Referral Fraud Protection for API Sign-ups

Waitlister's referral fraud protection now extends to API sign-ups. If you use the API to add subscribers, you can forward end-user signals so fraud detection works the same way it does for landing pages and forms.

What's New

Two new optional metadata fields on the Add Subscriber endpoint:

• metadata.client_ip — The end user's real IP address
• metadata.fingerprint — A client-side device fingerprint

When either field is provided, Waitlister applies the full fraud detection pipeline to referral sign-ups. When neither is provided, API sign-ups continue to work exactly as before.

Example

{
  "email": "[email protected]",
  "metadata": {
    "referred_by": "happy-star-4f3d",
    "client_ip": "203.0.113.42",
    "fingerprint": "abc123def456"
  }
}

Good to Know

• Only relevant when the sign-up includes a referred_by referral code — non-referral sign-ups are unaffected
• The client_ip is also used for IP geolocation enrichment, so your subscriber records show the end user's location instead of your server's
• Fraud protection level is controlled from your waitlist's Settings page

See the Add Subscriber documentation and Referral Program documentation for full details.