Question: I need a solution that offers multiple authentication methods, such as WhatsApp and email-based codes, to cater to different user preferences.

For a more complete solution that includes support for multiple authentication methods, including WhatsApp and email-based codes, check out OTPless. This modern authentication system offers multiple verification channels, including numeric codes sent over WhatsApp, SMS and email, as well as magic links. It's designed to improve user conversion and security by making authentication easier without sacrificing the security of one-time passwords.

Another good option is Clerk, a full-stack user management platform that handles authentication and user management. Clerk supports a variety of authentication needs, including multifactor authentication, email and SMS one-time passcodes, magic links and password-based authentication. It also includes support for multi-tenancy, custom roles and permissions, and integrates with popular frameworks and tools.

PropelAuth is another good option, particularly for businesses. It's a multi-tenant authentication and authorization service that includes passwordless magic links, SSO and 2FA. PropelAuth supports multiple sign-in methods and includes customizable roles and permissions, so it can be a secure and flexible option for many business needs.

If you're looking for a wider range of security features and integrations, Workflos is an AI-powered option that supports SAML 2.0, OpenID Connect and OAuth 2.0. It includes multi-factor authentication and fine-grained authorization, as well as a unified platform for managing more than 100,000 products across many categories. Workflos also offers a pay-as-you-go pricing model so it can be used for a variety of user needs.