Twilio provides a simple hosted API and markup language for businesses to quickly build scalable, reliable and advanced voice and SMS communications applications. Twilio provides a telephony infrastructure web service "in the cloud", enabling web programmers to integrate real-time phone calls into their applications. Twilio's simple Pay-As-You-Go pricing model means customers pay for capacity only when they need it, not before. Voice applications written on Twilio's cloud solution scale transparently, eliminating programming, operational and contractual headaches frequently associated with rapid growth or traffic spikes.
The SMS API allows users to send and receive SMS messages from their applications. The API can implement short code technology to allow both faster and higher volume sms messaging. Example uses of the API include sending customers automatic SMS messages, multi-factor authentication and interactive polling. The API uses a RESTful interface and responses are formatted in XML.