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
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.