How to Build Passwordless Auth With Twilio Verify in PHP

Summary

Passwordless authentication with PHP and Twilio Verify replaces password entry with a phone-based one-time passcode flow, intended to reduce password-related risk and simplify sign-in. The tutorial uses a Slim base project, Composer dependencies, Dotenv configuration, a Twilio Verify Service SID, and PHP session state to support the flow. Users submit a phone number through the root route; the server asks Twilio Verify to send an SMS OTP, redirects to /verify, and checks the submitted code through the verification endpoint. The example’s verification form restricts input to a six-digit numeric value, and the application reports whether verification succeeded or failed after testing locally with composer serve on port 8080.

Takeaways

1. 1

   The application uses GET and POST handlers for both / and /verify to display forms, send an OTP, and validate the submitted code.

2. 2

   The .env configuration contains TWILIO_ACCOUNT_SID, TWILIO_AUTH_TOKEN, and TWILIO_VERIFY_SERVICE_SID, which are loaded and required at startup.

3. 3

   The verification form uses pattern, maxlength, and numeric input settings to guide entry of a six-digit SMS code.