Quick start: Next.js (App Router)

npm install @gauge/support
# .env.local (server only: no NEXT_PUBLIC_ prefix, so none of these reach the browser)
GAUGE_APP_ID=<app id>
GAUGE_IDENTITY_SECRET=<identity secret>
GAUGE_WEBHOOK_SECRET=<whsec_…>

import { mintIntegrationToken } from '@gauge/support';
import { currentUser } from '@/lib/auth';

export const dynamic = 'force-dynamic';

export async function GET() {
  const user = await currentUser();
  if (!user) return Response.json({ error: 'sign in first' }, { status: 401 });
  const token = await mintIntegrationToken(process.env.GAUGE_IDENTITY_SECRET, {
    appId: process.env.GAUGE_APP_ID,
    userId: String(user.id),
    integration: 'customer',
    name: user.name,
    email: user.email,
  });
  return Response.json({ token }, { headers: { 'cache-control': 'no-store' } });
}

<script src="https://widget.gauge.chat/v1/<version>/widget.js"
  integrity="sha384-<integrity>" crossorigin="anonymous" async></script>
<script>
  window.addEventListener('load', function () {
    window.PulseWebchat.init({
      apiUrl: 'https://app.gauge.chat/backend',
      connectionId: '<chat connection id>',
      supportMode: true,
      integration: 'customer',
      getToken: function () { // called on every open, so the token is always fresh
        return fetch('/gauge-token', { credentials: 'include' })
          .then(function (r) { return r.json(); })
          .then(function (j) { return j.token; });
      },
    });
  });
</script>

import { verifyWebhook } from '@gauge/support';

const handled = new Set(); // use your database in production: ids repeat on retries and resends

export async function POST(request) {
  const raw = await request.text();
  const result = await verifyWebhook(process.env.GAUGE_WEBHOOK_SECRET, raw, request.headers);
  if (!result.valid) return new Response(result.reason, { status: 400 });
  const event = result.event;
  if (!handled.has(event.id)) {
    handled.add(event.id);
    console.info('gauge', event.event, event.id, event.livemode ? 'live' : 'sandbox');
  }
  return new Response(null, { status: 200 });
}