Vercel Marketplace integration

The Vercel Marketplace integration adds PostHog to your Vercel projects. There are two ways to set it up:

Add – Creates a new PostHog organization with billing through Vercel
Link Existing Account – Connects an existing PostHog organization. Billing stays with PostHog.

Billing depends on how you install

New accounts created through the Add flow are billed through Vercel. Linked accounts keep their existing PostHog billing. You cannot migrate an existing PostHog organization to Vercel billing.

Installing the integration

Add (new account)

Go to the PostHog integration page on Vercel Marketplace
Click Add

This creates a new PostHog organization and project, and adds environment variables to your Vercel project. Billing goes through your Vercel account.

Link Existing Account

If you already have a PostHog account, you can connect it to Vercel instead:

Go to the PostHog integration page on Vercel Marketplace
Click Link Existing Account
Log in to your PostHog account if prompted
Select the organization you want to link
Click Connect organization

You must have admin or owner access to the PostHog organization to link it. Billing stays with PostHog for linked accounts.

Environment variables

The integration adds these environment variables to your Vercel project:

NEXT_PUBLIC_POSTHOG_KEY - Your project API key, used to initialize the PostHog SDK
NEXT_PUBLIC_POSTHOG_HOST - The PostHog API host URL (either https://us.i.posthog.com or https://eu.i.posthog.com)

These NEXT_PUBLIC_* variable names work automatically in Next.js for both client and server environments. For other frameworks, you may need to copy the values to framework-specific variable names:

Framework	Rename to
Next.js	`NEXT_PUBLIC_POSTHOG_TOKEN`, `NEXT_PUBLIC_POSTHOG_HOST`
Vite/SvelteKit	`VITE_POSTHOG_TOKEN`, `VITE_POSTHOG_HOST`
Nuxt	`NUXT_PUBLIC_POSTHOG_TOKEN`, `NUXT_PUBLIC_POSTHOG_HOST`

Installing the SDK

The fastest way to add PostHog to your application is using our installation wizard. Alternatively, follow your framework's guide:

By default, you'll also get session replay and event autocapture. If you prefer to use feature flags only, you can opt out:

JavaScript
posthog.init('<ph_project_token>', {
  api_host: 'https://us.i.posthog.com',
  autocapture: false,
  disable_session_recording: true
})

Using feature flags

To use feature flags in your application:

JavaScript
if (posthog.isFeatureEnabled('new-checkout')) {
    // Show new checkout
} else {
    // Show old checkout
}

JavaScript
import { useFeatureFlagEnabled } from '@posthog/react'

function App() {
  const showNewCheckout = useFeatureFlagEnabled('new-checkout')

  return showNewCheckout ? <NewCheckout /> : <OldCheckout />
}

For more examples, see our feature flag code guide.

Creating feature flags and experiments

Access the PostHog dashboard from your Vercel project's Integrations tab or directly at app.posthog.com.

Feature flags and experiments you create automatically sync with Vercel's flags dashboard.

For full documentation:

Billing

Billing depends on how you installed the integration:

Add (new account) – Billed through your Vercel account. View usage in Vercel under Integrations → PostHog.
Link Existing Account – Billed through your existing PostHog account. View usage in PostHog billing settings.

See our pricing page for more details.

Limitations

One organization per Vercel team - Cannot link multiple PostHog organizations
Cloud only - No self-hosted support (US or EU regions available)
Region cannot be changed - US or EU is selected during installation
One-way team sync - Vercel team changes sync to PostHog, not vice versa

Vercel Marketplace integration

Contents