MCP Server for Google Cloud Healthcare API

Instructions

Implementation Reference

• src/server/connectors/fhir/FhirClient.ts:49-79 (handler)

  Core implementation of the find_patient tool: searches FHIR Patient resources using family name, given name, birthdate; extracts and formats patient demographics from the first matching result.

  async findPatient(args: any) {
    const params = new URLSearchParams();
    if (args.lastName) params.append('family', args.lastName);
    if (args.firstName) params.append('given', args.firstName);
    if (args.birthDate) params.append('birthdate', args.birthDate);
  
    const response = await this.client.get(`/Patient?${params}`);
    
    // Check if we have results
    if (!response.data?.entry?.[0]?.resource) {
        return this.formatResponse("fhir://Patient/search", { message: "No patients found" });
    }
  
    const resource = response.data.entry[0].resource;
    const name = resource.name?.[0] ?? {};
    const address = resource.address?.[0] ?? {};
  
    const patient = {
        name: name.given?.[0] ?? 'Unknown',
        familyName: name.family ?? 'Unknown',
        dob: resource.birthDate ?? 'Unknown',
        gender: resource.gender ?? 'Unknown',
        address: address.line?.[0] ?? 'Unknown',
        city: address.city ?? 'Unknown',
        state: address.state ?? 'Unknown',
        zip: address.postalCode ?? 'Unknown',
        id: resource.id ?? 'Unknown'
    };
  
    return this.formatResponse("fhir://Patient/search", patient);
  }

• src/server/constants/tools.ts:2-18 (schema)

  Tool definition including name, description, and input schema (requires lastName; optional firstName, birthDate, gender). Part of TOOL_DEFINITIONS array used for tool listing.

  {
    name: "find_patient",
    description: "Search for a patient by demographics",
    inputSchema: {
      type: "object",
      properties: {
        lastName: { type: "string" },
        firstName: { type: "string" },
        birthDate: { type: "string", description: "YYYY-MM-DD format" },
        gender: { 
          type: "string",
          enum: ["male", "female", "other", "unknown"]
        }
      },
      required: ["lastName"]
    }
  },

• src/server/handlers/ToolHandler.ts:66-67 (registration)

  ToolHandler switch statement registers/dispatches 'find_patient' tool call to FhirClient.findPatient.

  case "find_patient":
    return await this.fhirClient.findPatient(request.params.arguments);

• src/server/handlers/ToolHandler.ts:37-39 (registration)

  handleList method returns TOOL_DEFINITIONS for MCP listTools request, effectively registering available tools including find_patient.

  private handleList = async () => ({
    tools: TOOL_DEFINITIONS
  });