The following example shows how to add a response header in your Edge Middleware.
Your middleware file should be placed at the root of your project. If you are using the src directory, the file should be placed in the src directory.
middleware.ts
import { NextResponse } from 'next/server';
export default function middleware() {
// Store the response so we can modify its headers
const response = NextResponse.next();
// Set custom header
response.headers.set('x-modified-edge', 'true');
// Return response
return response;
}