All-in-MCP

Instructions

Implementation Reference

• src/apaper/server.py:372-453 (handler)

  MCP tool handler function 'search_crossref_papers' that implements the core logic for searching Crossref papers, formatting results, and handling errors. This is likely exposed as 'apaper_search_crossref_papers' via the proxy.
  @mcp.tool() def search_crossref_papers( query: str, max_results: int = 10, year_min: int | str | None = None, year_max: int | str | None = None, sort_by: str = "relevance", ) -> str: """ Search academic papers from Crossref database Args: query: Search query string (e.g., 'quantum computing', 'machine learning') max_results: Maximum number of papers to return (default: 10) year_min: Minimum publication year (optional) year_max: Maximum publication year (optional) sort_by: Sort order: relevance, published, indexed, updated (default: relevance) """ try: # Convert string parameters to integers if needed year_min_int = None year_max_int = None if year_min is not None: year_min_int = int(year_min) if year_max is not None: year_max_int = int(year_max) papers = crossref_searcher.search( query, max_results=max_results, year_min=year_min_int, year_max=year_max_int, sort_by=sort_by, ) if not papers: year_filter_msg = "" if year_min or year_max: year_range = f" ({year_min or 'earliest'}-{year_max or 'latest'})" year_filter_msg = f" in year range{year_range}" return f"No papers found for query: {query}{year_filter_msg}" year_filter_msg = "" if year_min or year_max: year_range = f" ({year_min or 'earliest'}-{year_max or 'latest'})" year_filter_msg = f" in year range{year_range}" result_text = f"Found {len(papers)} Crossref papers for query '{query}'{year_filter_msg}:\n\n" for i, paper in enumerate(papers, 1): result_text += f"{i}. **{paper.title}**\n" result_text += f" - Authors: {', '.join(paper.authors)}\n" if paper.doi: result_text += f" - DOI: {paper.doi}\n" if paper.citations > 0: result_text += f" - Citations: {paper.citations}\n" if paper.published_date and paper.published_date.year > 1900: result_text += f" - Year: {paper.published_date.year}\n" if paper.extra and paper.extra.get("journal"): result_text += f" - Journal: {paper.extra['journal']}\n" if paper.extra and paper.extra.get("volume"): result_text += f" - Volume: {paper.extra['volume']}\n" if paper.extra and paper.extra.get("pages"): result_text += f" - Pages: {paper.extra['pages']}\n" if paper.url: result_text += f" - URL: {paper.url}\n" if paper.abstract: # Truncate abstract for readability abstract_preview = ( paper.abstract[:300] + "..." if len(paper.abstract) > 300 else paper.abstract ) result_text += f" - Abstract: {abstract_preview}\n" result_text += "\n" return result_text except ValueError as e: return f"Error: Invalid year format. Please provide valid integers for year_min and year_max." except Exception as e: return f"Error searching Crossref: {str(e)}"
• src/apaper/platforms/crossref.py:165-224 (helper)

  Core search method in CrossrefSearcher class that queries the Crossref API, parses responses into Paper objects, and applies filters.
  def search( self, query: str, max_results: int = 10, year_min: Optional[int] = None, year_max: Optional[int] = None, sort_by: str = "relevance", **kwargs, ) -> list[Paper]: """ Search for papers using Crossref API Args: query: Search query string max_results: Maximum number of results to return year_min: Minimum publication year year_max: Maximum publication year sort_by: Sort order (relevance, published, indexed, updated) """ if not query.strip(): return [] try: params = { "query": query, "rows": min(max_results, 1000), # Crossref max is 1000 "sort": sort_by, "select": "DOI,title,author,abstract,published-print,published-online,created,URL,container-title,volume,issue,page,subject,is-referenced-by-count,type,publisher,ISSN,ISBN,link", } # Add year filters if specified filters = [] if year_min: filters.append(f"from-pub-date:{year_min}") if year_max: filters.append(f"until-pub-date:{year_max}") if filters: params["filter"] = ",".join(filters) response = self.client.get( self.WORKS_ENDPOINT, params=params, headers=self._get_headers() ) response.raise_for_status() data = response.json() works = data.get("message", {}).get("items", []) papers = [] for work in works: paper = self._parse_work(work) if paper: papers.append(paper) return papers[:max_results] except Exception as e: logger.error(f"Error searching Crossref: {e}") return []
• src/apaper/server.py:13-28 (registration)

  Import and instantiation of CrossrefSearcher used by the handler.
  from apaper.platforms import ( IACRSearcher, CryptoBibSearcher, CrossrefSearcher, GoogleScholarSearcher ) from apaper.utils.pdf_reader import read_pdf # Initialize FastMCP server mcp = FastMCP("apaper") # Initialize searchers iacr_searcher = IACRSearcher() cryptobib_searcher = CryptoBibSearcher(cache_dir="./downloads") crossref_searcher = CrossrefSearcher() google_scholar_searcher = GoogleScholarSearcher()