Install Check
Pick your agent. Every command is ready to paste.
npx skills add jsmastery-pro/skills --skill checkThe open skills CLI detects your agents (Claude Code, Cursor, Codex and 70+ more) and installs to the right folder. Add -g to install globally.
01
Install it
Run the command above, or upload the folder in Claude.
02
Ask naturally
Describe the task. Your agent loads check when the request matches its description.
03
Name it if needed
If it does not trigger, say “use the check skill”. In Codex, type $check.
Output style (plain words, no dashes, no hyphens)
Write everything this skill produces, files and messages alike, in plain simple language. Talk to the reader as you, warm and direct like a colleague, and present every step as a recommendation they may run or skip, never an order. Keep technical terms that carry real meaning; explain each in plain words. Never use a dash or a hyphen as punctuation: no em dash, no en dash, and no hyphenated compounds. Write read only, not read-only. Say it in simple words, or reword the sentence. Code, file paths, command flags, and values other skills match on keep their hyphens. Use short sentences, commas, or parentheses. Clear beats clever.
What this skill does
/check is the gate before merge. Two modes, separate jobs, usually both, verify first:
verify(runtime proof): run the real app and watch the change behave. Proves it works and conforms to the spec (every acceptance criterion met, every specced surface built), which green tests never reveal. Read only on code, no durable files, main thread. Typically after/develop.review(fresh model code review): a senior read of the diff on a different model than wrote the code (a model reviewing its own output shares its blind spots). Writes findings ranked by severity todocs/reviews/. Read only. Typically before a PR.
Neither mode edits code. verify points failures at /debug or /develop; review reports findings to fix.
Pick the mode (route before doing anything else)
First step, before reading any mode file or touching the repo. Look at what followed /check:
- Starts with
verify(orrun) → readmodes/verify.md, follow it fully. Pass remaining arguments (feature name, scope) through. - Starts with
review→ readmodes/review.md, follow it fully. Pass the steering through unchanged (e.g./check review with opus,/check review uncommitted). - No mode word, or ambiguous (bare
/check, or a feature name with no mode like/check auth) → do NOT guess, do NOT default. Show the two options as a plain text panel and stop and wait for the engineer's choice.
How to present the choice (plain text, works on every agent, no interactive modal):
Print exactly this, then stop and wait. Do not assume verify until they answer. Route on their typed word (verify / review / both).
Which check do you want to run? Type one:
• verify run the real app and prove the change works against its spec (usually right after /develop)
• review a fresh model senior read of the diff, ranked findings (usually right before a PR)
• both verify first, then review
No interactive picker or modal: a typed choice shown inline behaves the same in every AI tool. (The argument-hint frontmatter also surfaces verify | review in Claude Code autocomplete; other tools ignore it, which is why this inline panel is the portable path.)
If a feature name came with no mode (/check auth), carry it as the target once they pick; still ask the mode.
Do not mix modes in one run. On both, do verify first, then offer review next.
Portability (any OS, any agent)
Any Agent Skills client on macOS, Linux, or Windows. git is the only required CLI. Other shell snippets are POSIX reference, not literal scripts: use your agent's own cross platform file, process, and browser tools. Each mode file adds its own portability notes. No subagent support falls back to inline, noted per mode.
Bundled files: modes/verify.md, modes/review.md, plus review-agent-prompt.md and review-guide.md for review. Read only the mode file you routed to; resolve the review bundled files to absolute paths when spawning the reviewer.
Tips for Check
- • Start a fresh session after installing so your agent picks up the new skill.
- • It is part of a pack with 8 skills. Install only the ones you need with --skill to keep triggers precise.
- • If two skills overlap, mention the one you want by name.
Questions about Check
What does the Check skill do?
Confirm a change before merge. `/check verify` drives the real app to prove behavior against the spec (every acceptance criterion met, every surface built). `/check review` runs a senior code review on a fresh model, one that did not write the code. Verify after /develop, review before a PR. Writes to docs/reviews/, never edits code.
How do I install Check?
Run "npx skills add jsmastery-pro/skills --skill check" in your project. The skills CLI installs it for Claude Code, Cursor, Codex and 70+ other agents. In Claude on the web, upload the skill folder as a ZIP under Customize > Skills.
Does Check work in Cursor and Codex?
Yes. Check uses the open SKILL.md format, so it works in Claude Code, Claude, Cursor, OpenAI Codex, Gemini CLI, GitHub Copilot and other agents that support agent skills.
Is Check free?
Check is open source on GitHub under the MIT license. It is free to install; check the license before commercial use.
Who made Check?
Check is published by jsmastery-pro in the jsmastery-pro/skills repository, together with 7 other skills.




