number of results to skip (default: 0)
    fields: Comma-separated list of fields to return

Returns:
    List of citing papers

Implementation Reference

• src/semantic_scholar_mcp/server.py:433-482 (handler)

  The main handler function for the 'get_paper_citations' tool. It is registered via @mcp.tool() decorator, defines input schema via type annotations and docstring, fetches citations using make_api_request, formats them with format_paper, and returns formatted string output.

  @mcp.tool()
  async def get_paper_citations(
      paper_id: str, limit: int = 10, offset: int = 0, fields: Optional[str] = None
  ) -> str:
      """
      Get papers that cite a specific paper.
  
      Args:
          paper_id: Paper ID to get citations for
          limit: Maximum number of results (default: 10, max: 1000)
          offset: Number of results to skip (default: 0)
          fields: Comma-separated list of fields to return
  
      Returns:
          List of citing papers
      """
      params: Dict[str, Any] = {"limit": min(limit, 1000), "offset": offset}
  
      if fields:
          params["fields"] = fields
      else:
          params["fields"] = "paperId,title,authors,year,venue,citationCount"
  
      encoded_id = quote(paper_id, safe="")
      result = await make_api_request(f"paper/{encoded_id}/citations", params)
  
      if result is None:
          return "Error: Failed to fetch citations"
  
      if "error" in result:
          return f"Error: {result['error']}"
  
      citations = result.get("data", [])
      total = result.get("total", 0)
  
      if not citations:
          return "No citations found for this paper."
  
      formatted_citations = []
      for i, citation in enumerate(citations, 1):
          citing_paper = citation.get("citingPaper", {})
          if citing_paper:
              formatted_citations.append(f"{i}. {format_paper(citing_paper)}")
  
      result_text = (
          f"Found {total} total citations (showing {len(formatted_citations)}):\n\n"
      )
      result_text += "\n\n".join(formatted_citations)
  
      return result_text

• src/semantic_scholar_mcp/server.py:72-91 (helper)

  Helper function used to format individual paper details in the citations list output.

  def format_paper(paper: Dict[str, Any]) -> str:
      """Format a paper for display."""
      title = paper.get("title", "Unknown Title")
      authors = paper.get("authors", [])
      author_names = [author.get("name", "Unknown") for author in authors[:3]]
      author_str = ", ".join(author_names)
      if len(authors) > 3:
          author_str += f" (and {len(authors) - 3} others)"
  
      year = paper.get("year")
      year_str = f" ({year})" if year else ""
  
      venue = paper.get("venue", "")
      venue_str = f" - {venue}" if venue else ""
  
      citation_count = paper.get("citationCount", 0)
  
      paper_id = paper.get("paperId", "")
  
      return f"Title: {title}\nAuthors: {author_str}{year_str}{venue_str}\nCitations: {citation_count}\nPaper ID: {paper_id}"

• src/semantic_scholar_mcp/server.py:24-70 (helper)

  Core helper function that makes HTTP requests to the Semantic Scholar API, handles errors and rate limits, used by get_paper_citations to fetch the citations data.

  async def make_api_request(
      endpoint: str, params: Optional[Dict[str, Any]] = None, method: str = "GET"
  ) -> Optional[Dict[str, Any]]:
      """Make a request to the Semantic Scholar API."""
      url = f"{BASE_URL}/{endpoint.lstrip('/')}"
  
      headers = {
          "Accept": "application/json",
          "User-Agent": f"semantic-scholar-mcp/{USER_AGENT_VERSION}",
      }
  
      if API_KEY:
          headers["x-api-key"] = API_KEY
  
      try:
          async with httpx.AsyncClient(timeout=API_TIMEOUT) as client:
              if method == "GET":
                  response = await client.get(url, headers=headers, params=params)
              elif method == "POST":
                  response = await client.post(url, headers=headers, json=params)
              else:
                  raise ValueError(f"Unsupported HTTP method: {method}")
  
              response.raise_for_status()
              return response.json()
  
      except httpx.HTTPStatusError as e:
          if e.response.status_code == 403:
              if not API_KEY:
                  return {
                      "error": "Rate limit exceeded. The shared public rate limit (1000 req/sec) may be exceeded. Get a free API key from https://www.semanticscholar.org/product/api for dedicated limits."
                  }
              else:
                  return {
                      "error": f"API key may be invalid or rate limit exceeded: {str(e)}"
                  }
          elif e.response.status_code == 429:
              return {
                  "error": "Rate limit exceeded. Please wait a moment and try again, or get an API key for dedicated higher limits."
              }
          else:
              return {"error": f"HTTP error: {str(e)}"}
      except httpx.HTTPError as e:
          return {"error": f"HTTP error: {str(e)}"}
      except Exception as e:
          return {"error": f"Request failed: {str(e)}"}