tomopay-gateway

[](https://npmjs.com/package/agentic-mcp-pay) [](LICENSE)

Payment gateway for MCP servers — monetize your tools with one wrapper

Wrap any Model Context Protocol server with payment enforcement. Agents call your tools normally; the gateway intercepts, issues a payment challenge, verifies the proof, then executes. One function. No protocol lock-in.

npm install agentic-mcp-pay

Requires Node.js 18+.

import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
import { withPayments } from "agentic-mcp-pay";

const server = new McpServer({ name: "my-tools", version: "1.0.0" });

server.tool("analyze-data", {}, async (args) => {
  return { content: [{ type: "text", text: "analysis result" }] };
});

const { server: paidServer, cleanup, dashboardUrl } = withPayments(server, {
  pricing: {
    "analyze-data": { amount: 0.50, currency: "usd" },
  },
  payTo: "0xYourWalletAddress",
  protocols: ["x402"],
  dashboard: { port: 3100 },
});

// Connect to transport as normal
// paidServer.connect(transport);

| Protocol | Description | |----------|-------------| | x402 | Stablecoin micropayments (USDC on Base) via Coinbase facilitator | | mpp | Machine Payments Protocol (Stripe/Tempo) | | stripe | Traditional card payments via Stripe PaymentIntents | | mock | In-memory stub for testing — always verifies |

Agent calls tool
      │
      ▼
Gateway checks pricing table
      │
      ├─ No price set ──────────────────► Execute immediately (passthrough)
      │
      ├─ No _payment arg ───────────────► Return PAYMENT_REQUIRED + challenge
      │
      └─ _payment arg present
              │
              ▼