Standards

1. Identity Registry (ERC-721 based)

• Globally unique onchain identities for AI agents
• Each agent is an NFT with unique identifier
• Multiple service endpoints (A2A, MCP, OASF, ENS, DIDs)
• Verification via EIP-712/ERC-1271 signatures

Contract Addresses (same on 20+ chains):

• IdentityRegistry: 0x8004A169FB4a3325136EB29fA0ceB6D2e539a432
• ReputationRegistry: 0x8004BAa17C55a88189AE136b182e5fdA19dE9b63

Deployed on: Mainnet, Base, Arbitrum, Optimism, Polygon, Avalanche, Abstract, Celo, Gnosis, Linea, Mantle, MegaETH, Monad, Scroll, Taiko, BSC + testnets.

Agent Identifier Format:

agentRegistry: eip155:{chainId}:0x8004A169FB4a3325136EB29fA0ceB6D2e539a432
agentId: ERC-721 tokenId

2. Reputation Registry

• Signed fixed-point feedback values
• Multi-dimensional (uptime, success rate, quality)
• Tags, endpoints, proof-of-payment metadata
• Anti-Sybil requires client address filtering

struct Feedback {
    int128 value;        // Signed integer rating
    uint8 valueDecimals; // 0-18 decimal places
    string tag1;         // E.g., "uptime"
    string tag2;         // E.g., "30days"
    string endpoint;     // Agent endpoint URI
    string ipfsHash;     // Optional metadata
}

Example metrics: Quality 87/100 → value=87, decimals=0. Uptime 99.77% → value=9977, decimals=2.

3. Validation Registry

• Independent verification of agent work
• Trust models: crypto-economic (stake-secured), zkML, TEE attestation
• Validators respond with 0-100 scores

Agent Registration File (agentURI)

{
  "type": "https://eips.ethereum.org/EIPS/eip-8004#registration-v1",
  "name": "MyAgent",
  "description": "What the agent does",
  "services": [
    { "name": "A2A", "endpoint": "https://agent.example/.well-known/agent-card.json", "version": "0.3.0" },
    { "name": "MCP", "endpoint": "https://mcp.agent.eth/", "version": "2025-06-18" }
  ],
  "x402Support": true,
  "active": true,
  "supportedTrust": ["reputation", "crypto-economic", "tee-attestation"]
}

Integration

// Register agent
uint256 agentId = identityRegistry.register("ipfs://QmYourReg", metadata);

// Give feedback
reputationRegistry.giveFeedback(agentId, 9977, 2, "uptime", "30days", 
    "https://agent.example.com/api", "ipfs://QmDetails", keccak256(data));

// Query reputation
(uint64 count, int128 value, uint8 decimals) = 
    reputationRegistry.getSummary(agentId, trustedClients, "uptime", "30days");

Step-by-Step: Register an Agent Onchain

1. Prepare the registration JSON — host it on IPFS or a web server:

{
  "type": "https://eips.ethereum.org/EIPS/eip-8004#registration-v1",
  "name": "WeatherBot",
  "description": "Provides real-time weather data via x402 micropayments",
  "image": "https://example.com/weatherbot.png",
  "services": [
    { "name": "A2A", "endpoint": "https://weather.example.com/.well-known/agent-card.json", "version": "0.3.0" }
  ],
  "x402Support": true,
  "active": true,
  "supportedTrust": ["reputation"]
}

2. Upload to IPFS (or use any URI):

# Using IPFS
ipfs add registration.json
# → QmYourRegistrationHash

# Or host at a URL — the agentURI just needs to resolve to the JSON

3. Call the Identity Registry:

// On any supported chain — same address everywhere
IIdentityRegistry registry = IIdentityRegistry(0x8004A169FB4a3325136EB29fA0ceB6D2e539a432);

// metadata bytes are optional (can be empty)
uint256 agentId = registry.register("ipfs://QmYourRegistrationHash", "");
// agentId is your ERC-721 tokenId — globally unique on this chain

4. Verify your endpoint domain — place a file at .well-known/agent-registration.json:

// https://weather.example.com/.well-known/agent-registration.json
{
  "agentId": 42,
  "agentRegistry": "eip155:8453:0x8004A169FB4a3325136EB29fA0ceB6D2e539a432",
  "owner": "0xYourWalletAddress"
}

This proves the domain owner controls the agent identity. Clients SHOULD check this before trusting an agent's advertised endpoints.

5. Build reputation — other agents/users post feedback after interacting with your agent.

Cross-Chain Agent Identity

Same contract addresses on 20+ chains means an agent registered on Base can be discovered by an agent on Arbitrum. The agentRegistry identifier includes the chain: