For exact attribution, pass the visitor id (
window.trk.vid) at checkout for every processor —
the exact field differs per provider and is listed below and in
Pass the visitor id to checkout.- Paddle
- Polar
- Lemon Squeezy
- Creem
- Dodo Payments
Paddle (Billing)
- Credential: a single API key (
pdl_live_…), created at your Paddle dashboard → Authentication. - Permissions to enable: Customer (Read), Product (Read), Subscription (Read), Transaction (Read), Discount (Read). Choose Never expires.
- What’s pulled: completed transactions since the last sync.
- Visitor id field:
custom_data.vid(via Paddle.jscustomData: { vid }). - Coupons: resolved from the transaction’s discount code — useful for crediting an affiliate on a Paddle discount.

