Git hash in Next.js

A snippet to parse the git hash from the command line and add it as an environment variable to a Next.js app.

Git hash in Next.js

It's often useful to have a Git hash shown somewhere to help determine which version you're looking at. This snippet will add to a Next.js app as an environment variable.

const pkg = require('./package.json');

// starts a command line process to get the git hash
const commitHash = require('child_process')
  .execSync('git log --pretty=format:"%h" -n1')

module.exports = {
  // other configs
  env: {
    // add the package.json version and git hash to the environment
    APP_VERSION: pkg.version,
    COMMIT_HASH: commitHash

You can then use it in your code like this (example taken from this website):

<span className="text-gray-500 text-right text-xs my-4">
  v. {process.env.APP_VERSION} |{' '}

Or if you don't want to expose the hash in the frontend, you can attach it to the window object:

window.APP_VERSION = pkg.version;
window.COMMIT_HASH = commitHash;