Fastify

Fastify is a web framework for Node.js designed for high performance and low overhead. It features a powerful plugin architecture, built-in schema-based validation, and asynchronous request handling, enabling fast and efficient APIs. Its focus on speed, extensibility, and developer-friendly tooling makes it suitable for both small projects and large-scale production applications.

Example Use

This example assumes you are familiar with the @zeroad.network/token module, its use cases, and installation process. If not, please review the Node, Bun, and Deno page first.

The following demonstrates how to use the module with the fastify framework. It serves as a reference and starting point. Full examples are available in the examples section of our GitHub repository:

src/my-fastify-app/app.ts
import { randomUUID } from "node:crypto";

import Fastify from "fastify";
import { Site, FEATURES } from "@zeroad.network/token";

/**
 * Module initialization (once at startup)
 *
 * Option 1: Provide the pre-generated "Welcome Header" value, e.g., via process.env:
 *   const site = Site(process.env.ZERO_AD_NETWORK_WELCOME_HEADER_VALUE);
 *
 * Option 2: Pass an options object to define your site's feature list:
 *   const site = Site({
 *     siteId: 'd867b6ff-cb12-4363-be54-db4cec523235',
 *     features: [FEATURES.ADS_OFF, FEATURES.COOKIE_CONSENT_OFF, FEATURES.MARKETING_DIALOG_OFF]
 *   });
 */

const site = Site({
  // For demo purposes, we'll generate a siteId UUID
  siteId: randomUUID(),
  // Specify supported site features
  features: [FEATURES.ADS_OFF, FEATURES.COOKIE_CONSENT_OFF, FEATURES.MARKETING_DIALOG_OFF],
});

// -----------------------------------------------------------------------------
// Fastify app setup
// -----------------------------------------------------------------------------
const app = Fastify();

// Extend FastifyRequest interface to include tokenContext
declare module "fastify" {
  interface FastifyRequest {
    tokenContext: ReturnType<typeof site.parseToken>;
  }
}

// -----------------------------------------------------------------------------
// Middleware (Fastify hook)
// -----------------------------------------------------------------------------
app.addHook("onRequest", async (request, reply) => {
  // Inject the "X-Better-Web-Welcome" server header into every response
  reply.header(site.SERVER_HEADER_NAME, site.SERVER_HEADER_VALUE);

  // Parse incoming user token from client header
  // Attach parsed token data to request for downstream use
  request.tokenContext = site.parseToken(request.headers[site.CLIENT_HEADER_NAME]);
});

// -----------------------------------------------------------------------------
// Routes
// -----------------------------------------------------------------------------
app.get("/", async (request, reply) => {
  // Access parsed tokenContext for this request
  const tokenContext = request.tokenContext;

  // Render HTML template using tokenContext to display site feature states
  const state = (value: boolean) => (value && '<b style="background: #b0b0b067">YES</b>') || "NO";
  const template = `
    <html>
      <body>
        <h1>Hello</h1>
        <h3>Contents of "tokenContext" variable for this request:</h3>
        <pre style="display: inline-block; border: 1px solid #5b5b5ba4; padding: 0.5rem; background: #b0b0b067">tokenContext = ${JSON.stringify(tokenContext, null, 2)}</pre>

        <h3>Site Feature toggles to be used while rendering this page:</h3>
        <ul>
          <li>Skip rendering Advertisements: ${state(tokenContext.ADS_OFF)}</li>
          <li>Skip rendering Cookie Consent Dialog: ${state(tokenContext.COOKIE_CONSENT_OFF)}</li>
          <li>Skip rendering Marketing Dialog: ${state(tokenContext.MARKETING_DIALOG_OFF)}</li>
          <li>Remove Content Paywall: ${state(tokenContext.CONTENT_PAYWALL_OFF)}</li>
          <li>Provide SaaS Access to Basic Subscription Plan: ${state(tokenContext.SUBSCRIPTION_ACCESS_ON)}</li>
        </ul>
      </body>
    </html>
  `;

  reply.type("text/html").send(template);
});

app.get("/json", async (request) => {
  // Return JSON response with tokenContext for API usage
  return {
    message: "OK",
    tokenContext: request.tokenContext,
  };
});

// -----------------------------------------------------------------------------
// Start Fastify server
// -----------------------------------------------------------------------------
app.listen({ port: 3000 }, () => {
  console.log(`Fastify server listening at port 3000
    · HTML template example:        http://localhost:3000
    · Plain JSON endpoint example:  http://localhost:3000/json`);
});

Example Use​

Example Use