> ## Documentation Index
> Fetch the complete documentation index at: https://agno-v2-studio-tools-doc.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# StopAgentRun

> API reference for the StopAgentRun exception used to exit the tool call loop and complete the agent run.

The `StopAgentRun` exception allows you to exit the model execution loop and end the agent run. When raised from a tool function, the agent immediately exits the tool call loop, and the run status is set to `COMPLETED`. All session state, messages, tool calls, and tool results up to that point are stored in the database.

<Note>
  This does **not** cancel the agent run. It completes the run gracefully after exiting the tool call loop.
</Note>

## Constructor

```python theme={null}
StopAgentRun(
    exc: str,
    user_message: Optional[Union[str, Message]] = None,
    agent_message: Optional[Union[str, Message]] = None,
    messages: Optional[List[Union[dict, Message]]] = None,
)
```

### Parameters

<ResponseField name="exc" type="str" required>
  The reason for stopping execution. This message is logged and can be used for debugging or user feedback.
</ResponseField>

<ResponseField name="user_message" type="Union[str, Message]" optional>
  An optional message to display to the user about why execution stopped.
</ResponseField>

<ResponseField name="agent_message" type="Union[str, Message]" optional>
  An optional message from the agent's perspective about the stop.
</ResponseField>

<ResponseField name="messages" type="List[Union[dict, Message]]" optional>
  An optional list of messages to add to the conversation history before stopping.
</ResponseField>

## When to Use

Use `StopAgentRun` when:

* **Critical errors**: An error occurs that cannot be recovered from
* **Security triggers**: A security threshold or policy is violated
* **Task completion**: The task is fully completed and no further tool calls are needed
* **Resource limits**: A resource limit (time, cost, API calls) is reached
* **Manual intervention needed**: The situation requires human review or approval
* **Early termination**: You want to exit the tool call loop based on business logic

## Behavior

When `StopAgentRun` is raised:

1. The tool call loop exits immediately
2. No further tool calls are executed
3. The run status is set to `COMPLETED`
4. All session state is saved to the database
5. All messages and tool calls up to that point are preserved
6. The optional `user_message` or `agent_message` can be displayed to the user

## See Also

* [RetryAgentRun Exception](/reference/tools/retry-agent-run)
* [Exceptions & Retries Guide](/tools/exceptions)