react-doctor
millionco/react-doctor · Agent Skill
Run React Doctor to detect regressions in security, performance, correctness, and architecture, with score-based quality checks.
Jump to install ↓Overview
| Publisher | |
|---|---|
| Repository | millionco/react-doctor ↗ |
| Skill folder | react-doctor |
| Stars | 15,049 |
| Forks | 491 |
| Bundled files | 2 |
| License | MIT |
| Last updated | October 26, 2026 |
| Links | Skill source ↗ · Repository ↗ |
Mozgi check
What we found in the skill files. Details come with a subscription.
Installation
A skill is a folder with a SKILL.md file. Pick your agent and run the commands in a terminal (macOS, Linux or Git Bash on Windows) from your project root.
Copy the prompt into Claude, Codex or another assistant: it will review the skill and install it for you.
Install the “react-doctor” skill from mozgi.io (https://mozgi.io/skills/millionco-react-doctor/) for me. 1. Download the archive: https://mozgi.io/skills/millionco-react-doctor/download If it fails, take the skill folder from the source: https://github.com/millionco/react-doctor/tree/main/skills/react-doctor 2. Read SKILL.md and the other files. Check the skill is safe: no hidden commands, no sending data elsewhere, no scripts doing something other than described. If anything looks suspicious, stop and tell me. 3. Put the “react-doctor” folder into your agent's skills folder: .claude/skills/ for Claude Code, .agents/skills/ for Codex, .cursor/skills/ for Cursor, .gemini/skills/ for Gemini CLI. Inside the project if we are in one, otherwise in the home folder (~/.claude/skills/ etc.). 4. Make sure <skills folder>/react-doctor/SKILL.md exists. 5. Briefly tell me what this skill does and offer to try it on my task. If you cannot do a step yourself, tell me what to click or type.
git clone --depth 1 --branch main https://github.com/millionco/react-doctor.git /tmp/react-doctor mkdir -p .claude/skills cp -r /tmp/react-doctor/skills/react-doctor .claude/skills/react-doctor
Restart Claude Code — the skill appears in the list; call it manually with /react-doctor. For all projects use ~/.claude/skills.
git clone --depth 1 --branch main https://github.com/millionco/react-doctor.git /tmp/react-doctor mkdir -p .agents/skills cp -r /tmp/react-doctor/skills/react-doctor .agents/skills/react-doctor
Codex looks for skills in .agents/skills from the current folder up to the repo root; call one with /skills or $react-doctor. For all projects use ~/.agents/skills.
git clone --depth 1 --branch main https://github.com/millionco/react-doctor.git /tmp/react-doctor mkdir -p .cursor/skills cp -r /tmp/react-doctor/skills/react-doctor .cursor/skills/react-doctor
Cursor picks the skill up on start; call it with “/” in Agent chat. Cursor also reads .claude/skills and .agents/skills. For all projects use ~/.cursor/skills.
git clone --depth 1 --branch main https://github.com/millionco/react-doctor.git /tmp/react-doctor mkdir -p .gemini/skills cp -r /tmp/react-doctor/skills/react-doctor .gemini/skills/react-doctor
Gemini CLI offers to activate the skill when a task matches — you approve it. For all projects use ~/.gemini/skills.
Read SKILL.md and any companion files before deciding whether to install. Click a file to preview it.
SKILL.md contents
Original author text · read-onlyReact Doctor
Scans React codebases for security, performance, correctness, and architecture issues. Outputs a 0–100 health score.
After making React code changes:
Run npx react-doctor@latest --verbose --scope changed and check the score did not regress.
If the score dropped, fix the regressions before committing.
For general cleanup or code improvement:
Run npx react-doctor@latest --verbose (the default --scope full) to scan the full codebase. Fix issues by severity — errors first, then warnings.
For a focused UI design audit:
Run npx react-doctor@latest design --verbose. This selects only design-tagged UI composition, typography, interaction, accessibility, and motion rules, including focused rules that remain opt-in during a general health scan.
For runtime performance problems:
Run npx react-doctor@latest scan <url> --format json in an interactive terminal. React Doctor opens an isolated system Chrome profile, records a DevTools trace while the user reproduces the slow interaction, and flashes purple outlines with component names as React renders. It stops when they press Enter. Read the structured summary first, then inspect the returned local .json.gz trace for CPU, browser, and React component evidence.
