Connect Customer.io in GrowSurf before you import participants

In GrowSurf, open the Customer.io integration card, enter your Customer.io Site ID and Tracking API key, then save the connection. GrowSurf's docs and the current app both show this as the required setup.

Confirm the sync is live

Once connected, GrowSurf adds or updates Customer.io people whenever participants are added or referred. If you already imported people before connecting, use the documented export-and-import backfill flow so those records receive the GrowSurf attributes too.

Add the participant's share link to the main call to action

The most important personalized value is the participant's own referral link. In Customer.io email content, use {{customer.grsf_share_url}} anywhere the reader needs a one-click way to share, copy, or reopen the referral experience.

Support the CTA with live referral context

• Use {{customer.grsf_referral_status}} when you want the message to reflect whether a referral is still pending or has been awarded.
• Use {{customer.grsf_total_referral_count}} to differentiate first-time sharers from proven advocates.
• Use {{customer.grsf_next_milestone}} when you want the email to remind people what reward they are closest to earning.

Preview the message against a real synced person

Before sending, preview or test the email with a Customer.io person whose referral state you can verify in GrowSurf. That makes it easy to catch missing attributes, stale backfills, or broken CTA links before the campaign goes live.