How to Easily Manage Authentication in Express.js with FluidAuth

In every new application, authentication plays a crucial role in safeguarding user data and preventing misuse. Knowing who is accessing your API or web application helps maintain security and control. In this article, I’ll introduce FluidAuth, a tool I developed to simplify authentication in Express.js.

What is FluidAuth?

FluidAuth is an open-source tool that makes setting up authentication in your Express app straightforward. You can define a class, add the authentication providers you want, and call the authenticate function to choose your provider. If your provider uses OAuth2, FluidAuth also handles the Redirect URI seamlessly with the handleCallback function.

Here’s an example of how to set it up using GitHub as an OAuth2 provider:

const express = require('express');
const cookieParser = require('cookie-parser');
const { AuthService, Session } = require('@fluidauth/express');

const app = express();
const authService = new AuthService({
  providers: [new GithubProvider({
    credential: {
      clientId: "your-client-id",
      clientSecret: "your-client-secret",
      redirectUri: "your-redirect-uri",
    },
    async verifyUser(data) {
      const user = await findUserByEmail(data.email);
      return user ? { user } : { user: null, info: { message: "User not found" } };
    }
  })],
  session: new Session({ secret: "your-session-secret" }),
  redirect: { successRedirect: "/dashboard" },
});

app.use(express.json());
app.use(cookieParser());
app.use(authService.session());
app.use(authService.initialize());

app.listen(3000, () => console.log("Server running on port 3000"));

Session Management: Serialization and Deserialization

FluidAuth provides serialization and deserialization to manage user sessions securely. Serialization stores only an identifier, like a user ID, in the session. When you need to access the user, deserialization retrieves the user’s data from the database using that identifier. This helps minimize sensitive data stored in the session while ensuring security.

Here’s how it works:

Serialization:

authService.serializeUser(function(user) {
  return user.id; // Store only the user ID in the session
});

Deserialization:

authService.deserializeUser(function(id) {
  const user = users.find(user => user.id === id); // Find the user by ID
  return user || null; // Return the user object or null if not found
});

Still Evolving

FluidAuth is still in its early stages, and I’m working on adding more features and improving security best practices. The goal is to make it even easier to use and more secure over time.

Because FluidAuth is open source, anyone who wants to help improve it is welcome to fork the repository and contribute! You can check it out on GitHub: https://github.com/Itszavier/fluidauth-express.

Here’s the conclusion with your text added:

Conclusion

For more on FluidAuth, visit the documentation website where I’ve included all the information and guidance on how to use FluidAuth: https://fluidauth.vercel.app/.