You can use Environment Variables to store configuration options, or sensitive information such as API keys, passwords, and tokens.

Environment variables are injected to process.env when your Function is executed. You can access them the same way you would access them in Node.js:

export function handler(request: Request): Response {
  if (request.headers.get('Authorization') !== process.env.AUTH_TOKEN) {
    return new Response('Unauthorized', { status: 401 });
  }
 
  return new Response('Welcome!');
}

Development

During development, you can use the --env flag of the dev command to specify a .env file to load.

Adding environment variables

Head over to the settings tab of your Function, and scroll to the "Environment variables" section. Here, you can see all your Environment Variables, which are empty by default.

Enter a key and value, then click on "Add". You can keep adding Environment Variables until you're satisfied, and then click on "Submit" to save your changes.

Removing environment variables

To remove an Environment Variable, click on the "Remove" button next to it. Click on "Submit" to save your changes.