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ERC-8004

Type-safe Rust SDK for the ERC-8004 Trustless Agents standard — on-chain identity, reputation, and validation registries for AI agents.

What is ERC-8004?​

ERC-8004 enables discovery, reputation, and validation of AI agents across organizational boundaries without pre-existing trust. The standard defines three on-chain registries:

  • Identity Registry (ERC-721) — register agents as NFTs with metadata URIs, wallets, and service endpoints.
  • Reputation Registry — submit and query aggregated feedback scores for agents.
  • Validation Registry — request and respond to capability validation assessments.

Quick Start​

cargo add erc8004

Query an Agent (Read-Only)​

use alloy::{primitives::U256, providers::ProviderBuilder};
use erc8004::{Erc8004, Network};

let provider = ProviderBuilder::new()
    .connect_http("https://eth.llamarpc.com".parse()?);

let client = Erc8004::new(provider)
    .with_network(Network::EthereumMainnet);

// Identity Registry — ERC-721 agent identity
let identity = client.identity()?;
let owner  = identity.owner_of(U256::from(1)).await?;
let uri    = identity.token_uri(U256::from(1)).await?;
let wallet = identity.get_agent_wallet(U256::from(1)).await?;

Register an Agent (Write)​

use alloy::{network::EthereumWallet, providers::ProviderBuilder, signers::local::PrivateKeySigner};
use erc8004::{Erc8004, Network};

let signer: PrivateKeySigner = std::env::var("PRIVATE_KEY")?.parse()?;
let wallet = EthereumWallet::from(signer);

let provider = ProviderBuilder::new()
    .wallet(wallet)
    .connect_http("https://sepolia.base.org".parse()?);

let client = Erc8004::new(provider)
    .with_network(Network::BaseSepolia);

let agent_id = client.identity()?
    .register_with_uri("https://my-agent.example.com/erc8004.json")
    .await?;

Architecture​

ModuleDescription
Erc8004Top-level client — generic over P: Provider, builder pattern
IdentityIdentity Registry (ERC-721) — register, manage URIs, wallets, metadata
ReputationReputation Registry — submit / revoke feedback, read aggregated summaries
ValidationValidation Registry — request / respond to validation, query status
Network18 pre-configured deployments with CREATE2 deterministic addresses
typesOff-chain JSON types — RegistrationFile, ServiceEndpoint, Feedback

Design Highlights​

  • Zero async_trait — pure RPITIT, no trait-object overhead
  • Inline Solidity bindings — sol! macro preserves full type information
  • Provider-generic — works with any alloy transport (HTTP, WebSocket, IPC)
  • Lightweight instances — each registry call creates a zero-alloc contract handle

Source Code​