App Kit SDK: Onramp

The App Kit SDK includes the Onramp capability, an embeddable widget that lets your users buy USDC or EURC on Arc with fiat. The widget is hosted on Arc and handles KYC, payment processing, and settlement. You can try the live widget at https://onramp-demo.arc.io/. For local development and testing, use the sandbox environment.

Onramp requires an API key to integrate. Certain payment methods are only available to end users after completing KYB.

How it works

Your server creates a session for a specific user and destination wallet, then your client mounts the Onramp widget with that session. Sessions are valid for 30 minutes. The widget walks the user through the purchase, then delivers the crypto to the wallet address you specified. Lifecycle events flow back to your page so you can update your UI.

Supported payment methods and countries

Debit card, Apple Pay, and Google Pay are available for USDC and EURC on Arc in the US, UK, select EU countries, and other countries worldwide. Enabling these methods requires completing KYB in the Circle Console. Bank transfer is available for USDC on Arc in select US states and select EU countries. Credit cards aren’t supported.

API key

Onramp requires a Circle API key to authenticate your server. Obtain one from the Circle Console and keep it server-side only, since it grants full access to your Onramp integration. Pass it as apiKey in your Onramp config. API keys are environment specific. Sandbox and production each need their own key.

Quick look

This example fetches a session from your backend and mounts the Onramp widget inline:

TypeScript

// Fetch a session minted on your server
const session = await kit.onramp.fetchSession({
  url: "/api/onramp/sessions",
  body: {
    appUserId: "user-123",
    destinationAddress: "USER_WALLET_ADDRESS",
  },
});

// Mount the widget inline
const widget = kit.onramp.mountIframe({
  session,
  container: document.getElementById("onramp-root")!,
  onDepositSettled: ({ payload }) => console.log("settled", payload),
});

Onramp also requires a session route on your server. Follow the quickstart for the end-to-end flow.

Installation

Install the App Kit SDK to use Onramp. If you only need Onramp and don’t want to install the full App Kit SDK, install the standalone Onramp Kit.

npm install @circle-fin/onramp-kit

yarn add @circle-fin/onramp-kit

Onramp does not require a wallet adapter. The Onramp widget handles payment and delivery to the destination wallet.

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App Kit SDK: Onramp

How it works

Supported payment methods and countries

API key

Quick look

Installation

​How it works

​Supported payment methods and countries

​API key

​Quick look

​Installation

How it works

Supported payment methods and countries

API key

Quick look

Installation