message_history_hooks.py
"""
Message History Hooks
=============================
Access the current run's message history inside tool pre/post hooks
via run_context.messages.
"""
from agno.agent import Agent
from agno.models.openai import OpenAIChat
from agno.run.base import RunContext
from agno.tools import FunctionCall, tool
# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------
def pre_hook(run_context: RunContext, fc: FunctionCall):
msgs = run_context.messages
count = len(msgs) if msgs else 0
print(f"[pre-hook] {fc.function.name} - {count} messages in run")
def post_hook(run_context: RunContext, fc: FunctionCall):
msgs = run_context.messages
count = len(msgs) if msgs else 0
print(
f"[post-hook] {fc.function.name} returned '{fc.result}' - {count} messages in run"
)
@tool(pre_hook=pre_hook, post_hook=post_hook)
def get_weather(city: str) -> str:
"""Get the current weather for a city."""
return f"Sunny, 72F in {city}"
agent = Agent(
model=OpenAIChat(id="gpt-4o-mini"),
tools=[get_weather],
instructions=["Use the tools to help the user."],
)
# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------
if __name__ == "__main__":
agent.print_response("What is the weather in San Francisco?")
Run the Example
Set up your virtual environment
uv venv --python 3.12
source .venv/bin/activate
uv venv --python 3.12
.venv\Scripts\activate
Export your OpenAI API key
export OPENAI_API_KEY="your_openai_api_key_here"
$Env:OPENAI_API_KEY="your_openai_api_key_here"