> For the complete documentation index, see [llms.txt](https://docs.nekodex.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nekodex.org/nekodex-playground/docs-for-devs/contracts/order-gateway.md).

# Order Gateway

## Overview

The order gateway has two contracts

* DelayedOrderGateway
* orderGatewayV2 (used by front end and [API](/nekodex-playground/docs-for-devs/api.md))

DelayedOrderGateway is covered here; orderGatewayV2 is limited to use by the Perp v3 frontend and API (no external functions for direct contract interaction).

The order gateways have two key roles:

1. Route orders to the optimal liquidity source
2. Prevent trades from front-running the oracle using a 3 second delay

## Workflow

1. Call `createOrder()` to generate an order, including `createdAt` and `executableAt` timestamps
2. Wait for `executableAt()` timestamp
3. Call `executeOrder()` with `orderId` to execute a trade
4. Call `cancelOrder()` with `orderID` to cancel an unexecuted order

## Contract

<pre class="language-solidity" data-overflow="wrap"><code class="lang-solidity">struct DelayedOrder {
    DelayedOrderType orderType; // Types: OpenPosition or ClosePosition
    address sender; // Sender address
    uint256 <a data-footnote-ref href="#user-content-fn-1">marketId</a>; // See annotation
    uint256 createdAt; // block.timestamp
    uint256 executableAt; // block.timestamp + orderDelaySeconds
    bytes data;
}
</code></pre>

{% code overflow="wrap" %}

```solidity
/// @notice Create an order (but do not execute)
function createOrder(
    DelayedOrderType orderType, 
    bytes calldata data
) 

emit OrderCreated(
    orderId, 
    delayedOrder.sender, 
    marketId, 
    abi.encode(delayedOrder)
);
```

{% endcode %}

{% code overflow="wrap" %}

```solidity
/// @notice Execute an order (probably first call createOrder)
function executeOrder(
        uint256 orderId,
        bytes calldata makerData
)

returns (
        int256 base, 
        int256 quote
);
```

{% endcode %}

<pre class="language-solidity" data-overflow="wrap"><code class="lang-solidity"><strong>/// @notice Cancel unexecuted order
</strong><strong>function cancelOrder(
</strong>    uint256 orderId
)

emit OrderCanceled(
    orderId
);
</code></pre>

```solidity
/// @notice There are many public view functions available
function getCurrentNonce() public view returns (uint256) {
        return _getOrderGatewayStorage().nonce;
}

function getOrdersCount() public view returns (uint256) {
    return _getOrderGatewayStorage().orderIds.length();
}

function getOrderIds(uint256 start, uint256 end) public view returns (uint256[] memory) {
    return _getOrderGatewayStorage().orderIds.valuesAt(start, end);
}

function getUserOrdersCount(address taker) public view returns (uint256) {
    return _getOrderGatewayStorage().userOrderIdsMap[taker].length();
}

function getUserOrderIds(address taker, uint256 start, uint256 end) public view returns (uint256[] memory) {
    return _getOrderGatewayStorage().userOrderIdsMap[taker].valuesAt(start, end);
}

function getOrder(uint256 orderId) public view returns (DelayedOrder memory) {
    return _getOrderGatewayStorage().ordersMap[orderId];
}
```

[^1]: See [Contracts](/nekodex-playground/docs-for-devs/contracts.md#metadata)