Hey Keyur,
As can be seen under the "
Migrating an Existing App Engine App" pages of the documentation for Flexible Environment runtimes, the Search service exists and can be accessed in the same way for Flexible environment apps as for standard App Engine apps when using Java, Go, and python. For custom runtimes, you can see
this doc to see which images will work with Standard APIs such as the Search service (it seems JDK8 will work). Let me know if this helps answer your question. Feel free to report issues in the
Public Issue Tracker, such as if some behaviour doesn't match up to what the documentation says it should.
Cheers,
Nick
Cloud Platform Community Support