> ## Documentation Index
> Fetch the complete documentation index at: https://docs.xo.market/llms.txt
> Use this file to discover all available pages before exploring further.

# Orderbook API Reference

> Public REST surface of the XO CLOB orderbook.

The XO Orderbook API is the public REST surface of the CLOB. The endpoints in this section are generated from the live [OpenAPI spec](https://github.com/xomarket).

For narrative context on the smart-account identity model and EIP-712 signing domains, see [Smart accounts](/guides/smart-accounts).

## Server

|          | Value                          |
| -------- | ------------------------------ |
| URL      | `https://orderbooks.xo.market` |
| Chain id | `3223`                         |

The CTF Exchange address (`0x4bC5E872256D12E6017dfe466E04c867DC761B77`) and chain id (`3223`) are part of the EIP-712 order domain — signatures are tied to this deployment. See the [introduction](/) for the full contract list and the mainnet RPC / bundler endpoints.

## Wire conventions

* Prices are trimmed decimal strings (e.g. `"0.5"`, `"0.555"`).
* Sizes are decimal-string integers in human shares.
* Timestamps in trade and book responses are stringified Unix seconds / milliseconds.
* Token IDs are decimal U256 strings; condition IDs are `0x`-prefixed 32-byte hex.

<Note>
  Only XO smart-account orders (`signatureType = 3`) are accepted today. Direct EOA orders (`signatureType = 0`) will be rejected.
</Note>

## Next steps

<CardGroup cols={2}>
  <Card title="Authentication" icon="shield-halved" href="/api-reference/authentication">
    L1 ClobAuth and L2 HMAC headers.
  </Card>

  <Card title="Rate limits" icon="gauge-high" href="/api-reference/rate-limits">
    Per-tier request and connection limits.
  </Card>

  <Card title="Data API reference" icon="database" href="/data-api-reference/introduction">
    Market discovery and public portfolio reads.
  </Card>
</CardGroup>