When users click referral links, they land on your website first. Capture the referral code (ucc) on this landing page to properly attribute future conversions. Follow these steps to set up referral code capture:

​
Step 1: Set up your landing page

Create a landing page for referral traffic. Choose one approach:
  • Dedicated referral landing page
  • Home page with Cello New User Banner
See the landing page optimization guide for best practices.

​
Step 2: Install attribution script

The attribution script detects the ucc query parameter and stores it as a first-party cookie for later attribution of conversion events. Install the Cello attribution script - Attribution JS - using one of these methods:

Embedded Script Tag

Google Tag Manager

The attribution script also enables you to: See the Attribution JS reference for complete details.

​
Step 3: Verify installation

Verify that the ucc is available on your signup page:
  1. Test your website with these query parameters: 
    https://yourwebsite.com/?productId=test&ucc=test
  2. Verify these values are saved as cookies: cello-product-id and cello-referral
  3. On your signup page, test ucc access from the browser console: 
    window.CelloAttribution('getUcc')
    Expected response: 
    Promise {<fulfilled>: 'test'}
If this test passes, the script is installed correctly.
Using referral codes at signupUse getUcc() during user signup to retrieve the referral code, then pass it in the signup event to Cello.For complex flows, save the ucc with your user record so it’s available when sending signup events.