x402

An open protocol that uses HTTP 402 so a client can pay a server, usually in USDC, and retry. Named for the reserved HTTP status Payment Required.

What an agent can do: Let a machine pay for an HTTP resource without a human checkout page.
Networks: Base; Solana; other networks listed in seller documentation
Live?: Documented as live or generally available.
Evidence: Public launch by Coinbase on 6 May 2025. Linux Foundation announced operational launch of the x402 Foundation on 14 July 2026. Seller documentation lists multiple networks and facilitators.
Last verified: 7 September 2026