ERC-8004: Agent Trust Protocol

ERC-8004 establishes trust infrastructure for autonomous AI agents, enabling them to discover, identify, and evaluate other agents across organizational boundaries.

When to Use

• Registering an AI agent's identity on-chain
• Building reputation systems for AI agents
• Verifying agent identity before interactions
• Querying agent reputation and feedback
• Implementing trust-based agent interactions

Core Concepts

The Three Registries

Protocol Stack Position

Application Layer (Agent Apps, Marketplaces)
    ↓
Trust Layer (ERC-8004) ← This skill
    ↓
Payment Layer (x402)
    ↓
Communication Layer (A2A, MCP)

Installation

# JavaScript/TypeScript
npm install @chaoschain/sdk

# Python
pip install chaoschain-sdk

Contract Addresses

Celo Mainnet

Celo Sepolia (Testnet)

Agent Registration

1. Create Registration File

Create an agent registration file describing endpoints and capabilities:

{
  "type": "Agent",
  "name": "My AI Agent",
  "description": "Description of capabilities",
  "image": "ipfs://Qm...",
  "endpoints": [
    {
      "type": "a2a",
      "url": "https://example.com/.well-known/agent.json"
    },
    {
      "type": "mcp",
      "url": "https://example.com/mcp"
    },
    {
      "type": "wallet",
      "address": "0x...",
      "chainId": 42220
    }
  ],
  "supportedTrust": ["reputation", "validation", "tee"]
}

2. Upload to IPFS

import { upload } from "@chaoschain/sdk";

const agentMetadata = {
  type: "Agent",
  name: "My AI Agent",
  description: "AI agent for DeFi operations",
  // ...
};

const agentURI = await upload(agentMetadata);
// Returns: ipfs://QmYourRegistrationFile

3. Register Agent

import { IdentityRegistry } from '@chaoschain/sdk';
import { createPublicClient, http } from 'viem';
import { celo } from 'viem/chains';

const client = createPublicClient({
  chain: celo,
  transport: http('https://forno.celo.org'),
});

const registry = new IdentityRegistry(client);

// Register and get agent ID
const tx = await registry.register(agentURI);
const agentId = tx.events.Transfer.returnValues.tokenId;

console.log('Agent registered with ID:', agentId);

Reputation System

Give Feedback

import { ReputationRegistry } from '@chaoschain/sdk';

const reputation = new ReputationRegistry(client);

await reputation.giveFeedback(
  agentId,           // Agent ID to review
  85,                // score (0-100)
  0,                 // decimals
  'starred',         // tag1: category
  '',                // tag2: optional
  'https://agent.example.com',  // endpoint used
  'ipfs://QmDetailedFeedback',  // detailed feedback URI
  feedbackHash       // keccak256 of feedback content
);

Common Feedback Tags

Query Reputation

// Get all feedback for an agent
const feedback = await reputation.readAllFeedback(agentId);

// Get aggregated summary
const summary = await reputation.getSummary(agentId);
console.log('Average rating:', summary.averageScore);
console.log('Total reviews:', summary.totalFeedback);

Trust Verification Workflow

import { IdentityRegistry, ReputationRegistry } from '@chaoschain/sdk';

async function verifyAndInteract(targetAgentId, minReputation = 70) {
  // 1. Verify identity
  const identity = await identityRegistry.getAgent(targetAgentId);
  if (!identity) {
    throw new Error('Agent not registered');
  }

  // 2. Check reputation
  const summary = await reputationRegistry.getSummary(targetAgentId);
  if (summary.averageScore < minReputation) {
    throw new Error(`Agent reputation ${summary.averageScore} below threshold ${minReputation}`);
  }

  // 3. Get endpoint
  const agentData = await fetch(identity.agentURI).then(r => r.json());
  const endpoint = agentData.endpoints.find(e => e.type === 'a2a');

  // 4. Interact with verified agent
  const result = await interactWithAgent(endpoint.url);

  // 5. Submit feedback
  await reputationRegistry.giveFeedback(
    targetAgentId,
    result.success ? 90 : 30,
    0,
    result.success ? 'starred' : 'failed',
    '',
    endpoint.url,
    '',
    ''
  );

  return result;
}

Integration with x402 Payments

ERC-8004 and x402 work together for trustworthy paid agent interactions:

import { IdentityRegistry, ReputationRegistry } from '@chaoschain/sdk';
import { wrapFetchWithPayment } from 'thirdweb/x402';

async function payTrustedAgent(agentId, serviceUrl) {
  // 1. Verify trust
  const summary = await reputationRegistry.getSummary(agentId);
  if (summary.averageScore < 80) {
    throw new Error('Agent not trusted enough for payment');
  }

  // 2. Make paid request
  const fetchWithPayment = wrapFetchWithPayment({
    client,
    account,
    paymentOptions: { maxValue: "1000000" },
  });

  const response = await fetchWithPayment(serviceUrl);
  return response.json();
}

Use Cases

DeFi Trading Agents

Verify strategy agents before delegating funds:

const strategyAgents = await identityRegistry.searchByCapability('defi-trading');
const trustedAgents = [];

for (const agent of strategyAgents) {
  const summary = await reputationRegistry.getSummary(agent.id);
  if (summary.averageScore >= 85 && summary.totalFeedback >= 100) {
    trustedAgents.push(agent);
  }
}

Multi-Agent Workflows

Coordinate trusted agents for complex tasks:

const workflow = {
  research: await findTrustedAgent('research', 80),
  analysis: await findTrustedAgent('analysis', 85),
  execution: await findTrustedAgent('execution', 90),
};

// Execute with trust-verified agents
await executeWorkflow(workflow);

Validation Registry

For high-stakes operations, use Validation Registry for additional verification:

Celo Network Reference

Additional Resources

• EIP Specification
• Official Website
• Learning Portal
• Contracts Repository
• Builder Program

Related Skills

• x402 - Payment layer for AI agents
• celo-rpc - Celo blockchain interaction
• viem - TypeScript Ethereum library