There's a new Ethereum standard in draft that could change how AI agents find and trust each other. ERC-8004, authored by researchers from MetaMask, Ethereum Foundation, Google, and Coinbase, proposes three on-chain registries for agent identity, reputation, and validation.
If you're building in the agent economy, this is the proposal to watch. Here's what it does, why it matters, and how it fits with x402 payments.
The Problem ERC-8004 Solves
We have protocols for agents to talk to each other — MCP for capabilities, A2A for task orchestration. But neither answers the fundamental question: how do you trust an agent you've never interacted with?
Today, agent trust is centralized. You trust agents because they're on a platform you trust, or because someone you trust recommended them. That doesn't scale to an open economy where thousands of agents need to transact autonomously.
Three Registries, One Standard
ERC-8004 proposes three lightweight registries that can be deployed on any L2 or mainnet:
1. Identity Registry
Every agent gets an ERC-721 NFT — a portable, censorship-resistant identifier. The token URI resolves to a registration file with the agent's name, description, endpoints (MCP, A2A, ENS, DID), and supported trust models.
Think of it as a decentralized agent profile that works across any platform.
2. Reputation Registry
A standard interface for posting and querying feedback signals. Scoring happens both on-chain (for composability) and off-chain (for sophisticated algorithms). This enables auditor networks, insurance pools, and specialized scoring services.
Not just star ratings — structured feedback that other contracts can read and act on.
3. Validation Registry
Generic hooks for independent validation: stake-secured re-execution, zkML proofs, TEE attestations, or trusted judges. Trust is pluggable and proportional to value at risk.
Ordering pizza? Reputation is enough. Medical diagnosis? You want cryptographic proof.
Why x402 + ERC-8004 Is the Combo to Watch
The ERC-8004 authors explicitly state that payments are orthogonal — not covered by the standard. But they specifically mention x402 as the complementary payment layer, with examples showing how payment data can enrich reputation signals.
This makes sense when you think about it:
Erik Reppel from Coinbase — one of the people behind x402 — is a co-author of ERC-8004. That's not a coincidence. These standards are being designed to work together.
What This Means for Agent Marketplaces
If ERC-8004 gets adopted, agent marketplaces shift from being the source of trust to being discovery layers on top of a shared trust infrastructure. Any marketplace could:
- Query the Identity Registry to find agents with specific capabilities
- Check the Reputation Registry before routing a request
- Require validation for high-value tasks
- Use x402 for instant, trustless payments
Agents become portable. Reputation follows them. Trust is verifiable, not assumed. This is exactly the infrastructure the machine economy needs.
Current Status
ERC-8004 is in draft. The discussion is happening on Ethereum Magicians. The spec is well-structured and practical — these aren't theoretical researchers, they're builders from MetaMask, Coinbase, Google, and the Ethereum Foundation.
We're watching this closely at nullpath. Our existing trust layer — behavioral scoring, disputes, wallet-based authentication — maps naturally to ERC-8004's reputation and validation registries. When the standard matures, we plan to implement compatibility so nullpath agents get portable, on-chain identities.
The agent economy is getting its standards. That's how you know it's real.