---
title: Next.js consent and scripts
description: Register scripts in the Next.js c15t.config.ts used by the router guides.
group: frameworks
lastModified: "2026-10-10T14:59:21+01:00"
lastAuthor: Kaylee
---
## Register scripts in c15t.config.ts

The [runnable Next.js example](/docs/examples) loads PostHog under the
measurement category. Replace the placeholder `phc_your_project_key` with your
project key, or replace the helper with the
[integration](/docs/integrations/overview) your application uses. Include the
measurement category in your policy.

Put the scripts in `c15t.config.ts`, next to `next.config.ts`:

```ts title="c15t.config.ts"
import { posthog } from '@c15t/integrations/posthog';
import { defineConsentConfig } from 'c15t/next';

export default defineConsentConfig({
	scripts: [
		posthog({
			id: 'phc_your_project_key',
			initOptions: { cookieless_mode: 'never' },
			loadMode: 'after-consent',
		}),
	],
});
```

PostHog waits for measurement consent here. `cookieless_mode: 'never'` disables
cookieless capture after rejection. Remove any existing PostHog loader,
including `next/script` and tag-manager entries, so the integration loads once.

`withConsentManifest` in `next.config.ts` finds the file, and `ConsentRoot`
reads its `scripts` in the browser, so a Server Component layout renders
`ConsentRoot` without passing them. The file is bundled into the browser as
well as the server, so it must hold no secrets.

`scripts`, `vendors`, `clearOnRevocation`, `networkBlocker`, `persistence`,
`scriptLoader` and `options` can also be passed to `ConsentRoot` as props,
which win over the config. Functions can't cross from a Server Component to a
Client Component, so pass them as props only from a `'use client'` file.