Product design under non-custodial constraints: what subscriptions, refunds, and splits can each become, and why.
When a customer upgrades mid-cycle, someone calculates the credit for unused time — and everywhere else, you just trust that number. On Finality, the backend proposes the proration and the on-chain program recomputes it independently; if they disagree, the transaction fails. The story of why we put our own arithmetic in a cage.
Every payment platform promises fast detection and reliable settlement. Whether they can keep that promise depends on infrastructure most never mention: whose nodes are watching the chain. Why Finality runs its own on all five chains — the speed reason, the dependency reason, and the privacy reason.
Blockchains have no pull payments — every transfer needs the holder's signature, now. The industry's answer was reminder emails dressed as subscriptions. The story of the three design decisions that made automatic recurring billing real without custody: terms that live in the address, a keeper that can trigger but not decide, and an exit that's always open.
In Finality's affiliate system, commissions split out of the customer's payment transaction and land directly in the affiliate's wallet — the merchant physically cannot hold, delay, or forget them. Why we designed the money to route around our own customers, and why merchants thank us for it.
Closing a subscription vault on Finality returns everything in one transaction: the unused balance, and the few cents of blockchain rent nobody else bothers to give back. The story of a small product decision that defines what non-custodial actually means.
Subscriptions assume a merchant can charge a customer later. Blockchains have no such primitive. Here is the design that makes recurring billing work without custody.