What you can build
- A marketplace with on-chain escrow. Lock a buyer’s funds in a contract while a seller delivers, then capture them minus your fee.
- A payroll or payables platform. Collect from an employer, pay contractors to their own bank accounts in their own currencies.
- An embedded payments account. Give each of your customers payment details in their own company name, a balance, a statement and outgoing payments, under your brand.
How it works
You hold one HEVN account — your integrator account — and it creates and controls other HEVN accounts, one per customer. Those are your clients. Each client is a real account: it has a legal identity you submit for review once, rails that produce requisites in its own name, a balance, and a ledger. Every client balance is a stablecoin balance on that client’s own Base smart wallet. Fiat arriving over a rail is converted by a partner bank and settles into that wallet; fiat leaving is the same journey in reverse. See How money moves. Your backend authenticates with a developer key — a P-256 keypair whose private half never leaves your server. You register its public half once, together with the source IPs it may be used from, and the session it mints reaches this API and nothing else. The same key authorizes money movement: HEVN builds each payment, echoes its exact terms, you check them and sign, HEVN executes. Nothing is ever constructed by you, and nothing moves without your signature. See Developer key and Signing. A client becomes usable by passing four gates in order — created, verification document complete, application approved, rail active. After that, one payment is two calls:POST /dapi/v1/payouts
books and prices it, POST /dapi/v1/payouts/{payoutId}/confirm signs it.
Every route on these pages sits under https://api.hevn.finance/dapi/v1, or
https://sandbox-api.hevn.finance/dapi/v1 in the sandbox. The spec is served by the API itself:
browse it at /dapi/v1/docs and fetch the schema
from /dapi/v1/openapi.json.
What you get from HEVN, and what you keep
Two things HEVN switches on for you rather than the API: your integrator account itself, and the
permission to create clients. Both are a conversation, in the sandbox as in production — see
Going live.
Where to start
Quickstart
Nine steps in the sandbox: a client company that holds testnet USDC and has sent some of it out, signed by your key.
How money moves
One diagram and five rules: where a balance lives, who converts fiat, what is never instant.
Accounts and control
Who can move a client’s money, what HEVN cannot do alone, and what happens if your key leaks.