What is an API?
An API (Application Programming Interface) is a way for two different software systems to talk to each other. It defines what requests one system can send to another, and what it gets back in response — without either system needing to know how the other works internally.
A simple way to think about it: every time you use a messaging app, book a cab, or check the weather on your phone, an API is working behind the scenes to fetch or send that data.
How does an API work?
A business’s app sends a request to the API (say, “send this SMS to this number”), the API processes it and talks to the underlying service, then sends back a response (like a delivery status). The most common types are REST APIs (over the internet) and SMPP (commonly used for SMS at scale).
How Onextel helps with APIs
Onextel provides REST APIs and SMPP for SMS, along with APIs for RCS, WhatsApp Business, voice, and email — letting businesses plug messaging and calling directly into their own apps, CRMs, or websites without building it from scratch.
Why it matters
APIs let businesses automate communication — sending OTPs, alerts, or notifications straight from their own systems — instead of doing it manually.