Assigning permissions to individual users is a complex task, especially when you have a large number of users.

Role-Based Access Control (RBAC) is a popular approach to managing access permissions in software applications, allowing you to assign different roles and permissions to different users.

This article will guide you through building a Q&A platform using Next.js and Neon, and show you how to implement authentication and RBAC with Clerk.

What is Role-Based Access Control?

Before we get started, let's understand RBAC and how it will be implemented in the Q&A platform.

RBAC is a security method that allows users to interact with features of an application or system based on their roles and the permissions granted to those roles.

This approach simplifies access management by grouping permissions into roles instead of assigning them to individual users, making it easier to maintain and scale as your application grows.

By implementing RBAC, organizations can enforce the principle of least privilege, ensuring users only have access to the resources necessary for their specific responsibilities.

Below is a breakdown of the permissions for each role in the Q&A platform:

With that in mind, let us jump straight into building the Q&A platform and implement RBAC using Clerk.

What you'll build

Before writing any code, let's take a look at how our platform works.

The landing page enables users to sign up or sign in using the Start Exploring button. It features a clean design with a navigation menu and welcome message.

Once signed in, users can ask questions and provide answers. Each question displays the author's name, timestamp, and interaction options. Users can edit or delete their own content, and view answers from other contributors.

Administrators can review and moderate all submitted content through the Admin Dashboard. The page displays questions and answers with approval status indicators, allowing admins to approve or reject content using simple checkmark and X icons.

Finally, administrators can manage user permissions through the role management page. Using a search interface, admins can find users and assign appropriate roles (Admin, Moderator, Contributor, or Viewer) or remove existing roles.

Building the frontend

In this section, we will build the frontend of the Q&A platform. In order to follow along, you should have a basic understanding of React or Next.js, as well as Node.js installed.

Install dependencies

Start by running the following command in your terminal to bootstrap a Next.js application, accepting the default options as they are presented:

With the dependencies in place, let's create the components that used with the layout, starting with the type definitions we'll use throughout the process.

Creating the header and updating the homepage

The header component will allow our users to navigate to different parts of the application, as well as hold the Clerk UserButton component (to be done later in this guide).

Create the src/components/Header.tsx file and paste in the following code:

Create the Q&A section

Next, you'll build out the Q&A section, where signed-in users can ask and answer questions and anonymous users can view questions. We'll start by creating a few shared components that will be used throughout the application before creating the page that will display the Q&A section.

Let's start by creating a file named types/types.d.ts to define the types we'll be using. Populate it with the following code:

Now create a QuestionItem component that manages and displays a question and its answers. Moreover, the component allows adding, editing, and deleting of questions or answers.

Create the src/components/QuestionItem.tsx file and paste the following code into the file:

Your editor may be displaying an error regarding the AnswerItem component, which does not yet exist. This component is used to render answers for each question.

Create the src/components/AnswerItem.tsx file and paste the following code into the file:

Now you'll create the page that manages and displays questions and answers, handles form submissions, and interacts with the user. Note that the code below contains function placeholders that will be implemented later in this article to interact with the database.

Create the app/qa/page.tsx file and paste the following code into the file:

Creating the admin area

With the home page and Q&A page created, it's time to create the admin area. The admin area will be used to manage questions and answers.

Start by creating the src/components/QuestionCard.tsx which is used by the admin page for approving and managing questions and answers. Paste the following into that file:

Testing the application

With all of our pages created, you can test the application by running the following command in the terminal, which will start the dev server and allow you to view the application in your browser:

By default it runs on localhost:3000, but may use a different port if 3000 is already in use. Use the provided URL to access the application.

Now let's add authentication to the application using Clerk. In your browser, go to the Clerk dashboard to create an account if you don't already have one, which will automatically walk you through setting up your first application with Clerk. If you already have an account, sign in and create a new application, which will also guide you through setting up Clerk.

Follow steps 1-3 shown in the onboarding guide to install and configure Clerk in your Next.js application. Return to this page once you are finished to continue the tutorial.

Setting up Clerk in the application

At this point, the Clerk SDK should be installed, and the middleware should be defined per the quickstart instructions. Next, you'll need to wrap the application with the <ClerkProvider> which will allow Clerk to protect pages that require authentication.

Update the app/layout.tsx file to wrap the application with the <ClerkProvider>:

Test it out

If your application is no longer running, start it up again with npm run dev and use the updated header to log into the application. This will let you create a user account and redirect you back to the home page.

Once logged in, notice how the header includes the UserButton instead of the SignInButton.

