> ## Documentation Index
> Fetch the complete documentation index at: https://agno-v2-docs-scavio-google-v2.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Tool Hook in Toolkit with State Nested

> Chain two nested tool hooks so the first swaps a customer ID for the profile stored in session_state before the toolkit function runs.

Show how to use a tool execution hook, to run logic before and after a tool is called.

```python tool_hook_in_toolkit_with_state_nested.py theme={null}
"""Show how to use a tool execution hook, to run logic before and after a tool is called."""

import json
from typing import Any, Callable, Dict

from agno.agent import Agent
from agno.run import RunContext
from agno.tools import Toolkit
from agno.utils.log import logger

# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------


class CustomerDBTools(Toolkit):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        self.register(self.retrieve_customer_profile)

    def retrieve_customer_profile(self, customer: str):
        """
        Retrieves a customer profile from the database.

        Args:
            customer: The ID of the customer to retrieve.

        Returns:
            A string containing the customer profile.
        """
        return customer


# When used as a tool hook, this function will receive the contextual Agent, function_name, etc as parameters
def grab_customer_profile_hook(
    run_context: RunContext,
    function_name: str,
    function_call: Callable,
    arguments: Dict[str, Any],
):
    if run_context.session_state is None:
        run_context.session_state = {}

    session_state = run_context.session_state
    cust_id = arguments.get("customer")
    if cust_id not in session_state["customer_profiles"]:  # type: ignore
        raise ValueError(f"Customer profile for {cust_id} not found")
    customer_profile = session_state["customer_profiles"][cust_id]  # type: ignore

    # Replace the customer with the customer_profile
    arguments["customer"] = json.dumps(customer_profile)
    # Call the function with the updated arguments
    result = function_call(**arguments)

    return result


def logger_hook(name: str, func: Callable, arguments: Dict[str, Any]):
    logger.info("Before Logger Hook")
    result = func(**arguments)
    logger.info("After Logger Hook")
    return result


agent = Agent(
    tools=[CustomerDBTools()],
    tool_hooks=[grab_customer_profile_hook, logger_hook],
    session_state={
        "customer_profiles": {
            "123": {"name": "Jane Doe", "email": "jane.doe@example.com"},
            "456": {"name": "John Doe", "email": "john.doe@example.com"},
        }
    },
)

# This should work

# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------
if __name__ == "__main__":
    agent.print_response("I am customer 456, please retrieve my profile.")

    # This should fail
    # agent.print_response("I am customer 789, please retrieve my profile.")
```

## Run the Example

<Steps>
  <Snippet file="create-venv-step.mdx" />

  <Step title="Install dependencies">
    ```bash theme={null}
    uv pip install -U agno openai
    ```
  </Step>

  <Step title="Export your OpenAI API key">
    <CodeGroup>
      ```bash Mac/Linux theme={null}
      export OPENAI_API_KEY="your_openai_api_key_here"
      ```

      ```bash Windows theme={null}
      $Env:OPENAI_API_KEY="your_openai_api_key_here"
      ```
    </CodeGroup>
  </Step>

  <Step title="Run the example">
    Save the code above as `tool_hook_in_toolkit_with_state_nested.py`, then run:

    ```bash theme={null}
    python tool_hook_in_toolkit_with_state_nested.py
    ```
  </Step>
</Steps>

Full source: [cookbook/91\_tools/tool\_hooks/tool\_hook\_in\_toolkit\_with\_state\_nested.py](https://github.com/agno-agi/agno/blob/main/cookbook/91_tools/tool_hooks/tool_hook_in_toolkit_with_state_nested.py)