> 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/clearinghouse.md).

# Clearinghouse

All basic exchange functions are kept in the clearinghouse contract. This includes open and close position, and liquidation functions.

{% hint style="info" %}
Find parameters like `marketID` in [Contracts](/nekodex-playground/docs-for-devs/contracts.md#metadata)
{% endhint %}

## `openPosition`

Open a position or update the size of an existing position (you can only have one position in a given asset).

#### Parameters

<pre class="language-solidity"><code class="lang-solidity">struct OpenPositionParams {
        uint256 <a data-footnote-ref href="#user-content-fn-1">marketId</a>;
        address maker; // Maker type, e.g. spotHedgeMaker
        bool isBaseToQuote;
        bool isExactInput;
        uint256 amount;
        uint256 oppositeAmountBound; // Control slippage
        uint256 deadline; // Timestamp
        bytes makerData; // @param makerData Encoded calls are custom data defined by maker
    }
</code></pre>

#### Returns

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

## `closePosition`

Close a position. Note you can also close using `openPosition` and opening an equal size position of the opposite direction (e.g. long closes short).

#### Parameters

```solidity
struct ClosePositionParams {
        uint256 marketId;
        address maker;
        uint256 oppositeAmountBound;
        uint256 deadline;
        bytes makerData;
    }
```

#### Returns

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

## `liquidate`

Liquidate a position. Contract will test the position for eligibility before liquidation.

#### Parameters

```solidity
struct LiquidatePositionParams {
        uint256 marketId;
        address liquidator;
        address trader;
        uint256 positionSize;
    }
```

#### Returns

```solidity
returns (int256 liquidatedAccountBaseDelta, int256 liquidatedAccountQuoteDelta)
```

#### Event

```solidity
event Liquidated(
        uint256 indexed marketId,
        address indexed liquidator,
        address indexed trader,
        int256 positionSizeDelta,
        int256 positionNotionalDelta,
        uint256 price,
        uint256 penalty,
        uint256 liquidationFeeToLiquidator,
        uint256 liquidationFeeToProtocol
    )
```

## `setAuthorization`

Delegate open and close permissions; delegation is currently limited to order gateway contracts only.

## `isLiquidatable`

#### Parameters

```solidity
struct isLiquidatableParams {
        uint256 marketId;
        address trader;
        uint256 price;
    }
```

#### Returns

```solidity
bool
```

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