Nested Tool Hooks in Toolkit

Use of multiple hooks for complex validation and result sanitization.

Execute multiple hooks in a specific order to implement sequential validation, logging, and result sanitization for both synchronous and asynchronous AI tools.

import asyncio
import json
from inspect import iscoroutinefunction
from typing import Any, Callable, Dict

from agno.agent import Agent
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)
        self.register(self.delete_customer_profile)

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

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

        Returns:
            A string containing the customer profile.
        """
        logger.info(f"Looking up customer profile for {customer_id}")
        return json.dumps(
            {
                "customer_id": customer_id,
                "name": "John Doe",
                "email": "[e-mail]",
            }
        )

    def delete_customer_profile(self, customer_id: str):
        """
        Deletes a customer profile from the database.

        Args:
            customer_id: The ID of the customer to delete.
        """
        logger.info(f"Deleting customer profile for {customer_id}")
        return f"Customer profile for {customer_id}"


def validation_hook(name: str, func: Callable, arguments: Dict[str, Any]):
    if name == "retrieve_customer_profile":
        cust_id = arguments.get("customer_id")
        if cust_id == "123":
            raise ValueError("Cannot retrieve customer profile for ID 123")

    if name == "delete_customer_profile":
        cust_id = arguments.get("customer_id")
        if cust_id == "123":
            raise ValueError("Cannot delete customer profile for ID 123")

    logger.info("Before Validation Hook")
    result = func(**arguments)
    logger.info("After Validation Hook")
    # Remove name from result to sanitize the output
    result = json.loads(result)
    result.pop("name")
    return json.dumps(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


sync_agent = Agent(
    tools=[CustomerDBTools()],
    # Hooks are executed in order of the list
    tool_hooks=[validation_hook, logger_hook],
)


# ---------------------------------------------------------------------------
# Async Variant
# ---------------------------------------------------------------------------


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

        self.register(self.retrieve_customer_profile)
        self.register(self.delete_customer_profile)

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

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

        Returns:
            A string containing the customer profile.
        """
        logger.info(f"Looking up customer profile for {customer_id}")
        return json.dumps(
            {
                "customer_id": customer_id,
                "name": "John Doe",
                "email": "[e-mail]",
            }
        )

    def delete_customer_profile(self, customer_id: str):
        """
        Deletes a customer profile from the database.

        Args:
            customer_id: The ID of the customer to delete.
        """
        logger.info(f"Deleting customer profile for {customer_id}")
        return f"Customer profile for {customer_id}"


async def validation_hook_async(name: str, func: Callable, arguments: Dict[str, Any]):
    if name == "retrieve_customer_profile":
        cust_id = arguments.get("customer_id")
        if cust_id == "123":
            raise ValueError("Cannot retrieve customer profile for ID 123")

    if name == "delete_customer_profile":
        cust_id = arguments.get("customer_id")
        if cust_id == "123":
            raise ValueError("Cannot delete customer profile for ID 123")

    logger.info("Before Validation Hook")
    if iscoroutinefunction(func):
        result = await func(**arguments)
    else:
        result = func(**arguments)
    logger.info("After Validation Hook")
    # Remove name from result to sanitize the output
    if name == "retrieve_customer_profile":
        result = json.loads(result)
        result.pop("name")
        return json.dumps(result)
    return result


async def logger_hook_async(name: str, func: Callable, arguments: Dict[str, Any]):
    logger.info("Before Logger Hook")
    if iscoroutinefunction(func):
        result = await func(**arguments)
    else:
        result = func(**arguments)
    logger.info("After Logger Hook")
    return result


async_agent = Agent(
    tools=[CustomerDBToolsAsync()],
    # Hooks are executed in order of the list
    tool_hooks=[validation_hook_async, logger_hook_async],
)


# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    sync_agent.print_response("I am customer 456, please retrieve my profile.")
    asyncio.run(
        async_agent.aprint_response(
            "I am customer 456, please retrieve my profile.", stream=True
        )
    )
    asyncio.run(
        async_agent.aprint_response(
            "I am customer 456, please delete my profile.", stream=True
        )
    )

Run the Example

# Clone and setup repo
git clone https://github.com/agno-agi/agno.git
cd agno/cookbook/91_tools/tool_hooks

# Create and activate virtual environment
./scripts/demo_setup.sh
source .venvs/demo/bin/activate

python tool_hooks_in_toolkit_nested.py

For details, see Chained Toolkit Hooks cookbook.