# Orderbook

To indicate current pricing for Native APIs and aggregators, you must send price levels for each supported pair on every network. The recommended frequency is **every second for each pair on every supported network**. 

Below is the message format expected by Native:

```
{ 
  "messageType": "orderbook",
  "message": {
    "chainId": number,  // e.g. 1 (mainnet), 137 (polygon)
    "baseTokenAddress": string,  // e.g. 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2 (WETH)
    "quoteTokenAddress": string,  // e.g. 0xdac17f958d2ee523a2206206994597c13d831ec7 (USDT)
    "side": "buy" | "sell",
    "levels": [
      {
        // string representation of the quantity of current level e.g. (2.5 for 2.5 WETH)
        quantity: string,

        // string representation of the price per unit at that level 
        // (e.g. 3500 for "up to 2.5 WETH at 3500 USDT per WETH")
        price: string
      }
    ]
  }
}
```

{% hint style="info" %}
**Note**: The price levels must be returned in a non-cumulative manner.
{% endhint %}

For example, given the following price levels for the `WETH-USDT` pair:

```
[
   { quantity: "0.001", price: "1600" }, // The first 0.001 ETH is priced at 1600 USDT / WETH
   { quantity: "1", price: "1610" }, // The next 1 ETH is priced at 1610 USDT / WETH
   { quantity: "2", price: "1612" } // The next 2 ETH is priced at 1612 USDT / WETH
]
```

If someone wants to trade 3 WETH for USDT, the price calculation would be: `0.001 * 1600 + 1 * 1610 + 1.999 * 1612 = 4833.988`

{% hint style="info" %}
**Note:**

1. **Price caching:** Native will cache these price levels for a maximum of 5 seconds (or until new levels are published). Prices will be considered expired and invalid if you do not post new price levels within 5 seconds.
2. **Minimum order quantity:** The first level always represents the minimum amount you're looking to buy. If you want to support arbitrarily small amounts, set the first level quantity to "0".
   {% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.native.org/native-dev/build-with-native/market-makers/api-guide/websocket-integration/orderbook.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.