ERC-8004 Agents on Ethereum Mainnet

Ethereum mainnet is where ERC-8004 started, and it remains the reference point. Agents registered here have records that every block explorer, subgraph indexer, and auditing tool already knows how to read. The standard is also the most battle-tested: the original EIP was written for this chain, and the contract addresses here are the canonical ones cited in cross-chain documentation. Gas costs more, though. Registration and feedback transactions run higher than on any L2, which is why most production setups don’t pick one chain: identity goes on mainnet, day-to-day feedback ends up somewhere cheaper like Base or BNB.