All networks below are testnet. A merchant must have a wallet registered on a given chain for that chain to appear in
payment_requirements when creating an intent.Testnet Networks
| Network | CAIP-2 ID | Chain ID | USDC Contract | EIP-712 Domain |
|---|---|---|---|---|
| Base Sepolia | eip155:84532 | 84532 | 0x036CbD53842c5426634e7929541eC2318f3dCF7e | USDC |
| Ethereum Sepolia | eip155:11155111 | 11155111 | 0x1c7D4B196Cb0C7B01d743Fbc6116a902379C7238 | USDC |
| Arc Testnet | eip155:5042002 | 5042002 | 0x3600000000000000000000000000000000000000 | USDC |
| Solana Devnet | solana:devnet | N/A | 4zMMC9srt5Ri5X14GAgXhaHii3GnPAEERYPJgZJDncDU | N/A (SPL) |
Key Notes
Chain-agnostic intents — payment intents automatically include all chains on which the merchant has a registered wallet. Buyers choose which supported chain to pay from at checkout. EIP-712 domain name — all testnet chains use"USDC" as the domain name. Never hardcode "USD Coin". Always read usdcDomainName directly from the payment_requirements array returned by the API.
Solana uses SPL token transfers rather than EIP-3009. The signing flow is different: a two-step process where an unsigned transaction is fetched first, then signed with a Solana wallet. See Custom Integration — Solana for full details.
Arc Testnet is an EVM-compatible chain (Chain ID 5042002) and uses the standard EIP-3009 signing flow — the same as Base and Ethereum.
USDC atomic units — all amounts in the API are expressed in atomic USDC units (USDC × 1,000,000). $29.99 = "29990000". Never pass float values to value or maxAmountRequired.