What is a referral fee (affiliate fee)?

A referral fee is an on-chain commission paid to whoever brings trading volume to a protocol. When a user swaps through your link or embedded widget, the protocol's contract attributes that volume to you and sets aside a share of the fee it would have collected anyway. It is the DeFi equivalent of affiliate marketing, except the accounting and payout happen transparently on the blockchain rather than through a company's books.

Because settlement is on-chain and non-custodial, you are not trusting a platform to track and pay you later — the entitlement is recorded by the contract and you claim it yourself. That removes the usual affiliate risks of opaque dashboards, clawbacks, and delayed payouts. The trade itself is unaffected: the user still swaps at a routed price, and the referral share comes out of the protocol’s own fee rather than as an extra charge bolted on top.

Sally pays referral fees on both swap and liquidity volume routed through your widget or link on Base and BNB Smart Chain, and you collect what you have earned directly on-chain. Pairing the embeddable widget with referral attribution means a site can offer real trading to its audience and be compensated for the volume it generates, all without holding user funds.