If the user needs their authenticated browser state, use --cdp <remote-debugging-url>. This requires Chrome to already be running with remote debugging. Never ask for cookies or copy the user's browser profile. Treat the trace as sensitive local application data and never upload it without explicit permission.
/doctor — full local triage workflow
When the user types /doctor, says "run react doctor", or asks for a full triage / cleanup pass (not just a regression check), fetch the canonical local-triage playbook and follow every step in it:
curl --fail --silent --show-error \
--header 'Cache-Control: no-cache' \
https://www.react.doctor/prompts/react-doctor-agent.md
The playbook is the single source of truth — a scan → filter → triage → fix → validate loop that edits the working tree directly (never commits, never opens PRs). Updating the prompt at its source updates every agent on its next fetch — no skill reinstall needed.
Pair it with the matching per-rule prompts at https://www.react.doctor/prompts/rules/<plugin>/<rule>.md (fetched on demand inside the playbook) so each fix uses the canonical, reviewer-tested recipe.
Use --scope contextual --base origin/main when a team wants existing findings
in the code it is editing. Rules can select an element, function, file, or an
explicit set of related nodes. For exhaustive-deps, edits in the hook call or a
resolved local callback can surface a finding on an unchanged dependency array.
Rules without wider ownership keep changed-line filtering.
Configuring or explaining rules
When the user wants to understand a rule, disagrees with one, or wants to disable / tune which rules run (not fix code), read references/explain.md ↗ and follow it. Start with npx react-doctor@latest rules explain <rule>, then apply the narrowest control via npx react-doctor@latest rules disable|set|category|ignore-tag …, which edits your doctor.config.* (or package.json#reactDoctor).
Command
npx react-doctor@latest --verbose --scope changed
| Flag | Purpose |
| -------------------- | --------------------------------------------------------------------------------------- |
| . | Scan current directory |
| --verbose | Show affected files and line numbers per rule |
| --scope changed | Only report issues introduced vs the base branch (default: full) |
| --scope contextual | Report findings in modified functions, JSX elements, or files, as selected by each rule |
| --scope lines | Only report issues on the changed lines |
| --score | Output only the numeric score |
| design | Run only the focused UI design diagnostics |
Reuse a base scan
Save a complete --json scan, then pass --baseline base-report.json to report only new findings. This also works with --scope changed. Use the same version and rules for both scans. Findings are grouped by rule and file path, following Git renames. Only increases in each group's count are reported; groups without an increase skip location matching. Fingerprints, message similarity, and Git-adjusted line distance select the added findings. Formatting and edits that keep the same counts report no new findings. Saved reports must use the same textComponents, rawTextWrapperComponents, and respectInlineDisables settings. Regenerate the base report after changing these settings, or use a Git comparison. Older reports without fingerprints or sourceFilterConfigHash must be regenerated.
GitLab warning status
For GitLab CI, --warning-exit-code 123 returns 123 for non-blocking warnings. Pair it with allow_failure: { exit_codes: 123 }. Errors still return 1. Accepts integers from 2 to 255. --blocking warning still returns 1. --blocking none or --score skips this warning signal.
Frequently asked questions
What does the react-doctor skill do?
Run React Doctor to detect regressions in security, performance, correctness, and architecture, with score-based quality checks.
How do I install react-doctor?
Open the “Installation” block on this page and pick your agent — Claude Code, Codex, Cursor or Gemini CLI — for ready-made commands that copy the skill folder to the right place. Or copy the prompt from the “Via assistant” tab and let the assistant review and install the skill.
Which AI models work with react-doctor?
Skills are plain Markdown instructions (the Agent Skills format), so react-doctor works with any agent that reads SKILL.md: Claude Code, Codex, Cursor, Gemini CLI, GitHub Copilot, OpenCode and more. The model loads the instructions only when a task matches the skill's description.
Is react-doctor free?
The skill is published openly by millionco under the MIT license. The skill itself costs nothing — you only pay your AI provider for the tokens you use.
Is it safe to install skills?
A skill is a set of instructions your agent will follow, so read SKILL.md and its companion files before installing. Scripts in the skill folder only run if your agent runs them — keep an eye on what it does and do not grant unnecessary permissions.
How is a skill different from an MCP server or a plugin?
An MCP server or plugin gives the model new tools — code that runs and returns a result. A skill gives it knowledge and process: how to approach a task, which steps to follow and what good output looks like. It needs no server or API key.