> For the complete documentation index, see [llms.txt](https://foodcommerce-api-help.onlinesales.ai/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://foodcommerce-api-help.onlinesales.ai/user-tracking-events/js-sdk/track-purchases.md).

# Track Purchases

You can use the OnlineSales.ai pixel to track the visitors actions like a `Purchase`Tracked product purchases are used to compute the sales score, user's affinity to product, user's spend capacity and other signals which helps in measurement & optimising the campaigns. 

### Requirements

The pixel's [base code](/user-tracking-events/js-sdk/installing-the-tag.md#base-code) must already be installed on every page where you want to track conversions.

### Trigger

`purchase` event should be fired when a user completes the purchase of the product. i.e. after the payment is successful and the order id is generated.

### JS API

All events are tracked by calling one of the library's function with a JSON object as it's parameters.

Following is a function call to track when a visitor views cart on your website.

```javascript
// with minimum required parameters
_osSaleComplete({
    "products": [{
        "skuId": "XYZ-1231-1233",
        "sellerId": "SID-9999",
        "productPrice": "899",
        "quantity": "2" // optional. Defaults to 1
    },{
        "skuId": "ABC-1231-1233",
        "sellerId": "XID-123123",
        "productPrice": "99",
    }],
    "totalAmount": "998",
    "currency": "INR",
    "orderId": "OR-94716273-S",
    "cli_ubid": "ubid-83789ssb"
}) 
```

{% hint style="success" %}
This function takes the same parameters as the `_osViewCart` The only different is ViewCart event is fired on the load of cart page and `_osCheckout` is fired on a button click (which initiates the billing & payment process) of the cart page.
{% endhint %}

List of all the standard events can be found [here](/user-tracking-events/js-sdk/references.md#standard-events).

### Object Properties of *Products* key

You can include the following predefined object properties with any events that support them. Format your parameter object data using JSON.

| **Property Key** | **Parameter Description**                                                                                                                                   |
| ---------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| category         | Category of the menu item. This should be the same as what is given in the menu item catalog. While this is optional, this parameter is highly recommended. |
| productPrice     | Price of single menu item without the currency symbol                                                                                                       |
| currency         | Currency of the menu item's price. Eg: "INR". This should be a 3 letter ISO standard                                                                        |
| discount         | Discounted price of single menu item                                                                                                                        |
| skuId            | The id of the menu item. This should be the same as what is given in the menu item catalog. This is a mandatory parameter.                                  |
| sellerId         | The id of the restaurant who is selling this menu item. This is mandatory in case of aggregators.                                                           |
| quantity         | Number of product quantity added to the cart. This is optional and defaults to 1                                                                            |
| totalAmount      | Total cart amount. Sum of all the menu item's prices. This may include taxes / discounts in case of saleComplete event.                                     |
| orderId          | The order id which is generated and shown to the users on the website.                                                                                      |
| paymentMethod    | The payment method used to complete the transaction                                                                                                         |
| cli\_ubid        | Client generated user id. If set, this takes precedence over ubid passed in the cookie. Once generated for a user, it should be same for all the API calls. |

Complete list of object properties can be found [here](/user-tracking-events/js-sdk/references.md).

Example call of function with all the product properties

```javascript
// with all parameters
_osSaleComplete({
    "products": [{
        "skuId": "XYZ-1231-1233",
        "sellerId": "SID-9999",
        "category": "Pizza > Veg Pizza",
        "productPrice": "999", // price of single product
        "currency": "INR",
        "discount": "899", // discounted price of single product
        "quantity": "2"
    },{
        "skuId": "ABC-1231-1233",
        "sellerId": "XID-123123",
        "category": "Pizza > Veg Pizza",
        "productPrice": "999", // price of single product
        "currency": "INR",
        "discount": "899", // discounted price of single product
        "quantity": "2"
    }],
    "totalAmount": "3596",
    "currency": "INR",
    "orderId": "OR-94716273-S",
    "paymentMethod": "CreditCard",
    "cli_ubid": "ubid-83789ssb"
})
```