> ## Documentation Index
> Fetch the complete documentation index at: https://docs.agno.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Output Review HITL Example (AgentOS)

> Pausing after a step runs so a human can review the step output before the workflow continues in AgentOS.

```python output_review.py theme={null}
"""
Output Review HITL Example (AgentOS)

This example demonstrates pausing after a step runs so a human can review the
step output before the workflow continues in AgentOS.
"""

from agno.os import AgentOS
from agno.workflow import HumanReview, OnReject
from agno.workflow.step import Step
from agno.workflow.types import StepInput, StepOutput
from agno.workflow.workflow import Workflow
from workflow_db import db


def draft_email(step_input: StepInput) -> StepOutput:
    topic = step_input.input or "the schedule change"
    return StepOutput(
        content=f"Subject: Update: {topic}\n\n"
        "Hi team,\n\n"
        f"Please note that {topic}. Let me know if this creates any conflicts.\n\n"
        "Thanks"
    )


def send_email(step_input: StepInput) -> StepOutput:
    approved_draft = step_input.previous_step_content or "No approved draft"
    return StepOutput(content=f"Email queued for sending:\n\n{approved_draft}")


workflow = Workflow(
    name="output_review_workflow",
    description="Review a drafted email before it moves to the send step.",
    db=db,
    steps=[
        Step(
            name="draft_email",
            executor=draft_email,
            human_review=HumanReview(
                requires_output_review=True,
                output_review_message="Review this email draft before sending.",
                on_reject=OnReject.cancel,
            ),
        ),
        Step(name="send_email", executor=send_email),
    ],
)
workflow.id = "workflow-hitl-output-review"

agent_os = AgentOS(
    name="Workflow Output Review HITL",
    description="AgentOS workflow example for post-step output review.",
    workflows=[workflow],
    db=db,
)
app = agent_os.get_app()


if __name__ == "__main__":
    agent_os.serve(app="output_review:app", reload=True)
```

The example imports this helper module from the same directory:

```python workflow_db.py theme={null}
from agno.db.postgres import PostgresDb

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

## Run the Example

<Steps>
  <Snippet file="create-venv-step.mdx" />

  <Step title="Install dependencies">
    ```bash theme={null}
    uv pip install -U "agno[os]" fastmcp psycopg-binary starlette
    ```
  </Step>

  <Step title="Export your API keys">
    <CodeGroup>
      ```bash Mac/Linux theme={null}
      export JWT_VERIFICATION_KEY="your_jwt_verification_key_here"
      ```

      ```bash Windows theme={null}
      $Env:JWT_VERIFICATION_KEY="your_jwt_verification_key_here"
      ```
    </CodeGroup>
  </Step>

  <Snippet file="run-pgvector-step.mdx" />

  <Step title="Run the example">
    Save the code blocks above as `output_review.py` and `workflow_db.py` in the same directory, then run:

    ```bash theme={null}
    python output_review.py
    ```
  </Step>
</Steps>

Full source: [cookbook/05\_agent\_os/human\_in\_the\_loop/workflow/output\_review.py](https://github.com/agno-agi/agno/blob/main/cookbook/05_agent_os/human_in_the_loop/workflow/output_review.py)