Segment Integration

Send Featureflow flag exposures through Segment as Experiment Viewed events — Segment's A/B Testing spec — and every destination connected to your Segment source receives them in the shape it already understands. One integration, many tools. See A/B testing with your analytics tool for the whole loop.

Setup

The A/B Testing spec defines one event, Experiment Viewed, with four string properties: experiment_id, experiment_name, variation_id and variation_name. A Featureflow flag key serves as both experiment id and name, and a variant key as both variation id and name:

import Featureflow, { exposureIntegration } from 'featureflow-client';
import { AnalyticsBrowser } from '@segment/analytics-next';

const analytics = AnalyticsBrowser.load({ writeKey: 'YOUR-SEGMENT-WRITE-KEY' });

const featureflow = await Featureflow.init('your-js-client-key', {
  integrations: [
    exposureIntegration(({ key, variant }) => {
      analytics.track('Experiment Viewed', {
        experiment_id: key,
        experiment_name: key,
        variation_id: variant,
        variation_name: variant
      });
    })
  ]
});

Exposures go through your Segment instance, so they carry your Segment userId / anonymousId — no user-id mapping needed — and are deduplicated per user, flag and variant for the page's lifetime, so calling evaluate() on every render will not inflate your Segment volume.

Segment every downstream report by variant

To slice reports by variant in destinations that support user traits, also set a trait:

exposureIntegration(({ key, variant }) => {
  analytics.track('Experiment Viewed', { experiment_id: key, experiment_name: key, variation_id: variant, variation_name: variant });
  analytics.identify({ [`featureflow_${key}`]: variant });
})

Send only the flags you're experimenting with

exposureIntegration(send, { flags: ['checkout-v2', 'pricing-test'] })
// or a naming convention
exposureIntegration(send, { flags: (key) => key.startsWith('exp-') })

In your destinations

Destinations that implement the A/B Testing spec map Experiment Viewed to their own experiment event automatically — for example Amplitude, Mixpanel and others listed on the spec page. For a destination without a mapping, the event still arrives as a normal track call you can chart.

Notes

• If you use Segment and one of the tools with a direct recipe (Amplitude, Mixpanel, PostHog), pick one path per tool so exposures are not sent twice.
• Available from featureflow-client 2.6.0 / react-featureflow-client 2.6.0. On older versions, listen to the raw EVALUATION event and dedupe yourself.
• Server-side, the Node SDK emits a raw evaluation event you can forward with @segment/analytics-node using your own userId — see the Node SDK README.

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Any problems? Reach us via the in-app chat or at support@featureflow.io.