# SMS Rest API overview

This real-time SMS API is built to the very best practice architecture guidelines for RESTful API design. Ideal for developers anticipating a deeper and more extensive integration solution, you can send batches of up to 500 destination numbers per submission in real-time through our international SMS messaging gateway. Interact with Clickatell using JSON or XML.

## **Why use this API?**

* Extremely reliable and convenient to use, with an intuitive, hierarchical and consistent structure, supported by embedded resource links.
* Version control mechanisms to allow for future upgrades.
* Allows for the sending of multi-language Unicode message.
* Simplified token-based authentication on all API commands.
* Embedded resource links to our online technical documents.
* Schedule a message to be sent at a specific time, of up to 7 days ahead.
* Full two-way messaging capabilities.
* Delivery acknowledgment and Sender ID can be set up.
* Supports extended length messages.
* Provides the ability to receive real-time message status notifications to your system.

## **When to use this API**

The REST API is ideal for improving customer service and delighting your customers by using information from your existing CRM system.


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