drug_lookup

Instructions

Implementation Reference

• src/tools.js:113-123 (schema)

  Zod schema and configuration for the 'drug_lookup' tool. Defines input parameters (drugName string, optional searchField enum), the OpenFDA endpoint '/agent/v1/drugs/lookup', description, and per-call price of $0.01.

  // --- Drug Intelligence (OpenFDA — free, no license) ---
  {
    name: 'drug_lookup',
    description: 'Look up drug information including label data, adverse events, and related diagnosis codes. Source: OpenFDA (public domain).',
    price: '$0.01',
    endpoint: '/agent/v1/drugs/lookup',
    schema: {
      drugName: z.string().describe('Drug name (brand, generic, or substance — min 2 chars)'),
      searchField: z.enum(['brand_name', 'generic_name', 'product_ndc', 'substance_name']).optional().describe('Search field (default: brand_name)'),
    },
  },

• src/index.js:19-61 (registration)

  The generic tool registration loop in createMcpServer(). For each MCP_TOOLS entry (including drug_lookup), it registers an MCP tool via s.tool(...) with a dynamic handler that POSTs request params to the tool's endpoint URL. This is where 'drug_lookup' gets registered with the MCP server.

  for (const tool of MCP_TOOLS) {
    s.tool(tool.name, tool.description, tool.schema, async (params) => {
      const toolDef = getToolByName(tool.name);
      if (!toolDef) {
        return { content: [{ type: 'text', text: `Unknown tool: ${tool.name}` }], isError: true };
      }
      try {
        const response = await fetch(`${API_BASE_URL}${toolDef.endpoint}`, {
          method: 'POST',
          headers: {
            'Content-Type': 'application/json',
            ...(API_KEY && { 'X-API-Key': API_KEY }),
            'X-Agent-ID': 'mcp-client',
            'User-Agent': '@mymedi-ai/mcp-server/1.2.1',
          },
          body: JSON.stringify(params),
        });
        if (response.status === 402) {
          const paymentInfo = await response.json();
          return {
            content: [{ type: 'text', text: JSON.stringify({
              error: 'payment_required',
              message: `This tool costs ${toolDef.price} per call. Register at ${API_BASE_URL}/bot-marketplace/register for an API key with 10 free starter credits, or pay per call with on-chain USDC (no signup) via the x402 protocol.`,
              price: toolDef.price, register: `${API_BASE_URL}/bot-marketplace/register`, ...paymentInfo,
            }, null, 2) }], isError: true,
          };
        }
        if (!response.ok) {
          const error = await response.json().catch(() => ({ message: response.statusText }));
          return { content: [{ type: 'text', text: JSON.stringify({ error: true, status: response.status, ...error }, null, 2) }], isError: true };
        }
        const data = await response.json();
        const creditsSpent = response.headers.get('X-Credits-Spent');
        const creditsRemaining = response.headers.get('X-Credits-Remaining');
        if (creditsSpent) {
          data._billing = { creditsSpent: parseInt(creditsSpent, 10), creditsRemaining: creditsRemaining ? parseInt(creditsRemaining, 10) : undefined, priceUSD: toolDef.price };
        }
        return { content: [{ type: 'text', text: JSON.stringify(data, null, 2) }] };
      } catch (err) {
        return { content: [{ type: 'text', text: JSON.stringify({ error: true, message: err.message, hint: 'Ensure MCP_API_BASE_URL and MCP_API_KEY environment variables are set.' }, null, 2) }], isError: true };
      }
    });
  }