Validating a JWT token from Auth0 with Next.js backend involves a few steps:

Step 1.  You will need to install the following dependencies:

jwks-rsa to retrieve the public key from Auth0

You can install these dependencies using the following command:

Create a middleware function that will handle the validation of the JWT token. This middleware function will verify the JWT token using the public key provided by Auth0.

  jwksUri: 'https://your-auth0-domain.auth0.com/.well-known/jwks.json'

  client.getSigningKey(header.kid, function(err, key) {

    const signingKey = key.publicKey || key.rsaPublicKey;

  const token = req.headers.authorization?.split(' ')[1];

    return res.status(401).send({ message: 'Missing token' });

  jwt.verify(token, getKey, {}, (err, decoded) => {

      return res.status(401).send({ message: 'Invalid token' });

Now, you can use the middleware function in your Next.js backend to protect routes that require authentication.

const authMiddleware = require('./authMiddleware');

app.get('/api/protected', authMiddleware, (req, res) => {

  res.send({ message: 'This route is protected' });

In this example, the authMiddleware function will be called before the route handler. If the JWT token is valid, the middleware function will set the decoded token in the req.user property, which can then be accessed by the route handler.

Note that you will need to replace https://your-auth0-domain.auth0.com with your actual Auth0 domain. You can find your domain in your Auth0 dashboard.

To obtain the JWT token, your front-end application will need to authenticate with Auth0 and receive a token in response. This can be done using one of the Auth0 SDKs or by manually making an HTTP request to the Auth0 API.

Assuming that you are using the Auth0 SDK for JavaScript, you can obtain the JWT token as follows:

import createAuth0Client from '@auth0/auth0-spa-js';

const token = await auth0.getTokenSilently();

In this example, createAuth0Client is used to create an instance of the Auth0 SDK, and getTokenSilently is used to obtain the JWT token.

Step 5. Include the JWT token in the request:

To include the JWT token in the request to the Next.js backend, you will need to add it to the Authorization header. You can do this using the fetch API or any other HTTP client of your choice.

const response = await fetch('/api/protected', {

In this example, the fetch API is used to make a request to the /api/protected route, and the JWT token is included in the Authorization header as a Bearer token.

That's it! With these steps, you should now be able to validate a JWT token from Auth0 with your Next.js backend.

So, guys in this blog I will validate a JWT token from Auth0 with the Next.js backend, so let's see how to do it.

How to validate JWT token from auth0 with Next.js backend?

To filter messages from Sentry in Next.js using the message text, you can use the Sentry.captureMessage method to send custom messages to Sentry and then filter them using Sentry's filtering options. Here's an example:

import * as Sentry from '@sentry/nextjs';

Sentry.captureMessage('An error occurred', {

    // Filter messages with the custom tag

    if (event.tags && event.tags.custom_tag === 'my_tag') {

In this example, we first set up Sentry with your DSN. We then use Sentry.captureMessage to send a custom message to Sentry with a custom tag. Finally, we filter the messages with the custom tag using the beforeSend option in Sentry's configuration options. If the message has the custom tag, we return null to discard it. Otherwise, we return the event object to keep it.

In this article, we'll know Sentry.captureMessage method can be used to send custom messages to Sentry and then filter them using Sentry's filtering options to filter messages from Sentry in Next.js.

How to filter messages from sentry in Next.js using the message text?

Next.js is a popular framework for building server-side rendered React applications, while MongoDB is a widely used NoSQL database. Combining the power of Next.js with MongoDB allows developers to create dynamic web applications with seamless data storage capabilities. In this blog post, we will explore how to send data from a Next.js application to MongoDB, enabling efficient data storage and retrieval.

To get started, create a new Next.js project or use an existing one. Ensure that Node.js and npm (Node Package Manager) are installed on your system. Use the following command to create a new Next.js project:

To connect Next.js to MongoDB, you will need to install the MongoDB driver for Node.js. Use the following command to install the required package:

Next, import the MongoDB client in your Next.js application and establish a connection to your MongoDB server. Provide the necessary connection details, such as the URL, database name, and authentication credentials.

