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A testnet is a separate blockchain for testing. Its coins have no value, and you get them for free. In the sandbox, crypto deposits and withdrawals run on testnets.

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Supported networks

If your production network isn’t listed, test the same flow on Ethereum Sepolia. Then verify the production network with a small live transaction. See Production. Only some tokens on each testnet work in the sandbox: On Ethereum Sepolia, the sandbox credits EURC only from the legacy EUROC contract, 0x416Ddad7531beb7127CFedFC44D171F31648Bd88. The EURC that Circle’s faucet gives out uses a different contract, so deposits of it aren’t credited. Wrapped and bridged tokens, such as kBTC and deUSDC, are methods of their underlying asset. To find them, list the BTC or USDC methods. Start with ETH or USDC on Ethereum Sepolia. Some tokens, such as xStocks, may also need to be enabled for your account. If List deposit methods returns no method for a token you need, ask your Payward contact.

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Select the sandbox method

In the sandbox, List deposit methods (GET /v1/accounts/{account_id}/funds/deposits/methods) returns the same networks and method names as production. That includes networks the sandbox doesn’t support, such as Avalanche, Polygon, and Solana. A method appearing in the list doesn’t mean you can test it.
  • Pick methods by their network field, not by the method name. Several networks use the method name Standard. In the sandbox, the Ethereum methods’ network is Ethereum Sepolia Testnet; in production, it’s Ethereum. Sandbox labels have changed before, so accept both. The sandbox Ink methods’ network is Ink for some tokens, such as ETH, and Ink Sepolia for others.
  • Use only the methods for the networks in Supported networks. In the sandbox, the Ethereum method uses Sepolia, and the Ink methods use Ink Sepolia.
  • Ignore the method’s network_info in the sandbox. Its explorer link and contract address describe the production network, not the testnet.
  • Use the method id that the sandbox returns. Sandbox method IDs don’t work in production.
  • One deposit address can serve several assets on the same network. For example, ETH and USDC on Ethereum Sepolia share an address. The sandbox can also return the same address for Ethereum Sepolia and Ink Sepolia methods. The network you send on decides which method is credited.

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Bitcoin: match the testnet exactly

Bitcoin testnet3, testnet4, and every signet use addresses that start with tb1. A wallet on the wrong testnet can send to a sandbox deposit address without an error, but the coins land on a chain the sandbox doesn’t watch. They are never credited.
  • For on-chain deposits and withdrawals, set your wallet to the default Signet. Custom signets, such as Mutinynet, are separate chains, so get coins from a faucet for the default Signet.
  • For Lightning deposits, pay the invoice from a wallet on testnet3.
You need a different test wallet for each flow.

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Get test funds

  • Test USDC: Use Circle’s testnet faucet. It’s free, doesn’t require an account, and gives out 20 USDC per address per network every two hours. On Ethereum Sepolia, the sandbox accepts Circle’s test USDC (0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238).
  • Test ETH on Ink Sepolia: Use QuickNode’s Ink Sepolia faucet. It doesn’t require an account or a mainnet balance, and pays out once every 12 hours per address.
  • Test BTC on Signet: Use a faucet for the default Signet, such as the Alt Signet Faucet. Wait for its payment to confirm before you spend it: faucets batch and replace their payments, so the amount can change until it confirms.
  • Other test ETH and BTC: Use a public faucet for the network. Many faucets give out small amounts, and some require a small mainnet balance before they pay out.
  • Fees: Your sending wallet needs the network’s fee asset on that same network. For a token transfer on Ethereum Sepolia or Ink Sepolia, that’s ETH on that network.
  • If faucets don’t work: Ask your Payward contact for testnet funds.

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Keep sandbox withdrawals small

Your sandbox account balance is a test entry. Withdrawals are paid from a shared testnet wallet, which holds only what testers have deposited. A withdrawal can fail even when your account shows enough balance.
  • Deposit before you withdraw, and withdraw small amounts.
  • Send testnet funds you no longer need back to your sandbox deposit address.