A design system the agent cannot fake. Two offline tools read the census before writing a class, and prove the page before calling it done. Four skills explain the rest.
✓ Merged Official Hermes plugin catalog, Nov 5 2026 — PR #149421
A skill can explain the rules. Only code can guarantee that the class exists and that the packs are linked.
The agent asks in plain words — in Spanish or English — and gets the family, the pack to link, every class and the canonical markup extracted from the catalogue demo. 2,223 objects, in-process.
aurora_search("table that stacks on mobile")
Instead of guessing nz-card (which does not exist), it receives nz-table--apilable with its wrapper and its data-etiqueta.
Invented classes, packs used but not linked, gradients, !important, hand-written colours, emojis in the UI, duplicate headings, missing attribution. Failures and warnings, offline, in milliseconds.
aurora_validate(path="page.html")
The agent iterates until ok: true. The check is reproducible by anyone, on any machine, without a clone of the design system.
Safe by construction: no network, no subprocess, no writes, no hooks. The census is a generated JSON snapshot (data/censo.json) built from components.json by scripts/generar-censo.py.
Doctrine: step 0 version resolution, pinned links, the 12 hard rules and a need → object table.
Shape: archetypes, desktop canvas, mobile stacking, typographic scale, surface budget.
The judge: zero failures from the auditor plus real measurement in a browser before delivery.
When the model composes at runtime: openui-lang, spec, vanilla runtime and static baking.
LLM.md and components.json: about 20 KB instead of 340 KB of CSS in the context.This page is the proof. It is built with Aurora from the same census the skills describe, and it passes the same auditor with zero failures and zero warnings.
Watch a Hermes agent stop guessing: it searches the census, builds the page and validates it until the report is clean.
hermes plugins install aurora-design-system --enable
Hermes Agent 0.21 or newer. Verify with hermes plugins validate and hermes plugins doctor: two tools, four skills, zero network.
acceptance-criteria — a skill that fixes 3–7 falsifiable criteria before a task and refuses to close while anything is red. A separate repository, because it is a different idea: one is a design system, the other is a working discipline.
Not mock-ups. These are the design system's canonical examples, rendered by headless Chrome. The demo/ folder ships them as-is.