On September 16th, Google launched the AP2 proxy payment protocol, which may be written into the history of AI development. It is not just a technical standard, but more like a rallying call: AI agents will officially have the ability to "spend money" safely and compliantly, and an AI driven era of autonomous economy spanning finance and encryption is beginning. AP2 needs to solve three major trust problems: how can users prove that "I really authorized AI to spend this money"? How can merchants confirm the authenticity of requests? If AI buys the wrong thing, who is responsible? The answer proposed by Google is a "digital authorization letter", which converts every user's intention and approval into a chain of encrypted signature evidence, fully records the transaction process, and forms a verifiable audit trail. This protocol, together with MCP (Model Context Protocol) and A2A (Agent2Agent), constitutes the "trilogy" of AI agent interaction: MCP allows AI to access external tools and data, A2A enables different AI to securely communicate and collaborate, and AP2 enables the collaborative loop to enter the "value exchange" stage. It is worth noting that AP2 has been designed to support stablecoins and encrypted payments since its inception. Google collaborates with Coinbase, MetaMask, Ethereum Foundation, Mysten Labs, and others to launch the x402 extension, introducing stablecoin micro payments and instant settlements into AI agent interactions. This node is also considered a major tipping point in the encrypted world. Ten projects are seizing this new continent: Coinbase promotes x402 standardization and positions itself as the trading hub of AI proxy economy; MetaMask develops a self hosted proxy wallet to enhance security and user control; The Ethereum Foundation is attempting to make Ethereum the preferred settlement layer for the AI economy; Mysten Labs (Sui) supports real-time proxy transactions with a high-performance chain of 400 milliseconds; EigenCloud provides verifiability and security assurance; Crossmint and BVNK provide APIs and stablecoin financial infrastructure for enterprises, respectively; Mesh solves fragmented payment connections; Questflow creates a multi-agent collaboration and distribution market; Lightspark introduces the Bitcoin Lightning Network into AI payments. The giants of Web2 bring users and scenarios, while the native power of Web3 provides decentralized payments and autonomous philosophy. The significance of AP2 lies in the first large-scale convergence of two forces. It is not only the infrastructure of the AI economy, but also an amplifier for encrypted payments. For encryption projects, this is not following, but a historical opportunity to reshape the future of payments.