Design guidance for AI coding agents. 1 skill, 23 commands, live browser iteration, and 59 deterministic detector rules for AI-generated frontend design.

Quick start: From your project root, run npx impeccable install, then run /impeccable init inside your AI coding tool. Full docs: impeccable.style.

Anthropic's frontend-design was the first widely-used design skill for Claude. Impeccable started from there.

Every model trained on the same SaaS templates. Skip the guidance and you get the same handful of tells on every project: Inter for everything, purple-to-blue gradients, cards nested in cards, gray text on colored backgrounds, the rounded-square icon tile above every heading.

Impeccable adds:

• One setup flow. /impeccable init writes PRODUCT.md and offers DESIGN.md, so later commands know the audience, brand/product lane, voice, anti-references, colors, type, and components.
• 23 commands. A shared design vocabulary with your AI: polish, audit, critique, distill, animate, bolder, quieter, and more.
• 59 deterministic detector rules plus LLM-only critique checks. The CLI and browser extension run the deterministic rules with no LLM and no API key.

The skill installs as one command:

/impeccable <command> <target>

Start every new project with:

/impeccable init

init asks whether the surface is brand (marketing, landing, portfolio) or product (app UI, dashboard, tool), then writes design context that every later command reads.

All commands are accessed through /impeccable:

Use /impeccable pin <command> to create standalone shortcuts (e.g., pin audit creates /audit).

/impeccable audit blog           # Audit blog hub + post pages
/impeccable critique landing     # UX design review
/impeccable polish settings      # Final pass before shipping
/impeccable harden checkout      # Add error handling + edge cases

Or use /impeccable directly with a description:

/impeccable redo this hero section

The skill includes explicit guidance on what to avoid:

• Don't use overused fonts (Arial, Inter, system defaults)
• Don't use gray text on colored backgrounds
• Don't use pure black/gray (always tint)
• Don't wrap everything in cards or nest cards inside cards
• Don't use bounce/elastic easing (feels dated)

Visit the Neo Mirai case study to see a before/after case study of a real project transformed with Impeccable commands.

From the root of your project, run:

npx impeccable install

This shows the harness folders it detected (for example ~/.claude, ~/.codex, ~/.grok, or project-local .cursor), lets you keep the detected set or customize providers, then asks whether to install into the current project or globally. Use --providers=claude,codex,cursor,grok and --scope=project|global to skip those choices in scripts. On Claude Code, Cursor, Codex, GitHub Copilot, and Grok Build, it also installs the provider-native hook manifest for the current project. Works with Cursor, Claude Code, Gemini CLI, Codex CLI, Grok Build, and every other supported tool. Reload your harness afterward.

To refresh an existing install, run:

npx impeccable update

Codex users should open /hooks after install or update and approve the project hook when prompted. Codex tracks trust by hook definition, so updates that change .codex/hooks.json can require approval again. Grok Build users need project folder trust (/hooks-trust or launch with --trust) before .grok/hooks/ scripts run.

For teams that want to keep Impeccable vendored and updated through Git, add this repo as a submodule and link the compiled provider build into your harness folders:

git submodule add https://github.com/pbakaus/impeccable .impeccable
npx impeccable link --source=.impeccable --providers=claude,cursor
git add .gitmodules .impeccable .claude .cursor
git commit -m "Add Impeccable skills"

Use the providers your project needs, for example claude, cursor, gemini, codex, github, grok, opencode, pi, qoder, trae, trae-cn, rovo-dev, or vibe. The command links individual skill folders from .impeccable/dist/universal/ and leaves existing real skill directories untouched unless you pass --force.

To update later:

git submodule update --remote .impeccable
npx impeccable link --source=.impeccable --providers=claude,cursor

Claude Code:

/plugin marketplace add pbakaus/impeccable

Claude Code only. After adding the marketplace, open /plugin and install Impeccable from the list.

Grok Build:

grok plugin install pbakaus/impeccable#plugin --trust

Grok Build only. The #plugin suffix installs the slim plugin package (skills, agents, and hooks) instead of the full monorepo. Then run /impeccable init in a Grok session. Project-scoped installs via npx impeccable install --providers=grok also work and write .grok/skills/ plus .grok/hooks/impeccable.json.

Visit impeccable.style, download the ZIP for your tool, and extract to your project.

