@t402/fastify

Fastify plugin integration for the t402 Payment Protocol. This package provides a simple middleware function for adding t402 payment requirements to your Fastify applications.

Installation

npm install @t402/fastify

Quick Start

import Fastify from "fastify";
import { paymentMiddleware, t402ResourceServer } from "@t402/fastify";
import { ExactEvmScheme } from "@t402/evm/exact/server";
import { HTTPFacilitatorClient } from "@t402/core/server";

const app = Fastify();

const facilitatorClient = new HTTPFacilitatorClient({ url: "https://facilitator.t402.io" });
const resourceServer = new t402ResourceServer(facilitatorClient)
  .register("eip155:84532", new ExactEvmScheme());

// Apply the payment middleware with your configuration
app.addHook(
  "onRequest",
  paymentMiddleware(
    {
      "GET /protected-route": {
        accepts: {
          scheme: "exact",
          price: "$0.10",
          network: "eip155:84532",
          payTo: "0xYourAddress",
        },
        description: "Access to premium content",
      },
    },
    resourceServer,
  ),
);

// Implement your protected route
app.get("/protected-route", async (request, reply) => {
  return { message: "This content is behind a paywall" };
});

app.listen({ port: 3000 });

Configuration

The paymentMiddleware function accepts the following parameters:

paymentMiddleware(
  routes: RoutesConfig,
  server: t402ResourceServer,
  paywallConfig?: PaywallConfig,
  paywall?: PaywallProvider,
  syncFacilitatorOnStart?: boolean
)

Parameters

1. routes (required): Route configurations for protected endpoints
2. server (required): Pre-configured t402ResourceServer instance
3. paywallConfig (optional): Configuration for the built-in paywall UI
4. paywall (optional): Custom paywall provider
5. syncFacilitatorOnStart (optional): Whether to sync with facilitator on startup (defaults to true)

Route Configuration

const routes: RoutesConfig = {
  "GET /api/protected": {
    accepts: {
      scheme: "exact",
      price: "$0.10",
      network: "eip155:84532",
      payTo: "0xYourAddress",
      maxTimeoutSeconds: 60,
    },
    description: "Premium API access",
  },
};

Multiple Payment Networks

app.addHook(
  "onRequest",
  paymentMiddleware(
    {
      "GET /api/data": {
        accepts: [
          {
            scheme: "exact",
            price: "$0.10",
            network: "eip155:8453",
            payTo: evmAddress,
          },
          {
            scheme: "exact",
            price: "$0.10",
            network: "solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp",
            payTo: svmAddress,
          },
        ],
        description: "Data API access",
      },
    },
    new t402ResourceServer(facilitatorClient)
      .register("eip155:8453", new ExactEvmScheme())
      .register("solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp", new ExactSvmScheme()),
  ),
);

Paywall Configuration

The middleware automatically displays a paywall UI when browsers request protected endpoints.

Install the optional @t402/paywall package for a complete wallet connection and payment UI:

pnpm add @t402/paywall

const paywallConfig: PaywallConfig = {
  appName: "Your App Name",
  appLogo: "/path/to/logo.svg",
  testnet: true,
};

app.addHook("onRequest", paymentMiddleware(routes, resourceServer, paywallConfig));

Peer Dependencies

• fastify ^4.0.0 || ^5.0.0

Development

pnpm build    # Build the package
pnpm test     # Run unit tests

Related Packages

• @t402/core - Core protocol types and client
• @t402/express - Express.js middleware
• @t402/hono - Hono middleware
• @t402/paywall - Universal paywall UI component