# User Creation (via Authentication Code)

For every user on your platform there must exist an associated user on the Sentiance platform. The process of associating users between the platform is accomplished using the `createUser` method on the Sentiance SDK.

Your mobile application requires an **authentication code** in order to execute the `createUser` SDK method. The below instructions details how you can fetch an authentication code from the Sentiance Platform.

### Generate an authentication code for a user

1. Create a `user_link` API key from the "Insights-Control-Tower > Developer > API Keys"
2. Request a authentication code from <https://api.sentiance.com/users/auth-code> (method: POST)
   1. Use the `user_link` key as the `Authorization Bearer` header
   2. Set the request body as `{"external_id": "<user-id-on-your-platform">}`
3. Retrieve the `authentication_code` for the response body
4. Return the code to your mobile application
5. Use this code in `createUser` method. See [this](https://docs.sentiance.com/sdk/appendix/user-creation#creating-a-user-on-the-device) example.

{% hint style="info" %}
Other endpoints are available for specific regions. For our US customers, please use the \[<https://api.p15.sentiance.com/users/auth-code]\\(https://api.p15.sentiance.com/users/auth-code> endpoint. For our Indian customers, please use the <https://api.r16.sentiance.com/users/auth-code> endpoint
{% endhint %}

Note: An authentication code has a very small expiration (approx 10 mins)

You can find a code reference in our [sample application](https://github.com/sentiance/sample-apps-api/blob/master/src/routes.js#L38).

{% hint style="info" %}
This operation must be performed during the **signup** and **login** workflows of your application.

Similarly execute the "reset" SDK method when a user **logs out** of your application
{% endhint %}