Connect Customer.io in GrowSurf first

In GrowSurf, open the Customer.io integration card, add your Site ID and Tracking API key, then save the connection. This is the supported setup flow in both the GrowSurf docs and the current app UI.

Verify the sync is active before you build segments

After the integration is live, GrowSurf adds or updates Customer.io people whenever participants join or are referred. If you connected late, use the documented export-and-import backfill process so older records receive the same attributes.

Create a data-driven segment from the synced referral fields

In Customer.io, build a segment around the referral state you actually want to message. Common starting points are people whose referral count is still zero, people whose referral status has changed, or people who are close to the next milestone.

• Use {{customer.grsf_referral_status}} when you want the journey to react to pending versus awarded referrals.
• Use {{customer.grsf_total_referral_count}} when you want to distinguish new advocates from repeat referrers.
• Use {{customer.grsf_next_milestone}} when you want the journey to push people toward the next reward.

Attach the segment to the right Customer.io journey

Once the segment is defined, enroll it in a Customer.io journey for the actual outcome you want: first-share nudges, milestone reminders, or reward follow-ups. Customer.io's current docs describe this as a data-driven segment workflow, so you do not need a separate GrowSurf event bridge to start the journey.

Test with a real participant record

Preview the segment and journey against a Customer.io person whose state you can confirm in GrowSurf. That keeps the automation grounded in the same referral data your team already trusts.