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FAQ

How do I know when an invoice is paid?

You know an invoice is paid when halfin sends you the invoice.paid webhook and you have verified its signature. halfin watches the chain for you: as soon as a deposit appears it emits invoice.confirming, and once on-chain confirmations clear the per-chain threshold it emits invoice.paid. The webhook is the source of truth — not the customer returning to your site, and not a poll you happen to make at the right moment. If the amount misses the target you instead receive invoice.underpaid or invoice.overpaid, so every outcome is reported explicitly.

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halfin FAQ — how crypto payments work end to endHow halfin invoicing, checkout, deposit addresses, payouts, conversion, and webhooks work. Browse every question or read the cross-cutting answers.What is the redirect_url on an invoice?redirect_url is the hosted halfin payment page you send the customer to. It is a destination, not proof of payment — the invoice.paid webhook is the source of truth.What happens if an invoice is underpaid?When a customer sends too little, halfin records the shortfall and fires an invoice.underpaid webhook. You decide: top-up, partial settle, or refund.Are API keys scoped?Yes. A halfin API key carries only the permissions you grant it, scoped to the operations it needs — a read or invoice key cannot release payouts.Are API requests rate limited?Yes. Public auth endpoints are rate limited per IP and authenticated API-key requests are limited too. Design clients to back off and retry idempotently.Are crypto payments final?Yes — a confirmed on-chain transfer is irreversible and there are no chargebacks. Finality is a property of the chain, which is what makes reconciliation clean.Are there chargebacks with crypto payments?No. A confirmed on-chain payment is final, so there are no card-style forced reversals. A refund is a deliberate action you choose to issue.Are there monthly or setup fees?halfin's commercial pricing is not published on this site yet, so there is no monthly or setup figure to quote here. Building in the sandbox is free.Assets and networks questionsFrequently asked questions drawn from the halfin assets and networks pages. Each one links to a standalone answer.Can a customer pay an invoice late?A deposit that lands after a halfin invoice expires fires invoice.late_deposit — the funds are credited and matched to the invoice, and you decide how to treat the order.Can a customer reuse the same deposit address?Yes. A halfin static deposit address is persistent, so repeat deposits to the same address credit the same customer — no new invoice or address per top-up.Can I auto-convert incoming payments to a stablecoin?Yes. halfin balance conversion can run automatically toward a target asset such as a stablecoin, so incoming payments settle in one currency on credit.