# Background Execution (/examples/agents/advanced/background-execution)



Example demonstrating background execution with polling and cancellation.

```python title="background_execution.py"
"""
Example demonstrating background execution with polling and cancellation.

Background execution allows you to start an agent run that returns immediately
with a PENDING status, while the actual work continues in the background.
You can then poll for completion or cancel the run.

Requirements:
- PostgreSQL running (./cookbook/scripts/run_pgvector.sh)
- OPENAI_API_KEY set

Usage:
    .venvs/demo/bin/python cookbook/02_agents/14_advanced/background_execution.py
"""

import asyncio

from agno.agent import Agent
from agno.db.postgres import PostgresDb
from agno.models.openai import OpenAIResponses
from agno.run.base import RunStatus

# ---------------------------------------------------------------------------
# Config
# ---------------------------------------------------------------------------

db = PostgresDb(
    db_url="postgresql+psycopg://ai:ai@localhost:5532/ai",
    session_table="background_exec_sessions",
)


# ---------------------------------------------------------------------------
# Create and Run Background Examples
# ---------------------------------------------------------------------------


async def example_background_run_with_polling():
    """Start a background run and poll until complete."""
    print("=" * 60)
    print("Example 1: Background run with polling")
    print("=" * 60)

    agent = Agent(
        name="BackgroundAgent",
        model=OpenAIResponses(id="gpt-5-mini"),
        description="An agent that runs in the background",
        db=db,
    )

    # Start a background run — returns immediately with PENDING status
    run_output = await agent.arun(
        "What is the capital of France? Answer in one sentence.",
        background=True,
    )

    print(f"Run ID: {run_output.run_id}")
    print(f"Session ID: {run_output.session_id}")
    print(f"Status: {run_output.status}")
    assert run_output.status == RunStatus.pending, (
        f"Expected PENDING, got {run_output.status}"
    )

    # Poll for completion
    print("\nPolling for completion...")
    for i in range(30):
        await asyncio.sleep(1)
        result = await agent.aget_run_output(
            run_id=run_output.run_id,
            session_id=run_output.session_id,
        )
        if result is None:
            print(f"  [{i + 1}s] Run not found in DB yet")
            continue

        print(f"  [{i + 1}s] Status: {result.status}")

        if result.status == RunStatus.completed:
            print(f"\nCompleted! Content: {result.content}")
            break
        elif result.status == RunStatus.error:
            print(f"\nFailed! Content: {result.content}")
            break
    else:
        print("\nTimed out waiting for completion")

    print()


async def example_cancel_background_run():
    """Start a background run and cancel it before completion."""
    print("=" * 60)
    print("Example 2: Cancel a background run")
    print("=" * 60)

    agent = Agent(
        name="CancellableAgent",
        model=OpenAIResponses(id="gpt-5-mini"),
        description="An agent whose run can be cancelled",
        db=db,
    )

    # Start a long background run
    run_output = await agent.arun(
        "Write a very detailed essay about the history of computing. "
        "Make it at least 5000 words with sections and subsections.",
        background=True,
    )

    print(f"Run ID: {run_output.run_id}")
    print(f"Status: {run_output.status}")

    # Wait a moment for the run to start
    await asyncio.sleep(2)

    # Cancel the run
    print("Cancelling run...")
    cancelled = await agent.acancel_run(run_id=run_output.run_id)
    print(f"Cancel result: {cancelled}")

    # Check the final state
    await asyncio.sleep(1)
    result = await agent.aget_run_output(
        run_id=run_output.run_id,
        session_id=run_output.session_id,
    )
    if result:
        print(f"Final status: {result.status}")
    print()


async def example_cancel_before_start():
    """Cancel a run before it even starts (cancel-before-start semantics)."""
    print("=" * 60)
    print("Example 3: Cancel-before-start")
    print("=" * 60)

    from agno.run.cancel import cancel_run

    agent = Agent(
        name="PreCancelAgent",
        model=OpenAIResponses(id="gpt-5-mini"),
        description="An agent whose run is cancelled before starting",
        db=db,
    )

    # Pre-generate a run ID
    from uuid import uuid4

    run_id = str(uuid4())

    # Cancel the run BEFORE it starts
    print(f"Pre-cancelling run {run_id}...")
    cancel_run(run_id)

    # Now start the run with that ID — it should detect the cancellation
    run_output = await agent.arun(
        "This should be cancelled before it runs.",
        background=True,
        run_id=run_id,
    )

    print(f"Run ID: {run_output.run_id}")
    print(f"Initial status: {run_output.status}")

    # Wait and check — the background task should detect the cancellation
    await asyncio.sleep(2)
    result = await agent.aget_run_output(
        run_id=run_output.run_id,
        session_id=run_output.session_id,
    )
    if result:
        print(f"Final status: {result.status}")
    print()


async def main():
    await example_background_run_with_polling()
    await example_cancel_background_run()
    await example_cancel_before_start()
    print("All examples completed!")


if __name__ == "__main__":
    asyncio.run(main())
```

