Developers · SDK

@usdctofiat/offramp adds a USDC off-ramp in one function call.

The SDK is the fast path to selling USDC from your own app. One call validates input, approves USDC, registers the seller, creates the deposit on Base, and delegates pricing. It targets Base mainnet and is permissionless for deposit creation.

Install from npmClone a starter
01

Install and create a deposit

  1. 01Install the package: bun add @usdctofiat/offramp (npm and pnpm work too).
  2. 02Pass a viem WalletClient: the user's wallet, a server wallet, or a bot wallet.
  3. 03Call offramp(walletClient, { amount, platform, currency, identifier }).
  4. 04Read the returned depositId and txHash, or scaffold a project with npx create-offramp-app@latest.
02

The SDK surface

ExportWhat it does
offramp(walletClient, params)One-call sell-USDC flow returning { depositId, txHash, resumed, otcLink? }
deposits(address)List deposits for an address without indexing protocol state
close(walletClient, depositId)Withdraw unfilled USDC from an existing deposit
enableOtc / disableOtc / getOtcLinkManage private one-buyer restriction on a deposit
useOfframp() / usePeerExtensionRegistration()React hooks from @usdctofiat/offramp/react
PLATFORMS, CURRENCIESTyped const maps with identifiers, validation, and currency lists
03

Resumable by design

Creating a deposit spans several onchain steps. If a previous call left a deposit mid-flight, calling offramp() again picks up where it left off rather than creating a duplicate. The result's resumed flag is true when an existing undelegated deposit was adopted instead of created.

That makes the SDK safe to retry from a server or bot: an idempotency-friendly entry point that reconciles against onchain state instead of assuming a clean slate.

04

Error handling

ConcernHow the SDK signals it
Typed errorsOfframpError carries a code from OFFRAMP_ERROR_CODES
PayPal or Wise setupEXTENSION_REGISTRATION_REQUIRED signals technical setup only; enforce provider policy separately
ValidationPLATFORMS and CURRENCIES expose identifier and currency validation
No key custodyThe SDK signs with your WalletClient and never stores private keys
05

Where to go next

Starter templates

Next.js, Vite, and Telegram-bot starters plus runnable scripts.

Peerlytics API

Fetch route, orderbook, deposit, and intent context.

Private OTC in code

Restrict a deposit to one approved buyer wallet and share a link.

Keep exploring

Peerlytics APIDeveloper hub

Common questions

Is @usdctofiat/offramp free?

Yes. The SDK is free to install and integrate, and creating deposits needs no API key because your wallet signs. Peerlytics analytics and API credits are available separately through Peerlytics.

Does the SDK custody keys or move fiat?

No to both. It signs with the viem WalletClient you provide and never holds private keys. Fiat moves directly between buyer and seller on the chosen payment app; the SDK only handles the onchain USDC and deposit lifecycle.

How do I test an integration?

There is no public sandbox; the SDK targets Base mainnet, so a test deposit is real and discoverable on the open orderbook. Use the 1 USDC minimum and either restrict it as an OTC deposit (pass otcTaker so only your wallet can fill it) or close() it quickly. Confirm onchain and via deposits().