Price terms as published

Each line is the vendor’s own wording, split from the price capture checked on 2026-09-30. Nothing here is rounded, converted or re-worded — the full sentences stay in the review below. Lines that carry only a price continue the plan named on the line above, in the vendor’s own order.

2 price terms for Impeccable
#Plan / termChecked
1Free (Apache-2.0 open source2026-09-30
2no paid tier on the official site)2026-09-30

One-liner: Impeccable is an open-source (Apache-2.0) design language for AI coding agents: one installable skill, 24 shared commands (polish, audit, critique, distill, animate, bolder, quieter …), live browser iteration, and 61 deterministic detector rules that flag the visual tells every model learned from the same SaaS templates.

Verified facts (checked 2026-09-30)

Attribute Value Source
GitHub stars 72,630 pbakaus/impeccable via GitHub API, 2026-09-30
Forks 4,385 GitHub API
Open issues / PRs 53 / 10 GitHub API (search, same day)
License Apache-2.0 GitHub API license field
Created 2025-11-16 GitHub API
Last push 2026-09-30 (same-day) GitHub API
Primary language JavaScript GitHub API
Install npx impeccable install → /impeccable init README + impeccable.style
Scope 1 skill, 24 commands, 61 detector rules README headline
Supported agents Claude Code, Cursor, Codex CLI, Gemini CLI, GitHub Copilot (VS Code 1.109.3+), Grok Build, Hermes Agent, opencode, Qoder, Trae, Veto and others README install sections
Price Free; no paid tier listed anywhere on repo or site README + impeccable.style (2026-09-30)

What problem it solves

Every model was trained on the same handful of SaaS templates, so unguided AI frontends converge on the same tells: Inter for everything, purple-to-blue gradients, cards nested in cards, gray text on colored backgrounds, the rounded icon tile above every heading, bounce easing. Impeccable started from Anthropic’s frontend-design skill and went substantially further.

Three layers, per the README:

  • Product truth. /impeccable init writes a PRODUCT.md recording audience, purpose, constraints and voice, so later commands stop confusing brand facts with surface-level styling. DESIGN.md holds the visual system, generated by /impeccable document from existing code.
  • A shared vocabulary. 24 commands under one /impeccable namespace — craft, shape, critique, audit, polish, bolder, quieter, distill, harden, onboard, animate, colorize, typeset, layout, delight, overdrive and more. You say /impeccable quieter instead of writing a paragraph about spacing.
  • Deterministic checks. 61 detector rules run in the CLI and a browser extension with no LLM and no API key, so “is this page full of AI tells?” gets a repeatable answer instead of another model’s opinion.

How it installs

The skill ships a small launcher that runs a self-contained engine binary (downloaded once into ~/.impeccable/bin/ if not present). npx impeccable install detects your harness folders (~/.claude, ~/.codex, .cursor, …) and installs per provider and per scope; on Claude Code, Cursor, Codex, Copilot and Grok Build it also writes the provider-native hook manifest. Claude Code can also take it from the plugin marketplace. Worth knowing: Codex re-approves hooks after updates that change .codex/hooks.json, and Cursor’s skill path wants the Nightly channel with Agent Skills enabled.

The caveats

  • It is guidance, not generation. Commands steer your existing agent; they do not replace it. A weak underlying model still produces weak design.
  • No independent usage data. The star velocity (72K in ~10 months) and community write-ups are real signals, but there is no neutral benchmark that design quality measurably improves after install.
  • Hook surface area. Project-native hooks mean the tool edits config in several agent ecosystems at once; read what lands in your repo before committing it.
  • Young project, fast mover. Pushed same-day at time of writing — expect commands and rules to churn between minor versions.

FAQ

Is Impeccable free? Yes — Apache-2.0, and neither the repo nor impeccable.style lists any paid tier as of 2026-09-30.

Does it need an API key? The deterministic detectors run with no LLM and no key. The /impeccable * commands run through the AI coding tool you already use.

Which agents does it support? Claude Code, Cursor, Codex CLI, Gemini CLI, GitHub Copilot in VS Code, Grok Build, Hermes Agent, opencode, Qoder, Trae, Veto and more — the installer detects what you have and configures per provider.

Sources

  1. https://github.com/pbakaus/impeccable — README full text (fetched 2026-09-30)
  2. https://api.github.com/repos/pbakaus/impeccable — stars, forks, license, dates (2026-09-30)
  3. GitHub search API — open issues (53) / PRs (10) counts (2026-09-30)
  4. https://impeccable.style — official docs site, hero copy and quick start (extracted 2026-09-30)
  5. dev.to — “Ship AI-generated frontend designs that don’t look like AI slop” (third-party explainer)
  6. v0l0 (GitHub directory listing) — “24 commands, 61 deterministic design detectors” cross-check
  7. lovestack.io Claude Code skill directory — “started from Anthropic’s frontend-design skill” origin cross-check