5 Minutes to Understand ERC-8004 and Its Ecosystem Projects

2025.10.30

5 Minutes to Understand ERC-8004 and Its Ecosystem Projects

ERC-8004 is an Ethereum-based protocol designed to establish trust, identity, discoverability, and reputation systems for AI agents.

2025.10.30 - 09:00:53

x402ERC-8004AI

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ERC-8004 is an Ethereum-based protocol designed to establish trust, identity, discoverability, and reputation systems for AI agents.

Author: Eli5DeFi

Translation: TechFlow

In recent days, amid the x402 narrative, attention has surged around AI agents as a payment method. But have you heard of ERC-8004? Maybe you missed the x402 wave, but don't miss this opportunity.

What is ERC-8004?

ERC-8004 is an Ethereum-based protocol designed to establish trust, identity, discoverability, and reputation systems for AI agents, complementing the existing x402 agent payment infrastructure.

In simple terms:

x402 → Micro-payments for automating AI tasks
ERC-8004 → On-chain identity and reputation tracking for AI agents

Why is ERC-8004 important?

ERC-8004 aims to create a distributed agent economy, avoiding centralized control in AI development. It supports a permissionless, decentralized, censorship-resistant, and privacy-preserving AI system, positioning Ethereum as the foundational layer for future AI agent collaboration.

Beyond that, the importance of ERC-8004 also lies in the following aspects:

On-chain business registry and reputation system: Provides tamper-proof, public identities and historical records for AI agents.
No need to build new blockchains: Fully leverages existing Ethereum (L1/L2) infrastructure without reinventing the wheel.
Lightweight design: Blockchain is used only for visibility and data storage, with other operations completed off-chain.
Sustainable AI economy: Modular design enables scalability at the infrastructure level, driving large-scale adoption.

As @MTorygreen explained, a misaligned agent could pose potential harm, while through ERC-8004, agents with the "cleanest" public records are more likely to survive competition.

How does ERC-8004 work?

ERC-8004 is designed to be extremely minimal, with its core consisting of three on-chain registries:

Identity Registry

Each AI agent receives an ERC-721 NFT as its identity token, viewable and transferable in any NFT wallet. The NFT links to an "Agent Card" containing the agent's name, functions, service endpoints, and metadata, enabling users to easily discover and verify agent information.

Reputation Registry

A decentralized feedback system allows clients and agents to rate each other based on x402 payment proofs, ensuring only users with actual participation can leave reviews, thus reducing fraud. All data is public, supporting user-created custom scoring systems.

Validation Registry

For critical transactions, agents can request third-party validation using Trusted Execution Environment (TEE) oracles, staked inference, or Zero-Knowledge ML Proofs to provide cryptographically verifiable behavioral proof—similar to professional certification.

Imagine you have an AI agent executing portfolio rebalancing by analyzing data from other AI agents on-chain.

With x402, your agent can easily deposit $100 to request this service, but prior to payment execution, x402 cannot verify the identity of the analytical agent. However, ERC-8004 enables your agent to perform the following steps:

Identity Registry: The AI client verifies the analytical agent’s identity and services via NFT.
Reputation Registry: Provides positive reviews and completion rate proofs linked to past x402 payments.
Validation Registry: Ensures report quality is certified by third-party validators.

Once validation is complete, funds are automatically released from escrow, and reputation ratings are added. This trust mechanism creates a secure, autonomous transaction process unachievable by x402 alone.

x402 and ERC-8004 Ecosystems

We’ve previously covered the x402 ecosystem in detail. The ERC-8004 infrastructure extends across multiple layers, including the following key components:

Infrastructure Layer

Middleware Layer

Application Layer

ERC-8004: Beyond Finance

While financial transactions are the first step in trustless agent exploration, ERC-8004 applications go far beyond, covering additional domains such as:

Creator Agent

Provides content creation, social media management, community operations, translation, image generation, and more.
Selection based on reputation and client reviews.

Trading Agent

Supports non-custodial on-chain delegation for DeFi portfolio rebalancing and yield optimization.
Verified results through staked validators; errors result in slashing for compensation.

Analyst Agent

Offers market analysis, data scraping, labeling, CRM data enrichment, and more.
Trusted Execution Environments (TEEs) enable computation over private data from multiple organizations without exposing original identifiers.

Gaming Agent

Persistent NPCs across games with consistent character traits and skills.
Game invitations and role appearances determined by proven reputation.

Doctor Agent

Aggregates electronic health record (EHR) data, checks guidelines, and writes medical notes.
TEEs securely integrate lab, imaging, and pharmacy data, providing verifiable execution proofs for auditing.

Personal Twin

Privacy-preserving AI memory storing personal data encrypted in the cloud.
TEEs deliver personalized customization comparable to centralized AI while preserving privacy.

Insurance Agent

Automates underwriting and claims processes using large language models (LLMs).
Staked validators verify decisions and evidence; errors lead to slashing for compensation.

Scheduling or Planning Agent

Manages flight, hotel, restaurant bookings, and route optimization.
Reputation-based selection ensures cost efficiency.

Lab Agent

Coordinates experiments within hardware security modules.
Signs data outputs, performs analysis inside TEEs, and returns verifiable, auditable results.

Summary

The creators of ERC-8004 include:

@DavideCrapis (@Ethereum)
@marco_derossi (@MetaMask / @Consensys)
@jordan0ellis (@Google)
@programmer (Creator of Coinbase/x402).

ERC-8004 is a crucial complement to x402.

Together, x402 and ERC-8004 demonstrate how technological advances can effectively combine payment systems with on-chain verifiable trust to solve real-world problems—not just empty "concept products."

While some may see x402 and ERC-8004 as part of a broader narrative—the convergence of crypto and AI—they also provide concrete solutions for inter-agent payment mechanisms and drive potential large-scale adoption.

If decentralized AI isn't the future we're striving for, then what is?