Configuring RBAC with Clerk

Now let's add RBAC to the application using Clerk metadata. The role for a specific user will be set in the Clerk metadata, which is arbitrary data that is stored alongside a user that can be accessed and modified through the Clerk API, as well as directly in the Dashboard.

Set a role for the user

Log into the Clerk dashboard and navigate to the Users page and select your user account. Scroll down to the User metadata section and select Edit next to the Public option.

Add the following JSON and select Save to manually add the admin role to your own user account in order for it to have all the system permissions. Later in the tutorial, you will add a basic admin tool to change a user's role.

Include the user role with the Clerk metadata

Next, you'll need to update the token created by Clerk to include the metadata when it's created. This will allow you to check the role of the user without having to make an additional API call.

In the Clerk Dashboard, navigate to the Sessions page. Under the Customize session token section, select Edit. In the modal that opens, enter the following JSON and select Save.

Declare the role types for the Metadata

Go back to the project and create a global type file to add type definitions for the metadata. Create the types/global.d.ts file and paste the following code into the file:

Updating your middleware

The middleware is used to check each request it comes in and apply authentication logic. Let's update the middleware to check the role of the user and redirect them to the appropriate page.

Update src/middleware.ts as follows:

Setting user roles from the application

Now we can define a new page in the application that will let admins set user roles. We'll start by creating the server actions that will be used to set the user role by passing in the role name.

Create the src/app/admin/set-user-roles/actions.ts file and paste the following code into the file:

Finally, we'll create a page that allows admins to search through users using the Clerk Backend API and the above server actions to set their role.

Create a file called src/app/admin/set-user-roles/page.tsx and paste in the following code to populate the page:

Add three more users to the Q&A platform, then go to Admin page and click the Set Roles button. Search for the users you added and set their roles by clicking either the Make Admin, Make Moderator, Make Contributor, or Make Viewer button.

Integrate with Postgres using Neon

In this section, you will learn how to integrate Neon Postgres with Clerk in the Q&A platform, using drizzle-orm and drizzle-kit to interact with the database.

Creating the database

Start by creating a new Neon database. Open your browser and go to neon.tech. Create an account if you don't already have one, then create a new database. Once the database is created, you'll be presented with a Quickstart screen. Select the Copy snippet button to copy it to your clipboard:

Paste it into your .env.local file as DATABASE_URL like so:

Install the dependencies

Now you'll need to install the following dependencies:

• drizzle-orm - The ORM that the application will use to interact with the database.
• drizzle-kit - The tool that will generate migrations and interact with the database.
• @neondatabase/serverless - The driver that will be used to connect to the database.

Run the following command to install the dependencies:

Setting up the database schema

Next you'll create the schema file which drizzle-orm will use to interact with the database, while drizzle-kit will be used to apply schema changes to the database.

Create a new file called src/db/schema.ts and paste in the following code:

If you go to the tables section in your Neon dashboard, you should see that two tables named questions and answers were created.

Defining database interactions

Now that the database schema is set up, you can start defining database interactions. We're going to start with the database calls used by the main Q&A section of the app.

Create src/app/qa/actions.ts and paste in the following:

Now we can wire up the placeholder functions in src/app/qa/actions.ts with the new database interactions we just created.

Update the src/app/qa/page.tsx file like so:

Now the server actions will prevent users from editing questions or answers that do not belong to them, but we can create a better user experience by making sure only the person who posted the question or answer can edit or delete it. The useUser hook from Clerk can be used to get the current user's information.

Update the QuestionItem component like so:

Next let's create a set of server actions used by the admin area to manage questions and answers. Notice in the following code we dont need to check the user's role, because we are using the Clerk middleware to protect this route.

Create the src/app/admin/actions.ts file and add the following content:

Test it out!

After completing all the steps throughout this guide, you can now start up the application once more to test out all the features!

Here are a couple of things to try:

• Create a new question as a user of each role.
• Try approving and disapproving questions and answers.
• Try editing and deleting questions and answers.
• Explore the data in the Neon database.

Conclusion

In this tutorial, you have learned how to integrate Clerk for authentication, configure RBAC using metadata, and enforce role-based restrictions to ensure users only access features appropriate to their roles. Also, you learned how to integrate Neon Postgres database with Drizzle ORM for seamless data management and how to conditionally render UI based on user roles.

By following this tutorial, developers can build secure applications by implementing Role-Based Access Control (RBAC) with Clerk.

Here is the source code (remember to give it a star ⭐).