FusionAuth
FusionAuth is the authentication and authorization platform engineered for developers who demand flexibility and control. Built from the ground up to integrate with any stack, every feature — from user registration to MFA and SSO — is exposed via a modern, well-documented API.
Support for every major identity protocol is included out of the box: OIDC, SAML, OAuth2, JWT, passwordless login, social sign-on, and more. Whether you’re building a greenfield app or retrofitting auth into a legacy system, FusionAuth adapts to your use case — not the other way around.
Need compliance? FusionAuth helps you meet GDPR, HIPAA, and COPPA standards quickly and reliably.
Deploy it your way: install on Linux, Windows, macOS, Docker, or Kubernetes — or go with FusionAuth Cloud, our managed SaaS hosting. No black boxes. No vendor lock-in. Just powerful, customizable auth that works the way you do.
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Kinde
Kinde is auth for modern applications. Our powerful user authentication integrates in minutes and has a free tier to let you get started straight away. Every aspect of Kinde is designed to help your business grow and scale. From startup to IPO in a single platform.
Authentication happens at some of the most important, and highly impactful, places in your customers' journey. Our powerful builder allows you to make sure that your pages are on brand and as beautiful as the rest of your website and product experience.
Up-level your security with multi-factor authentication (MFA). Give your users access to advanced authentication options, protecting them from reused or breached passwords.
Take control of user authorization and access with enterprise SSO and custom SAML so that you can support your biggest customers as quickly as possible.
Manage users from one beautiful dashboard or using the API. Add and invite users, manage roles and permissions, and get a complete picture of your user activity.
Controlling who can access which individual pieces of data and interface is critical to protecting your business and your customers. Hierarchical role-based access control is the best way to manage this. Allowing strict control and flexible assignment – aligning everything from your business view of the world right down to the code you ship to customers.
Kinde was created by founders and engineers to help businesses generate more revenue, reduce costs and make lifelong loyal customers – in one place. Every day, Kinde gives our community of founders and partners across the globe, the infrastructure they need to build anything they can imagine.
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Nextacular
Nextacular is an open-source starter kit crafted to accelerate the creation of full-stack, multi-tenant SaaS applications. Utilizing modern technologies such as Next.js, Tailwind CSS, and Prisma, it presents a comprehensive set of features designed to simplify the development journey. Among its offerings are authentication mechanisms using magic links and social logins facilitated by NextAuth, as well as seamless database integration with relational databases like PostgreSQL and MySQL. The kit also supports multi-tenancy, enabling service to multiple customers across various subdomains or bespoke domains from a single, unified codebase. Furthermore, Nextacular incorporates functionality for teams and workspaces, enabling users to easily invite colleagues to collaborate within designated workspaces. In addition, the platform features a customizable landing page, efficient billing and subscription management via Stripe integration, and versatile design components crafted with Tailwind CSS that can be adapted to fit your unique design system. With these capabilities, Nextacular empowers developers to focus on building innovative solutions without getting bogged down in repetitive setup tasks.
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SaaSy Land
SaaSy Land serves as an open-source starter template tailored for Next.js 14 full-stack projects, crafted to streamline the creation and deployment of SaaS offerings, marketing websites, blogs, and additional applications. It features sophisticated authentication options such as email verification, password resets, magic links, and OAuth provider integration, all powered by NextAuth. The template accommodates various database setups, ensuring efficient data handling and quick content delivery. Additionally, it comes with a Markdown and MDX-integrated blog system that supports SEO-friendly content management, along with Stripe integration for hassle-free online transactions and transactional email support via Resend and React Email. Utilizing Tailwind CSS and Shadcn UI components, SaaSy Land guarantees a contemporary and customizable aesthetic. Comprehensive documentation aids in straightforward customization, empowering developers to concentrate on the unique functionalities pertinent to their business. With everything meticulously configured and adhering to industry standards, you can significantly reduce both time and effort in your development process, ultimately allowing for a more efficient launch of your projects.
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