mosaic
Work on Mosaic UI: styling a component with slot recipes (`defineSlotRecipe` / `useRecipe` / slots / variants), or building a flow — authoring a state machine…
npx skills add https://github.com/clerk/javascript --skill mosaicMosaic UI
Two things live under Mosaic, and this skill covers the how-to for both:
- Styled components are authored with StyleX —
stylex.createdeclares the styles,themePropsemits the part's public identity (the.cl-<slot>class plusdata-<axis>attrs), andmergeStylePropsfuses the two with the consumer'sclassName/style. - Flows follow a machine → controller → view split that keeps Clerk resource logic out of visual components and makes behavior testable without a running Clerk app:
machine Pure flow rules: states, events, guards, async invokes, errors.
No React hooks. No Clerk hooks. No Clerk resource objects.
controller Clerk/data adapter: reads Clerk hooks/resources, injects async
effects into machine context, gates permissions, derives view props.
The only layer that may import Clerk hooks or call resource methods.
view Rendering only: receives a snapshot plus explicit props, renders UI,
sends events. No Clerk imports. No data-fetching. No mutations.
references/mosaic-architecture.md (repo root, read by all agents) is the
canonical contract for the whole design system — the --cl-* tokens, the
.cl-<slot> + data-<axis> styling API, the CSS build, and the "Flow and data
architecture" section that defines the split. Read it for the what; this skill
is the how-to.
Which reference to read
| You are… | Read |
|---|---|
Building on / authoring a headless primitive (@clerk/headless) | references/headless.md |
Styling a component (tokens, stylex.create, themeProps, CSS build) | references/stylex.md |
| Building an enter/exit transition, or any motion that reads as wrong | references/motion.md |
| Authoring or debugging a state machine, or wiring one to React | references/machines.md → in-tree machine/README.md |
| Writing the controller (Clerk adapter, permissions, revalidate) | references/controllers.md |
| Writing the view (rendering a snapshot, sending events) | references/views.md |
| Testing a machine, controller, or view | references/testing.md |
| Migrating a legacy component into Mosaic (the end-to-end workflow) | references/migration.md |
| Running the parity audit that guards a migration | references/parity-audit.md |
The migration workflow (migration.md) ties the flow references together: it
treats the legacy component as the spec and drives you through the machine,
controller, and view layers, then verifies parity with parity-audit.md.