With Traffic Policy, you can connect your API to ngrok’s log exporting system for smarter troubleshooting, testing, and integration of logging services like Datadog for your API gateway and upstream services. This rule:
  1. Checks if the response status code is not in the 200 range
  2. Logs the unsuccessful request with a custom message and metadata
on_http_request:
  -     actions:
      -         type: custom-response
        config:
          status_code: 503
          body: <html><body><h1>Service Unavailable</h1><p>Our servers are currently down for maintenance. Please check back later.</p></body></html>
          headers:
            content-type: text/html
on_http_response:
  -     name: Log unsuccessful requests
    expressions:
      - res.status_code < '200' && res.status_code >= '300'
    actions:
      -         type: log
        config:
          metadata:
            message: Unsuccessful request
            edge_id: <YOUR-NGROK-DOMAIN>
            success: false
See the log Traffic Policy action docs for more information.