ERC-8004: Building Trustless AI Agents on Ethereum

Frequently Asked Questions

01.What is ERC-8004 in simple terms?

ERC-8004 is an Ethereum standard that gives AI agents a verifiable on-chain identity, reputation score, and validation layer. It operates through three lightweight registries: Identity, Reputation, and Validation. Agents register with an ERC-721 token, accumulate cryptographically signed feedback from real interactions, and prove reliability through pluggable validation methods including zkML proofs and TEE attestations. Over 100,000 agents registered across 19 EVM chains within weeks of the January 2026 mainnet deployment.

02.How is ERC-8004 different from ERC-6551?

ERC-8004 handles agent identity, discovery, and trust. ERC-6551 handles asset custody by giving NFTs their own smart contract wallet accounts. They solve entirely different problems and are designed to work together. An agent can carry an ERC-8004 identity NFT for its public on-chain profile while using an ERC-6551 token-bound account for asset custody and transaction execution. The standard was authored by engineers from MetaMask, Ethereum Foundation, Google, and Coinbase.

03.Which blockchains support ERC-8004?

ERC-8004 is live on 19 EVM chains including Ethereum, Base, BNB Chain, Arbitrum, Optimism, Polygon, Avalanche, Scroll, Linea, Mantle, Gnosis, Celo, and Taiko. BNB Chain leads adoption with 44,051 registered agents, followed by Ethereum at 36,512 as of March 2026 (The Defiant, March 2026). All contracts deploy to vanity addresses beginning with 0x8004.

04.How does the ERC-8004 reputation registry prevent fake reviews?

The reputation registry requires signed feedback authorization from the server agent before any review can be submitted. The server must sign a cryptographic token via EIP-191 or ERC-1271 proving an actual interaction occurred. Agent owners cannot review their own agents at the contract level. The getSummary() function intentionally requires an explicit list of trusted client addresses rather than returning unfiltered aggregates, which pushes Sybil resistance to the consumer layer and makes mass-gaming structurally harder.

05.Do I need to write Solidity to register an ERC-8004 agent?

No Solidity is required for basic registration. No-code portals like Chitin Protocol on Base let you upload a JSON registration file and mint an identity NFT through a standard web interface, with Arweave permanent storage included. For deeper integration including custom reputation logic, validation flows, and programmatic registration, SDKs are available in Python via Praxis Protocol, Go, and JavaScript. The reference implementation is open source at github.com/erc-8004/erc-8004-contracts.