Glossary

Crypto payments borrow vocabulary from two worlds at once — card processing and public blockchains — and the two do not always mean the same thing by the same word. This glossary defines the terms the way halfin uses them, so that when a webhook fires, an invoice goes underpaid, or a deposit waits on confirmations, you know exactly what is being described. Each definition is a general, technically correct explanation first, then a note on what it means in a crypto-payment context.

How to read these definitions

Every term page follows the same shape: a precise definition that would be correct anywhere in crypto or payments, followed by what the term means specifically when you are taking money in or sending it out through halfin. The aim is that you can hand any one of these pages to a teammate who has never touched a blockchain and they will understand both the concept and why it matters to your integration.

Where a term has a narrow technical meaning that differs from casual usage, the definition says so plainly. "Confirmations" is a count of blocks, not a vague sense of certainty. A "stablecoin" is a token, not the network it runs on. An "underpaid" invoice is a specific recorded state with an exact shortfall, not a failure. Getting these distinctions right is the difference between an integration that reconciles cleanly and one that drifts.

How the terms group together

Most of the vocabulary clusters around the two halves of a payment — money coming in and money going out — plus the settlement mechanics that sit underneath both and the integration surface you build against. Reading by cluster is usually faster than reading alphabetically.

Why these definitions are worth pinning down

A crypto payment crosses systems that each define correctness differently. The chain decides when a transaction is final; halfin decides when an invoice is paid; your backend decides when an order ships. If your team's mental model of a word like "confirmed" or "settled" does not match what the platform actually does, the gap surfaces as a reconciliation problem weeks later — an order fulfilled before a transaction held, or a balance that does not tie out.

Precise shared vocabulary is the cheapest way to avoid that. When everyone — finance, support, and engineering — means the same thing by "overpaid" or "reorg," the edge cases stay edge cases instead of becoming incidents. Start with the terms below, or jump straight into a definition from the list.

• Stablecoin — a token designed to track the value of a fiat currency, and the most common asset merchants choose to settle in.
• Webhook — the HMAC-signed event halfin sends your backend when something changes, which you verify before acting on it.
• Rate lock — the moment an invoice's exchange rate is fixed, so the fiat figure you booked is the one you reconcile.