A-Identity Docs : Passport & Wallet for the Agentic Economy

Robinhood Chain is Robinhood’s own Arbitrum Orbit L2, built for tokenized real-world assets, with ETH as the gas token and Ethereum for data availability. A-Identity runs agent identity there, and settles paid trust calls there in USDG.

Why this chain

Agents will trade here

It is the chain built around tokenized stocks and ETFs, and Robinhood has opened its surfaces to AI agents while stating plainly that it does not supervise them. That gap is the product.

ERC-8004 is already live

The canonical identity and reputation registries were deployed here by their authors, at the same addresses they carry on X Layer and Celo. Nothing had to be forked.

Gasless payments work

USDG implements EIP-3009, so a buyer can sign a transfer and never touch gas. Our facilitator broadcasts it.

Mainnet (4663) is live for us: agent #0 on the canonical registry is ours, and paid trust calls settle here in USDG. Testnet (46630) is beta, and carries the full canonical ERC-8004 trio plus a deployed AgentSpendPolicy vault. Every claim on this page is checkable at /proof/robinhood.

Network config

Field	Mainnet	Testnet
Chain ID	`4663`	`46630`
CAIP-2	`eip155:4663`	`eip155:46630`
Native currency	ETH (18 decimals)	ETH (18 decimals)
RPC (HTTP)	`https://rpc.mainnet.chain.robinhood.com`	`https://rpc.testnet.chain.robinhood.com`
Block explorer	robinhoodchain.blockscout.com	explorer.testnet.chain.robinhood.com
Faucet	n/a (bridge real ETH)	faucets.chain.link/robinhood-testnet

Two things will bite you here.There is no canonical Circle USDC on either network. Do not copy a USDC address from another chain: it will not be the same token. The settlement token we use on mainnet is Paxos USDG at 0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168, which is the address Paxos documents for this chain. Our registry deliberately leaves the USDC slot empty and names USDG as its own thing.CreateX is not deployed here, on either network, so CREATE3 is unavailable. The deterministic deployer that IS present is the Safe Singleton Factory (0x914d7Fec6aaC8cd542e72Bca78B30650d45643d7), alongside the Arachnid CREATE2 factory. That is what makes the canonical ERC-8004 addresses reproducible here.

Connect with viem

import { defineChain } from 'viem'

export const robinhoodChain = defineChain({
  id: 4663,
  name: 'Robinhood Chain',
  nativeCurrency: { name: 'Ether', symbol: 'ETH', decimals: 18 },
  rpcUrls: { default: { http: ['https://rpc.mainnet.chain.robinhood.com'] } },
  blockExplorers: { default: { name: 'Blockscout', url: 'https://robinhoodchain.blockscout.com' } },
})

export const robinhoodTestnet = defineChain({
  id: 46630,
  name: 'Robinhood Chain Testnet',
  nativeCurrency: { name: 'Ether', symbol: 'ETH', decimals: 18 },
  rpcUrls: { default: { http: ['https://rpc.testnet.chain.robinhood.com'] } },
  blockExplorers: { default: { name: 'Blockscout', url: 'https://explorer.testnet.chain.robinhood.com' } },
})

import { createPublicClient, http } from 'viem'
import { robinhoodChain } from './chain'

const client = createPublicClient({ chain: robinhoodChain, transport: http() })

// Agent #0 is the first agent ever registered on this chain.
const owner = await client.readContract({
  address: '0x8004a169fb4a3325136eb29fa0ceb6d2e539a432',
  abi: [{ type: 'function', name: 'ownerOf', stateMutability: 'view', inputs: [{ type: 'uint256' }], outputs: [{ type: 'address' }] }],
  functionName: 'ownerOf',
  args: [0n],
})

