> ## Documentation Index
> Fetch the complete documentation index at: https://phidatainc-redirect-agent-platform-overview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.
# Human-in-the-Loop
> Pause agents for approval before executing sensitive tools.
[Human-in-the-Loop](/hitl/overview) solves three problems that appear when agents move from answering questions to taking actions:
1. **Irreversible operations.** Sending an email, deleting a record, or posting to a channel cannot be undone. A human checkpoint prevents mistakes that require cleanup or apologies.
2. **Missing context.** The agent knows what action to take but lacks a critical detail. A deployment needs a target environment. A booking needs a budget. Rather than guessing, the agent pauses and asks.
3. **Audit trail.** Sensitive operations need accountability. Slack threads already contain the discussion that led to the action. Rendering the approval in the same thread keeps the decision and its context together.
## Quick start
The Slack interface renders HITL pauses as interactive cards in the thread. Users approve, reject, or provide input without leaving Slack.
```python agent.py theme={null}
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 send_email(to: str, subject: str, body: str) -> str:
"""Send an email."""
...
db = SqliteDb(db_file="agent.db")
agent = Agent(
name="Assistant",
model=OpenAIResponses(id="gpt-5.4"),
tools=[send_email],
db=db,
)
agent_os = AgentOS(
agents=[agent],
db=db,
interfaces=[Slack(agent=agent)],
)
app = agent_os.get_app()
if __name__ == "__main__":
agent_os.serve(app="agent:app", reload=True)
```
```python team.py theme={null}
from agno.agent import Agent
from agno.team import Team
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 send_email(to: str, subject: str, body: str) -> str:
"""Send an email."""
...
db = SqliteDb(db_file="agent.db")
researcher = Agent(name="Researcher", model=OpenAIResponses(id="gpt-5.4"))
writer = Agent(name="Writer", model=OpenAIResponses(id="gpt-5.4"), tools=[send_email])
support_team = Team(
name="Support Team",
mode="coordinate",
members=[researcher, writer],
model=OpenAIResponses(id="gpt-5.4"),
db=db,
)
agent_os = AgentOS(
teams=[support_team],
db=db,
interfaces=[Slack(team=support_team)],
)
app = agent_os.get_app()
if __name__ == "__main__":
agent_os.serve(app="team:app", reload=True)
```
When a member agent calls a tool that requires confirmation, the team pauses.
```python workflow.py theme={null}
from agno.agent import Agent
from agno.workflow import Step, Workflow
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 send_email(to: str, subject: str, body: str) -> str:
"""Send an email."""
...
db = SqliteDb(db_file="agent.db")
researcher = Agent(name="Researcher", model=OpenAIResponses(id="gpt-5.4"))
writer = Agent(name="Writer", model=OpenAIResponses(id="gpt-5.4"), tools=[send_email])
research_flow = Workflow(
name="Research",
steps=[
Step(name="Research", agent=researcher),
Step(name="Write", agent=writer),
],
db=db,
)
agent_os = AgentOS(
workflows=[research_flow],
db=db,
interfaces=[Slack(workflow=research_flow)],
)
app = agent_os.get_app()
if __name__ == "__main__":
agent_os.serve(app="workflow:app", reload=True)
```
Workflow step pauses surface in Slack the same way.
HITL requires a [database](/features/storage) to persist paused runs.
## Pause types
| Pause type | Slack card | Trigger |
| ---------------------------------------------- | ---------------------------------------------------- | ----------------------------------- |
| [Confirmation](/hitl/user-confirmation) | Approve/Reject buttons | `@tool(requires_confirmation=True)` |
| [User input](/hitl/user-input) | Text fields or dropdowns | `@tool(requires_user_input=True)` |
| [External execution](/hitl/external-execution) | Confirm button, result fed back | `@tool(external_execution=True)` |
| [User feedback](/hitl/dynamic-user-input) | Dynamic forms: checkboxes, dropdowns, text questions | `UserFeedbackTools()` |
See the [HITL overview](/hitl/overview) for details on each pause type.
## Next steps
All pause types and how to use them
All parameters and endpoints