Stackdriver Trace is automatically enabled for all apps running on the App Engine standard environment. App Engine standard environment apps do not require any additional instrumentation libraries.
For setup in the App Engine flexible environment, see the following section, VMs and containers.
VMs and containers
An app that is running on a VM or container is not automatically traced. This includes VM instances from Compute Engine and App Engine flexible environment, and containers in Google Kubernetes Engine. Use the libraries listed below, or the Stackdriver Trace API, to send traces to the service.
After deployment, you can view recorded traces and inspect the RPCs in your app.