---
title: "Guardrails Concepts"
description: ""
---

NeMo Guardrails provides configurable safety checks that evaluate user inputs and model outputs before responses are returned to your application. Guardrails runs as an Inference Gateway (IGW) middleware plugin, integrated into the inference pipeline through VirtualModels.

---

- **[Architecture](/documentation/guardrail-models/core-concepts/architecture)** — How guardrails runs as IGW middleware, VirtualModel wiring, and model routing.
- **[Configurations](/documentation/guardrail-models/core-concepts/configurations)** — Define rails, models, and prompts that make up a guardrail policy.
- **[Inference](/documentation/guardrail-models/core-concepts/running-inference)** — Run inference through a guarded VirtualModel and configure request options.
- **[Checks](/documentation/guardrail-models/core-concepts/running-checks)** — Evaluate messages against rails without running inference.
