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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Auth0 takes a modern approach to Identity and enables organizations to provide secure access to any application, for any user. Auth0 is highly customizable, and simple yet flexible. Safeguarding billions of login transactions each month, Auth0 delivers convenience, privacy, and security so customers can focus on innovation.
With Auth0, you can rapidly integrate authentication and authorization for web, mobile, and legacy applications, with new Fine Grained Authorization (FGA) that goes beyond role-based access control.
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Just Ship
Just Ship is a completely free and open-source SaaS starter kit crafted with Svelte 5 and SvelteKit, aimed at streamlining web application development by offering a range of essential functionalities right from the start. It features user authentication through magic links and Google social login, while user information is securely stored in a Turso database. The kit comes with more than 30 pre-designed styles powered by daisyUI, ensuring support for dark mode and providing various landing page components to enhance quick UI development. Integrated payment processing via Stripe allows for effortless payment acceptance and webhook management. Analytics are effectively handled through PostHog, which includes configurations that circumvent ad blockers by using Vercel as a proxy, alongside support for A/B testing and feature flags to optimize user engagement. Moreover, it simplifies SEO tag management through the load function and enables email communications via Postmark, with deployment made easy through Vercel, ensuring a comprehensive toolkit for developers looking to launch their applications efficiently. This all-in-one solution not only accelerates the development process but also empowers developers with the tools they need to create robust web experiences.
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LaunchFast
LaunchFast delivers all-inclusive SaaS starter kits tailored for frameworks like Astro, Next.js, and SvelteKit, aimed at accelerating project launches by incorporating vital functionalities such as SEO optimization, analytics tracking, user authentication, payment processing, and email capabilities. These versatile kits offer support for a range of databases, including MongoDB, Firestore, PostgreSQL, Redis, and SQLite, ensuring adaptability in managing data effectively. Additionally, they enable effortless file and document storage by leveraging services such as AWS S3, Cloudflare R2, Firebase Storage, and Supabase Storage. The user authentication process is simplified with options for email and password logins, OAuth 2.0, password reset capabilities, and email verification, along with social login features from major platforms like Google, Facebook, and GitHub. To facilitate billing and payment processing, the kits are integrated with Stripe and LemonSqueezy, allowing for international transactions while ensuring tax compliance. Furthermore, the content management aspect is optimized through the creation of dynamic blog pages and responsive documentation, making use of Markdown and MDX, which enhances overall user experience and engagement. LaunchFast's starter kits are designed to empower developers to focus on building innovative applications rather than getting bogged down by foundational setup tasks.
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