Twilio webhooks

Twilio webhooks trigger HTTP POST requests to your server the instant a user sends a text, places a call, or interacts with your application.

Twilio webhooks eliminate polling by pushing real-time event data directly to your application via HTTP. When a customer sends an SMS to your Twilio number or an Programmable Voice call connects, Twilio executes a request to your configured URL (often a Node.js or Python endpoint). Your server responds with TwiML (Twilio Markup Language) to control the next move: play an MP3, record a message, or route a text to a CRM. Security is handled through X-Twilio-Signature headers, ensuring every payload originates from Twilio's infrastructure rather than a malicious actor.

https://www.twilio.com/docs/usage/webhooks