---
title: Get started in testnet
slug: concepts/onchain-payments/get-started-in-testnet
description: Learn how to test USDC transfers in Cross River's sandbox using Sepolia and Solana testnets, with step-by-step instructions for setup, token acquisition, and transaction verification.
docTags: 
createdAt: 2025-11-23T08:55:46.746Z
---

## Test USDC transfers

Test USDC transfers in the Cross River sandbox environment using supported blockchain test networks. Both Ethereum (Sepolia) and Solana (Devnet) are available for end-to-end testing.

## Prerequisites

- A [registered](docId\:Z-MVwOV-p00-xX082NabK) sandbox account in the Cross River developer environment.
- A **testnet blockchain wallet address** on Ethereum (Sepolia) and or Solana (Devnet).
- **Test USDC tokens** funded through public faucets.

## Get testnet tokens

Test tokens are required to simulate stablecoin payment flows in the sandbox environment. Each blockchain uses separate assets for testing, including **USDC** for payment simulation and **ETH** or **SOL** for network fees.

| Asset    | Network                              | Source                                                                           | Description                                                                                                                                                                              |
| -------- | ------------------------------------ | -------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **USDC** | Ethereum (Sepolia) & Solana (Devnet) | [Circle Faucet](https://faucet.circle.com/)                                      | Provides test **USDC** on both **Sepolia** and **Devnet** networks. Requires a wallet configured for the corresponding test network, such as MetaMask for Sepolia or Phantom for Devnet. |
| **ETH**  | Ethereum (Sepolia)                   | [Google Cloud Faucet](https://cloud.google.com/application/web3/faucet/ethereum) | Provides test **ETH** for Sepolia network fees. Each request grants a limited amount for development use.                                                                                |
| **SOL**  | Solana (Devnet)                      | [Solana Faucet](https://faucet.solana.com/)                                      | Provides test **SOL** for Solana Devnet network fees. Requires a Solana compatible wallet.                                                                                               |

:::hint{type="warning"}
**IMPORTANT**

Testnet assets have no monetary value and are intended for development and testing only. Always confirm that the correct test network is selected before initiating transfers.
:::

## Run your first test

The sandbox environment supports testing of both inbound and outbound stablecoin payment flows.

::::WorkflowBlock
:::WorkflowBlockItem
**Test an inbound payment (external to Cross River)**

1. **Retrieve a receiving address:** Call `GET /v1/accounts/{accountNumber}/account-addresses` to retrieve a Cross River-managed receiving address associated with the account for the selected blockchain network.
2. **Fund a test wallet:** Request test USDC and the corresponding network token using the public faucet links listed in the table in the [Get testnet tokens](docId\:kKg6wDGvPtdFwWN7gCCRH) section.
3. **Initiate the transfer:** Send test USDC from an external testnet wallet to the retrieved receiving address.
4. **Onchain confirmation:&#x20;**&#x4F;nce the transaction is confirmed on the test network, Cross River detects the transfer and makes the payment available for PII submission.
5. **Provide PII:** Submit the required sender PII using `POST /v1/payments/{id}/pii`.
6. **Verify receipt:** After required PII is submitted and the payment is completed, Cross River issues a `Crypto.Payment.Received` webhook. Webhook logs can be used to confirm successful receipt of the inbound payment and account credit.
:::

:::WorkflowBlockItem
**Test an outbound payment (Cross River to external)**

1. **Create an external destination wallet:&#x20;**&#x43;all `POST /v1/accounts/{accountNumber}/external-addresses`to register a destination blockchain address for testing.
2. **Send a payment:**
   1. Call `POST /v1/payments` to initiate a USDC payment from the Cross River sandbox account to the registered external address.
   2. Set the `blockchain` field to either **ethereum** or **solana**, based on the selected test network.
3. **Confirm transaction status:&#x20;**&#x41;fter the transaction is broadcast and confirmed, a `Crypto.Payment.Sent`webhook is issued containing the payment ID and blockchain transaction hash.
:::
::::

[Learn about Cross River onchain payment APIs](docId\:lnZ2VwmXVahA4yP7mayED)&#x20;

[Learn more about using the Cross River sandbox environment](docId\:wmg-1Fqwq3bj-D3c3HFfs)

## Additional considerations

- **Supported assets in sandbox:** USDC on Ethereum Sepolia and Solana Devnet.&#x20;
- **Settlement timing:** Confirmation typically occurs within seconds, subject to blockchain network conditions and applicable review processes.&#x20;
- **Network fees:&#x20;**&#x54;estnet network fees may apply as part of the sandbox testing flow. These fees are paid using the applicable test network token.&#x20;