Developers

Add a USDC off-ramp in one function call.

Start with the free SDK: it creates delegated deposits. Add private buyers, lifecycle webhooks, and Peerlytics credits when your product needs market data and webhook operations. A wallet signs; the SDK never holds keys or fiat.

Install the SDKClone a starter
sell-usdc.ts
import { offramp } from "@usdctofiat/offramp";
 
// Sell 100 USDC for USD via Venmo, non-custodial
const deposit = await offramp(wallet, {
  amount: "100",
  platform: "venmo",
  currency: "USD",
  identifier: "@yourhandle",
});

Build paths

Pick the integration shape before choosing code.

Wallet appsReact hooks, user signatures, PayPal/Wise extension recovery, and state reconciliation.App guide Bots and workersServer-wallet deposits, retry discipline, duplicate prevention, and webhook-backed state.Bot guide Coding agentsSkill files, llms.txt, starters, and a prompt path that prevents invented protocol wiring.Agent guide Peerlytics APIOrderbook, analytics, credit-backed API calls, and cross-product webhook management.API guide Verify extensionWise and PayPal setup recovery plus supported browser metadata capture flows.Extension guide

SDK surface

Compact primitives that match the real protocol lifecycle.

offramp()

Create or resume a sell-USDC deposit, delegate pricing, and return depositId + txHash.

deposits()

List deposits for an address when the app needs narrow owner-state reconciliation.

close()

Withdraw unfilled USDC from an existing deposit with the signer wallet.

OTC helpers

Restrict an order to one taker wallet, generate a share link, or remove the restriction.

React hooks

useOfframp() and usePeerExtensionRegistration() for wallet-app frontends.

Typed maps

PLATFORMS, CURRENCIES, validation helpers, and OfframpError codes.

Resource bundle

OFFRAMP_DEVELOPER_RESOURCES and playbooks for apps, bots, agents, OTC, webhooks, and Peerlytics.

What it costs

The SDK is free. A buyer-side fee on delegated fills, and Peerlytics for deeper data.

What you pay to use USDCtoFiat
Sell USDC$0

Create and manage deposits from your own wallet. No platform fee, no custody — keep your spread and pay only Base gas.

Integrate the SDK$0

@usdctofiat/offramp creates deposits with no API key. Deeper Peerlytics analytics, webhooks, and API credits are available through Peerlytics.

Start sellingPeerlytics analytics
The only feeDelegate

0.10%on filled volume

Delegate keeps your rate competitive automatically. Its manager fee is buyer-side: deducted from the USDC USDC released to the buyer on delegated fills — never from your fiat proceeds or your quoted rate.

See Delegate

Delegate is optional. Price and manage your own rate from your wallet at no cost, or build it into your app with the free SDK.

Production flow

Build the shortest path first, then add private orders and observability.

  1. 01Create a delegated deposit from the user wallet or bot wallet with offramp().
  2. 02Use deposits() to reconcile local state after refreshes, retries, or bot restarts.
  3. 03Pass otcTaker when the buyer is known and the order should not be public fillable.
  4. 04Register webhooks through Peerlytics when your product needs asynchronous lifecycle state.
  5. 05Add @peerlytics/sdk when you need orderbook reads, market analytics, and credit-backed API access.

Webhook events

HMAC-signed callbacks for the off-ramp lifecycle.

deposit.createdSeller deposit exists on Base
deposit.partially_filledPart of the deposit has filled
deposit.filledThe deposit has fully filled
deposit.closedSeller withdrew or closed remaining balance
otc.takenPrivate order was taken by the approved buyer

Developer questions

Does the SDK custody keys?

No. The SDK signs with the viem WalletClient you pass: your user's wallet, a server wallet, or a bot wallet. It never holds private keys.

Does the SDK move fiat?

No. Fiat moves directly between the buyer and seller on the chosen payment app. The SDK only handles the onchain USDC and deposit lifecycle.

Do I need an API key to create deposits?

No. Creating deposits is permissionless, since your wallet signs. An API key is only needed to register webhooks and to use the Peerlytics API.

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 own wallet can fill it) or accept that a buyer could take it before you call close(). Confirm it onchain and via deposits(), then close() it.

How are webhooks verified?

Each delivery carries X-Usdctofiat-Signature: t=<unix>,v1=<hex>, an HMAC-SHA256 over timestamp.rawBody. The reference verifier in the starters repo treats timestamps older than 5 minutes as stale to guard against replays; you set that window in your own verifier, the sender does not enforce it.