# @urbicon-ui/design-engine

The deterministic core of the Urbicon UI **design loop** — extracted from
`@urbicon-ui/mcp-server` so one engine can back the MCP server, a CLI, and editor
hooks alike.

**Zero runtime dependencies.** Pure TypeScript over Web/Node built-ins; no framework,
no parser, no third-party packages.

## Modules

Each module is independent and also available as a subpath export.

| Import                               | What it does                                                                                                                                                                                                                                 | Question it answers                         |
| ------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------- |
| `@urbicon-ui/design-engine/linter`   | Two-axis design linter: deterministic **correctness** rules (token whitelist, `dark:`/`focus:`, z-index, dynamic classes) + system-agnostic **craft** heuristics (generic fonts, animated dimensions, grey-on-colour, touch targets, …) | _Is it correct — and does it look generic?_ |
| `@urbicon-ui/design-engine/manifest` | Parse/edit `design.manifest.md` (product intent, token overrides, pattern usages, ADRs) + the validation-history ndjson; scan `data-design-pattern` markers                                                                                  | _What has this project decided?_            |
| `@urbicon-ui/design-engine/rubric`   | The eight-criterion design-quality rubric                                                                                                                                                                                                    | _Is it good?_ (judged)                      |

The package root (`@urbicon-ui/design-engine`) re-exports all three.

```ts
import { lintDesign } from '@urbicon-ui/design-engine/linter';
import { parseManifest, scanMarkers } from '@urbicon-ui/design-engine/manifest';
import { RUBRIC_CRITERIA, renderRubric } from '@urbicon-ui/design-engine/rubric';
```

## Notes

- Shipped as TypeScript source (no build step), like the rest of the Urbicon UI
  tooling — consume it with a TypeScript-aware runtime (Bun) or bundler.
- The linter's token whitelist is drift-guarded against the real CSS sources via a
  test; keep it in sync when foundation/semantic tokens change.

The engine is consumed by [`@urbicon-ui/design`](https://www.npmjs.com/package/@urbicon-ui/design)
(the `urbicon` CLI) and by the MCP server — both are thin surfaces over it, so the linter,
the manifest parser and the rubric behave identically whichever way they are reached.