Behind the x402 Craze: How ERC-8004 Builds the Foundation of Trust for AI Agents
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Behind the x402 Craze: How ERC-8004 Builds the Foundation of Trust for AI Agents
If the emergence of x402 verifies the huge demand for AI agent payments, then ERC-8004 represents another more fundamental core element necessary for building this vast machine economy.
Navigating Web3 tides with focused insightsAuthor: Lacie Zhang, Bitget Wallet Researcher
1. Introduction: From the Buzz Around x402 to the Emergence of ERC-8004
Recently, as the x402 protocol—designed for automated micro-payments between AI agents—has become a market hotspot, discussions about its early potential have been widespread. However, beneath the spotlight on x402, a more foundational standard—ERC-8004—is quietly drawing the attention of astute observers.
A new question arises: if x402 already addresses payment issues, what is the role of ERC-8004? Are they competing?
The answer appears to be no. Instead, they resemble a pair of intricately designed, mutually complementary components within the AI agent commercial landscape.
Source: X post by Davide Crapis, Head of AI at the Ethereum Foundation
A notable detail is that Erik Reppel, the creator of x402 from Coinbase, is also one of the final signatories of the ERC-8004 protocol. Joining him in signing the standard are core representatives from MetaMask, Google, and the Ethereum Foundation. This heavyweight lineup and significant personnel overlap strongly suggest that the two are not competitors, but rather co-architects of a broader vision.
The logic of this vision is clear: if the emergence of x402 validates the massive demand for AI agent payments, then ERC-8004 represents another fundamental building block necessary for constructing this vast machine economy. It targets precisely the core challenge that x402 alone cannot solve—where does trust come from in an economy of autonomously collaborating AI agents? Bitget Wallet Research may guide you to the answer in this article.
2. The "Trust" Problem in Agent Collaboration: A Dilemma x402 Cannot Solve Alone
In AI agent commercial collaboration, payment—the issue addressed by x402—is merely the final step in the cycle. A more fundamental question comes first: how can one AI agent be certain that another AI agent it hires is trustworthy? In other words, how can an agent prove its ability to deliver on tasks?
To answer this, we must examine the foundational framework of agent-based commerce. According to the theory supported by Davide Crapis of the Ethereum Foundation, a decentralized AI agent commerce system must rest on three pillars to operate stably: Discovery, Communication, and Computation.
Source: X post retweeted by Davide Crapis
As shown in the table above, the x402 protocol primarily addresses payment standards within the communication layer, but it cannot resolve critical identity verification and reputation assessment. Before any payment occurs, AI agents must first be securely "discovered" to establish trust and collaboration—this is exactly what ERC-8004 aims to solve: building a decentralized trust layer.
Launched jointly by the Ethereum Foundation's dAI team and Consensys, along with institutions such as MetaMask, Google, and Coinbase, ERC-8004 is designed to serve as the on-chain "trust layer" for AI agents. It functions as a decentralized commercial registry and directory system—providing each AI agent with verifiable identity, complete performance history, and capability proofs. All information is immutably recorded on-chain and publicly accessible to all participants.
Source: Official ERC-8004 website
3. ERC-8004: The Decentralized Trust Layer for Agents
Positioned as foundational infrastructure for the agent economy, ERC-8004’s core value lies in using blockchain technology to solve the fundamental problem of untrusted identities among AI agents, freeing them from reliance on centralized platforms and enabling verifiable, cross-platform collaboration.
This mechanism begins with ecosystem contributors inputting trust data: AI developers register unique agent identities; application developers continuously provide behavioral feedback to accumulate reputation data; and validation services act as independent auditors, offering trusted on-chain verification of agent outcomes.
Source: Compiled by Bitget Wallet
All this information flows into the ERC-8004 registry, which integrates three core functions:
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Identity Registry: Using the ERC-721 NFT standard, it assigns each AI agent a unique digital identity. This design ensures identity portability and allows linking to standardized "Agent Cards" that detail the agent’s name, capabilities, and metadata, ultimately enabling permissionless, cross-platform discovery.
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Reputation Registry: Built upon identity registration, this acts as a decentralized review system. Clients or other agents can submit structured feedback. Crucially, these evaluations can be linked to x402 payment proofs, ensuring only genuine transaction participants can leave reviews—effectively reducing fraud and guaranteeing transparency of all reputation data.
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Validation Registry: This provides ultimate assurance for high-risk or high-value transactions. Agents can request third-party trusted validation, such as TEE oracles, staked inference, or zero-knowledge machine learning proofs (ZK-ML). These methods offer cryptographic proof for specific model executions and outputs, creating a verifiable accountability mechanism akin to professional certifications in traditional markets.
Based on the trusted data foundation provided by ERC-8004, a new downstream application ecosystem is flourishing—such as agent discovery and query browsers (Explorers), marketplaces (Marketplaces) allowing agents to freely trade based on reputation, specialized rating agencies (Rating Agencies), and even innovative services like InfoFi and AgentFi. These advanced applications are all built upon verified agent identities and audit records, marking the formal establishment of a permissionless, efficient, collaborative agent service ecosystem.
4. Synergy in Action: The Complete Lifecycle of an Agent Transaction
How do these components work together in practice? The full lifecycle of a decentralized AI agent transaction clearly illustrates this workflow.
Source: Compiled by Bitget Wallet
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First, the requesting agent uses the ERC-8004 Identity and Reputation Registries to discover and evaluate services, searching and filtering for agents with specific capabilities and good credit standing.
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After mutual agreement, the requester locks the required fees into a smart contract via the x402 payment protocol (i.e., financial guarantee).
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Next, the service agent begins executing the task under third-party verification. Its output runs on a verifiable computing layer like EigenCompute, generating cryptographic proof. An independent third-party validator agent then records the audit result into the ERC-8004 Validation Registry.
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Finally, during automatic settlement, the x402 smart contract detects the trusted signature in the ERC-8004 Validation Registry. Once task completion is confirmed, funds are automatically released to the service agent.
In this closed-loop process, ERC-8004 handles access and acceptance, x402 manages payment, and verifiable computing ensures process integrity—each component is indispensable. This also suggests that unlike x402, where early gains are concentrated in payment tokens, the ERC-8004 ecosystem (as shown below) will span multiple layers including infrastructure, middleware, and applications.
Source: BlockFlow
5. Conclusion: Order and the Future of the Machine Economy
It must be acknowledged that ERC-8004 is still in its early stages of promotion and adoption—whether related products can overcome cold-start challenges and realize its grand vision of comprehensive "machine economy identity verification" remains to be seen. Additionally, the cost and specific implementation paths for third-party validation, as well as interoperability with protocols like x402, are major variables yet to be resolved.
Yet one thing is certain: the emergence of protocols like ERC-8004 marks a shift in the machine economy—from "wild growth" toward "establishing order." It offers autonomous AI agents their first cross-platform identity and credit system.
If x402 is the "currency" of the machine economy, then ERC-8004 provides the "passport" and "credit report," heralding the dawn of a permissionless, efficient, collaborative, and trustworthy agent service ecosystem.
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