# Guardrails AI

5 Hacker News commenters recommended Guardrails AI and 1 criticized it, November 2025 to November 2026. It was recommended in 7 of 13 months.

**Verdict:** Developers recommend it for forcing AI agents to pass tests and build checks, and for being simpler with less code. It is free software.

## Why people recommend it

- Forces agents to run tests and builds (2 comments): "it forces the agent to do arbitrary requirements such as: ensure it still runs / compiles, run all tests" ([source](https://news.ycombinator.com/item?id=47916546)) "I force my agents to run tests, test if the project builds, and even look for human validation" ([source](https://news.ycombinator.com/item?id=47418246))
- Simpler with much less code (2 comments): "I wanted something slightly simpler, but similar with more 'guard rails'" ([source](https://news.ycombinator.com/item?id=48207659)) "works just as good, drastically less code" ([source](https://news.ycombinator.com/item?id=47041129))

## Alternatives hackers recommend

- [Pydantic](https://hackerapproved.com/p/pydantic.md): 62 recommend
- [Zod](https://hackerapproved.com/p/zod.md): 58 recommend
- [clojure.spec](https://hackerapproved.com/p/clojure-spec.md): 18 recommend
- [Malli](https://hackerapproved.com/p/malli.md): 15 recommend

## Cite as

Hacker Approved, "Guardrails AI", https://hackerapproved.com/p/guardrails/ (counts from 1,795,640 Hacker News comments, November 2025 to November 2026).