Coinbase launched x402, an open HTTP-based payment standard that lets AI agents and applications pay for online services using stablecoins instead of creating traditional accounts. The protocol uses the HTTP 402 “Payment Required” status code, which had remained unused since the 1990s.
“We are excited to introduce x402–a new open source payments protocol built on HTTP rails,” Coinbase Developer Platform said on May 6, 2025.
The mechanism works through a cryptographic signature handshake. An application requests a service and receives an HTTP 402 response. The AI agent signs a transaction using USDC, primarily on Base (Coinbase’s Ethereum layer-2 network), and the service provider verifies and settles payment onchain. The protocol also supports Solana, Polygon, Arbitrum, and traditional card payments.
Cloudflare co-developed the protocol and reported that more than half of internet traffic is now non-human. The company’s network processes more than 1 billion HTTP 402 responses per day. Stripe also contributed as a co-developer.
Governance and Adoption
The Linux Foundation announced the launch of the x402 Foundation on April 2, 2026, to govern the protocol. The foundation became fully operational on July 14, 2026, with 40 member organizations. By the article date, membership had grown to 57 organizations, including Visa, Mastercard, American Express, PayPal, Shopify, Circle, Anthropic, NEAR, AWS, Microsoft, and Google.
Michael Hursta became executive director of the x402 Foundation on October 1, 2026.
Transaction Volume and Activity
As of November 1, 2026, x402 had processed 196 million transactions across 12 chains and settled $42 million in value. In October 2026 alone, the protocol processed 5.1 million transactions worth $274,000.
The protocol saw rapid early adoption. In Q2 2026, 97% of onchain agent transactions used x402, according to data tracked on agenteconomy.to. However, activity was concentrated: more than half of x402’s lifetime transactions came from a two-month period in late 2025 when traders ran automated scripts to mint and sell PING token. Volume declined significantly after that period.
Technical Developments and Competition
Coinbase released x402 V2 in December 2025, which added wallet-based identity features. In May 2026, the protocol added batch settlement functionality.
The protocol faces competition from alternative agent payment standards. Stripe and OpenAI developed the Agentic Commerce Protocol. Visa created the Trusted Agent Protocol. Stripe and Tempo jointly built the Machine Payments Protocol, which also uses the HTTP 402 code but adds session-based billing; it has supported x402 payments since June 2026. Despite these competing efforts, Stripe and Visa hold premier membership status in the x402 Foundation.
Coinbase operates Agentic.Market, a marketplace built on x402 where AI agents can discover and pay for services. Anthropic, Circle, and NEAR joined as launch partners. CoinGecko provides API data for the protocol.
