# API

You can trade permissionlessly using CAP's smart contracts without a UI.

### Parameter Formatting

All numbers should be submitted in **base units** (8 decimals) unless otherwise noted. So 10 ETH would be submitted as `10 * 10^8 = 1000000000`.

Parameters that require specific formatting:

#### productId

The product you want to trade, submitted in bytes32 format.

* ETH-USD: `0x4554482d55534400000000000000000000000000000000000000000000000000`
* BTC-USD: `0x4254432d55534400000000000000000000000000000000000000000000000000`

**currency**

The address of the currency you want to use for your trade.

* ETH: `0x0000000000000000000000000000000000000000`
* USDC: `0xff970a61a04b1ca14834a43f5de4533ebddb5cc8`

### Trading

Go to the [trading contract ](https://arbiscan.io/address/0xbEd32937D8A5D1421241F52809908f1a17D75bDb)and connect your wallet.

#### Submit an order

Scroll down to submitOrder and enter:

* **`payableAmount`** is your margin if submitting an ETH based trade. Enter the amount in wei (18 decimals). For ERC20 based trades, leave this blank and enter the amount in the **margin** field.
* **`productId`**.
* **`currency`**.
* **`isLong`**. Enter 1 to go long, 0 to go short.
* **`margin`**. In base units.
* **`size`**. In base units. Size / margin determines your position's leverage.

#### Cancel an order

If your order has not yet been executed by the oracle, you can cancel it. Scroll down to cancelOrder and enter:

* **`productId`.** Your order's productId.
* **`currency`**. Your order's currency.
* **`isLong`**. Your order's direction (1 for long, 0 for short).

#### Close a position

Scroll down to submitCloseOrder and enter:

* **`payableAmount`** is the fee to pay if submitting an ETH based trade. Enter the amount in wei (18 decimals), usually 0.1% \* your trade size. Otherwise leave blank.
* **`productId`**. Your position's productId.
* **`currency`**. Your position's currency.
* **`isLong`**. Your position's direction.
* **`size`**. In base units. The amount you want to close.