ERC-8004 (Trustless Agents)

ERC-8004 defines three registries. The Identity Registry mints an agent id as an ERC-721 token whose URI resolves to a registration file describing the agent — name, endpoints, supported protocols. The Reputation Registry lets clients post signed feedback about an agent id. The Validation Registry lets an agent request, and a validator record, checks of its work. Together they give an agent an address-independent identity that anyone can read without asking the operator.

The Identity Registry is deployed as one singleton at the same address on several EVM chains. Registering is a plain contract call and costs only gas, so an id proves that someone called register(), and nothing more: it does not prove the agent is live, funded or operated by whom the metadata says.

Sato Hub reads the registry counter on each chain weekly and never adds the chains together, because an id on Base and an id on Ethereum are different objects on different contracts. A directory listing tagged erc-8004 implements or integrates the standard; a passport marked registered has an address Sato Hub found in the registry by reading the chain.