## Background task lifetime [#background-task-lifetime]

`background=True` detaches the run from its consumer while the event loop remains alive. These standalone scripts use `asyncio.run`: when the main coroutine exits, unfinished tasks are cancelled, including after a polling timeout. Keep the loop alive until the desired terminal state, or explicitly cancel and observe the run before leaving. A saved pending row alone does not restart execution.

A running AgentOS server can keep work alive after client disconnects. For recovery across process restarts, configure its [durable queue](/agent-os/background-execution/overview).

## Run the Example [#run-the-example]

<Steps>
    <Step title="Set up your virtual environment">
      <CodeBlockTabs defaultValue="Mac">
        <CodeBlockTabsList>
          <CodeBlockTabsTrigger value="Mac">
            Mac
          </CodeBlockTabsTrigger>

          <CodeBlockTabsTrigger value="Windows">
            Windows
          </CodeBlockTabsTrigger>
        </CodeBlockTabsList>

        <CodeBlockTab value="Mac">
          ```bash
          uv venv --python 3.12
          source .venv/bin/activate
          ```
        </CodeBlockTab>

        <CodeBlockTab value="Windows">
          ```bash
          uv venv --python 3.12
          .venv\Scripts\activate
          ```
        </CodeBlockTab>
      </CodeBlockTabs>
    </Step>

  <Step title="Install dependencies">
    ```bash
    uv pip install -U agno "psycopg[binary]" openai sqlalchemy
    ```
  </Step>

  <Step title="Export your OpenAI API key">
    <CodeBlockTabs defaultValue="Mac/Linux">
      <CodeBlockTabsList>
        <CodeBlockTabsTrigger value="Mac/Linux">
          Mac/Linux
        </CodeBlockTabsTrigger>

        <CodeBlockTabsTrigger value="Windows">
          Windows
        </CodeBlockTabsTrigger>
      </CodeBlockTabsList>

      <CodeBlockTab value="Mac/Linux">
        ```bash
        export OPENAI_API_KEY="your_openai_api_key_here"
        ```
      </CodeBlockTab>

      <CodeBlockTab value="Windows">
        ```bash
        $Env:OPENAI_API_KEY="your_openai_api_key_here"
        ```
      </CodeBlockTab>
    </CodeBlockTabs>
  </Step>

    <Step title="Run PgVector">
      <CodeBlockTabs defaultValue="macOS / Linux">
        <CodeBlockTabsList>
          <CodeBlockTabsTrigger value="macOS / Linux">
            macOS / Linux
          </CodeBlockTabsTrigger>

          <CodeBlockTabsTrigger value="Windows">
            Windows
          </CodeBlockTabsTrigger>
        </CodeBlockTabsList>

        <CodeBlockTab value="macOS / Linux">
          ```bash
          docker run -d \
            -e POSTGRES_DB=ai \
            -e POSTGRES_USER=ai \
            -e POSTGRES_PASSWORD=ai \
            -e PGDATA=/var/lib/postgresql \
            -v pgvolume:/var/lib/postgresql \
            -p 5532:5432 \
            --name pgvector \
            agnohq/pgvector:18
          ```
        </CodeBlockTab>

        <CodeBlockTab value="Windows">
          ```powershell
          docker run -d `
            -e POSTGRES_DB=ai `
            -e POSTGRES_USER=ai `
            -e POSTGRES_PASSWORD=ai `
            -e PGDATA=/var/lib/postgresql `
            -v pgvolume:/var/lib/postgresql `
            -p 5532:5432 `
            --name pgvector `
            agnohq/pgvector:18
          ```
        </CodeBlockTab>
      </CodeBlockTabs>
    </Step>

  <Step title="Run the example">
    Save the code above as `background_execution.py`, then run:

    ```bash
    python background_execution.py
    ```
  </Step>
</Steps>

Full source: [cookbook/02\_agents/14\_advanced/background\_execution.py](https://github.com/agno-agi/agno/blob/8f36eaf2d18e91afa7b327eec66a3cd3685dcb87/cookbook/02_agents/14_advanced/background_execution.py)
