Async Tool Decorator

Define an async generator tool with @tool and stream its yielded results.

async_tool_decorator.py

"""
Async Tool Decorator
=============================

Demonstrates async tool decorator.
"""

import asyncio
import json
from typing import AsyncIterator

import httpx
from agno.agent import Agent
from agno.tools import tool

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


@tool(show_result=True)
async def get_top_hackernews_stories(agent: Agent) -> AsyncIterator[str]:
    num_stories = agent.dependencies.get("num_stories", 5) if agent.dependencies else 5

    async with httpx.AsyncClient() as client:
        # Fetch top story IDs
        response = await client.get(
            "https://hacker-news.firebaseio.com/v0/topstories.json"
        )
        story_ids = response.json()

        # Yield story details
        for story_id in story_ids[:num_stories]:
            story_response = await client.get(
                f"https://hacker-news.firebaseio.com/v0/item/{story_id}.json"
            )
            story = story_response.json()
            if "text" in story:
                story.pop("text", None)
            yield json.dumps(story)


agent = Agent(
    dependencies={
        "num_stories": 2,
    },
    tools=[get_top_hackernews_stories],
    markdown=True,
)
# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------

if __name__ == "__main__":
    asyncio.run(
        agent.aprint_response("What are the top hackernews stories?", stream=True)
    )

Run the Example

1. Set up your virtual environment

   Mac

   uv venv --python 3.12
   source .venv/bin/activate
   

   uv venv --python 3.12
   .venv\Scripts\activate
   
2. Install dependencies

   uv pip install -U agno openai
   
3. Export your OpenAI API key

   Mac/Linux

   export OPENAI_API_KEY="your_openai_api_key_here"
   

   $Env:OPENAI_API_KEY="your_openai_api_key_here"
   
4. Run the example

   Save the code above as async_tool_decorator.py, then run:

   python async_tool_decorator.py
   

Full source: cookbook/91_tools/tool_decorator/async_tool_decorator.py