# API Authentication

This allows you to generate a Promotexter token by authenticating with a client token. The new token can then be used as a bearer token for API requests, such as Viber, WhatsApp, SMS, and Email APIs.
To generate a client token, please refer <a href="https://promotexter-api.redocly.app/clienttoken" target="_blank" rel="noopener noreferrer">here</a>. <br><br>
**Note:** Alternatively, you can use the traditional approach of an API key and secret for authenticating Viber, WhatsApp, SMS, and Email APIs, if your system integration requires it.

 - [POST /generate-token](https://promotexter-api.redocly.app/api/api-authentication/generatepromotextertoken.md): Generate a Promotexter token using the client token and expiresInSeconds required field.<br><br><b>Authentication:</b> use a valid <b>client token</b> in the Authorization header using the format <cod