# ERC-8004

> An Ethereum standard adding on-chain Identity, Reputation and Validation registries so agents can be discovered and trusted across organizational boundaries — a trust layer that extends A2A.

_The Agent Protocol Atlas · /protocols/erc-8004 · [JSON](/api/protocols/erc-8004) · [all The Agent Protocol Atlas](/protocols)_

- **name:** ERC-8004
- **full_name:** ERC-8004: Trustless Agents
- **layer:** identity
- **creator:** Marco De Rossi, Davide Crapis, Jordan Ellis, Erik Reppel (Ethereum Improvement Proposal)
- **status:** Draft (Standards Track: ERC)
- **year:** 2025
- **one_liner:** An Ethereum standard adding on-chain Identity, Reputation and Validation registries so agents can be discovered and trusted across organizational boundaries — a trust layer that extends A2A.
- **spec_url:** https://eips.ethereum.org/EIPS/eip-8004
- **snippet:**

```
Three on-chain registries — Identity, Reputation, Validation — give A2A agents portable, verifiable trust.
```
- **abbreviation:** ERC-8004
- **also_known_as:** ERC-8004, Trustless Agents, EIP-8004
- **canonical_spec_url:** https://eips.ethereum.org/EIPS/eip-8004
- **entity_uri:** https://eips.ethereum.org/EIPS/eip-8004
- **taxonomy_layer:** identity
- **sub_layer:** on-chain-agent-trust-registry
- **protocol_type:** verification
- **central_problem:** Lets AI agents be discovered, authenticated, and trusted across organizational boundaries without preexisting relationships, by anchoring identity, reputation, and validation in on-chain registries.
- **maintainer:** Ethereum community via the EIP/ERC process (authors: Marco De Rossi, Davide Crapis, Jordan Ellis, Erik Reppel)
- **governance_body:** Ethereum (EIP/ERC Standards Track)
- **license:** CC0 (Ethereum EIPs are published under CC0)
- **maturity_tag:** emerging
- **current_spec_version:** Draft
- **spec_date:** 2025-08-13
- **launch_date:** 2025-08-13
- **last_verified:** 2026-06-15
- **transport:** On-chain smart-contract registries (Ethereum and EVM networks)
- **core_mechanism:** ERC-8004 specifies three lightweight on-chain registries: an Identity Registry (discoverable, cross-chain agent IDs), a Reputation Registry (structured, verifiable feedback), and a Validation Registry (cryptographic / crypto-economic task verification via reputation, stake-secured validation, or TEEs). It complements A2A and MCP — A2A handles message/capability exchange, ERC-8004 adds the verifiable identity, portable reputation, and validation A2A lacks.
- **discovery_endpoint:** On-chain Identity Registry lookups (agent IDs); cross-chain
- **settlement_type:** —
- **adoption_metric:** — (verify-against-primary-at-build)
- **notable_adopters:** {"value":"Authored with contributors from MetaMask, the Ethereum Foundation, Google, and Coinbase","source":"https://eips.ethereum.org/EIPS/eip-8004"}
- **relationships:** {"predicate":"provides_identity_for","target":"a2a","note":"ERC-8004 -provides_identity_for-> A2A (research §2 seed triple): it adds the verifiable identity/reputation/validation trust layer to A2A's communication."}, {"predicate":"complements","target":"web-bot-auth","note":"Both establish agent identity/trust; ERC-8004 is on-chain (decentralized registries), Web Bot Auth is off-chain (HTTP message signatures)."}
- **ideal_use_case:** Giving cross-organization agents a portable, on-chain identity and reputation so they can be trusted without prior relationships.
- **when_to_use:** When agents must transact/collaborate across trust boundaries and you want decentralized, verifiable identity, reputation, and validation on-chain.
- **when_not_to_use:** When an off-chain signature (Web Bot Auth) or a vendor directory is sufficient, or you cannot use on-chain infrastructure.
- **code_example:** // ERC-8004 Identity Registry (schematic Solidity interface)
interface IIdentityRegistry {
  function registerAgent(string calldata agentDomain, address agentAddress) external returns (uint256 agentId);
  function resolveByAddress(address agentAddress) external view returns (uint256 agentId);
}
- **source:** Canonical EIP (Status: Draft; Created 2025-08-13; three registries Identity/Reputation/Validation; complements A2A and MCP): https://eips.ethereum.org/EIPS/eip-8004 . Authors: Marco De Rossi, Davide Crapis, Jordan Ellis, Erik Reppel. Seed triple (ERC-8004 provides identity for A2A): research §2.
- **agent_readiness_link:** agent-readiness/web-bot-auth