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loop_confirmation.py
"""
Loop Confirmation HITL Example (AgentOS)

This example demonstrates pausing before a Loop starts so a human can decide
whether to run the iterative work.
"""

from agno.os import AgentOS
from agno.workflow.loop import Loop
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 prepare_data(step_input: StepInput) -> StepOutput:
    topic = step_input.input or "quarterly performance"
    return StepOutput(
        content=f"Prepared data for '{topic}'.\n"
        "- Baseline metrics loaded\n"
        "- Candidate refinements identified"
    )


def refine_analysis(step_input: StepInput) -> StepOutput:
    previous_content = step_input.previous_step_content or "No previous analysis"
    return StepOutput(
        content=f"Refinement pass complete.\n\nInput considered:\n{previous_content}\n\n"
        "- Quality score improved\n"
        "- Narrative tightened"
    )


def finalize_results(step_input: StepInput) -> StepOutput:
    previous_content = step_input.previous_step_content or "No refinement output"
    return StepOutput(content=f"Final results:\n\n{previous_content}")


workflow = Workflow(
    name="loop_confirmation_workflow",
    description="Ask for human confirmation before an iterative refinement loop.",
    db=db,
    steps=[
        Step(name="prepare_data", executor=prepare_data),
        Loop(
            name="refinement_loop",
            steps=[Step(name="refine_analysis", executor=refine_analysis)],
            max_iterations=3,
            requires_confirmation=True,
            confirmation_message="Start the refinement loop?",
        ),
        Step(name="finalize_results", executor=finalize_results),
    ],
)
workflow.id = "workflow-hitl-loop-confirmation"

agent_os = AgentOS(
    name="Workflow Loop Confirmation HITL",
    description="AgentOS workflow example for loop start confirmation.",
    workflows=[workflow],
    db=db,
)
app = agent_os.get_app()


if __name__ == "__main__":
    agent_os.serve(app="loop_confirmation:app", reload=True)
The example imports this helper module from the same directory:
workflow_db.py
from agno.db.postgres import PostgresDb

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

​
Run the Example

1

Set up your virtual environment

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[os]" cel-python fastmcp psycopg-binary starlette
3

Export your API keys

export JWT_VERIFICATION_KEY="your_jwt_verification_key_here"

$Env:JWT_VERIFICATION_KEY="your_jwt_verification_key_here"
4

Run PgVector

docker run -d \
  -e POSTGRES_DB=ai \
  -e POSTGRES_USER=ai \
  -e POSTGRES_PASSWORD=ai \
  -e PGDATA=/var/lib/postgresql/data/pgdata \
  -v pgvolume:/var/lib/postgresql/data \
  -p 5532:5432 \
  --name pgvector \
  agnohq/pgvector:18
5

Run the example

Save the code blocks above as loop_confirmation.py and workflow_db.py in the same directory, then run:
python loop_confirmation.py
Full source: cookbook/05_agent_os/human_in_the_loop/workflow/loop_confirmation.py