Request Interception

The AWS_LWA_LAMBDA_RUNTIME_API_PROXY environment variable redirects Lambda Runtime API requests to a custom proxy URL. The proxy can intercept requests and apply operations such as inspection, modification, tracing, or payload capturing.

Configuration

AWS_LWA_LAMBDA_RUNTIME_API_PROXY=http://127.0.0.1:9002

How It Works

  • The proxy intercepts requests between the adapter and the Lambda Runtime API
  • The event payload received by your web app is wrapped inside the GET response body
  • This proxy does not affect the extension registration API
  • It is meant only for interacting with data received and sent by the web application

Use Cases

  • Request/response tracing
  • Payload capturing and logging
  • Obfuscation of sensitive data
  • Header modification