Clinical Trials MCP Server

Instructions

Implementation Reference

• build/index.js:722-783 (handler)

  The handler function for 'get_study_details' tool, which fetches study details from the ClinicalTrials.gov API using an NCT ID.

  async handleGetStudyDetails(args) {
      if (!args?.nctId || !/^NCT\d{8}$/.test(args.nctId)) {
          throw new McpError(ErrorCode.InvalidParams, "Valid NCT ID is required (format: NCT########)");
      }
      try {
          // Use the same endpoint as search but filter by NCT ID
          const response = await this.axiosInstance.get("/studies", {
              params: {
                  format: "json",
                  "query.term": args.nctId,
                  "filter.ids": args.nctId,
                  pageSize: 1,
              },
          });
          if (!response.data.studies || response.data.studies.length === 0) {
              return {
                  content: [
                      {
                          type: "text",
                          text: `No study found with NCT ID: ${args.nctId}`,
                      },
                  ],
                  isError: true,
              };
          }
          const study = response.data.studies[0];
          const detailedInfo = this.formatDetailedStudy(study);
          return {
              content: [
                  {
                      type: "text",
                      text: JSON.stringify(detailedInfo, null, 2),
                  },
              ],
          };
      }
      catch (error) {
          if (axios.isAxiosError(error)) {
              if (error.response?.status === 404) {
                  return {
                      content: [
                          {
                              type: "text",
                              text: `Study not found: ${args.nctId}`,
                          },
                      ],
                      isError: true,
                  };
              }
              return {
                  content: [
                      {
                          type: "text",
                          text: `Clinical Trials API error: ${error.response?.data?.message || error.message}`,
                      },
                  ],
                  isError: true,
              };
          }
          throw error;
      }
  }

• build/index.js:106-120 (registration)

  The registration of the 'get_study_details' tool in the MCP server tool list.

  {
      name: "get_study_details",
      description: "Get detailed information about a specific clinical trial",
      inputSchema: {
          type: "object",
          properties: {
              nctId: {
                  type: "string",
                  description: "NCT ID of the study (e.g., NCT00000419)",
                  pattern: "^NCT\\d{8}$",
              },
          },
          required: ["nctId"],
      },
  },

• build/index.js:615-616 (registration)

  Tool routing logic to call 'handleGetStudyDetails' when 'get_study_details' is requested.

  case "get_study_details":
      return await this.handleGetStudyDetails(request.params.arguments);