ERC-8004: Trustless Agents

Implementation of the ERC-8004 protocol for agent discovery and trust through reputation and validation.

Testnet Contract Addresses

ETH Sepolia

• IdentityRegistry: 0x8004a6090Cd10A7288092483047B097295Fb8847
• ReputationRegistry: 0x8004B8FD1A363aa02fDC07635C0c5F94f6Af5B7E
• ValidationRegistry: 0x8004CB39f29c09145F24Ad9dDe2A108C1A2cdfC5

Base Sepolia

• IdentityRegistry: 0x8004AA63c570c570eBF15376c0dB199918BFe9Fb
• ReputationRegistry: 0x8004bd8daB57f14Ed299135749a5CB5c42d341BF
• ValidationRegistry: 0x8004C269D0A5647E51E121FeB226200ECE932d55

Linea Sepolia

• IdentityRegistry: 0x8004aa7C931bCE1233973a0C6A667f73F66282e7
• ReputationRegistry: 0x8004bd8483b99310df121c46ED8858616b2Bba02
• ValidationRegistry: 0x8004c44d1EFdd699B2A26e781eF7F77c56A9a4EB

Polygon Amoy

• IdentityRegistry: 0x8004ad19E14B9e0654f73353e8a0B600D46C2898
• ReputationRegistry: 0x8004B12F4C2B42d00c46479e859C92e39044C930
• ValidationRegistry: 0x8004C11C213ff7BaD36489bcBDF947ba5eee289B

Hedera Testnet

• IdentityRegistry: 0x4c74ebd72921d537159ed2053f46c12a7d8e5923
• ReputationRegistry: 0xc565edcba77e3abeade40bfd6cf6bf583b3293e0
• ValidationRegistry: 0x18df085d85c586e9241e0cd121ca422f571c2da6

HyperEVM Testnet

• IdentityRegistry: 0x8004A9560C0edce880cbD24Ba19646470851C986
• ReputationRegistry: 0x8004b490779A65D3290a31fD96471122050dF671
• ValidationRegistry: 0x8004C86198fdB8d8169c0405D510EC86cc7B0551

SKALE Base Sepolia Testnet

• IdentityRegistry: 0x4fa7900596c9830664406d3796952c59ec4133d9
• ReputationRegistry: 0x9b9d23a47697691ef1016906d1f8ddfc009e6a69
• ValidationRegistry: 0x34ae1196b1609e01ebc90b75c802b2ea87203f13

About

This project implements ERC-8004, a protocol that enables discovering, choosing, and interacting with agents across organizational boundaries without pre-existing trust. It provides three core registries:

• Identity Registry: A minimal on-chain handle based on ERC-721 with URIStorage extension that gives every agent a portable, censorship-resistant identifier
• Reputation Registry: A standard interface for posting and fetching feedback signals, enabling composable reputation systems
• Validation Registry: Generic hooks for requesting and recording independent validator checks (e.g., stakers re-running jobs, zkML verifiers, TEE oracles)

Project Structure

contracts/
├── IdentityRegistry.sol     - ERC-721 based agent registration
├── ReputationRegistry.sol   - Feedback and reputation tracking
└── ValidationRegistry.sol   - Validation request/response system

test/
└── ERC8004.ts              - Comprehensive test suite

ERC8004SPEC.md              - Full protocol specification

Key Features

Identity Registry

• ERC-721 NFT-based agent registration with auto-incrementing agent IDs
• Token URI points to agent registration file (IPFS, HTTPS, etc.)
• On-chain metadata storage for key-value pairs (e.g., agentWallet, agentName)
• Support for metadata during registration

Reputation Registry

• Clients can give feedback (0-100 score) with optional tags and off-chain file references
• Pre-authorization via cryptographic signatures (feedbackAuth)
• Support for feedback revocation and responses
• On-chain aggregation (count, average score) with filtering by client addresses and tags
• Multiple feedback entries per client-agent pair

Validation Registry

• Agents request validation from specific validators
• Validators respond with 0-100 scores and optional tags
• Support for progressive validation states
• Track all validations per agent and per validator
• On-chain aggregation with filtering

Installation

npm install

Running Tests

Run all tests:

npm test

Or using Hardhat directly:

npx hardhat test

The test suite includes comprehensive coverage of:

• Agent registration and metadata management
• Feedback submission, revocation, and responses
• FeedbackAuth signature verification (EIP-191)
• Validation requests and responses
• Permission controls and access restrictions
• Summary calculations with filtering
• Edge cases and error conditions

Development

This project uses:

• Hardhat 3 with native Node.js test runner (node:test)
• Viem for Ethereum interactions
• TypeScript for type safety
• OpenZeppelin Contracts for ERC-721 implementation

Protocol Overview

Agent Registration

Each agent is uniquely identified by:

• namespace: eip155 (for EVM chains)
• chainId: The blockchain network identifier
• identityRegistry: The registry contract address
• agentId: The ERC-721 token ID

Trust Models

ERC-8004 supports three pluggable trust models:

1. Reputation: Client feedback and scoring
2. Validation: Stake-secured re-execution, zkML proofs, or TEE oracles
3. TEE Attestation: Trusted Execution Environment verification

Security Considerations

• Pre-authorization mitigates unauthorized feedback but doesn't prevent Sybil attacks
• On-chain pointers and hashes ensure immutable audit trails
• Validator incentives and slashing managed by specific validation protocols
• Reputation aggregation expected to evolve with off-chain services

Resources

• ERC-8004 Full Specification
• Hardhat Documentation
• EIP-721: Non-Fungible Token Standard

License

CC0 - Public Domain