Navigating Authentication with tRPC and authCallback on localhost:3000
Understanding the Challenge
Many developers using tRPC (a powerful type-safe end-to-end data fetching and mutation library for React) find themselves grappling with authentication on their local development server, often running on localhost:3000. The authCallback function in tRPC is a crucial component for handling user authentication, but its integration can be tricky, particularly when you're working on your local machine. This article aims to demystify the process, providing a clear guide on how to implement authCallback efficiently for seamless authentication in your tRPC-powered local development setup.
Scenario & Code
Imagine you're building a React application that uses tRPC for fetching and mutating data. You want to implement user authentication to protect sensitive resources. Let's look at a simplified example of a tRPC router setup:
import { initTRPC } from '@trpc/server';
import { type inferAsyncReturnType } from '@trpc/server/dist/declarations/src/internals/utils';
import { type NextApiRequest, type NextApiResponse } from 'next';
const createContext = ({
req: NextApiRequest,
res: NextApiResponse,
}: {
req: NextApiRequest;
res: NextApiResponse;
}) => {
// Extract user information from request (session, token, etc.)
const user = req.session?.user;
return {
user,
};
};
const router = initTRPC.createRouter({
context: createContext,
});
export const appRouter = router.router;
export type AppRouter = typeof appRouter;
export type inferAppRouter = inferAsyncReturnType<AppRouter>;
In this setup, the createContext function is responsible for extracting user information from the request. This information is then passed to the context object within the router, making it accessible to all your tRPC procedures.
Key Insights
-
Understanding the Purpose of
authCallback: TheauthCallbackfunction within tRPC is responsible for handling the user authentication process. It allows you to control the flow of execution based on the user's authentication status. -
Implementing
authCallbackonlocalhost:3000: ImplementingauthCallbackon your local development server, often atlocalhost:3000, requires careful consideration of how you manage authentication tokens. It's common to store tokens within the browser's local storage or session storage, ensuring that the token is available on subsequent requests to your tRPC endpoints. -
Working with
fetch: When interacting with your tRPC API from your React application, you'll often use thefetchAPI. Be mindful of setting the appropriate headers, including the authentication token (if available), when making requests to your tRPC endpoints.
Example: Implementing Authentication
Let's assume you use a simple JWT (JSON Web Token) based authentication system. Here's how you can integrate authCallback and handle authentication on your localhost:3000 server:
- Create a middleware function:
import { createTRPCRouter, publicProcedure } from '../trpc';
import { getServerSession } from 'next-auth/next';
// Middleware function for protected routes
const protectedProcedure = publicProcedure.use(async (opts) => {
const session = await getServerSession({ req: opts.ctx.req });
if (!session) {
throw new Error('Unauthorized');
}
return { user: session.user };
});
export const router = createTRPCRouter({
// ... other procedures
protectedRoute: protectedProcedure.query(async () => {
// Access authenticated user data here
const user = await getUserData(ctx.user.id);
return user;
}),
});
- Handle authentication within your React component:
import { useSession } from 'next-auth/react';
import { useQuery } from '@trpc/react-query';
import { router } from '../trpc/server';
function MyComponent() {
const { data: session } = useSession();
const { data, isLoading } = useQuery(['protectedRoute'],
router.protectedRoute,
{ enabled: !!session });
if (isLoading) {
return <p>Loading...</p>;
}
if (!session) {
return <p>Please sign in to access this page.</p>;
}
return (
<div>
{/* Display protected data here */}
<h1>Welcome, {session.user.name}</h1>
<p>Data: {data?.name}</p>
</div>
);
}
export default MyComponent;
Important Considerations:
-
Security Best Practices: When handling authentication tokens on
localhost:3000, prioritize security. Do not store tokens in plain text or expose them directly in your client-side code. Always use secure communication channels and consider using HTTPS, even on localhost, for enhanced protection. -
Testing: Thoroughly test your authentication flow on both your local development server (
localhost:3000) and in your production environment to ensure seamless user experience. -
Debugging: Utilize developer tools (like browser console and network tabs) to identify any issues with authentication and token management.
Additional Resources:
Conclusion
Implementing authCallback within your tRPC setup on localhost:3000 provides a robust foundation for user authentication. By understanding the concepts and following best practices, you can build secure and user-friendly applications, ensuring a smooth development workflow.
