> ## Documentation Index
> Fetch the complete documentation index at: https://phidatainc-redirect-agent-platform-overview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Dynamic State

This example demonstrates how to use tool hooks to dynamically manage session state. It shows how to create a customer management system that updates session state through tool interactions rather than direct modification.

<Steps>
  <Step title="Create a Python file">
    ```python dynamic_session_state.py theme={null}
    import json
    from typing import Any, Callable, Dict

    from agno.agent import Agent
    from agno.db.in_memory import InMemoryDb
    from agno.models.openai import OpenAIResponses
    from agno.tools.toolkit import Toolkit
    from agno.utils.log import log_info, log_warning
    from agno.run import RunContext


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

        def process_customer_request(
            self,
            agent: Agent,
            customer_id: str,
            action: str = "retrieve",
            name: str = "John Doe",
        ):
            log_warning("Tool called, this shouldn't happen.")
            return "This should not be seen."


    def customer_management_hook(
        run_context: RunContext,
        function_name: str,
        function_call: Callable,
        arguments: Dict[str, Any],
    ):
        if not run_context.session_state:
            run_context.session_state = {}

        action = arguments.get("action", "retrieve")
        cust_id = arguments.get("customer_id")
        name = arguments.get("name", None)

        if not cust_id:
            raise ValueError("customer_id is required.")

        if action == "create":
            run_context.session_state["customer_profiles"][cust_id] = {"name": name}
            log_info(f"Hook: UPDATED session_state for customer '{cust_id}'.")
            return f"Success! Customer {cust_id} has been created."

        if action == "retrieve":
            profile = run_context.session_state.get("customer_profiles", {}).get(cust_id)
            if profile:
                log_info(f"Hook: FOUND customer '{cust_id}' in session_state.")
                return f"Profile for {cust_id}: {json.dumps(profile)}"
            else:
                raise ValueError(f"Customer '{cust_id}' not found.")

        log_info(f"Session state: {run_context.session_state}")


    def run_test():
        agent = Agent(
            model=OpenAIResponses(id="gpt-5.2"),
            tools=[CustomerDBTools()],
            tool_hooks=[customer_management_hook],
            session_state={"customer_profiles": {"123": {"name": "Jane Doe"}}},
            instructions="Your profiles: {customer_profiles}. Use `process_customer_request`. Use either create or retrieve as action for the tool.",
            resolve_in_context=True,
            db=InMemoryDb(),
        )

        prompt = "First, create customer 789 named 'Tom'. Then, retrieve Tom's profile. Step by step."
        log_info(f"Prompting: '{prompt}'")
        agent.print_response(prompt, stream=False)

        log_info("\n--- TEST ANALYSIS ---")
        log_info(
            "Check logs for the second tool call. The system prompt will NOT contain customer '789'."
        )


    if __name__ == "__main__":
        run_test()
    ```
  </Step>

  <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">
    <Snippet file="set-openai-key.mdx" />
  </Step>

  <Step title="Run Agent">
    ```bash theme={null}
    python dynamic_session_state.py
    ```
  </Step>
</Steps>