prerender-hapi

Hapi plugin for Prerender.io. Intercepts requests from bots and crawlers and serves prerendered HTML, so your JavaScript-rendered app is fully indexable by search engines and social media scrapers.

Compatible with @hapi/hapi v21+ and Node.js 18+.

Installation

npm install prerender-hapi

Usage

const Hapi = require('@hapi/hapi');

const server = Hapi.server({ host: 'localhost', port: 3000 });

await server.register({
  plugin: require('prerender-hapi'),
  options: {
    token: 'YOUR_PRERENDER_TOKEN'
  }
});

The plugin registers an onRequest extension that transparently proxies bot requests to Prerender.io and returns the prerendered HTML. Regular browser requests are unaffected.

Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | token | string | process.env.PRERENDER_TOKEN | Your Prerender.io token | | serviceUrl | string | process.env.PRERENDER_SERVICE_URL or https://service.prerender.io/ | Prerender service URL (use this for self-hosted Prerender) | | protocol | string | null | Force a protocol (http or https). Defaults to the server's protocol | | beforeRender | async function(request) | async () => null | Called before each prerender request. Return a cached response object { status, headers, body } to skip the Prerender.io call | | afterRender | async function(request, response) | async () => {} | Called after a successful prerender. Use this to cache the response. Can be sync or async |

Environment variables

PRERENDER_TOKEN=your_token_here
PRERENDER_SERVICE_URL=https://service.prerender.io/  # optional

Self-hosted Prerender

await server.register({
  plugin: require('prerender-hapi'),
  options: {
    serviceUrl: 'http://your-prerender-server:3000'
  }
});

Caching example

const cache = new Map();

await server.register({
  plugin: require('prerender-hapi'),
  options: {
    token: 'YOUR_PRERENDER_TOKEN',
    beforeRender: async (request) => {
      return cache.get(request.url.href) || null;
    },
    afterRender: (request, response) => {
      cache.set(request.url.href, response);
    }
  }
});

How it works

Requests are prerendered when all of the following are true:

• The HTTP method is GET
• The User-Agent matches a known bot/crawler (Googlebot, Bingbot, Twitterbot, GPTBot, ClaudeBot, etc.)
  — OR the URL contains _escaped_fragment_
  — OR the X-Bufferbot header is present
• The URL does not end with a static asset extension (.js, .css, .png, .woff2, .webp, etc.) — matched case-insensitively

Everything else passes through to your normal route handlers.

License

MIT