Paper Search MCP

Instructions

Implementation Reference

• src/mcp/handleToolCall.ts:291-313 (handler)

  Executes the 'search_scihub' tool by calling the SciHub searcher's search method and optionally downloading the PDF.

  case 'search_scihub': {
    const { doiOrUrl, downloadPdf, savePath } = args;
    const resolvedSavePath = savePath || './downloads';
  
    const results = await searchers.scihub.search(doiOrUrl);
    if (results.length === 0) {
      return jsonTextResponse(`No paper found on Sci-Hub for: ${doiOrUrl}`);
    }
  
    const paper = results[0];
    let responseText = `Found paper on Sci-Hub:\n\n${JSON.stringify(PaperFactory.toDict(paper), null, 2)}`;
  
    if (downloadPdf && paper.pdfUrl) {
      try {
        const filePath = await searchers.scihub.downloadPdf(doiOrUrl, { savePath: resolvedSavePath });
        responseText += `\n\nPDF downloaded successfully to: ${filePath}`;
      } catch (downloadError: any) {
        responseText += `\n\nFailed to download PDF: ${downloadError.message}`;
      }
    }
  
    return jsonTextResponse(responseText);
  }

• src/mcp/schemas.ts:134-140 (schema)

  Zod input schema for validating arguments to the 'search_scihub' tool.

  export const SearchSciHubSchema = z
    .object({
      doiOrUrl: z.string().min(1),
      downloadPdf: z.boolean().optional().default(false),
      savePath: z.string().optional()
    })
    .strip();

• src/mcp/tools.ts:314-337 (registration)

  Registers the 'search_scihub' tool in the TOOLS array with metadata and JSON input schema.

  {
    name: 'search_scihub',
    description:
      'Search and download papers from Sci-Hub using DOI or paper URL. Automatically detects and uses the fastest available mirror.',
    inputSchema: {
      type: 'object',
      properties: {
        doiOrUrl: {
          type: 'string',
          description: 'DOI (e.g., "10.1038/nature12373") or full paper URL'
        },
        downloadPdf: {
          type: 'boolean',
          description: 'Whether to download the PDF file',
          default: false
        },
        savePath: {
          type: 'string',
          description: 'Directory to save the PDF file (if downloadPdf is true)'
        }
      },
      required: ['doiOrUrl']
    }
  },

• src/platforms/SciHubSearcher.ts:241-345 (helper)

  Core helper function in SciHubSearcher that fetches paper information from Sci-Hub mirrors using web scraping to extract PDF URLs and metadata.

  private async fetchPaperInfo(doiOrUrl: string): Promise<Paper | null> {
    let currentMirror = await this.getCurrentMirror();
    let retries = 0;
    
    // 清理 DOI 格式
    const cleanedQuery = doiOrUrl.replace(/^doi:\s*/i, '');
    
    while (retries < this.maxRetries) {
      try {
        const searchUrl = `${currentMirror}/${cleanedQuery}`;
        logDebug(`Searching on ${currentMirror} for: ${cleanedQuery}`);
        
        const response = await this.axiosInstance.get(searchUrl);
        
        if (response.status === 200) {
          const $ = cheerio.load(response.data);
          
          // 检查是否找到论文
          const pdfFrame = $('#pdf');
          const pdfEmbed = $('embed[type="application/pdf"]');
          const pdfIframe = $('iframe[src*=".pdf"]');
          
          let pdfUrl = '';
          
          // 尝试多种方式获取 PDF URL
          if (pdfFrame.length > 0) {
            pdfUrl = pdfFrame.attr('src') || '';
          } else if (pdfEmbed.length > 0) {
            pdfUrl = pdfEmbed.attr('src') || '';
          } else if (pdfIframe.length > 0) {
            pdfUrl = pdfIframe.attr('src') || '';
          } else {
            // 查找下载按钮
            const downloadButton = $('button[onclick*="download"]');
            if (downloadButton.length > 0) {
              const onclickAttr = downloadButton.attr('onclick') || '';
              const match = onclickAttr.match(/location\.href='([^']+)'/);
              if (match) {
                pdfUrl = match[1];
              }
            }
          }
          
          // 处理相对 URL
          if (pdfUrl && !pdfUrl.startsWith('http')) {
            if (pdfUrl.startsWith('//')) {
              pdfUrl = 'https:' + pdfUrl;
            } else if (pdfUrl.startsWith('/')) {
              pdfUrl = currentMirror + pdfUrl;
            }
          }
          
          if (pdfUrl) {
            // 提取标题（尝试从页面标题或 citation 信息获取）
            let title = $('title').text();
            const citation = $('#citation').text();
            if (citation) {
              // 从引用信息中提取标题
              const titleMatch = citation.match(/([^.]+)\./);
              if (titleMatch) {
                title = titleMatch[1].trim();
              }
            }
            
            // 清理标题
            title = title.replace(/\s*\|\s*Sci-Hub.*$/, '')
                        .replace(/Sci-Hub\s*:\s*/, '')
                        .trim();
            
            return PaperFactory.create({
              paperId: cleanedQuery,
              title: title || `Paper: ${cleanedQuery}`,
              source: 'scihub',
              authors: [],
              abstract: '',
              doi: this.isValidDOIOrURL(cleanedQuery) && cleanedQuery.includes('10.') 
                   ? cleanedQuery 
                   : '',
              publishedDate: null,
              pdfUrl: pdfUrl,
              url: searchUrl,
              extra: {
                mirror: currentMirror,
                fetchedAt: new Date().toISOString()
              }
            });
          } else {
            logDebug(`Paper not found on ${currentMirror}`);
            currentMirror = await this.markMirrorFailed(currentMirror);
            retries++;
          }
        } else {
          logDebug(`Unexpected status ${response.status} from ${currentMirror}`);
          currentMirror = await this.markMirrorFailed(currentMirror);
          retries++;
        }
      } catch (error: any) {
        logDebug(`Error fetching from ${currentMirror}:`, error.message);
        currentMirror = await this.markMirrorFailed(currentMirror);
        retries++;
      }
    }
    
    return null;
  }