---
canonical: "https://www.softatlas.io/bandwidth/products/authentication-api"
name: "Authentication API"
provider: "Bandwidth"
category: "IT & Security / Identity & Access Management / Multi-Factor Authentication"
review_count: 0
ai_powered: false
website: "https://www.bandwidth.com/products/authentication-api"
updated: "2026-07-29"
---

# Authentication API

By [Bandwidth](/bandwidth.md)

The Authentication API provides tools for verifying user identities through phone number verification and two-factor authentication.

## Features
- Verify user identities through phone number verification
- Implement two-factor authentication for enhanced security
- Customize authentication messages and codes
- Use existing phone numbers for sending authentication codes
- Pay only for successful authentication attempts
- Send one-time passcodes via SMS and voice
- Integrate authentication capabilities with existing telecom infrastructure
- Support landline authentication with voice calling

## Built for
DEVELOPERS, OPERATIONS, CUSTOMER_SUPPORT

Source: https://www.softatlas.io/bandwidth/products/authentication-api