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This example shows how to use Agent Control’s @control() decorator inside a Google ADK app. Use this example if you want ADK as the host framework but prefer Agent Control’s decorator model for tool protection. If you want the default framework-native path, use /examples/google-adk-plugin.

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What It Demonstrates

  • @control() on ADK tool functions
  • automatic step registration from decorated functions
  • pre-tool blocking for restricted cities
  • post-tool output filtering for synthetic unsafe output
  • optional sdk-local execution without changing the agent code

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Prerequisites

  1. Start the Agent Control server from the repo root: 
    make server-run
  2. Install the example dependencies: 
    cd examples/google_adk_decorator
uv pip install -e . --upgrade
  3. Set your Google API key: 
    export GOOGLE_API_KEY="your-key-here"
  4. Optional environment variables: 
    export AGENT_CONTROL_URL=http://localhost:8000
export GOOGLE_MODEL=gemini-2.5-flash

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Setup

Default server execution: 
cd examples/google_adk_decorator
uv run python setup_controls.py
Optional sdk-local execution: 
cd examples/google_adk_decorator
uv run python setup_controls.py --execution sdk
The example code does not change between modes. The only difference is where the controls run:
  • server - evaluation happens on the Agent Control server
  • sdk - evaluation happens locally in the Python SDK after the controls are fetched
The setup script creates namespace-scoped controls for this example:
  • adk-decorator-block-restricted-cities
  • adk-decorator-block-internal-contact-output

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Run

cd examples/google_adk_decorator
uv run adk run my_agent

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Suggested Scenarios

Safe request: 
What time is it in London?
Restricted city blocked before the tool call: 
What is the weather in Pyongyang?
Synthetic unsafe tool output blocked after the tool call: 
What time is it in Testville?

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Files

  • setup_controls.py - creates the decorator example controls
  • my_agent/agent.py - ADK app that wraps tools with @control()
  • .env.example - environment variables for local runs

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Notes

  • This example focuses on tool-level protection only.
  • The guarded tool implementations are marked with tool metadata before @control() runs. That is needed because the current Python SDK infers tool vs llm from function metadata at decoration time.
  • If you want the recommended packaged integration, use /examples/google-adk-plugin.
  • If you want the ADK-native callback integration pattern, use /examples/google-adk-callbacks.

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Source Code

View the complete example with all scripts and setup instructions: Google ADK Decorator Example