Learn / What is x402?
What is x402?
x402 is an open payment protocol that lets any web server charge for a request by replying with HTTP status 402 Payment Required plus machine-readable payment terms. An AI agent that receives the 402 pays the quoted amount in stablecoin (almost always USDC on Base or Solana), retries the request with a payment receipt, and gets the resource — all in one automated round-trip that settles in under two seconds for a fraction of a cent.
Where x402 came from
Coinbase introduced x402 in May 2025 as a way to give autonomous agents a native way to pay for APIs, data, and tools without accounts, cards, or API keys. In July 2026 Coinbase donated the protocol to the Linux Foundation's newly launched x402 Foundation, whose 40 founding members include Visa, Mastercard, American Express, Stripe, Google, AWS, Circle, Cloudflare, Shopify, and the Solana and Stellar foundations.
How big is it
As of July 2026, roughly 169 million cumulative agentic transactions have been processed, with x402 moving about 75 million payments (~$24M) in a single 30-day window — an average payment of roughly $0.32. About 98.6% of machine payments settle in USDC.
Why it matters
x402 turns the web's oldest unused status code into the metering layer of the agent economy. If AI agents are going to buy compute, data, and services on their own, they need a payment method with no signup friction and sub-cent fees — that is exactly the niche x402 occupies.
Frequently asked questions
Is x402 a cryptocurrency?
No. x402 is a protocol — a set of rules built on HTTP. Payments made through it settle in existing stablecoins, primarily USDC on the Base and Solana networks.
Who controls x402?
Since July 2026 the protocol is governed by the x402 Foundation under the Linux Foundation, with 40 member organizations spanning card networks, processors, clouds, stablecoin issuers, and blockchains.
What does an x402 payment cost?
Network fees are typically around $0.0001 and settlement takes under two seconds; typical payments themselves are sub-dollar micropayments.
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