The Eve of the AI Agent Economic Explosion: How x402 and ERC-8004 are Reshaping Payment Standards in Machine Society?

As AI Agents gradually become independent economic entities, the infrastructure construction of a machine society is accelerating. This article breaks down the “four-layer standards” that constitute the core of the AI Agent economy: the Collaboration Layer (A2A), the Payment Layer (AP2), the Encrypted Payment Layer (x402), and the Trust Layer (ERC-8004). Among them, the AP2/x402 protocol, driven by Google, addresses the payment settlement issues between Agents, while the ERC-8004 proposed by the Ethereum community focuses on introducing verifiable identification, reputation, and work results for Agents. The active participation of mainstream fintech giants like Visa and Cloudflare marks the transition of the AI Agent economy from theory to a stage of co-building standards, containing significant alpha opportunities in Layer1 public chains and protocol application layers.

Four Core Pillars of the AI Agent Economy: Language, Payment, Trust, and Value

The market generally agrees that AI Agents will become an important economic entity in the future. The core logic behind this is their role transformation as “assets that can automatically generate continuous cash flow” and the efficiency improvements brought by Agent-to-Agent (A2A) collaboration. To support this entirely new machine economy, a complete set of standardized protocol systems is essential, which can be broken down into four key levels:

1. A2A (Agent-to-Agent) Collaboration Layer: Defines the “language” and “social rules” between Agents, enabling them to connect, negotiate, and request capabilities across domains, forming the basis of the most efficient business model in the machine economy.
2. AP2 (Agent Payments Protocol) Payment Layer: Proposed by Google in September 2025, it aims to establish a unified process, account authorization, and payment verification standards for Agent-led payments, similar to the “payment protocol” of the banking system in the real world.
3. x402 (Encryption Payment/Micropayment Layer): As an encryption payment extension of AP2, it introduces encrypted assets, stablecoins, and on-chain payment capabilities into the Agent interaction process, achieving decentralized, automated “scan-to-transfer” between machines.
4. ERC-8004 (Trust/Verification Layer): Proposed by the Ethereum community in August 2025, it introduces a trustless identity, reputation, and verification mechanism for the Agent system, addressing key trust issues such as “Who am I?” and “Why should I choose you?” It serves as the “on-chain resume” and “credit report” for the Agent world.

This four-layer collaborative model jointly constructs a complete machine society: Agents possess language (A2A), can make payments (AP2/x402), and have identification and reputation (ERC-8004), providing the necessary settlement and coordination capabilities for large-scale machine economies.

Alpha Opportunities in the Value Layer and Identity Layer: Ecosystem Layout of x402 and ERC-8004

In the core protocols mentioned above, x402 (Value Layer) and ERC-8004 (Identification Layer) are the areas most closely associated with the encryption market and most likely to capture early alpha value.

1. Underlying Public Chain: Seizing the High Ground of AI Settlement and Execution

The underlying public chain plays a key role in the AI Agent economy as the “core of standard setting” and “execution efficiency”:

2. Protocol Layer and Application Layer: The core logic of machine society operations

The protocol and application layer are key areas for value capture in the x402/ERC-8004 narrative, focusing on projects that provide agency frameworks, payment routing, reputation management, and specific AI services:

In addition, traditional protocols such as Safe (evolved into machine account custody layer), Superfluid (continuous micropayments), ENS/EAS (reputation and credential modules), and SUI (early participants of AP2), all have great potential for value recombination in the new narrative of AI Agent.

Conclusion

The entry of tech giants like Google and Visa, along with the standardization advancement of Ethereum community ERC-8004, is pushing the AI Agent economy from a grand vision towards the practical infrastructure construction phase. x402 addresses the problem of “how to pay” between machines, while ERC-8004 resolves the issue of “who to trust.” The combination of the two lays the foundation for the commercial operation of the Agent economy. For the crypto market, this indicates that a new cycle driven by the “machine economy” is brewing. Currently, investors should closely monitor projects that are deeply involved in the implementation of x402 and ERC-8004 standards on underlying chains (such as Base, Solana) and protocol layers (such as PayAI, Daydreams), as they are likely to become focal points for value capture in the next wave.