drug_interactions

Instructions

Implementation Reference

• src/tools.js:129-132 (schema)

  Input schema for drug_interactions tool: accepts an array of 2-5 drug names to check for interactions.

    schema: {
      drugs: z.array(z.string()).min(2).max(5).describe('Array of 2-5 drug names to check for interactions'),
    },
  },

• src/tools.js:124-132 (registration)

  Registration of the drug_interactions tool as part of the MCP_TOOLS array. It has name, description, price, endpoint, and Zod schema.

  {
    name: 'drug_interactions',
    description: 'Check drug-drug interaction signals from FDA adverse event co-reports. Returns co-reported reactions and signal strength. Source: OpenFDA FAERS (public domain).',
    price: '$0.03',
    endpoint: '/agent/v1/drugs/interactions',
    schema: {
      drugs: z.array(z.string()).min(2).max(5).describe('Array of 2-5 drug names to check for interactions'),
    },
  },

• src/index.js:19-61 (handler)

  Generic handler that forwards the drug_interactions request to the remote API endpoint /agent/v1/drugs/interactions via fetch, passing the params as JSON body. All tools use this same generic handler.

  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 };
      }
    });
  }