x402 V2 Launch: Multi-chain and Bank Card Integration Drive AI Native Payment Ecosystem Expansion

The x402 Payment Protocol officially released version 2 on December 11, 2025, further strengthening its core position in AI-native payments and autonomous machine transactions. Since its launch six months ago, x402 has processed over 100 million payments through API, AI agents, and Web services. The V2 version consolidates the key upgrades accumulated during this period.

The most notable highlight of this update is the unification of “multi-chain + traditional payment networks” into a standardized payment format. The new protocol standardizes network and asset identification, enabling developers to seamlessly route payments between blockchains like Base, Solana, and traditional networks such as ACH and bank card networks. As a result, x402 is gradually becoming a neutral payment layer that connects crypto finance with traditional finance, simplifying cross-network settlement processes and providing more compatible payment infrastructure for AI agents, automation services, and Web applications.

The Wallet Sessions feature introduced in V2 is another major functionality. Sessions are bound to wallets rather than API keys, allowing users to continue accessing services after completing a payment. This is suitable for subscription models and high-frequency call scenarios, such as generative AI inference, automated API calls, and autonomous agent operations. This mechanism aims to reduce repeated on-chain operations, lower computation and payment costs, and improve overall operational efficiency.

The protocol also achieves scalability of the payment layer through a modular architecture. Responsibilities between clients, servers, and payment service providers are clearly separated, and any chain, asset, or payment scheme can be integrated as independent modules without modifying the core protocol. This provides developers with more flexibility to incorporate additional ecosystem resources and payment pathways.

To enhance the autonomous capabilities of AI agents, V2 introduces the Discovery extension, allowing services to publish metadata for payment service providers to fetch and index, enabling automatic discovery, reading pricing information, and initiating payments. The related Software Development Kit (RSDK) has been completely rewritten based on early user feedback, adopting a plugin architecture for easier extension and deployment.

The x402 protocol continues to use the HTTP 402 “Payment Required” status code as its core mechanism, with most payments settled using stablecoins on Layer 2 networks like Base for faster and lower-cost transactions.

It is noteworthy that the x402 Foundation was established in September 2025, with members including industry giants such as Cloudflare, Google, and Visa, indicating that the protocol is moving toward open standardization and accelerating the global expansion of next-generation AI-native payment ecosystems.