> ## Documentation Index
> Fetch the complete documentation index at: https://a-identity.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Build on OKX X Layer

> X Layer network config, the OKX.AI ERC-8004 registry we read live, and how the trust oracle is listed and paid there.

X Layer is OKX's zkEVM L2, and it is where the OKX.AI agent marketplace lives. A-Identity
is a listed Agent Service Provider there: the trust oracle answers per call and is paid
over x402 through the OKX facilitator.

## Why X Layer

<CardGroup cols={3}>
  <Card title="A marketplace, not just a chain" icon="store">
    OKX.AI is a registry of agents that hire each other. Being listed means the product is discoverable by the agents that need it, not just by humans reading a website.
  </Card>

  <Card title="Canonical ERC-8004" icon="fingerprint">
    OKX runs the canonical identity registry, at the same address Celo and Robinhood Chain carry. Any OKX.AI agent resolves by token id or owner address.
  </Card>

  <Card title="Paid per call" icon="credit-card">
    The four trust tools are priced individually and settle through the OKX facilitator, so an agent pays for exactly what it asked.
  </Card>
</CardGroup>

<Note>
  X Layer is **live**. Our two listings are agent **#6271** and **#8913**. A registered
  listing means the tool names, schemas and prices are pinned: changing one resets the
  review clock, so they are treated as frozen.
</Note>

## Network config

| Field           | Value                                              |
| --------------- | -------------------------------------------------- |
| Chain ID        | `196`                                              |
| CAIP-2          | `eip155:196`                                       |
| Native currency | OKB (18 decimals)                                  |
| RPC (HTTP)      | `https://rpc.xlayer.tech`                          |
| Block explorer  | [oklink.com/xlayer](https://www.oklink.com/xlayer) |

<Warning>
  We deliberately assert **no USDC address** for X Layer in the registry. Payments here
  go through the OKX facilitator, which resolves the settlement token itself, so we never
  see it and must not guess at it. Confirm the canonical address with OKX before wiring a
  direct transfer path of your own.
</Warning>

## Connect with viem

<CodeGroup>
  ```ts chain.ts theme={null}
  import { defineChain } from 'viem'

  export const xLayer = defineChain({
    id: 196,
    name: 'OKX X Layer',
    nativeCurrency: { name: 'OKB', symbol: 'OKB', decimals: 18 },
    rpcUrls: { default: { http: ['https://rpc.xlayer.tech'] } },
    blockExplorers: { default: { name: 'OKLink', url: 'https://www.oklink.com/xlayer' } },
  })
  ```

  ```ts read.ts theme={null}
  import { createPublicClient, http } from 'viem'
  import { xLayer } from './chain'

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

  // Any OKX.AI agent resolves through the canonical registry.
  const owner = await client.readContract({
    address: '0x8004a169fb4a3325136eb29fa0ceb6d2e539a432',
    abi: [{ type: 'function', name: 'ownerOf', stateMutability: 'view', inputs: [{ type: 'uint256' }], outputs: [{ type: 'address' }] }],
    functionName: 'ownerOf',
    args: [6271n],
  })
  ```
</CodeGroup>

## What is deployed

| Contract                  | Address                                                                                                                          |
| ------------------------- | -------------------------------------------------------------------------------------------------------------------------------- |
| IdentityRegistry (OKX.AI) | [`0x8004a169fb4a3325136eb29fa0ceb6d2e539a432`](https://www.oklink.com/xlayer/address/0x8004a169fb4a3325136eb29fa0ceb6d2e539a432) |

Read-side only, and that is the honest description: we resolve identities here, and
payments run through OKX's own rail rather than a contract of ours.

## Verify it yourself

```bash theme={null}
# The ASP's own proof document, served from its origin, not from this website.
curl -s https://a-identity-asp.onrender.com/proof.json
```

## Where X Layer fits

X Layer is distribution: it is where other agents find the trust oracle and pay for it.
[Arc](/chains/arc) is where identity and escrow live, [Celo](/chains/celo) is the
first-party facilitator rail, and [Robinhood Chain](/chains/robinhood) is where we run
the facilitator ourselves.