Error message: Cannot find module ‘@mdx-js/mdx’ in NodeJS when using Gatsby

In this tutorial, we will discuss a common error that occurs when using Node.js and Gatsby together: "Cannot find module ‘@mdx-js/mdx’". This error typically occurs when trying to run a Gatsby project that uses MDX (Markdown for the component era) files.

There are a few possible reasons why you may be encountering this error. The most common reason is that the required @mdx-js/mdx package is not installed in your project’s dependencies. Another possible reason is that the package is installed but not properly configured or imported in your project.

To resolve this issue, follow the steps outlined below:

1. Open your project’s terminal or command prompt and navigate to the root directory of your Gatsby project.

2. Check if the @mdx-js/mdx package is installed in your project’s dependencies by running the following command:

npm ls @mdx-js/mdx

If the package is installed, it will be listed in the dependencies tree. If it is not installed, you will need to install it by running the following command:

npm install @mdx-js/mdx

1. Once the @mdx-js/mdx package is installed, make sure it is properly configured in your project. Check your project’s package.json file to ensure that the package is listed in the dependencies section:

"dependencies": {
  "@mdx-js/mdx": "^2.0.0"
}

1. If the @mdx-js/mdx package is properly installed and configured in your project, but you are still encountering the error, it is possible that the package is not being imported correctly in your code. Check the files where you are using MDX and make sure that the @mdx-js/mdx package is imported:

import { mdx } from '@mdx-js/mdx'

1. After verifying that the @mdx-js/mdx package is properly installed, configured, and imported in your project, try running your Gatsby project again:

gatsby develop

If you have followed all of the steps outlined in this tutorial and are still encountering the "Cannot find module ‘@mdx-js/mdx’" error, there may be other underlying issues with your Gatsby project or Node.js setup. In this case, it may be helpful to seek assistance from the Gatsby community or consult the Gatsby and Node.js documentation for further troubleshooting steps.

By following the steps outlined in this tutorial, you should be able to resolve the "Cannot find module ‘@mdx-js/mdx’" error in your Gatsby project and successfully run your project with MDX files.