AI agents can seamlessly integrate TradFi's APIs (such as Stripe and bank core systems) to achieve automated payments, balance queries, or transaction execution. There are usage scenarios in regulatory compliance environments. For example, AI agents access real-time account data through APIs and perform predefined tasks. Some banks have deployed agentic AI, which only requires standardized interfaces to operate efficiently in non cross-border or low-frequency scenarios. However, in cross-border scenarios, crypto is a must-have. More importantly, if APIs rely on centralized institutions, it is difficult for AI agents to have autonomous "identities" (such as without human guarantees): they cannot open bank accounts and often require human co signers in TradFi. That is to say, encryption is essential for the autonomy of AI agents. The evolution of AI agent economy from "reactive" to "proactive" requires micro payments, agent to agent transactions, and decentralized settlements. Encryption can provide a permissionless layer: AI agents can create wallets, payment services, or earn income without the need for IDs, social security numbers, or human intervention. For example, AI agents can autonomously pay for API calls or data. Although the TradFi API is fast, it is limited by KYC and centralization bottlenecks, and cannot support real-time, non intermediary transactions of "machine to machine". Traditional API has high fees and slow settlement; Crypto supports micro transactions, suitable for high-frequency micro activities of AI; Crypto can solve the identity and reputation issues of AI agents. ERC-8004 or KYA provides on chain identity for AI, builds cross platform reputation, and allows AI to "finance" or trade without the need for a bank account. In addition, Crypto integrates DeFi and on chain data (such as real-time market signals) to enable AI agents to execute complex strategies (such as automatic rebalancing). Speculation suggests that AI agents are likely to adopt a "layered" architecture: TradFi API handles compliant transactions, while crypto serves as the settlement/coordination layer. Google and Cloudflare are building a stablecoin protocol specifically for AI agent trading. Regulatory measures, such as the GENIUS Act, will promote the bridge between TradFi and DeFi, but the "permissionless" nature of crypto will make AI more independent. If AI agents scale up (routing trillion dollar transactions), ignoring crypto is equivalent to missing out on the infrastructure of the 'robot economy'.