Coinbase-incubated x402 payments protocol built for AIs rolls out V2

About six months after launching, x402, the Coinbase-incubated open-source payment protocol built for AI agents, is rolling out a major upgrade. x402 V2 essentially takes the original, simple single-call payments system into a full-fledged, unified payment layer for the internet.

“x402 launched in May 2025 with a simple idea: embed payments directly into HTTP using the long-dormant 402 status code,” Coinbase Developer Platform engineers Erik Reppel, Carson Roscoe, and Josh Nickerson wrote in a blog on Thursday. “V2 evolves the specification based on learnings from 6 months of x402 performing real-world payments.”

In six months, x402 has reportedly processed over 100 million payments across various APIs, apps, and AI agents, according to the post.

In short, V2 is a series of backend improvements meant to make it easier to create customizable payment flows, better wallet and identity features, and support “legacy payment rails,” among other improvements. 

“V2 of the x402 protocol represents the next step in making value move across the internet as easily as information,” the developers wrote.

Perhaps the biggest upgrade is the work done to unify x402’s payment interface. x402 V2 standardizes how networks and assets are identified on the protocol, “creating a single payment format that works across chains and with legacy payment rails.” 

This means that x402 will become “multi-chain by default,” capable of supporting tokens native to Base or Solana, among other blockchains, without requiring custom logic. Moreover, the system is also compatible with “legacy payment rails,” like ACH and card networks, the blog says. 

The updated system also rolls out dynamic ‘payTo' routing, which can support payment flows like usage-based billing, subscriptions, prepaid payments, and multi-step transactions. Developers can also inject “lifecycle hooks” for conditional tools or metric monitoring, and create more customizable paywalls. 

“By expanding compatibility, simplifying the developer experience, and enabling new payment and identity models, V2 turns x402 into a more flexible layer for human, app, and agent-driven payments,” the developers wrote. 

In September, Cloudflare and Coinbase co-launched the x402 Foundation to promote the adoption of the x402 protocol. Coinbase Developer Platform has also recently unveiled Payments MCP, a protocol to enable large language models like Anthropic’s Claude and Google’s Gemini to access blockchain wallets.