> ## Documentation Index
> Fetch the complete documentation index at: https://docs.kameleoon.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Initialize session

> Initialize a Product Recommendation API session to obtain a device ID and session ID before calling any other recommendation endpoints.

Before using any other API method in the Product Recommendation API, call the `init` API. The initialization process accepts the current user identifier and requests the project settings and user preferences.

## HTTP Request

```html theme={null}
GET https://api.products.kameleoon.com/init
```

## When to initialize

Depending on your platform, there are different requirements for when you need to run `init`:

* **cURL**: Initialize each time the page is rendered.
* **Web**: Initialize each time the page is opened (including single-page applications).
* **iOS** or **Android**: Initialize each time the application launches.

On the first launch on a new device, a device identifier is missing. Call the `init` method without a device ID to generate one. For backend recommendation logic with Kameleoon Web Experimentation, call this API and store the IDs in the `KameleoonProducts_session_code` cookie for `sid` and `KameleoonProducts_device_id` for `did`.

## Query parameters

| Parameter | Type   | Required | Description                                                                                                                                                                                                                                                                                                                                                                                                |
| --------- | ------ | -------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `shop_id` | String | True     | Your Store Key. You can find this in **Recommendations** > **Settings** > **Store settings** in the Kameleoon app. You can also contact your Customer Success Manager for the key                                                                                                                                                                                                                          |
| `did`     | String | False    | A device ID. If a device ID already exists, specify it here. If you don't specify a `did`, the API will generate new one in the Kameleoon database. Use this generated id as the device ID for all future requests                                                                                                                                                                                         |
| `sid`     | String | True\*   | A session ID is a temporary identifier assigned to the user for the current session. It must be a unique string and will be regenerated every time a new session starts. For the initial init request, do not include a `sid`. The `sid` will be generated by Kameleoon and returned in the API response. If a `sid` is specified in the request and it does not exist in the system, an error will occur. |

<Note>
  While the `sid` parameter is required, do not add it during the first initialization, as the system generates it and returns it in the response (as `seance`).

  Once generated, use the system-generated `sid` for requests within the current session.
</Note>