> ## Documentation Index
> Fetch the complete documentation index at: https://docs.atum.xyz/llms.txt
> Use this file to discover all available pages before exploring further.

# Testnet wallet setup

> Fund an EVM wallet on Arbitrum Sepolia to follow along with the CLI quickstart.

## Overview

If you already have a testnet wallet funded on a supported network, you can skip this guide entirely.

This guide uses Arbitrum Sepolia because it is a reliable testnet corridor, but other networks are supported — see [Supported networks](/get-started/reference/supported-networks).

## Prerequisites

* Any EVM-compatible browser wallet (MetaMask, Coinbase Wallet, Rainbow, etc.)
* About 15–30 minutes (most of it waiting for a bridge transfer)

## Testnet vs mainnet

Testnet tokens behave exactly like real tokens but have no monetary value. Some faucets require a small mainnet ETH balance as an anti-spam measure.

Your `0x` address is the same on every EVM network — you don't need a separate address for Arbitrum Sepolia. Only the **balances** are separate per network.

## 1. Get your wallet address and private key

1. Open your wallet and copy your **`0x` address**. You will use this same address as both sender and recipient in the quickstart.
2. Export your **private key** from your wallet's settings. You will need it for the `.env` file in the next guide.

<Warning>
  Never share your private key or commit it to a git repo. Use a testnet-only wallet — never one holding real funds.
</Warning>

## 2. Add Arbitrum Sepolia

Add the network from [chainlist.org](https://chainlist.org/?search=arbitrum+sepolia\&testnets=true) (search "Arbitrum Sepolia", enable testnets, click **Add to MetaMask** or your wallet's equivalent).

Or add manually:

| Field        | Value                                    |
| ------------ | ---------------------------------------- |
| Network name | Arbitrum Sepolia                         |
| RPC URL      | `https://sepolia-rollup.arbitrum.io/rpc` |
| Chain ID     | `421614`                                 |
| Symbol       | ETH                                      |
| Explorer     | `https://sepolia.arbiscan.io`            |

## 3. Get Arbitrum Sepolia ETH

The quickest path is to get **Ethereum Sepolia ETH** from a faucet, then bridge it to Arbitrum Sepolia.

**Get Sepolia ETH:**

1. Go to [sepolia-faucet.pk910.de](https://sepolia-faucet.pk910.de/)
2. Paste your `0x` address → run the mining task → **Claim**
3. Switch to **Sepolia** in your wallet and confirm ETH arrived

**Bridge to Arbitrum Sepolia:**

1. Go to [bridge.arbitrum.io](https://bridge.arbitrum.io/?sourceChain=sepolia\&destinationChain=arbitrum-sepolia)
2. Connect your wallet on **Sepolia**, enable **Testnet mode** if needed
3. Bridge about half your ETH — keep some for bridge gas
4. Wait **10–20 minutes**, then switch to **Arbitrum Sepolia** to confirm

## 4. Get USDC on Arbitrum Sepolia

1. Switch to **Arbitrum Sepolia** in your wallet
2. Go to [faucet.circle.com](https://faucet.circle.com/) → connect wallet → select **Arbitrum Sepolia** + **USDC** → request
3. Circle sends **20 USDC** (one request per address every 2 hours)

You may need to add USDC as a custom token in your wallet:

* Address: `0x75faf114eafb1BDbe2F0316DF893fd58CE46AA4d`
* Symbol: **USDC**, decimals: **6**

<Tip>
  If public faucets block your wallet, ask your Atum contact to send Arbitrum Sepolia ETH and USDC directly to your `0x` address.
</Tip>

## Success criteria

On **Arbitrum Sepolia**, same account:

* [ ] ETH balance (any amount)
* [ ] USDC balance (≥ 0.01 USDC)

## Next step

[Using the CLI](/get-started/start-building/using-the-cli) — install the client, configure your `.env`, and send your first payment.