React Doctor

SkillSecurity

Diagnose and fix React codebase health issues. Use when reviewing React code, fixing performance problems, auditing security, or improving code quality.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the React Doctor skill

What this skill tells your AI

The instructions your AI receives, as published by posthog/posthog in .agents/skills/react-doctor/SKILL.md and read by ahel’s review.

Scans your React codebase for security, performance, correctness, and architecture issues. Outputs a 0-100 score with actionable diagnostics.

Usage

npx -y react-doctor@latest . --verbose

Workflow

  1. Run the command above at the project root
  2. Read every diagnostic with file paths and line numbers
  3. Fix issues starting with errors (highest severity)
  4. Re-run to verify the score improved

Rules (47+)

  • Security: hardcoded secrets in client bundle, eval()
  • State & Effects: derived state in useEffect, missing cleanup, useState from props, cascading setState
  • Architecture: components inside components, giant components, inline render functions
  • Performance: layout property animations, transition-all, large blur values
  • Correctness: array index as key, conditional rendering bugs
  • Next.js: missing metadata, client-side fetching for server data, async client components
  • Bundle Size: barrel imports, full lodash, moment.js, missing code splitting
  • Server: missing auth in server actions, blocking without after()
  • Accessibility: missing prefers-reduced-motion
  • Dead Code: unused files, exports, types

Score

  • 75+: Great
  • 50-74: Needs work
  • 0-49: Critical

Signals

GitHub stars
40k
Forks
3k
Last commit
Sep 2026

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Catalog kind
skill
Gateway key
react-doctor-posthog
Source
github.com/posthog/posthog