---
title: "How to Build Passwordless Auth With Twilio Verify in Rust"
description: "Passwordless authentication replaces passwords with one-time codes delivered by SMS, and this tutorial builds a Rust app around that flow. The app uses Twilio Verify for OTP generation and validation, with GET and POST routes at \"/\" for collecting a phone number and at \"/verify\" for entering the received code. It sets up a Cargo project with Axum, Handlebars templates, sessions, dotenvy configuration, and the rustlio Twilio client, while environment variables hold the Account SID, Auth Token, and Verify Service SID. The implementation also serves HTML forms and static assets, with verification status rendered as a success or error message. Running cargo run starts the server on port 8080, where users can submit a number, receive an SMS, and see whether the verification code is valid."
---

# How to Build Passwordless Auth With Twilio Verify in Rust

[Twilio](https://yomu.fyi/company/twilio) · Matthew Setter · Aug 19, 2026

**Type:** Tutorial

## Summary

Passwordless authentication replaces passwords with one-time codes delivered by SMS, and this tutorial builds a Rust app around that flow. The app uses Twilio Verify for OTP generation and validation, with GET and POST routes at "/" for collecting a phone number and at "/verify" for entering the received code. It sets up a Cargo project with Axum, Handlebars templates, sessions, dotenvy configuration, and the rustlio Twilio client, while environment variables hold the Account SID, Auth Token, and Verify Service SID. The implementation also serves HTML forms and static assets, with verification status rendered as a success or error message. Running cargo run starts the server on port 8080, where users can submit a number, receive an SMS, and see whether the verification code is valid.

## Context

Typing or generating unique passwords for each account or website is described as a hassle. The tutorial presents passwordless authentication as a more streamlined alternative that can reduce password-related breaches, eliminate password management, and simplify the login experience.

## Approach / What changed

The implementation creates a Rust application with Axum routes and HTML templates for requesting and validating OTP codes. Twilio Verify handles OTP generation and validation, while dotenvy supplies the Twilio Account SID, Auth Token, and Verify Service SID through environment variables. Sessions, static asset routes, and verification status templates complete the application flow.

## Takeaways

- The authentication flow uses a phone number as the user identifier, sends a temporary OTP through Twilio Verify, and validates the submitted code through the same service.
- The application exposes GET and POST routes at "/" for requesting an OTP and at "/verify" for submitting the received code.
- The setup requires TWILIO\_ACCOUNT\_SID, TWILIO\_AUTH\_TOKEN, and TWILIO\_VERIFY\_SERVICE\_SID environment variables, plus a Twilio Verify service configured in the Twilio Console.

**Tags:** [Authentication](https://yomu.fyi/topic/authentication), [Axum](https://yomu.fyi/topic/axum), [Rust](https://yomu.fyi/topic/rust), [Twilio](https://yomu.fyi/topic/twilio)

- Source: [Twilio](https://www.twilio.com/en-us/blog/developers/tutorials/product/build-passwordless-auth-with-twilio-verify-rust)
- Source URL: https://www.twilio.com/en-us/blog/developers/tutorials/product/build-passwordless-auth-with-twilio-verify-rust
- Ingested by Yomu: 2026-09-09T13:35:11.622Z

[Read original post](https://www.twilio.com/en-us/blog/developers/tutorials/product/build-passwordless-auth-with-twilio-verify-rust)