DataSag guides · Updated 27 October 2026

Track custom events on Next.js App Router

Use data-datasag-goal for a click goal, or call window.datasag.track after a completed action. Choose a stable event name and distinguish a click from a successful conversion. This guide applies to Next.js App Router.

Start with the Next.js App Router installation

Import Script from next/script in your root layout. Render the DataSag Script once inside body so it persists across child routes. Keep the existing html, body, providers and children in place. Use strategy="afterInteractive" and replace YOUR_PUBLIC_KEY with the public key copied from your DataSag project.

A Script in a page component or nested layout may disappear or be reintroduced as the route tree changes. Put the single shared installation in the root layout. Browser-only event calls belong in client components, never in a Server Component render.

Use the public project key from the DataSag project you are inspecting. A test on a preview domain does not confirm that the production domain has the same code or settings.

Track custom events in Next.js App Router

  1. Identify the client component that owns the successful action. Add the event after the signup or form request confirms success, not in the Server Component that renders the page or in a rendering expression.
  2. Type the optional window.datasag API in a browser helper or Window declaration. Keep the root next/script installation separate. If tracking has not loaded, decide how your action handler handles that state instead of hiding TypeScript errors.
  3. Test an accepted form submission and a rejected one from the published route. Inspect the named event payload. Revisit the page through Next.js navigation and repeat to catch listeners that accidentally accumulate across component mounts.

The client success handler emits the agreed event once, while failed submissions and component renders do not.

Complete the collection checks

  1. Write the event definition first. For example, signup_click means a visitor pressed a signup link, while signup_completed means your application confirmed account creation.
  2. For click intent, add data-datasag-goal to the element. The tracker delegates clicks, so you do not also need a JavaScript handler for the same goal.
  3. For a completed action, call the JavaScript API in the success handler. Wait for the tracker to be available. An optional guard avoids a crash but intentionally drops the event if the tracker has not loaded.
  4. Send only the context needed for the report, such as a form or plan name. Do not include email addresses, passwords, payment details or freeform form contents.
  5. Complete one successful and one failed attempt. Inspect /api/track for the exact eventName and properties. Only the successful attempt should emit a completed-action event.
  6. Check the event report available to your plan. Collection and access to reports are separate; review current plan details before depending on a particular report.
<!-- Click intent: use this OR your own click handler -->
<a href="/signup" data-datasag-goal="signup_click">Create account</a>

// JavaScript: inside the confirmed-success handler
window.datasag?.track('signup_completed', { form: 'main_signup' });

Call the event in the successful client-side action handler. In TypeScript, add an optional Window.datasag type or access the API from a typed helper; do not silence all type errors.

What a successful check looks like

A controlled successful action produces one event with the agreed name. A validation failure does not emit a success event. Network evidence matches the report definition.

Record the public path you tested, the browser state, the approximate time and the observed request. Check one direct page load and one later navigation so the result covers more than the homepage.

Common mistake

A goal attribute on a submit button measures clicks, including attempts that fail. Do not report those clicks as completed signups or purchases.

Installation snippet for Next.js App Router

The shared installation belongs in app/layout.tsx, inside the root body. Use this as the installation reference while checking the procedure above.

import Script from "next/script";

// Inside the existing root layout body, alongside {children}:
<Script
  id="datasag"
  src="https://www.datasag.com/tracker.js"
  data-datasag-key="YOUR_PUBLIC_KEY"
  strategy="afterInteractive"
/>

Related Next.js App Router guides

Full Next.js App Router setup guide · Search and AI visibility

References

Official Next.js App Router documentation covers the integration point. For DataSag data handling, read the privacy policy. Use support if a request fails after these checks.