How to inject ToolContext (user session) when testing locally with adk web?

[this-dave]

I'm developing a multi-agent system where specialist agents need access to the current user's context (specifically their email) for authorization checks. The tools use ToolContext to access context.session.user_id.
When deployed to production (Vertex AI), the ToolContext works perfectly. However, during local development with adk web, the ToolContext appears to be empty or not properly initialized, making it impossible to test authorization flows locally.

Current Setup:

pythonfrom typing import TypedDict
from google.adk.tools import ToolContext

class ProjectOutput(TypedDict):
    status: str
    message: str

async def update_project(
    project_key: str, 
    context: ToolContext
) -> ProjectOutput:
    """Update project settings (requires authorization)"""
    
    # Need user email for permission check
    user_email = context.session.user_id  # This is None in adk web
    
    # Check if user has permission
    if not await check_user_permission(project_key, user_email):
        return {"status": "error", "message": "Permission denied"}
    
    # ... actual update logic

Problem:
When running adk web src/agents/, the ToolContext doesn't contain any session information, causing the authorization logic to fail.
Question:

Is there a way to inject or mock session data into ToolContext for local testing with adk web?
What's the recommended pattern for handling user context in tools that works both in production and local development?
Should we avoid ToolContext for user authentication and use a different approach?

Environment:

Google ADK version: latest
Python 3.13
Testing with: adk web

Any guidance on best practices for local development with user context would be appreciated!