Supported networks

Gateway Nanopayments supports gas-free USDC payments on the EVM blockchains in the Gateway supported blockchains reference. Solana is the only Gateway blockchain not currently supported. Use the SupportedChainName value from the table when initializing GatewayClient or configuring the SDK:

const client = new GatewayClient({
  chain: "base", // SupportedChainName from the supported blockchains table
  privateKey: "0x...",
});

When using GatewayClient, deposits and payments are scoped to the blockchain you configure on the client. If you want to pay on Base, initialize the client for Base and deposit there. To avoid long deposit wait times, use the Bridge capability in Arc App Kits to bridge your USDC to a fast-finality blockchain before depositing. The Fast deposits section offers third-party alternatives for faster deposits.

Contract addresses

If you are constructing EIP-712 signatures manually (without the SDK), you need the contract addresses for your target chain:

GatewayWallet address (used as verifyingContract in the EIP-712 domain): EVM contract addresses
USDC token address (used as the asset in payment requirements): USDC contract addresses

The SDK’s CHAIN_CONFIGS constant provides these values programmatically. See the SDK reference for details.

Testnet faucets

To test nanopayments, you need testnet USDC and native gas tokens:

Circle Faucet: testnet USDC for supported testnet blockchains
For native gas tokens (required for onchain deposit transactions), use the blockchain-specific faucets listed on each testnet’s documentation site

Circle CLI

Agent marketplace

x402 facilitators

Contract addresses

Testnet faucets

​Contract addresses

​Testnet faucets

Contract addresses

Testnet faucets