Healthcare MCP Server

Instructions

Implementation Reference

• server/health-topics-tool.js:15-110 (handler)

  The main handler function implementing the health_topics tool logic: validates input, checks cache, queries Health.gov API, processes and cleans topic data, caches results, and formats success/error responses.

  async getHealthTopics(topic, language = 'en') {
    // Input validation
    if (!topic) {
      return this.formatErrorResponse('Topic is required');
    }
    
    // Validate language
    if (!['en', 'es'].includes(language.toLowerCase())) {
      language = 'en';
    }
    
    // Create cache key
    const cacheKey = this.getCacheKey('health_topics', topic, language);
    
    // Check cache first
    const cachedResult = this.cache.get(cacheKey);
    if (cachedResult) {
      console.error(`Cache hit for Health Topics search: ${topic}`);
      return cachedResult;
    }
    
    try {
      console.error(`Searching Health Topics for: ${topic}, language: ${language}`);
      
      // Build API URL with parameters for topicsearch
      const params = {
        keyword: topic,
        lang: language
      };
      
      const url = this.buildUrl(`${this.baseUrl}/topicsearch.json`, params);
      
      // Make the request
      const data = await this.makeRequest(url);
      
      // Process the response
      let topics = [];
      let totalResults = 0;
      
      if (data && data.Result && data.Result.Resources) {
        const rawTopics = data.Result.Resources.Resource || [];
        totalResults = rawTopics.length;
        
        // Process each topic
        for (const rawTopic of rawTopics) {
          const processedTopic = {
            title: rawTopic.Title || '',
            url: rawTopic.AccessibleVersion || rawTopic.LastUpdate || '',
            last_updated: rawTopic.LastUpdate || '',
            section: rawTopic.Sections?.Section?.[0]?.Title || '',
            description: rawTopic.Sections?.Section?.[0]?.Description || '',
            content: []
          };
          
          // Extract content from sections
          if (rawTopic.Sections && rawTopic.Sections.Section) {
            for (const section of rawTopic.Sections.Section) {
              if (section.Content) {
                // Clean and limit content
                let content = section.Content;
                if (typeof content === 'string') {
                  // Remove HTML and limit size
                  content = content.replace(/<[^>]*>/g, ' ').replace(/\s+/g, ' ').trim();
                  if (content.length > 500) {
                    content = content.substring(0, 497) + '...';
                  }
                  if (content) {
                    processedTopic.content.push(content);
                  }
                }
              }
            }
          }
          
          topics.push(processedTopic);
        }
      }
      
      // Create result object
      const result = this.formatSuccessResponse({
        search_term: topic,
        language: language,
        total_results: totalResults,
        health_topics: topics
      });
      
      // Cache for 24 hours (86400 seconds)
      this.cache.set(cacheKey, result, 86400);
      
      return result;
      
    } catch (error) {
      console.error(`Error searching Health Topics: ${error.message}`);
      return this.formatErrorResponse(`Error searching health topics: ${error.message}`);
    }
  }

• server/index.js:187-202 (schema)

  Input schema definition for the health_topics tool, specifying required 'topic' parameter and optional 'language' (en/es).

  inputSchema: {
    type: "object",
    properties: {
      topic: {
        type: "string",
        description: "Health topic to search for information",
      },
      language: {
        type: "string",
        description: "Language for content (en or es)",
        enum: ["en", "es"],
        default: "en",
      },
    },
    required: ["topic"],
  },

• server/index.js:309-311 (registration)

  Tool registration in the main CallToolRequestSchema handler switch statement, dispatching calls to the HealthTopicsTool.getHealthTopics method.

  case "health_topics":
    result = await healthTopicsTool.getHealthTopics(args.topic, args.language);

• server/index.js:31-31 (registration)

  Instantiation of the HealthTopicsTool instance used by the server.

  const healthTopicsTool = new HealthTopicsTool(cacheService);

• server/health-topics-tool.js:16-24 (schema)

  Inline input validation schema enforcing required topic and valid language (en/es).

  // Input validation
  if (!topic) {
    return this.formatErrorResponse('Topic is required');
  }
  
  // Validate language
  if (!['en', 'es'].includes(language.toLowerCase())) {
    language = 'en';
  }