Cursor:

cp -r dist/cursor/.cursor your-project/

Note: Cursor skills require setup:

1. Switch to Nightly channel in Cursor Settings → Beta
2. Enable Agent Skills in Cursor Settings → Rules

Learn more about Cursor skills

Claude Code:

# Project-specific
cp -r dist/claude-code/.claude your-project/

# Or global (applies to all projects)
cp -r dist/claude-code/.claude/* ~/.claude/

OpenCode:

cp -r dist/opencode/.opencode your-project/

Pi:

cp -r dist/pi/.pi your-project/

Gemini CLI:

cp -r dist/gemini/.gemini your-project/

Note: Gemini CLI skills require setup:

1. Install preview version: npm i -g @google/gemini-cli@preview
2. Run /settings and enable "Skills"
3. Run /skills list to verify installation

Learn more about Gemini CLI skills

Codex CLI:

# Project-local
cp -r dist/agents/.agents your-project/
mkdir -p your-project/.codex
cp dist/codex/.codex/hooks.json your-project/.codex/hooks.json

# Or install the skill user-wide. Copy .codex/hooks.json into each project
# where you want the design hook to run.
mkdir -p ~/.agents/skills
cp -r dist/agents/.agents/skills/* ~/.agents/skills/

The asset-producer subagent ships nested inside the skill's own agents/ folder, which Codex auto-discovers. No separate .codex/agents/ copy is needed. The hook is project-local because Codex discovers hooks from .codex/hooks.json next to trusted project config.

GitHub Copilot:

cp -r dist/github/.github your-project/

Trae:

# Trae China (domestic version)
cp -r dist/trae/.trae-cn/skills/* ~/.trae-cn/skills/

# Trae International
cp -r dist/trae/.trae/skills/* ~/.trae/skills/

Note: Trae has two versions with different config directories:

• Trae China: ~/.trae-cn/skills/
• Trae International: ~/.trae/skills/

After copying, restart Trae IDE to activate the skills.

Rovo Dev:

# Project-specific
cp -r dist/rovo-dev/.rovodev your-project/

# Or global (applies to all projects)
cp -r dist/rovo-dev/.rovodev/skills/* ~/.rovodev/skills/

Qoder:

# Project-specific
cp -r dist/qoder/.qoder your-project/

# Or global (applies to all projects)
cp -r dist/qoder/.qoder/skills/* ~/.qoder/skills/

Mistral Vibe:

# Project-specific
cp -r dist/vibe/.vibe your-project/

# Or global (applies to all projects)
cp -r dist/vibe/.vibe/skills/* ~/.vibe/skills/

Grok Build:

# Project-specific
cp -r dist/grok/.grok your-project/

# Or global (applies to all projects)
cp -r dist/grok/.grok/skills/* ~/.grok/skills/

Prefer npx impeccable install --providers=grok or grok plugin install pbakaus/impeccable#plugin --trust so the design hook installs too. Project hooks need /hooks-trust (or --trust) once per folder.

Google Antigravity:

# Project-specific
cp -r dist/antigravity/.agent your-project/

# Or global (applies to all projects)
mkdir -p ~/.gemini/config/skills
cp -r dist/antigravity/.agent/skills/* ~/.gemini/config/skills/

Once installed, every command runs through the single /impeccable skill:

/impeccable audit        # Find issues
/impeccable polish       # Final cleanup
/impeccable distill      # Remove complexity
/impeccable critique     # Full design review

Type /impeccable alone to see the full command list.

Most commands accept an optional argument to focus on a specific area:

/impeccable audit the header
/impeccable polish the checkout form

If you reach for one command often, pin it with /impeccable pin audit to get /audit as a standalone shortcut.

Note: Codex uses skills here, not /prompts: commands. Open /skills or type $impeccable. Repo-local installs live in .agents/skills/; user-wide installs live in ~/.agents/skills/. GitHub Copilot uses .github/skills/. Restart the tool if a newly installed skill does not appear.

As you run commands, Impeccable writes working files under .impeccable/: critique and polish screenshots, live-mode session and preview state, runtime caches, and per-developer config. Most of it is ephemeral and should not be committed, while a few files are shared project artifacts that belong in the repo. Add this block to your project's .gitignore:

# impeccable-ignore-start
# Ephemeral output, runtime state, and per-dev overrides.
# Unanchored: .impeccable may sit at the repo root or under a nested
# workspace (apps/web/.impeccable/...); anchored patterns would miss it.
# Shared artifacts stay tracked: config.json, live/config.json,
# design.json, critique/*.md.
.impeccable/config.local.json
.impeccable/hook.cache.json
.impeccable/hook.pending.json
.impeccable/*.png
.impeccable/live/server.json
.impeccable/live/sessions/
.impeccable/live/previews/
.impeccable/live/annotations/
.impeccable/live/cache/
.impeccable/live/manual-edit-apply-transaction.json
.impeccable/live/manual-edit-events.jsonl
.impeccable/live/manual-edit-evidence/
.impeccable/live/pending-manual-edits.json
.impeccable/live/deferred-svelte-component-accepts.json
.impeccable/live/*.png
# impeccable-ignore-end

The block is wrapped in # impeccable-ignore-start / # impeccable-ignore-end markers so you can recognize and refresh it later. Patterns are unanchored on purpose: in a monorepo the active project (and its .impeccable/ directory) often lives under a nested workspace path like apps/web/, and a root-anchored pattern would miss it.

