Twilio API

Twilio provides a robust, cloud-based REST API for embedding programmable communications: send SMS, make voice calls, and manage video sessions at scale.

The Twilio API is the developer's toolkit for global communication, virtualizing the world’s telecom infrastructure. Developers use its RESTful endpoints to programmatically integrate SMS, Voice, and Video directly into applications: for example, sending a two-factor authentication code via text or initiating a VoIP call from a web browser. The platform handles carrier complexity and global reach, allowing you to focus on application logic. Key components include the Programmable Messaging API for SMS/MMS and the Programmable Voice API for call control, all secured via HTTP Basic authentication using your Account SID and Auth Token.

https://www.twilio.com/docs/api