Question: I need a way to authenticate users securely and reliably, can you suggest a multifactor authentication API?

If you're looking for a more mature solution for multifactor authentication, Clerk is worth a look. It's a full-stack user management platform with a library of embeddable UI components, flexible APIs and admin dashboards. Clerk supports many authentication options, including multifactor authentication, advanced security, session management and social sign-on. It also has features for multi-tenancy and integrates with popular frameworks, so it's adaptable for a variety of use cases.

Another top contender is Auth0, an authentication and authorization platform that's secure and flexible. It offers Universal Login, Single Sign-On and Multifactor Authentication, so it's good for managing customer identities in a wide range of industries. Auth0 integrates with more than 30 SDKs and Quickstarts, and it offers a free tier so you can try it out before you pay.

If you're a business that needs a more comprehensive verification and authentication service, Telesign offers a variety of APIs for SMS, voice and phone number intelligence. Its Verify API offers multifactor authentication, silent verification and fraud detection for better security and faster user onboarding. With service in more than 230 countries, Telesign is a good option for e-commerce and financial services.

SecureAuth is another option worth considering, particularly if you want a passwordless continuous authentication service. It offers continuous authentication, invisible MFA, device trust and risk engine, so it can offer a strong but frictionless authentication experience. SecureAuth is good for a variety of use cases, including cyber insurance compliance and VDI security, so it's adaptable for a variety of situations where you want to improve security and user experience.