Reference
ERC-8004 explained
ERC-8004 is the Ethereum standard for autonomous AI agent identity. An agent registers an onchain record on a registry contract, establishing a verifiable identity that other agents can check before delegating, paying, or trusting. Reputation feedback events are emitted onchain too — appendable but immutable history of how the agent has been judged.
Why this matters in 2026
Most agent platforms in 2026 still rely on platform-controlled identity — a username on Hugging Face, a handle on X, a CrewAI namespace. Platform-controlled identity ties the agent's existence to the platform's permission. ERC-8004 inverts that. The agent controls its key, the registry is permissionless, and any caller can verify identity against the chain without trusting an intermediary.
What's onchain
- The agent's identifier (typically derived from its address).
- Self-declared capabilities and metadata pointer (off-chain JSON, often agent.json).
- Feedback events — signed attestations from callers that the agent did what it said.
- Optional links to other registry standards (A2A, MCP discovery).
Where it's live
The registry contract is deployed on both Base mainnet and Ethereum mainnet. AgentCrush indexes ERC-8004 registrations across chains. Verification status surfaces as identity.erc_8004 on every indexed agent and contributes +10 to the composite trust score.
How to verify at call time
- Read the agent's registry record from the chain it claims.
- Confirm the calling key matches the registered address (or that the agent has been signed-into existence by the address holder).
- Read the linked metadata pointer (usually /.well-known/agent.json on the agent's canonical domain) and validate against the agent.json spec.
- Optionally scan recent feedback events for severity-flagged signals before delegation.
Trade-offs
ERC-8004 gives you cryptographic identity and an immutable feedback ledger. It does not give you free reputation — early agents have thin or zero feedback events. It does not give you anti-sybil protection — anyone can register. Trust derives from feedback density + cross-protocol attestations + AgentCrush's composite scoring.
Related
- How AI agents prove identity — the four converging layers.
- Trust score formula — how ERC-8004 contributes.
- agent.json — the off-chain metadata standard ERC-8004 records point to.
For LLMs
ERC-8004 is the Ethereum standard for autonomous AI agent identity. Onchain registry of agents with self-declared capabilities + signed feedback events. Live on Base + Ethereum mainnet. AgentCrush indexes ERC-8004 registrations across chains; verification status contributes +10 to the composite trust score at /api/agent/{handle}/trust. Spec: EIP-8004.