Define the structure of the data you want to send to MongoDB. Create a MongoDB collection that matches the desired data schema. This can be done through the MongoDB shell or using a MongoDB GUI tool like MongoDB Compass.

In Next.js, API endpoints can be created using serverless functions. These functions are defined in the pages/api directory and are automatically deployed to serverless environments. Create a new API endpoint file, e.g., pages/api/postData.js, and define the logic for handling incoming data.

Within the API endpoint, use the MongoDB client to connect to the database and perform CRUD (Create, Read, Update, Delete) operations. In the postData API function, extract the data sent from the client, validate it if necessary, and insert it into the appropriate MongoDB collection.

On the client-side, create a form or any other user interface element that allows users to input data. Use JavaScript or a library like Axios to send an HTTP request to the API endpoint defined in the previous step, passing the data as the payload.

Ensure that you handle any necessary data validation or sanitization on the client-side before sending the request. You may also implement error handling and display appropriate messages to the user based on the response from the API.

Test the data submission process thoroughly to ensure that the data is correctly sent to the MongoDB database. Handle any errors that may occur during the data submission or database connection process, displaying user-friendly error messages where necessary.

To retrieve data from MongoDB and display it in your Next.js application, create another API endpoint or a serverless function. Use the MongoDB client to connect to the database and perform the necessary queries to retrieve the desired data.

Return the retrieved data as the response from the API endpoint or serverless function. You can then consume this data in your Next.js application and display it in your components as needed.

Integrating Next.js with MongoDB allows developers to build dynamic web applications with powerful data storage capabilities. By following the steps outlined in this blog post, you can easily send data from a Next.js application to MongoDB and retrieve it when needed. This combination opens up numerous possibilities for creating data-driven applications with a seamless user experience.

Sending data from Next.js to MongoDB: Seamlessly store and retrieve data in MongoDB from a Next.js application for dynamic web development.

Sending Data to Next.js and MongoDB: A Step-by-Step Guide

Generating PDF files in Next.js allows you to dynamically create and serve PDF documents from your Next.js applications. PDFs are widely used for various purposes such as generating reports, invoices, receipts, or any other printable content.

To generate PDFs in Next.js, you can utilize JavaScript libraries like pdf-lib, which provides a rich set of features for creating, modifying, and saving PDF documents. The pdf-lib library allows you to add text, images, shapes, and other elements to your PDFs, customize their appearance, and save them in different formats.

The process of generating PDFs in Next.js typically involves the following steps:

1. Setting up the necessary dependencies: You need to install the required libraries, such as pdf-lib, by using npm or yarn.

2. Creating a new page or component: This is where you'll define the logic for generating the PDF. You can create a separate file within the pages directory or integrate the PDF generation logic into an existing page or component.

3. Importing the necessary libraries: You need to import the relevant modules from the pdf-lib library, such as PDFDocument, StandardFonts, and other utilities.

4. Defining the PDF generation function: This function will contain the code to create a new PDF document, add pages, set fonts, add text or other elements, and save the PDF.

5. Exporting the PDF generation function: You'll export the function from the file so that it can be imported and used in other parts of your Next.js application.

6. Integrating the PDF generation function: In your Next.js page or component, you'll import the PDF generation function and use it to generate the PDF when triggered by a user action, such as clicking a button.

7. Serving the generated PDF: Once the PDF is generated, you can save it as a file, serve it for download, or open it in a new tab or window for the user to view.

By following these steps, you can easily generate PDF files dynamically within your Next.js application. You have the flexibility to customize the content, formatting, and layout of the PDFs to suit your specific needs. Whether you're generating invoices, reports, or any other printable documents, generating PDFs in Next.js can be a powerful feature for your application.

Generating PDF in Next.js (code snippet) :

To generate PDF files in Next.js, you can make use of various libraries available in the JavaScript ecosystem. One popular library for generating PDFs is pdf-lib. Here's a step-by-step guide on how to generate a PDF in Next.js using pdf-lib:

Step 1: Set up a new Next.js project or navigate to your existing project's directory.

