Add CLItrail to Preact

Where the CLItrail tag goes in Preact, in its own idiom, with the consent, CSP and client-side routing details and how to check it works.

Written for Preact 10 with Vite (@preact/preset-vite) and preact-iso 2

#Where the tag goes

Edit index.html. Put the tag on every page that shows your install command; site-wide is best, after your existing analytics tags.

<!doctype html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <script defer src="https://YOUR_SERVICE/browser.js" data-website="YOUR_WEBSITE_ID"></script>
  </head>
  <body>
    <!-- …your app's root element and module script -->
  </body>
</html>

Use the loader in place of the tag: nothing from CLItrail loads until startClitrail() runs. Load the loader before your consent manager's script and call startClitrail() from the manager's accept callback (most managers also run it on later visits once a choice is stored; check yours). Use the marketing category when installs go to Google Ads, Meta, TikTok or X Ads, and the analytics category when they only reach GA4 or your webhooks.

Consent loader

// Loads CLItrail only after the visitor agrees. Call startClitrail() from your
// consent manager's "accepted" callback; nothing is fetched or stored before that.
window.startClitrail = () => {
  if (document.getElementById('clitrail')) return;
  const tag = document.createElement('script');
  tag.id = 'clitrail';
  tag.src = 'https://YOUR_SERVICE/browser.js';
  tag.dataset.website = 'YOUR_WEBSITE_ID';
  document.head.append(tag);
};

<head>
  <meta charset="utf-8" />
  <!-- …your analytics tags first -->
  <script defer src="/clitrail-consent.js"></script>
</head>

#Client-side routing

preact-iso changes pages without a reload. Render <ClitrailRoutes /> once inside <LocationProvider>: it records a visit each time the path changes.

Route helper

// Records a visit when client-side navigation opens a new page path. The tag records
// the page the browser loaded, so that page is never recorded twice; before the SDK has
// started (for example, before consent) it records nothing.
declare global {
  interface Window {
    InstallAttribution?: { init(options: { service: string; project: string }): Promise<unknown>; ready?: Promise<unknown> };
  }
}

let recorded: string | undefined;

export function recordVisit(): void {
  if (typeof window === 'undefined') return;
  recorded ??= new URL(performance.getEntriesByType('navigation')[0]?.name ?? location.href).pathname;
  const sdk = window.InstallAttribution;
  if (!sdk?.ready || location.pathname === recorded) return;
  recorded = location.pathname;
  sdk.ready = sdk.init({ service: 'https://YOUR_SERVICE', project: 'YOUR_WEBSITE_ID' });
}

import { useEffect } from 'preact/hooks';
import { useLocation } from 'preact-iso';
import { recordVisit } from './clitrail';

// Render once inside <LocationProvider>: records a visit whenever the path changes.
export function ClitrailRoutes() {
  const { path } = useLocation();
  useEffect(() => { recordVisit(); }, [path]);
  return null;
}

#Content Security Policy

Your host's header settings (for example _headers on Cloudflare Pages or Netlify, vercel.json, or your server), or a <meta http-equiv="Content-Security-Policy"> tag: add https://YOUR_SERVICE to script-src and connect-src, and blob: to worker-src (only Safari before 26 needs that one).

script-src 'self' https://YOUR_SERVICE;
connect-src 'self' https://YOUR_SERVICE;
worker-src 'self' blob:;

#Verify it works

Run npm run dev or deploy.
Open a page with the tag in Chrome or Firefox (accept analytics first if you gate CLItrail on consent), open the developer console and run await InstallAttribution.ready. It resolves to { ok: true, urlId, hasAnalyticsContext, expiresAt }.
In the CLItrail dashboard, open Visits & identities: the visit is listed.
Anything else names the cause: disabled (no consent yet, or data-enabled="false"), opfs_unavailable (the page is not served over https or from localhost), Error (the service refused the visit: add the page's origin, including a development origin such as http://localhost:3000, under Settings → Additional domains). If InstallAttribution is undefined, the tag did not load: check the Network tab and your Content-Security-Policy.

Then run your installer on the same computer and check Install events, or run the hook with --doctor.

#Notes

With preact-router instead of preact-iso, call recordVisit() from the Router's onChange.

Preact documentation: preactjs.com/guide/v10/preact-iso

Using other install paths or destinations? The setup generator puts this snippet together with your hooks and destination checklist.