UI Kit (@byline/ui)

Companions:

• Getting Started — onboarding flow that pulls in @byline/ui styles and components.
• Upstream: github.com/infonomic/uikit  — the source of truth for the foundational components and stylesheets.

Overview

@byline/ui is Byline's framework-agnostic React primitives package — Button, Card, Modal, Input, Drawer, Table, Search, Datepicker, every icon, every loader, plus the cascade-layered stylesheet system and a generic DraggableSortable over @dnd-kit/sortable. The entire surface is synced verbatim from @infonomic/uikit , the upstream open-source project the Byline maintainers also author. Byline does not fork these components; the upstream repository remains the single source of truth.

Why a single package

Earlier iterations of Byline depended directly on @infonomic/uikit as a runtime peer. That worked, but it meant:

• Two repos in the "getting started" mental model.
• CSS imports and Tailwind glob configuration that referenced both packages by name.
• Brand inconsistency: every consumer's node_modules carried the @infonomic/uikit lockfile entry; admin DOM classes carried the upstream prefix.

Folding the foundational surface into @byline/ui cleans up all three. The upstream package stays as the design-and-development home for the primitives — the place where new components are built, refined, and tested in Storybook — but Byline ships a single, self-contained UI dependency.

Philosophy of the upstream kit

A short summary of what @infonomic/uikit is opinionated about — paraphrased from its README . These shape what Byline inherits.

• CSS Modules over utility-first frameworks for the kit itself. The kit composes styles in CSS Modules so consumers can use Tailwind, vanilla CSS, or any other system on top of the kit without fighting a utility-first style budget inside the components. The argument is that atomic CSS belongs in application layout and one-off styling; component libraries should ship semantic, overridable styles.
• Wrap best-in-class headless primitives. Many components (Modal, Tabs, Menu, Tooltip, Select, etc.) are built on Base UI , with Day Picker for calendars and a few other carefully chosen primitives elsewhere. The kit's job is to give consumers a stable contract — variant, intent, sizing — so a future swap from one headless library to another doesn't break the consumer's API.
• Framework-agnostic style system. The CSS layer machinery is designed to work with React, Vue, Solid, Svelte, Astro, or plain HTML. Byline currently consumes only the React entry point, but the kit's structure leaves room for a Vue or Svelte adapter without restructuring the styles.
• Style overrides without !important. Cascade layers (@layer) are used so any consumer-side CSS — outside any layer — automatically wins specificity over the kit's component styles. This is the single most load-bearing decision in the kit's design.
• Variant and intent as separate axes. Variant is shape (outlined, filled, gradient, underlined); intent is semantic (primary, secondary, noeffect, info, success, warning, danger). Most components accept both. Intent-based design tokens (--fill-primary-strong, --text-on-danger-weak, etc.) follow an element-intent-emphasis-state taxonomy.
• A .not-dark escape hatch. Components can opt out of the inherited light/dark mode without rewriting the theme.

For the full rationale and design-system architecture, see the upstream README .

CSS cascade layers (byline-prefixed)

The kit's stylesheets declare a strict layer order at the top of the cascade:

@layer byline-base,
  byline-functional,
  byline-utilities,
  byline-theme,
  byline-typography,
  byline-components;

Each component CSS Module wraps its rules in @layer byline-components { ... }. Anything a consumer writes outside any @layer automatically wins specificity, so overrides are CSS-clean — no !important, no specificity ladders.

The layer prefix is byline-, not infonomic-, even though the source files come from upstream. The sync script renames every @layer infonomic-* declaration to @layer byline-* as part of the post-sync rewrite. The DOM-level :global(.infonomic-X) class hooks (paired with className="infonomic-X" in the components) are deliberately not renamed — they're a separate surface, intended for consumer-side theme overrides keyed by the upstream's stable class names.

What's synced and what's not

The sync script (packages/ui/scripts/sync-from-uikit.sh) mirrors eight subtrees from upstream into packages/ui/src/:

Plus src/uikit.ts, the upstream's react.ts barrel renamed on copy. Byline's src/react.ts re-exports from ./uikit.js and adds the dnd helpers; the four subsystem barrels (admin.ts, fields.ts, forms.ts, services.ts) carry the Byline-specific surface.

