x402 explained: Coinbase's payment standard for AI agents
AI agents can now pay for web services with x402
x402 is an open payment standard from Coinbase. It uses the HTTP 402 "Payment Required" code, which was reserved in the 1990s for future online payments and then left unused for about 30 years.
The standard is designed for small payments made by software, such as AI agents that browse the web and call online services for users. Cloudflare says more than half of internet traffic is now non-human, and it reports seeing a billion HTTP 402 responses on its network every day.
Three facts about x402
- x402 is a set of rules for payments on the web, not a blockchain and not a coin.
- Payments are mostly made in USDC, a stablecoin, on Base, Coinbase's Ethereum layer-2 network.
- The x402 Foundation under the Linux Foundation now governs the protocol, with support from more than 50 companies including Visa, Mastercard and Google.
What x402 is and how it works
Coinbase launched x402 in May 2025 with partners including AWS, Anthropic, Circle and NEAR. A stablecoin is a digital token designed to hold a steady value, usually linked to the US dollar.
When a client asks a server for a service, the server can reply with 402 and include the price, accepted tokens and a wallet address. A wallet is a digital tool for holding and sending crypto. The client signs a payment authorization and sends the request again. The server checks and settles the payment, then returns the requested content.
A facilitator, a service that verifies and settles payments, does much of the onchain work. This means sellers do not need their own crypto setup. On EVM chains, x402 uses EIP-3009, which lets a buyer sign a permission to transfer tokens, so the buyer does not need to hold ETH for gas.
The protocol works with any chain. Base is the main settlement chain, and it also supports Solana, Polygon, Arbitrum and others, as well as traditional card payments. Settlement on Base takes seconds and costs well under a cent, according to the source.
Fast growth, then lower recent activity
Coinbase released x402 V2 in December 2025, which added wallet-based identity, automatic service discovery and support for more chains. In May 2026, it added batch settlement, where agents give sellers signed vouchers that can be settled in bulk.
According to Fireblocks, which cited data from tracker agenteconomy.to, x402 had processed more than 196 million transactions across 12 chains as of November 1, 2026, settling more than $42 million in total. Coinbase says more than 97% of onchain agent transactions in Q2 2026 used x402.
Fireblocks also reported that more than half of lifetime transactions came from a two-month period in late 2025, when traders ran automated scripts to mint and sell PING, a token issued through x402. In October 2026, x402 processed 5.1 million transactions worth about $274,000.
Companies involved and no official token
Cloudflare and Stripe co-developed the x402 Foundation with Coinbase. Cloudflare has x402 support in its Agents SDK and a monetization gateway, while Stripe can turn x402 payments into its standard PaymentIntents for familiar reporting and payouts.
Other companies named include Agentic.Market, Coinbase's marketplace launched in April 2026, CoinGecko for market data, AWS for agent payment management, and Google, whose agent-to-agent extension uses x402 for crypto settlement between agents.
x402 has no official native token. Payments use existing stablecoins, mostly USDC. The source states that speculative "x402" tokens on various chains are not issued or backed by Coinbase or the x402 Foundation.
Foundation grows as rival standards emerge
The Linux Foundation announced the x402 Foundation on April 2, 2026, with Coinbase contributing the protocol. It became fully operational on July 14, 2026, with 40 member organizations. The member list has since grown to 57, including Visa, Mastercard, American Express, PayPal, Google, Shopify, Circle, Stripe and AWS. Michael Hursta became executive director on October 1, 2026.
Rival options also exist. The Agentic Commerce Protocol from Stripe and OpenAI and Visa's Trusted Agent Protocol are competing for a role in agent payments, even though Stripe and Visa are also premier members of the x402 Foundation. Stripe has also co-developed the Machine Payments Protocol with Tempo, which uses HTTP 402 but adds session-based billing.
The source says the open question is whether x402's transaction counts turn into steady, real commerce.
Where this information comes from
Newisty Editorial Team covers technology, cryptocurrency, digital products, online platforms, developer tools and the wider digital economy. Our content is researched from official sources, company announcements, public documentation, market data and other primary or reputable sources. Articles are reviewed and edited before publication for clarity, accuracy and useful context.