Human-in-the-Loop

Pause agents and teams for approval directly in Slack, rendered as interactive TaskCards.

When an agent or team pauses for human-in-the-loop, the Slack interface renders the pause as an interactive TaskCard in the channel. The user resolves it with buttons and inputs, and the run resumes. All four pause types are supported.

Example

A paused run is persisted to the database and resumed by run_id when the user resolves the TaskCard, so the Slack interface needs a db.

cookbook/05_agent_os/interfaces/slack/hitl_simple.py

import json
import httpx
from agno.agent import Agent
from agno.db.sqlite import SqliteDb
from agno.models.openai import OpenAIResponses
from agno.os import AgentOS
from agno.os.interfaces.slack import Slack
from agno.tools import tool


@tool(requires_confirmation=True)
def get_top_hackernews_stories(num_stories: int) -> str:
    """Fetch top stories from Hacker News."""
    response = httpx.get("https://hacker-news.firebaseio.com/v0/topstories.json")
    story_ids = response.json()
    return json.dumps(story_ids[:num_stories])


db = SqliteDb(
    db_file="tmp/hitl_simple.db",
    session_table="agent_sessions",
)

agent = Agent(
    name="HN Agent",
    id="hn-agent",
    model=OpenAIResponses(id="gpt-5.4"),
    tools=[get_top_hackernews_stories],
    db=db,
)

agent_os = AgentOS(
    agents=[agent],
    db=db,
    interfaces=[Slack(agent=agent, reply_to_mentions_only=True)],
)
app = agent_os.get_app()

if __name__ == "__main__":
    agent_os.serve(app="hitl_simple:app", reload=True, port=7777)

Pause Types

Each pause type renders a different TaskCard:

Pause type	Slack UI	Trigger
Confirmation	Approve / Reject buttons. Multiple pending tools render as separate rows.	@tool(requires_confirmation=True)
User input	Text fields, or dropdowns for Literal/Enum-typed fields.	@tool(requires_user_input=True)
User feedback	Option buttons from a structured question.	UserFeedbackTools
External execution	Confirm button. The tool runs outside the agent, result is fed back.	@tool(external_execution=True)

Rejections collect a reason where applicable, which is passed back to the agent so it can adjust.

Teams and Workflows

The same TaskCards work for teams and workflows. When a member agent inside a team pauses, the pause propagates to the team run and surfaces in Slack. Workflow step and executor pauses surface the same way.

Pattern	Cookbook
Agent confirmation	hitl_confirmation.py
User input	hitl_user_input.py
External execution	hitl_external_execution.py
Structured feedback	hitl_user_feedback.py
Team confirmation	team_hitl_confirmation.py

Next Steps

Task	Guide
Understand pause types	HITL overview
Set up the Slack interface	Slack introduction
Manage approvals in AgentOS	Approvals overview