Your AI doesn’t need more templates. It needs a design LANGUAGE.

That’s the pitch behind Impeccable, and it’s built by somebody whose name carries weight in web tooling: Paul Bakaus, the creator of jQuery UI, with years on Google’s web tooling after that. Impeccable is one skill that makes your AI harness itself better at design — vocabulary and principles your agent uses to judge design calls, so output gets consistent instead of random.

It had 84,763 stars as of October 2026 and it’s Apache-2.0 licensed. Inside: 24 commands, 61 deterministic detector rules that catch classic AI design tells with no LLM or API key needed, and an init step that writes a PRODUCT.md so every command knows your product.

Here’s what makes a design language different from a template pack, how the commands and detectors actually work, and how to install it.

A design language for AI is not a template pack

Understand the distinction, because it’s the whole idea.

Templates tell the agent what to copy. A language tells the agent how to judge. Impeccable packs a career of design craft into vocabulary and principles your harness reasons with: when a design is almost there but not right, the language gives the agent words for what’s wrong and moves for fixing it.

That’s why the word “harness” matters. The harness is everything around the model — the tools, rules, and checks wrapped around it. Upgrade the harness and every output improves, on every task, not just the one page you’re staring at. A template fixes one page. A language fixes the machine that makes the pages.

It also stacks with the rest of a design setup instead of replacing it. In the Repo Week design trilogy: Day 2’s taste skill hands your agent references, Day 3’s DESIGN.md hands it a spec, and Impeccable — Day 4 — gives it the words and rules to reason about design. Taste judges. The system specifies. The language explains. Together, your agent stops guessing and starts designing. The full series roundup is here: https://bigjermsays.com/how-to-make-money-with-ai-build-a-system-not-a-side-hustle/, and the working tools I keep around these workflows are in the shop: https://bigjermsays.com/shop/.

24 commands: one design language for AI, spoken out loud

Impeccable runs through a single command — /impeccable — with 24 moves. The headliners from the source material:

Polish. The final-pass command: tighten, align, and clean up a design that’s almost there.

Audit. A structured audit that gets the problems listed — not a vibe-based opinion, a list you can work through.

Critique. The hard feedback. The design equivalent of a reviewer who isn’t trying to be nice.

Distill. Strips a bloated design back to what actually matters. Most AI designs don’t need more; they need less, in the right places.

Animate, Bolder, Quieter. Animate adds motion with intent. Bolder turns the volume up. Quieter dials a loud design back down. Three dials, one vocabulary — the agent knows what each word demands because the language defines it.

That’s the trick a language pulls off that a prompt can’t: the same command means the same thing every time, on every project, because the meaning lives in the skill — not in how well you phrased your request that morning.

61 deterministic detector rules: catching AI design tells

The second half of Impeccable is a lie detector for AI design.

The skill ships 61 deterministic detector rules that catch the classic tells: Inter used everywhere, purple-to-blue gradients, cards inside cards, gray text sitting on colored backgrounds. You know every one of these on sight — they’re the fingerprints that make a page read as “AI-made” before you’ve read a single word.

Two things make the detectors special. First, they’re deterministic: no guessing, just checks that pass or fail on your actual files. Second, they run with no LLM and no API key. The rules check your code directly, every time, for free. That means you can run them constantly — as a habit, not an event — and the tells get caught when they’re cheap to fix.

Pair the two halves and you see the design: commands give the agent a way to fix design, detectors give it a way to prove what’s wrong. Language plus evidence.

How to install Impeccable

From your project root, run the install:

npx impeccable install

Then initialize it in your agent:

/impeccable init

Init writes a PRODUCT.md — a durable file of product truth that the skill keeps working from, so every command knows your product instead of starting from zero each session. Project site for the full documentation: impeccable.style.

Total setup is minutes. The payoff compounds every time the harness makes a design call with the language loaded.

The repo, in detail

Repository: github.com/pbakaus/impeccable
Site: impeccable.style
License: Apache-2.0
Stars: 84,763 as of October 2026

What it is: a single design skill, by Paul Bakaus (creator of jQuery UI), that gives your AI harness a design language — 24 /impeccable commands (polish, audit, critique, distill, animate, bolder, quieter, and more), 61 deterministic detector rules for AI design tells that run with no LLM or API key, and an init flow that writes a PRODUCT.md of durable product truth.

Who it’s for: builders who already generate plenty of design output and need it to be consistently good — especially anyone whose pages keep coming back with the same AI tells. If Days 2 and 3 of a design stack are about inputs (references and specs), Impeccable is about judgment, and judgment is what scales across a whole product.

How you’d use it: install from your project root, run init so PRODUCT.md captures what your product is, then work the commands into your normal loop — audit before you ship, distill when a page bloats, polish as the final pass.

FAQ

What does “harness” mean, and why does it matter?

The harness is everything around the model — the tools, rules, and checks in your agent setup. The model is rented; the harness is yours. Upgrading the harness improves every output the model produces inside it, which is why a design language beats a one-off template.

Do the detector rules need an API key or a model call?

No. The 61 detector rules are deterministic checks that run on your files directly — no LLM, no API key. They either pass or fail, and they cost nothing to run as often as you want.

How is Impeccable different from taste-skill or a DESIGN.md?

Different layer of the same stack. Taste gives references and a point of view; a DESIGN.md gives a written spec; Impeccable gives the vocabulary, commands, and hard rules for reasoning about design decisions. They complement each other — the strongest setup runs all three.

The bottom line

Templates run out. Languages don’t. Impeccable gives your harness the words, the commands, and the lie detectors to make design calls like somebody who’s done it for twenty years — because the person who wrote it has. Save the whole design trilogy. Your agent is about to stop guessing.

Big Jerm