The Linux Foundation has formally launched the x402 Foundation, backed by major card networks and tech firms, to standardize internet-native payments between software agents. The protocol activates the long-reserved HTTP 402 "Payment Required" code to let clients pay servers directly with small stablecoin transfers, typically USDC, without accounts or prior relationships. Over the past 30 days, x402 processed about 75 million transactions totaling $24 million, with an average payment of 32 cents.
What is x402?
When the web's architects wrote the rules for how browsers and servers communicate, they set aside a response code numbered 402 and labeled it "Payment Required," expecting someone would eventually build payments into the web itself. Card fees made charging a fraction of a cent pointless, so the web monetized through ads, subscriptions and API keys instead, and 402 sat unused for thirty years. Coinbase filled that gap in May 2025 by building the x402 protocol and then handing it over to the Linux Foundation.
Under x402, a server that wants payment answers a request with a 402 and a price. The client signs a stablecoin transfer, usually USDC, resends the request with the payment attached, and gets the data. The exchange takes seconds and needs no account, no card, and no prior relationship between the two sides. That is why the AI industry cares: an autonomous agent cannot open a bank account, pass a credit check or sign a SaaS contract, but can sign a transaction.
Premier members and governance
Premier members of the x402 Foundation include Ripple, Visa, Mastercard, American Express, Stripe, Adyen, Fiserv, Shopify, Google, Amazon Web Services, Cloudflare, Circle, MoonPay, and the Solana and Stellar foundations. Forty companies now govern the protocol. Google has wired x402 into its own agent payments protocol, and Cloudflare ships it in its agent toolkit.
Usage and scale
The protocol handled about 75 million transactions over the past 30 days, or roughly 29 every second, moving about $24 million between some 94,000 buyers and 22,000 sellers. That works out to an average payment of about 32 cents, meaning the machine-to-machine thesis works as designed, as no card network can process such small charges profitably. Still, $24 million a month is a fraction of what any of x402's premier members move in a day.
Separately, onchain data provider DefiLlama tracks a metric it labels DEX volume for x402, which reached nearly $970,000 in a single day on Dec. 3 and has fallen steadily since, coming in at just about $16,000 on July 13 and roughly $572,000 across the past 30 days.