Set up middleware in a development and debugging environment in middleware.development.json. The application will use this file when NODE_ENV is set to development. For more information, see Environment-specific configuration.

Here is the default version created by the Application generator

  "final:after": {
    "strong-error-handler": {
      "params": {
        "debug": true,
        "log": true

For information on the properties you can set in this file, see middleware.json.