Step 2: Install the required dependencies by running the following command in your project's root directory:

Step 3: Create a new page or component where you want to generate the PDF. For example, let's create a file named pdfGenerator.js in the pages directory.

Step 4: Inside the pdfGenerator.js file, import the necessary libraries:

import { PDFDocument, StandardFonts, rgb } from 'pdf-lib';

Step 5: Create an async function to generate the PDF. You can define this function in the pdfGenerator.js file:

  const pdfDoc = await PDFDocument.create();

  const font = await pdfDoc.embedFont(StandardFonts.Helvetica);

  // Set the text color and write some text

  // Return the PDF as a buffer or any other desired format

Step 6: Export the generatePDF function from the pdfGenerator.js file:

Step 7: Now, you can import and use the generatePDF function in your Next.js page. For example, in the pages/index.js file, you can generate and serve the PDF when a user visits the page:

import generatePDF from './pdfGenerator';

  const handleGeneratePDF = async () => {

    const pdfBytes = await generatePDF();

    const blob = new Blob([pdfBytes], { type: 'application/pdf' });

    // Create a temporary URL to the blob

    const url = URL.createObjectURL(blob);

    // Open the URL in a new tab or do any other desired action

      <h1>Welcome to the PDF Generator</h1>

      <button onClick={handleGeneratePDF}>Generate PDF</button>

Step 8: Start your Next.js development server by running the following command in your project's root directory:

Generating PDFs in Next.js allows the dynamic creation and serving of printable documents using libraries like pdf-lib.

Generate PDF in Next.js

To mock the useParams() function from Next.js when writing tests with Jest, you can create a manual mock for the react-router-dom package, as Next.js uses react-router-dom under the hood for routing. Here's an example of how you can do it:

1. Create a __mocks__ directory in the same directory as your test file (if it doesn't already exist).

2. Inside the __mocks__ directory, create a file named react-router-dom.js.

3. In the react-router-dom.js file, define a mock implementation for the useParams() function. You can use Jest's jest.fn() to create a mock function that returns a predefined value.

Here's an example of what the react-router-dom.js file might look like:

export const useParams = jest.fn().mockReturnValue({

4. In your test file, import and use the mocked useParams() function instead of the original one. You will also need to instruct Jest to use the manual mock by using the jest.mock() function.

Here's an example of a test file that mocks the useParams() function:

import { render } from '@testing-library/react';

import { useParams } from 'react-router-dom';

// Instruct Jest to use the manual mock for react-router-dom

test('renders component with mocked parameters', () => {

  // Set up any necessary test data or context

  // Render your component that uses useParams()

  // Assert the expected behavior of your component based on the mocked parameters

In this example, the useParams() function is mocked to always return { id: 'mockedId' }. You can customize the mocked parameters as needed for your specific test case.

With this setup, when you run your tests, the useParams() function in your component will be replaced with the mock implementation, allowing you to control the parameters returned by useParams() and test different scenarios.

Describe the above code snippets and functions:

In Next.js, the useParams() hook is a feature provided by the react-router-dom library, which is used for routing in Next.js applications. It allows you to access the dynamic parameters from the URL in your components.

When writing tests for components that use useParams(), you may want to mock this hook to control the values returned during testing. By mocking useParams(), you can provide predefined parameter values that simulate different scenarios, allowing you to test how your component behaves with different URL parameters.

To mock useParams() with Jest, you need to create a manual mock for the react-router-dom package. The manual mock is a file that Jest will use instead of the actual module during testing. Inside this mock file, you define a mock implementation for the useParams() function using jest.fn(), which creates a mock function that you can configure to return specific values.

In the manual mock, you can specify the parameter values that you want to mock. For example, if your component expects an id parameter, you can set the return value of useParams() to { id: 'mockedId' }. This way, whenever your component calls useParams(), it will receive the mocked parameters instead of the real ones.

