Stripe's Agent Commerce Protocol (ACP) and x402 both enable AI agents to pay for HTTP-served goods. ACP is anchored to Stripe's existing card and stablecoin rails; x402 is anchored to open EVM stablecoin rails. The choice is mostly about who you want as the trust anchor.
x402 is the right pick when you want open rails, on-chain audit, and minimal counterparty trust. ACP is the right pick when you want Stripe-grade dispute handling and your agent population is comfortable with PSP-style auth.
Both protocols define how an autonomous agent can authenticate and settle payment for a request. ACP layers this on top of card and stablecoin rails Stripe already operates; x402 builds it on neutral on-chain rails.
ACP gives you Stripe Dashboard, payouts, and dispute tooling for free. x402 gives you a tx hash per call and a public ledger if you operate a take-rate proxy yourself.