Your coding agent just handed you 400 lines that compile, pass tests, and are quietly wrong. Guard Skills is the AI code review tool that catches that before it lands — no CI setup, no cloud, no cost.
Add Guard Skills to your workflowIf you've been pairing with an AI coding agent for more than a week, you've seen the pattern. The code compiles. The tests pass. The PR description is confident. And then, somewhere in review, you realize the agent swallowed an exception with a blanket try/catch, hardcoded a return ok past the failure path, or "cleverly" abstracted three unrelated things into one god-class. None of that shows up in a build check. It only shows up when a human reads the diff and gets that sinking feeling.
That's the gap this project targets. Guard Skills is an AI code review tool built specifically to catch the systematic failure modes of AI-generated code — the smells, the hallucinations, the fake confidence — before the work reaches your repo, your PR, or your production environment.
The project comes from amElnagdy and sits at over 1,100 stars on GitHub for a reason: it doesn't try to be another platform or another CI bot. It's a collection of focused skills your agent can invoke, reviewed and maintained in the open under an MIT license. You can read every rule it applies. There are no black boxes here.
Most review tools run after you open a PR. Guard Skills runs inside the agent conversation, on the diff your agent just produced — the moment before it becomes a PR. Think of it as a second-pass quality gate: you let the agent do the work, then you tell it to review its own output with a guardrail it can't argue with.
This is the one you'll reach for daily. It applies Clean Code, SOLID, DRY/KISS/YAGNI, plus an AI-specific layer most rule packs miss: catch-all error swallowing, hardcoded success returns, hallucinated APIs, premature abstraction, and comment pollution. It even references published research on duplication growth and agents declaring success despite failed tests. You'll feel it the first time your agent asks before changing a contract instead of silently refactoring behavior.
AI agents love writing tests that catch nothing. This guard runs nine universal rules across pytest, PHPUnit/Pest, Jest/Vitest, Go, and more: mock only at system boundaries, never mock your own state objects, parametrize instead of copy-pasting, and treat production regression tests as sacred. A generated test file full of MagicMock() state and log-message assertions comes back as "do not merge" with rule-by-rule fixes.
Documentation is a list of claims, and this guard verifies every one against the codebase. Hallucinated symbols, broken samples, @param tags that don't match the real signature, docs-vs-code drift — gone. Your README stops referencing functions that don't exist, and "blazingly fast" leaves the building.
If you build WordPress plugins or WooCommerce stores with AI help, these two are worth the install alone. wp-guard enforces escaping, sanitization, nonces, capability checks, prepared queries, and translation-ready strings. woo-guard adds HPOS-safe order access, CRUD over direct meta, truthful feature-compatibility declarations, and server-side checkout validation. That's real money-handling discipline — the kind of thing a generic code review tool simply won't know to check.
People often ask me how Guard Skills compares to tools like CodeRabbit, Snyk DeepCode, or GitHub Copilot's code review. Fair question — I've used all of them. Here's the honest take:
CodeRabbit is a solid PR-review bot — it comments on your pull requests in CI and scales to big teams. Guard Skills doesn't compete with that workflow; it replaces the need for it on agent-generated work. It reviews the diff in your terminal, inside the agent session, before a PR exists. No cloud processing, no per-seat pricing, no waiting for a bot to wake up. For solo devs and small teams shipping agent output, that's a materially different (and much cheaper) loop.
Snyk DeepCode is security-first static analysis; Copilot's review gives inline PR suggestions. Both are useful — and both are narrow. Guard Skills covers the whole surface: code quality, test quality, docs accuracy, plus platform rules for WordPress and WooCommerce. And unlike Copilot review, it doesn't just suggest — it gates, with named rules your agent must fix. Want the deeper breakdown? I compared all three head-to-head in this Notion battle review.
The honest tradeoff: CodeRabbit and Copilot give you review at scale across every PR in a busy repo. Guard Skills gives you review at the source — the moment AI work is produced — for free, with rules you can read and extend. Different jobs, and for agent-driven development the second one is where the damage actually happens.
Because Guard Skills is built on the Skills CLI, install is a single command:
npx skills add amElnagdy/guard-skills
Then run a guard on whatever your agent just produced:
Use $clean-code-guard on the diff you just produced. Use $test-guard on the tests you just wrote. Use $docs-guard on this README update before we ship it.
That's it. It works with Claude Code, Codex, Cursor, OpenCode, and other supported agents. Each skill is a folder with a small SKILL.md entrypoint and progressive-disclosure references, so it loads cheaply and only pulls deeper guidance when the task needs it. No executable scripts, no network calls, no credentials — the whole package is inspectable, which is honestly refreshing in 2026.
Yes — it's MIT-licensed and lives entirely on GitHub at amElnagdy/guard-skills. No SaaS, no trial, no "contact sales." You can fork it, read every rule, and contribute. That's rare for an AI code review tool in 2026.
It does. Guard Skills installs through the Skills CLI, which supports Claude Code, Codex, Cursor, OpenCode, and other agents. Install per-project or globally, and invoke guards with the $guard-name syntax in any supported agent.
Copilot code review comments on pull requests after you've pushed them. Guard Skills reviews the diff inside the agent conversation, before the PR exists — and it's a gate with named rules, not inline suggestions. Different point in the pipeline, and a much cheaper one to fix things at.
That's exactly what wp-guard and woo-guard are for: escaping and sanitization, nonce and capability checks, prepared queries, HPOS-safe order access, and checkout validation. Pair them with clean-code-guard and you've got a proper shipping gate for client work.
You don't need to — but you'll want to. The intended loop is: let the agent do the work, then run the relevant guard on the diff before you present, commit, or merge it. It takes seconds and it's where the value lives. For a walkthrough with real examples, this Dev.to guide shows the full flow.
Free, open source, and working in two minutes. Your future self — and your codebase — will thank you.