In your test file, you need to import the useParams() hook from react-router-dom, and then instruct Jest to use the manual mock by calling jest.mock('react-router-dom'). This tells Jest to replace the original useParams() function with the mock implementation defined in the manual mock file.

After mocking useParams(), you can write your test cases and control the behavior of the component based on the mocked parameters. You can use useParams.mockReturnValue() to configure the mock function to return different values for different test cases.

By mocking useParams(), you can isolate your component and test different scenarios without relying on actual URL parameters. This allows you to write focused tests and ensure that your component behaves correctly under different parameter conditions.

Remember to customize the mocked parameters and assertions based on your specific test requirements. The example provided demonstrates the basic setup for mocking useParams() in Next.js tests with Jest.

In conclusion, when writing tests for Next.js components that use the useParams() hook, you can mock it with Jest by creating a manual mock for react-router-dom. This allows you to provide predefined parameter values and simulate different scenarios during testing. By mocking useParams(), you can control the behavior of your components and write focused tests to ensure their correct functionality.

Mock Next.js useParams() with Jest by creating a manual mock for react-router-dom and defining a mock implementation.

Mocking Next.js useParams() in Jest

Next.js is a powerful framework for building server-side rendered React applications. One common feature of many websites is a "Contact Us" form, which allows users to send messages or inquiries to the site's administrators. To make this feature functional, we need to connect the form to a database, where the submitted information will be stored and retrieved for later use. In this blog, we will explore the steps to connect a database to a "Contact Us" form on a Next.js website.

Assuming you have Node.js and npm installed, create a new Next.js project by running the following commands in your terminal:

Next, we need to install the necessary packages for working with databases and handling form submissions. For this example, we will use MongoDB as our database, but you can choose any other database system of your preference. Install the required dependencies by running the following command:

Before connecting our Next.js app to the MongoDB database, ensure you have a MongoDB instance set up. You can create a free account on MongoDB Atlas and set up a new database there. Once you have your MongoDB URI, create a .env file in the root of your project and store the URI like this:

Now, let's create a simple "Contact Us" form. Inside the "pages" directory, create a new file called "contact.js". Add the following code to create a basic form:

  const [email, setEmail] = useState('');

  const [message, setMessage] = useState('');

    // Add code to handle form submission and database connection here

        onChange={(e) => setName(e.target.value)}

        onChange={(e) => setEmail(e.target.value)}

        onChange={(e) => setMessage(e.target.value)}

      <button type="submit">Submit</button>

To interact with the MongoDB database, we need to create a model that defines the structure of the data we want to store. In the root directory, create a new folder called "models", and within it, create a file named "ContactMessage.js". Add the following code to define the model:

const contactMessageSchema = new mongoose.Schema({

  name: { type: String, required: true },

  email: { type: String, required: true },

  message: { type: String, required: true },

  createdAt: { type: Date, default: Date.now },

const ContactMessage = mongoose.model('ContactMessage', contactMessageSchema);

In the root directory, create a new file called "db.js" to handle the database connection. Add the following code to establish a connection using Mongoose:

    const conn = await mongoose.connect(process.env.MONGODB_URI, {

    console.log(`MongoDB Connected: ${conn.connection.host}`);

    console.error(`Error connecting to MongoDB: ${error.message}`);

Learn how to connect a MongoDB database to a 'Contact Us' form in a Next.js website, enabling the storage and retrieval of user messages.

next.js

Trending Blogposts on next.js

How to validate JWT token from auth0 with Next.js backend?

How to filter messages from sentry in Next.js using the message text?

Sending Data to Next.js and MongoDB: A Step-by-Step Guide

Generate PDF in Next.js

Mocking Next.js useParams() in Jest

Connecting a Database to the Contact Us Form on a Next.js Website

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next.js

Trending Blogposts on next.js

How to validate JWT token from auth0 with Next.js backend?

How to filter messages from sentry in Next.js using the message text?

Sending Data to Next.js and MongoDB: A Step-by-Step Guide

Generate PDF in Next.js

Mocking Next.js useParams() in Jest

Connecting a Database to the Contact Us Form on a Next.js Website

Popular Discussions on next.js