impeccable
by pbakaus · linked, not rehosted
A design language for coding agents — with a detector that actually fails your build, not just an opinion.
Add it to your project
Give your agent this prompt — it sets the repo up for you:
Install impeccable with `npx impeccable install`, then run its detector against my current UI and show me every rule it flags, with the file and line.
Open source (Apache-2.0) · all rights to pbakaus.
What it's for & howRead it ↓Collapse ↑
What it is
Paul Bakaus' answer to the fact that coding agents produce competent, forgettable interfaces. It is not a style guide — it ships 59 deterministic detector rules, a palette seeder, a concept seeder and a live browser loop where you click an element, get three variants, and the accepted one is written back into the real source.
Positioned explicitly as a successor to Anthropic's frontend-design skill, built for
14 agent harnesses at once.
When to reach for it
- Before the first component exists — it decides the direction, it does not decorate later.
- When output "looks fine" but you cannot say why it looks like everything else.
- When you want a gate that can say no rather than a document nobody reads.
The part most people miss
scripts/concept-seed.mjs exists because the author measured the problem:
30 of 35 concepts were identical across 16 different prompt framings. The model
cannot roll its own dice. The script assigns an index away from the model's own shortlist
and adds six challengers — reproducible via --reroll.
Honest limits
- It is a monorepo, not a small skill: roughly 15 MB, ~3,500 files in the tarball.
- The skill ships no LICENSE file inside the skill folder. Apache-2.0 is declared in the frontmatter and in the repo, but if you redistribute it, carry the notice yourself.
- Its
DESIGN.mdschema collides with other builders that write the same filename. Decide who owns that file before running two systems in one project.