SolidJS Authentication: What Framework Should You Use?

SolidJS has gained strong momentum among frontend developers who want React-like reactivity without the runtime overhead. Its fine-grained reactivity model and compiler-driven updates make it both fast and predictable — ideal for building modern, high-performance web apps. With SolidStart maturing, more teams are now using it for full-stack development.

But authentication remains a common pain point. Implementing secure sessions, managing refresh tokens, and handling social logins all introduce complexity that’s easy to underestimate. Many SolidJS projects start with a quick JWT-based setup — storing tokens in localStorage and manually attaching them to API requests. It works for a prototype, but it’s brittle at scale: tokens leak, sessions expire inconsistently, and logout flows break under concurrency or SSR.

If you’re building with SolidJS today, the question isn’t whether you need authentication — it’s how to add it securely, without reinventing session logic for the hundredth time.

How Do I Add Authentication in SolidJS?

SolidJS doesn’t include a built-in authentication system, so developers typically choose between a few common approaches. Each option varies in complexity, scalability, and security — and the right choice depends on how far you expect your app to grow.

• Manual JWT / DIY setup: The simplest path is to store JWTs in localStorage and attach them to fetch requests. This works for prototypes but exposes tokens to XSS attacks and makes session refresh logic unreliable.
• Firebase or Auth0: These managed services handle the heavy lifting for you — from signup forms to OAuth. They’re fast to integrate but can introduce vendor lock-in, pricing surprises, and limited backend flexibility.
• Authentication frameworks like SuperTokens: A balanced approach that gives you full control over your backend while providing ready-to-use frontend components, session management, and social login integrations — all open source and easily adaptable to SolidJS.

If you care about long-term security and flexibility, an open-source authentication framework offers a safer, more scalable foundation than one-off JWT logic or vendor-locked SDKs.

What Features Should a SolidJS Authentication Framework Provide?

A good authentication framework should handle the complex parts of identity management so you can focus on your app, not on token lifecycles or OAuth edge cases. The goal is to simplify signup and login, without sacrificing flexibility or security.

• Signup and login forms out of the box: Save time on UI work while ensuring consistent validation and error handling.
• Session management with refresh tokens: Keep users logged in securely without exposing tokens or forcing frequent reauthentication.
• Social login providers (Google, GitHub, etc.): Reduce signup friction and improve user adoption with built-in OAuth flows.
• Passwordless or OTP login: Support email or phone-based login for better UX and fewer password resets.
• Seamless integration with SolidJS frontends and backend APIs: Enable smooth communication between the client and server while maintaining session integrity.

A SolidJS-ready authentication framework should abstract away token logic, handle sessions automatically, and integrate naturally with your existing stack — giving you production-grade security without slowing development.

SuperTokens: An Authentication Framework for SolidJS Developers

SuperTokens gives SolidJS developers the tools to add secure authentication without managing sessions or token logic manually. It’s an open-source framework that integrates cleanly with both SolidJS frontends and Node.js backends, offering a balance of simplicity and flexibility.

• Frontend: Use drop-in UI components or lightweight API calls to handle signup, login, and session management directly within your SolidJS app.
• Backend: Compatible with Node.js frameworks like Express or Fastify, often used alongside SolidStart for full-stack setups.
• Supported flows: Email-password, passwordless, third-party logins (Google, GitHub, etc.), and even multi-factor authentication (MFA).
• Plugin architecture: Extend functionality easily — add CAPTCHA checks, rate limiting, or custom validation logic without forking the codebase.

Initialization example:

supertokens.init({
  recipeList: [/* authentication recipes here */],
});

SuperTokens provides a developer-friendly way to build authentication in SolidJS apps — combining security, modularity, and open-source control without locking you into a proprietary service.

Step-By-Step: Adding SuperTokens to a SolidJS App

Implementing SuperTokens in a SolidJS project follows a straightforward flow that connects the frontend and backend securely while keeping code minimal.

1. Install the SuperTokens Backend (Node)

Add the server SDK and initialize the authentication recipes (for example, Session.init() and EmailPassword.init()) within your Node.js or Fastify backend.

supertokens.init({
  recipeList: [/* Session.init(), EmailPassword.init(), ... */],
});

This step configures your server to handle session creation, verification, and refresh securely.

2. Configure the SolidJS Frontend

Point the client toward the backend’s authentication routes and ensure requests include credentials for cookie-based sessions.

await fetch("/api/user", { credentials: "include" });

This allows SolidJS components to interact with protected endpoints, without manually attaching JWTs.

3. Add a Signup or Login Form

Use SuperTokens’ prebuilt UI components or connect a custom form that posts to the authentication endpoints. This simplifies form handling, validation, and error management while supporting both email-password and social login flows.

4. Test Authentication and Route Protection

Once users can sign in, you should verify session persistence after reloads and restrict access to protected routes when no session exists.

if (!session) navigate("/login");

Testing ensures stable session handling and secure access control.

In short, SuperTokens handles the session layer while keeping your SolidJS codebase lean and maintainable. For detailed setup commands and extended examples, refer to the SuperTokens documentation.

Alternatives to SuperTokens for SolidJS Authentication

While SuperTokens offers an open-source, framework-friendly approach, several other authentication options are available for SolidJS developers. Each comes with its own benefits and trade-offs depending on your project’s scale, budget, and security requirements.

• Firebase Auth: A quick way to get started with authentication by using Google’s ecosystem. It offers hosted UI components and SDKs for all major frameworks, including web. However, it can introduce long-term vendor lock-in, and costs can rise as user counts grow.
• Auth0: A feature-rich platform that supports nearly every authentication flow imaginable. Ideal for enterprise use cases, but the pricing model and reliance on a third-party vendor can make it less attractive for smaller teams or privacy-sensitive projects.
• Clerk and Magic: Designed for fast developer onboarding with ready-made UIs and SaaS-hosted APIs. They provide great developer experience but rely on external services, which limits flexibility for custom session handling or on-prem deployment.
• Manual JWT or session logic: Building your own authentication layer gives full control and zero dependencies, but maintaining secure session management at scale is error-prone. It’s generally suitable only for prototypes or small internal tools.

Ultimately, SuperTokens stands out for SolidJS developers who need scalable, open-source authentication that integrates easily with both frontend and backend frameworks — offering flexibility without vendor lock-in.

FAQs About SolidJS Authentication

Does SolidJS have a built-in authentication system?

No. SolidJS focuses on UI reactivity and doesn’t include built-in authentication or session handling, so developers need to integrate external authentication solutions.

Can I use NextAuth with SolidJS?

Not directly. NextAuth is designed specifically for Next.js and depends on its routing and API structure, which SolidJS doesn’t share.

What’s the easiest way to add authentication to SolidJS?

Use a dedicated authentication framework like SuperTokens, which provides backend recipes and frontend helpers tailored for frameworks like SolidJS and SolidStart.

Does SuperTokens support passwordless login in SolidJS?

Yes. SuperTokens offers a passwordless recipe that supports login via email or phone, and enables smoother, secure authentication without passwords.

Conclusion

Authentication is one area where shortcuts don’t scale. DIY JWT setups often expose tokens or fail to handle refresh logic securely. Managed platforms like Firebase or Auth0 simplify onboarding but trade flexibility for vendor lock-in and rising costs.

SuperTokens offers a balanced path forward — an open-source solution that integrates cleanly with SolidJS, supports modern authentication flows, and keeps control in your hands.

Start building securely: Try SuperTokens with your SolidJS app today by using the quickstart guide.