PostHog is now available in the Vercel Marketplace as a feature flags, experimentation and Analytics provider.

With this integration, you can now:

• Declare flags in code using Flags SDK and the @flags-sdk/posthog adapter

• Toggle features in real time for specific users or cohorts

• Roll out changes gradually using percentage-based rollouts

• Run A/B tests to validate impact before a full release

This integration helps teams building on Vercel ship with more confidence. You can test in production, reduce release risk, and make data-driven decisions based on real user behavior, all within your existing Vercel workflows.

Create a flags.ts file with an identify function and a flag check:

import { postHogAdapter } from '@flags-sdk/posthog'
import { flag, dedupe } from 'flags/next'
import type { Identify } from 'flags'
export const identify = dedupe(async () => ({
  distinctId: 'user_distinct_id'  // replace with real user ID
})) satisfies Identify<{ distinctId: string }>
export const myFlag = flag({
  key: 'my-flag',
  adapter: postHogAdapter.isFeatureEnabled(),
  identify,
})

Check out the PostHog template to learn more about this integration.