What is deployed

Contract	Network	Address
IdentityRegistry	mainnet	`0x8004a169fb4a3325136eb29fa0ceb6d2e539a432`
ReputationRegistry	mainnet	`0x8004BAa17C55a88189AE136b182e5fdA19dE9b63`
USDG (settlement)	mainnet	`0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168`
IdentityRegistry	testnet	`0x8004A818BFB912233c491871b3d84c89A494BD9e`
ReputationRegistry	testnet	`0x8004B663056A597Dffe9eCcC1965A193B7388713`
ValidationRegistry	testnet	`0x8004Cb1BF31DAf7788923b405b754f57acEB4272`

We did not deploy the mainnet registries. They were already live at their canonical cross-chain addresses when we arrived; what is ours is agent #0, the first token that registry ever minted. On testnet the ValidationRegistry implementation was the one piece missing, and we deployed it by replaying the canonical Safe-Singleton-Factory calldata, which reproduces the same address rather than forking a new one. There is no ValidationRegistry in the mainnet family, mirroring Celo and X Layer, so a KYA result cannot be anchored on-chain there. It is still verified off-chain and recorded; we simply do not claim an anchor that does not exist.

The x402 facilitator

An x402 facilitator is the service a seller calls to verify a payment and settle it. No published facilitator serves this chain, so a seller here has nothing to point an x402 client at. We run one, and it is open: To be precise about what that does and does not claim: gasless EIP-3009 relaying on USDG predates us on this chain by weeks, and an x402 settlement is indistinguishable on-chain from any other relayed authorization. What we could not find, and therefore built, is a facilitator serving the x402 HTTP protocol here.

Endpoint	Access
`GET /api/facilitator/supported`	open
`POST /api/facilitator/verify`	open, read-only
`POST /api/facilitator/settle`	allowlisted by payTo, because we pay the gas
`GET /api/facilitator/proof`	open

Base URL: https://a-identity-backend.onrender.com/api/facilitator. Both x402 wire spellings are accepted for network: the v1 slug (rhchain) and the v2 CAIP-2 id (eip155:4663). The signing domain is proven, not pasted. USDG exposes neither version() nor eip712Domain(), so the EIP-712 domain cannot be read from the contract. We rebuild each candidate domain and accept only the one that reproduces the live DOMAIN_SEPARATOR. If none matches, no payment challenge is served at all, because inviting a buyer to sign against a guessed domain produces an authorization nobody can settle.

Verify it yourself

# The signing domain, straight from the token. Compare it to what /supported publishes.
curl -sX POST https://rpc.mainnet.chain.robinhood.com -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_call","params":[{"to":"0x5fc5360D0400a0Fd4f2af552ADD042D716F1d168","data":"0x3644e515"},"latest"]}'
# -> 0x7a3d7400b27830f4f91c2c16a082486d67c1befecaec2f53b33f1f35d5b62036

# Our provenance ledger, with a live re-read of ownerOf(0) on every request.
curl -s https://a-identity-backend.onrender.com/api/proof/robinhood

# Every settlement, with the transaction that proves it.
curl -s https://a-identity-backend.onrender.com/api/facilitator/proof

Where this chain fits

Arc is where escrow and the spend vault live. X Layer is where the trust oracle is listed. Celo is where x402 settles through a first-party facilitator someone else runs. Robinhood Chain is the one where we had to build the rail ourselves, and it is the chain whose users are agents trading real-world assets, which is exactly the population that needs a policy layer in front of it.

Get Started

Live on OKX.AI

Concepts

Protocols

Chains

The App

Build on Robinhood Chain

Why this chain

Agents will trade here

ERC-8004 is already live

Gasless payments work

Network config

Connect with viem

What is deployed

The x402 facilitator

Verify it yourself

Where this chain fits

​Why this chain

Agents will trade here

ERC-8004 is already live

Gasless payments work

​Network config

​Connect with viem

​What is deployed

​The x402 facilitator

​Verify it yourself

​Where this chain fits

Why this chain

Network config

Connect with viem

What is deployed

The x402 facilitator

Verify it yourself

Where this chain fits