Let's talk about the V2 upgrade of the X402 and share some key points.

Author: Haotian; Source: X, @tmel0211

Let's talk about the V2 upgrade of x402 and share some points that I think are key:

1) Wallet Identity + Reusable Sessions

In V1, every API call had to go through the complete on-chain transaction process. If an Agent continuously initiated payment requests, it would generate a large number of on-chain transactions. Coupled with latency and gas accumulation, it simply couldn't run in some high-frequency application scenarios;

V2 will introduce the Sign-In-With-X (SIWx) mechanism. The Agent verifies the wallet identity once, and subsequent calls can directly reuse the session without having to confirm on-chain every time.

V2 will introduce the Sign-In-With-X (SIWx) mechanism. The Agent verifies the wallet identity once, and subsequent calls can directly reuse the session without having to confirm on-chain every time.

This essentially upgrades x402 from pay-per-use to a subscription membership system, reducing the performance and technical barriers required in high-frequency scenarios; 2) CAIP standard multi-chain compatibility V1 is mainly based on the Base + EIP3009 USDC combination mechanism. Other chains can only encapsulate, bridge, or relay to access it, which is significantly more technically complex. V2 achieves unified multi-chain asset identification through CAIP, enabling seamless integration with Solana, Monad, Avalanche, other L2 blockchains, and even traditional fiat currency payment channels. This makes the x402 protocol more open and convenient for integration with more chains. This adjustment is necessary because x402 cannot remain merely a protocol; ultimately, it will be a competition within the multi-chain ecosystem. Only by maximizing the combination of Base's first-mover advantage, Solana's high performance, and BSC's liquidity can it succeed. 3) Extensions Extensibility Mechanism: V2 introduces the concept of Extensions, allowing for the expansion of new functionalities without forking the main protocol. Automatic Discovery, dynamic PayTo routing, and various future innovative features can all be added as Extensions. This actually lays the foundation for infrastructure and application innovation at the Facilitator and Provider levels. Devs can explore various payment model innovations based on the x402 protocol, including dynamic pricing, multi-party revenue sharing, conditional payments, delayed settlement, and so on. 4) Plug-in SDK + Automatic Discovery Mechanism The V1 integration experience was still at the manual operation level. Modifying SDK source code and manually matching the Facilitator list were manageable in small-scale application scenarios, but became problematic at a large scale. V2 changed the SDK architecture; the Facilitator can automatically crawl and index the metadata of x402 services, and price, routing, and support chain information are all automatically synchronized. Essentially, the technical threshold has been further lowered, and the open environment is more user-friendly. That's all. V1 ran a large number of transactions, proving the feasibility of the x402 narrative, but also exposed many problems, such as a closed ecosystem, high integration barriers, and unfriendly implementation for high-frequency applications. Clearly, the rapid advancement of V2 is to solve the problem of further large-scale deployment of x402. Now, all that's missing is some interesting and innovative gameplay!