title: How to add add custom header in Cloudfront Lambda@Edge Origin Request?
body: <p>I have a Cloudfront distribution with a custom origin.</p>
  
  <p>I want to use a Lambda@Edge Origin Request to modify and add some extra headers to be forwarded to my origin server.</p>
  
  <p>Below is my Lambda function. The <code>custom_header</code> is visible in Cloudwatch logs for my Lambda, but doesn't show up in my custom server request headers :(.</p>
  
  <pre><code>exports.handler = (event, context, callback) =&gt; {
    const request = event.Records[0].cf.request;
    const headers = request.headers;
  
    headers['custom_header'] = [{ key: 'custom_header', value: 'custom_header' }];
  
    return callback(null, request);
  }
  </code></pre>
  
  <p>I expect <code>custom_header</code> to be visible in my Node.js route under <code>req.headers</code>.</p>