OAuth for agents deployed to Agent Engine

[isubo]

The documentation provides an example of how to organize authentication when Runner is used. However, it is not clear how to pass authentication result back to ADK when the agent is deployed to Agent Engine.

[ssvaidyanathan]

@seanzhou1023 - do we have a fix in progress? I am following the instructions from https://google.github.io/adk-docs/tools/authentication/#authentication-logic-within-the-tool-function that includes the agent_cli.py as well but I keep getting an error while submitting authentication details back to the agent "Unable to coerce value: %r" % value. I've tried different ways to create the Content object. It keeps returning the same error

[hangfei]

This is a document issue. Move to doc repo.