Handling File Attachments in ADK (Python) & Integration with NotebookLM Enterprise

[ldessemon2]

I have deployed two custom agents using the Google ADK (Python) and registered them with Gemini Enterprise (via Vertex AI Agent Engine). I have two specific integration questions:

• File Context Handling: When a user uploads a file in the Gemini Enterprise chat interface, how is this payload passed to my backend ADK python agent? Does the ADK Session or Context object expose these files as Artifacts, or do I need to define a specific Tool input schema to accept file bytes/metadata?

• NotebookLM Interoperability: Is there a supported pattern (such as the Agent2Agent / A2A protocol) that allows my custom ADK agent to query the NotebookLM Enterprise agent? Alternatively, is there an API to programmatically access the specific source-grounding contexts used by NotebookLM from within my custom agent's logic?