Excluded from the sync:

• *.astro files — Byline doesn't ship Astro components.
• theme/ — Byline doesn't currently use the upstream theme/ subtree.
• *.stories.* — Storybook stories live upstream.
• __tests__/, *.test.* — tests stay upstream too.

The Byline-owned subtrees (admin/, fields/, forms/, services/, dnd/) are never touched by the sync.

The sync workflow

When upstream ships a new component or fixes a bug:

cd packages/ui
pnpm sync:uikit           # default upstream path: ../../../../../uikit/packages/uikit
# or:
UIKIT_PATH=/abs/path pnpm sync:uikit

The script:

1. Captures upstream's git SHA and dirty-flag for the manifest.
2. Rsyncs each synced subtree with --delete --delete-excluded so removed-upstream files are also removed locally.
3. Renames @layer infonomic-* → @layer byline-* across all synced *.css files.
4. Copies upstream's react.ts into src/uikit.ts with a "do not edit by hand" header.
5. Writes src/.uikit-sync.json recording the upstream SHA, timestamp, and which subtrees were synced.

The manifest is committed alongside the synced content, so a PR diff makes the upstream version bump visible:

{
  "upstream": "@infonomic/uikit",
  "upstreamSha": "70d936a49b9b233dc718ccf1f29acb3daf3009f1",
  "upstreamDirty": false,
  "syncedAt": "2026-05-03T19:55:10Z",
  "syncedDirs": ["components", "icons", "hooks", "lib", "loaders", "styles", "utils", "widgets"],
  "syncedFiles": ["uikit.ts"]
}

Edit upstream, never the synced copy. Hand-editing files inside packages/ui/src/{components,icons,hooks,lib,loaders,styles,utils,widgets}/ will be silently overwritten on the next sync.

Public API

Byline ships the kit through a small set of subpath exports:

The /react/ segment is intentional: it leaves room for a future /vue/ or /svelte/ namespace if a non-React adapter ever ships, without breaking existing imports. A single barrel (rather than per-area subpaths) dodges the Vite optimizeDeps Context-identity trap — see the comment at the top of packages/ui/src/react.ts.

Byline-owned admin surfaces — FormRenderer, FieldRenderer, every per-type field widget, AdminGroup / AdminRow / AdminTabs, StatusBadge, DiffModal, BylineFieldServicesProvider, LocalDateTime, DateTimeFormatter, useFormContext, useFieldValue — live in @byline/admin/react. See docs/Collections and docs/Fields for the import patterns.

Consumer setup

In a consumer app's root CSS:

@import "@byline/ui/reset.css";
@import "@byline/ui/styles.css";
@import "@byline/ui/typography.css";  /* optional */

@import "./tailwind.css";              /* optional, after the above */
@import "./app.css";                   /* application styles */

In components — primitives from @byline/ui/react, admin-aware components from @byline/admin/react:

// Generic primitives — Button, Modal, Search, etc.
import { Button, Card, Container, Search } from '@byline/ui/react'

// Admin-aware surfaces — field widgets, form runtime, editor-shared widgets.
import { FormRenderer, LocalDateTime, DateTimeFormatter } from '@byline/admin/react'

// Admin services Context — providers + hooks for the document editor.
import { BylineFieldServicesProvider, useBylineFieldServices } from '@byline/admin/react'

Tailwind integration mirrors the upstream pattern — see the upstream README  for the full @theme block and the optional ShadCN compatibility layer (both apply unchanged to @byline/ui).

License and credit

@byline/ui is MPL-2.0. The synced foundational surface originates in @infonomic/uikit, which is MIT-licensed. The Infonomic copyright headers are preserved in the synced files; the upstream LICENSE file is reproduced in the Byline repo as part of the sync content where applicable.

If you find a bug or want a new component in the foundational kit, contribute upstream at github.com/infonomic/uikit  — the change will land in Byline on the next sync.