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This example is available on GitHub: examples/01_standalone_sdk/11_async.py
Run agents asynchronously for non-blocking execution and concurrent operations:
examples/01_standalone_sdk/11_async.py
"""
This example demonstrates usage of a Conversation in an async context
(e.g.: From a fastapi server). The conversation is run in a background
thread and a callback with results is executed in the main runloop
"""

import asyncio
import os

from pydantic import SecretStr

from openhands.sdk import (
    LLM,
    Agent,
    Conversation,
    Event,
    LLMConvertibleEvent,
    get_logger,
)
from openhands.sdk.conversation.types import ConversationCallbackType
from openhands.sdk.tool import Tool, register_tool
from openhands.sdk.utils.async_utils import AsyncCallbackWrapper
from openhands.tools.execute_bash import BashTool
from openhands.tools.file_editor import FileEditorTool
from openhands.tools.task_tracker import TaskTrackerTool


logger = get_logger(__name__)

# Configure LLM
api_key = os.getenv("LLM_API_KEY")
assert api_key is not None, "LLM_API_KEY environment variable is not set."
model = os.getenv("LLM_MODEL", "openhands/claude-sonnet-4-5-20250929")
base_url = os.getenv("LLM_BASE_URL")
llm = LLM(
    usage_id="agent",
    model=model,
    base_url=base_url,
    api_key=SecretStr(api_key),
)

# Tools
cwd = os.getcwd()
register_tool("BashTool", BashTool)
register_tool("FileEditorTool", FileEditorTool)
register_tool("TaskTrackerTool", TaskTrackerTool)
tools = [
    Tool(
        name="BashTool",
    ),
    Tool(name="FileEditorTool"),
    Tool(name="TaskTrackerTool"),
]

# Agent
agent = Agent(llm=llm, tools=tools)

llm_messages = []  # collect raw LLM messages


# Callback coroutine
async def callback_coro(event: Event):
    if isinstance(event, LLMConvertibleEvent):
        llm_messages.append(event.to_llm_message())


# Synchronous run conversation
def run_conversation(callback: ConversationCallbackType):
    conversation = Conversation(agent=agent, callbacks=[callback])

    conversation.send_message(
        "Hello! Can you create a new Python file named hello.py that prints "
        "'Hello, World!'? Use task tracker to plan your steps."
    )
    conversation.run()

    conversation.send_message("Great! Now delete that file.")
    conversation.run()


async def main():
    loop = asyncio.get_running_loop()

    # Create the callback
    callback = AsyncCallbackWrapper(callback_coro, loop)

    # Run the conversation in a background thread and wait for it to finish...
    await loop.run_in_executor(None, run_conversation, callback)

    print("=" * 100)
    print("Conversation finished. Got the following LLM messages:")
    for i, message in enumerate(llm_messages):
        print(f"Message {i}: {str(message)[:200]}")


if __name__ == "__main__":
    asyncio.run(main())
Running the Example
export LLM_API_KEY="your-api-key"
cd agent-sdk
uv run python examples/01_standalone_sdk/11_async.py

​
Async Streaming

Use astream() to process events as they occur without blocking: 
async def run_agent():
    conversation = Conversation(agent=agent, workspace=cwd)
    conversation.send_message("Write 3 facts about Python to FACTS.txt")
    
    async for event in conversation.astream():
        print(f"Event: {event}")

​
Concurrent Agents

Run multiple agent tasks in parallel using asyncio.gather(): 
async def main():
    # Create multiple conversation tasks
    tasks = [
        run_task("task 1"),
        run_task("task 2"),
        run_task("task 3")
    ]
    results = await asyncio.gather(*tasks)

​
Next Steps