Yantrix MCP

Instructions

Implementation Reference

• src/index.ts:166-223 (handler)

  The `CallToolRequestSchema` handler dynamically resolves tools (including 'company_lookup' if present in the registry) by name and delegates execution to `callTool`.

  server.setRequestHandler(CallToolRequestSchema, async (request) => {
    const { name, arguments: args } = request.params;
  
    let registry: Registry;
    try {
      registry = await fetchRegistry();
    } catch (error) {
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify({ error: "Failed to fetch tool registry", detail: String(error) }),
          },
        ],
      };
    }
  
    const tool = registry.tools.find((t) => t.name === name);
    if (!tool) {
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify({
              error: `Tool '${name}' not found`,
              available_tools: registry.tools.map((t) => t.name),
            }),
          },
        ],
      };
    }
  
    try {
      const result = await callTool(tool, args as Record<string, unknown>);
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify(result, null, 2),
          },
        ],
      };
    } catch (error) {
      return {
        content: [
          {
            type: "text",
            text: JSON.stringify({
              error: "Tool call failed",
              tool: name,
              service: tool.service,
              detail: String(error),
            }),
          },
        ],
      };
    }
  });

• src/index.ts:88-132 (handler)

  The generic `callTool` function that performs the actual network request for tools fetched from the registry.

  async function callTool(
    tool: RegistryTool,
    args: Record<string, unknown>
  ): Promise<unknown> {
    const headers: Record<string, string> = {
      "Content-Type": "application/json",
    };
  
    if (X_PAYMENT_HEADER) {
      headers["X-PAYMENT"] = X_PAYMENT_HEADER;
    }
  
    if (DEV_MODE) {
      headers["X-Dev-Mode"] = "true";
    }
  
    const response = await fetch(tool.endpoint, {
      method: tool.method,
      headers,
      body: JSON.stringify(args),
    });
  
    if (response.status === 402) {
      const detail = await response.json().catch(() => ({}));
      return {
        error: "Payment Required",
        amount_usdc: tool.cost_usdc,
        service: tool.service,
        instructions:
          "Set X_PAYMENT_HEADER env var with a valid x402 payment proof, or set DEV_MODE=true for testing.",
        detail,
      };
    }
  
    if (!response.ok) {
      const text = await response.text().catch(() => "Unknown error");
      return {
        error: `HTTP ${response.status}`,
        service: tool.service,
        detail: text,
      };
    }
  
    return await response.json();
  }