PostHog

posthog() from consentlayer/providers/posthog sends page views, events and errors to PostHog. It is built on PostHog’s npm SDK, posthog-js, an optional peer dependency:

pnpm add posthog-js

import { posthog } from 'consentlayer/providers/posthog'

posthog({ apiKey: process.env.NEXT_PUBLIC_POSTHOG_KEY })

The SDK is imported with a dynamic import() when the provider loads, and session recording, which pulls in more code, is off by default and imported only once enabled and consented to.

Options

Option	Type	Default	Description
`apiKey`	`string \| undefined`	Required	The project API key.
`apiHost`	`string`	`'https://us.i.posthog.com'`	The ingestion host, or a reverse-proxy path.
`uiHost`	`string`	None	PostHog’s app URL, such as `https://us.posthog.com`, for toolbar links when `apiHost` is a proxy.
`cookieless`	`boolean`	`true`	`true` loads PostHog at boot in cookieless mode (`cookieless_mode: 'on_reject'`). `false` makes the provider require analytics consent and load nothing before it.
`autocapture`	`boolean`	`false`	PostHog autocapture.
`recording`	`boolean`	`false`	Session recording, started after analytics consent. Imports `posthog-js/dist/posthog-recorder` on first use. Recording must also be enabled in the PostHog project settings.
`errors`	`boolean`	`true`	Sends `captureError` errors to PostHog error tracking with `captureException`.
`groupType`	`string`	`'company'`	The group type `analytics.group()` uses.
`defer`	`false \| 'idle' \| 'interaction' \| number`	`false`	See Loading SDKs later.
`events`	`string[] \| false`	All events	The event names `track()` sends to it; `false` sends none. See Routing events.

How it works

PostHog never captures page views, page leaves, exceptions, heatmaps or dead clicks on its own, and its feature flags, surveys and remote script loading are disabled: page views, events and errors come from ConsentLayer. It starts opted out of capturing and persistence. With the default cookieless: true, PostHog counts visitors in its cookieless mode until analytics consent is granted, then opts in and uses cookies; this requires cookieless mode to be enabled in the PostHog project settings. identify and group are sent only with analytics consent.

Page views are captured as $pageview with $current_url and title. track captures the event name with its params merged with options.providers.posthog. identify sends the user ID, with the email as a person property when it is known. reset calls PostHog’s reset() and re-applies the current consent.

Reverse proxy

Ad blockers drop requests to posthog.com. Serving them through your own domain avoids this.

Add the rewrites from PostHog’s guide, then set apiHost to the proxy path and uiHost to PostHog’s app URL. For an EU project, replace us with eu in every host.

export default {
  skipTrailingSlashRedirect: true,
  async rewrites() {
    return [
      { source: '/ingest/static/:path*', destination: 'https://us-assets.i.posthog.com/static/:path*' },
      { source: '/ingest/array/:path*', destination: 'https://us-assets.i.posthog.com/array/:path*' },
      { source: '/ingest/:path*', destination: 'https://us.i.posthog.com/:path*' },
    ]
  },
}

posthog({ apiKey, apiHost: '/ingest', uiHost: 'https://us.posthog.com' })