> ## Documentation Index
> Fetch the complete documentation index at: https://agency-swarm.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Guardrails Overview

> Screen agent inputs and review outputs with guardrails.

Guardrails are checkpoint functions that keep agent behavior safe and predictable. Use them to validate incoming messages before execution and validate responses before delivery.

## Choose the Right Guardrail

| Type                  | Runs When                                      | On Failure                                                                       | Page                                                                   |
| --------------------- | ---------------------------------------------- | -------------------------------------------------------------------------------- | ---------------------------------------------------------------------- |
| **Input Guardrails**  | Before the agent processes input               | Return guidance (non-strict) or raise `InputGuardrailTripwireTriggered` (strict) | [Input Guardrails](/additional-features/guardrails/input-guardrails)   |
| **Output Guardrails** | After the agent drafts output, before delivery | Retry up to `validation_attempts`, then raise `OutputGuardrailTripwireTriggered` | [Output Guardrails](/additional-features/guardrails/output-guardrails) |

## Runnable GitHub Examples

* Input guardrails example: [`examples/guardrails_input.py`](https://github.com/VRSEN/agency-swarm/blob/main/examples/guardrails_input.py)
* Output guardrails example: [`examples/guardrails_output.py`](https://github.com/VRSEN/agency-swarm/blob/main/examples/guardrails_output.py)

## Best Practices

* Keep each guardrail focused on one responsibility.
* Write clear `output_info` messages so the model knows how to recover.
* Use non-strict mode for guidance and strict mode for hard requirements.
* For tool argument validation (field/model validators), use [Input Validation](/core-framework/tools/custom-tools/validation).