Lucid Agents Docs

ERC-8004 is an Ethereum standards-track Draft for agent identity, reputation, and validation registries. Draft specifications may change incompatibly.

Lucid can discover or register an EVM identity, publish registration/OASF metadata, enrich an Agent Card, and operate identity and reputation clients. It does not turn registry presence into an authorization decision.

Support matrix

Capability	Status	Lucid behavior
Identity registry reads/writes	Supported	Register, lookup, metadata, agent wallet, transfer, approval
Registration document	Supported	Generate ERC-8004 registration-v1 JSON and service links
Domain proof	Partial	Message builder and signer; no challenge service or verifier
Reputation registry	Supported	Read summaries/feedback and submit/revoke/respond
Validation registry	Experimental/deprecated	Manual compatibility client only; absent from default clients
OASF service record	Supported	Structured strict-mode record derived partly from entrypoints
EVM chains	Limited	Deployment map for Ethereum, Ethereum Sepolia, and Base Sepolia
Solana identity	Not supported	Payment receiving may still use Solana independently
Trust/safety proof	Not provided	Registry data is evidence that callers must evaluate

Identity is separate from payment

Identity registration is EVM-only and has gas, custody, and on-chain side-effects. Payment receiving is independent: an agent may register identity on Base Sepolia and receive an x402 payment on a supported Solana network.

x402Support in a registration document is a self-description. It does not prove that a payment endpoint is online, correctly configured, or safe.

Trust model

An ERC-8004 identity can establish ownership of an on-chain token and point to off-chain service metadata. Reputation can establish who submitted a feedback event. Neither establishes that:

the described endpoint is currently operated by the owner;
the agent's output is correct or free of prompt injection;
feedback is objective, independent, or Sybil-resistant;
a score is relevant to the action a caller is authorizing;
referenced off-chain content has remained unchanged.

Applications should filter reviewers, verify service/domain bindings, combine several signals, and retain a separate authorization policy.

On-chain and off-chain data

The registry identifier uses an EVM chain, registry contract, and agent ID. Lucid emits a CAIP-10-style agentRegistry such as:

eip155:84532:0x8004A818BFB912233c491871b3d84c89A494BD9e

The on-chain identity points to an agentURI. Host the registration document at that exact URI, version it deliberately, and monitor it for drift. Avoid putting secrets, mutable personal data, or confidential evidence in permanent on-chain metadata or hashes.

Registration safety

const result = await createAgentIdentity({
  runtime,
  domain: 'service.example',
  rpcUrl: process.env.RPC_URL,
  chainId: 84532,
  autoRegister: false,
});

if (!result.record) {
  throw new Error(`Expected an existing identity: ${result.status}`);
}

Keep auto-registration out of request handling. If it is enabled in a deployment step, verify the exact registry addresses, fund a dedicated wallet, cap transaction authority, wait for confirmation, and record the transaction and resulting agent ID.

Validation status

The package retains createValidationRegistryClient() for backward compatibility, but the upstream validation design is still evolving. Lucid does not create result.clients.validation by default. Do not advertise inference validation as an operational capability merely because a trust-model string appears in a card.

Verification checklist

Resolve the chain and registry address from trusted configuration.
Verify the registry deployment and contract version against the official contracts repository.
Resolve the agent ID and current owner on-chain.
Fetch the exact agentURI over an allowed scheme and enforce size/time limits.
Verify domain proof, signature, nonce, and service endpoint ownership where your policy requires them.
Evaluate reputation by reviewer identity, tag, time, and application context—not an unqualified aggregate.
Fail closed when identity is a requirement. Lucid bootstrap may otherwise log a warning and continue without a record.

See the complete @lucid-agents/identity reference for configuration, registry operations, OASF, security, and troubleshooting.