> ## Documentation Index
> Fetch the complete documentation index at: https://docs.qwedai.com/llms.txt
> Use this file to discover all available pages before exploring further.

# QWED vs Guardrails AI

> Compare QWED and Guardrails AI for LLM verification, AI agent security, schema validation, and deterministic output checking.

QWED and Guardrails solve different problems in an AI stack.

Guardrails helps you constrain structure. QWED helps you verify correctness.

## Core difference

| Tool       | Primary job                       | Best at                                          |
| ---------- | --------------------------------- | ------------------------------------------------ |
| Guardrails | Output structure and policy rules | JSON schemas, validators, formatting constraints |
| QWED       | Deterministic verification        | Math, logic, code, SQL, tool-call verification   |

## When Guardrails is enough

Use Guardrails when you need:

* Valid JSON or XML
* Required fields and schema checks
* Basic policy filters
* Controlled output formats for downstream parsing

## When you need QWED

Use QWED when you need:

* Formal verification for LLM outputs
* AI agent security before tool execution
* Verified tool calls and MCP security
* Deterministic checks for numbers, logic, code, and SQL

## Best-practice stack

Use both together:

1. Guardrails enforces the response format.
2. QWED verifies whether the contents are actually correct.

## Related docs

* [LLM verification with formal methods](/advanced/llm-verification)
* [QWED vs RAG for LLM verification](/advanced/qwed-vs-rag)
* [QWED vs Guardrails, RAG, and RLHF for LLM verification](/advanced/comparison)
* [QWED Open Responses: verified tool calls for AI agents](/open-responses/overview)