Keep these tracked (they are shared project artifacts, do not add them to .gitignore):

• .impeccable/config.json (unified shared config)
• .impeccable/live/config.json (live-mode framework wiring)
• .impeccable/design.json (shared design spec)
• .impeccable/critique/*.md (review reports)

If an ephemeral file (a screenshot, config.local.json) was committed before you added the block, .gitignore will not untrack it automatically. Run git rm --cached <path> to stop tracking it without deleting your local copy.

On Claude Code, GitHub Copilot, Codex, Cursor, and Grok Build, npx impeccable install and npx impeccable update install a provider-native hook manifest along with the skill payload. The hook runs the Impeccable design detector on direct UI file edits and surfaces findings back into the agent flow. Claude Code, GitHub Copilot, Codex, and Grok Build surface findings after the edit (and run a deeper pass on Stop where supported). Cursor blocks bad proposed writes before they land.

Installed hook surfaces:

• Claude Code: .claude/settings.local.json (gitignored, machine-local) runs ${CLAUDE_PROJECT_DIR}/.claude/skills/impeccable/scripts/hook.mjs. A hook moved into the shared settings.json is honored in place.
• GitHub Copilot: .github/hooks/impeccable.json (committed, shared by the Copilot CLI and the cloud agent) runs .github/skills/impeccable/scripts/hook.mjs. The Copilot CLI activates it once the file is on the repository's default branch and the folder is trusted.
• Cursor: .cursor/hooks.json runs .cursor/skills/impeccable/scripts/hook-before-edit.mjs.
• Codex: .codex/hooks.json runs .agents/skills/impeccable/scripts/hook.mjs.

The installer preserves unrelated hook entries and settings. If a hook manifest is malformed, install/update aborts by default; rerun with --force to back up the malformed file as .bak and replace it.

On an interactive install/update, Impeccable explains the hook and offers to install it (default yes). Your choice is remembered per-developer in the gitignored .impeccable/config.local.json, so you are not asked again; --no-hooks skips it for that run without recording anything. Hook lifecycle settings live under the hook key of .impeccable/config.json; detector ignores live under detector, shared by /impeccable hooks and npx impeccable detect.

For debugging, set hook.auditLog in .impeccable/config.json to a path (or the legacy IMPECCABLE_HOOK_LOG env var) to write one NDJSON line per hook invocation. Leave it unset for normal use.

Codex requires one platform step that Impeccable cannot safely skip: open /hooks after install or update and approve the project hook. There is no Codex marketplace/plugin install flow for this hook.

Full hook docs: impeccable.style/docs/hooks.

Manual copy commands are fallback/debug instructions. The normal path is:

npx impeccable install
npx impeccable update

Impeccable includes a standalone CLI for detecting anti-patterns without an AI harness:

npx impeccable detect src/                   # scan a directory
npx impeccable detect index.html             # scan an HTML file
npx impeccable detect https://example.com    # scan a URL (Puppeteer)
npx impeccable detect --json .               # CI-friendly JSON output
npx impeccable detect --no-config src/       # raw scan, ignoring project config/context
npx impeccable ignores list                  # show detector ignores
npx impeccable ignores add-file "src/legacy/**"
npx impeccable ignores add-value overused-font Inter --reason "Brand font"

The detector catches 59 deterministic issues across AI slop (side-tab borders, purple gradients, bounce easing, dark glows) and general design quality (line length, cramped padding, small touch targets, skipped headings, and more).

By default, detect respects the same .impeccable/config.json and .impeccable/config.local.json detector config as the design hook: detector.ignoreRules, detector.ignoreFiles, detector.ignoreValues, and detector.designSystem.enabled. Hook lifecycle settings such as hook.enabled only affect automatic hook execution.

For a waiver that should travel with one file instead of the repo config, add an inline comment in the file: <!-- impeccable-disable overused-font: exported brand doc -->. The marker works in any comment syntax, scopes to the whole file (or one line with impeccable-disable-line / impeccable-disable-next-line), and is bypassed by --no-inline-ignores or --no-config.

Full detector docs: impeccable.style/docs/detector.

• Cursor
• Claude Code
• GitHub Copilot
• Gemini CLI
• Codex CLI
• Grok Build
• OpenCode
• Pi
• Kiro
• Trae
• Rovo Dev
• Qoder
• Mistral Vibe
• Google Antigravity

Join the community and ecosystem conversations:

• GitHub Discussions: file bugs, request features, and help newcomers.
• Impeccable on npm: grab the CLI, follow releases, and star the package.
• Follow @pbakaus on Twitter for release notes, sample lint reports, and video highlights of new rules.

See DEVELOP.md for contributor guidelines and build instructions.

Apache 2.0. See LICENSE.

Created by Paul Bakaus