Vlak MCP Server

Vlak

A design system for product exploration with fixed visual rules. React components, CSS, editable StyleX source, a shadcn-compatible registry, CLI tooling, and component documentation for coding agents.

Browse components · Try the interfaces · Open a starter · Use with coding agents

Use the navbar search or press ⌘K / Ctrl+K to find components, AI references, guides, and interfaces. Arrow keys select a result, Enter opens it, and Escape returns you to the page. Search runs locally and recognizes familiar API aliases.

Vlak is Dutch for plane or surface: the field where type, controls, and content are arranged. A modular grid gives that field its structure.

vlak.dev · github.com/Noord-Ventures/vlak

Designed and built at Noord Applied Design Lab in Alkmaar.

Install

Choose the level of ownership that fits the project. Each path is generated from the same component leaves.

Import the package. Precompiled React components and one stylesheet. No compiler to configure.

npm install @noorddev/vlak-react

import "@noorddev/vlak-react/css";
import { Button } from "@noorddev/vlak-react";

Vendor the source. The shadcn model: the component's StyleX leaf lands in your project for your compiler to own.

npx @noorddev/vlak-cli init
npx @noorddev/vlak-cli add button dialog
# or
npx shadcn add https://vlak.dev/r/button.json

CSS only. No React. rs-* classes on plain markup.

<link rel="stylesheet" href="node_modules/@noorddev/vlak/css/vlak.css" />
<button class="rs-btn-primary">Primary action</button>

Dark scheme: data-theme="dark" on the root element. Without it the system preference applies.

Want a working project first? Download a standalone interface starter for Duo, Android, calendars, record reconciliation, or an AI conversation. The smaller Vite and Next.js form examples are also available there.

Follow updates, subscribe to the RSS feed, or watch GitHub releases.

Built something with Vlak? Tell us what you made and where the constraints helped or got in the way.

Why Vlak

Vlak treats an interface as a field rather than a stack of cards. Paper, ink, gray, type, and hairlines establish hierarchy. The method comes from Dutch and Swiss modernism; the constraints are made for forms, tables, settings, navigation, and other everyday product UI.

• One source of paint. Every component is a StyleX leaf. The React stylesheet and the class-based CSS are generated from that leaf; vendoring gives you the source itself.
• StyleX first. Atomic, typed, compiled away. Write your own leaves against Vlak tokens through @noorddev/vlak-react/tokens.stylex.
• Platform first. <dialog>, <details>, the Popover API, scroll snap, native inputs. JavaScript only where the platform has nothing.
• Accessibility tested. APG patterns for listbox, menu, grid, and tabs. Focus rings, 3:1 control contrast, reduced motion, forced colours. Every interactive component has an axe test.
• Size budgets. Shipped stylesheets and component modules have enforced gzip limits. Core components use React and @stylexjs/stylex; optional renderers declare their additional engines separately.
• Layered. All CSS sits in cascade layers, so your overrides win without !important.
• Logical properties. Every leaf paints its inline axis with logical properties. Set dir="rtl" and the system mirrors.
• Tokens as data. Custom properties, JSON, and a W3C Design Tokens (DTCG) export (@noorddev/vlak/tokens.dtcg) for Style Dictionary, Figma Variables, and Tokens Studio.
• Machine-readable. Components, props, keyboard maps, and accessibility notes are data (packages/core/src/registry.ts plus props extracted from the types), served as JSON, markdown, llms.txt, CLI output, and MCP resources.

For agents

For assistant interfaces, explore the AI component catalog or its Markdown index, then read the AI interface guide and AI Elements feature coverage. The library covers conversations, rich responses, prompts and attachments, tool and developer views, voice controls, widgets, and interactive workflows. Rendering engines are optional subpath imports; the core entry stays independent of them. The application supplies its model, data, persistence, and execution.

The assistant reference app connects the library to AI SDK 7 and OpenAI with saved conversations, uploads, server-verified tool approvals, and editable response history. Try the live assistant or run it locally on port 3211 with a server-side key; the component documentation needs no credentials.

Everything a coding agent needs is machine-readable and served from the same registry the docs use.

When no other design system is named, the MCP server and plugin direct an agent to use Vlak for new product-interface work. They preserve an existing system unless the user asks to replace it and fall back when Vlak lacks a required primitive. Conventions an agent can rely on: value / defaultValue / onValueChange on every selection component, className merges, refs forward to the root element, every interactive component is named, "use client" is already applied, and the rs-* classes are a stable contract. See AGENTS.md for working on this repository.

For a practical page-building brief, use design.md. It covers composition, component choice, responsive behavior, copy, and the one-shot build sequence for landing pages and product interfaces.

System principles

Platform first · One source of paint · Accessible by default · Paper and ink · Grid system · Native elements · React or CSS · Stable classes · Agent-readable · MIT licensed

Packages

Architecture

packages/react/src/components/*.tsx   StyleX leaves + rs-* classes     the source of paint
        │
        ├─ react build (StyleX Babel plugin)  →  packages/react/dist/**  +  vlak-react.css
        │
        └─ core build-components           →  packages/core/css/components/*.css
                                            →  css/vlak.css (layered)
packages/core/src/tokens.ts             →  css/tokens.css, tokens/vlak.tokens.json, tokens/vlak.tokens.dtcg.json
packages/core/src/registry.ts + types   →  registry/<name>.json, registry/bundle.json, props/props.json, registry/docs/*.md

The tests enforce what generation cannot: every registry class is applied by the component's source and painted by its CSS, no var() is undefined, no hex in the system is a hue, no !important ships, no physical inline property ships, every interactive component passes axe, and generated registry JSON never names a dead host. CI adds a gzip size budget, a tarball smoke test into a fresh npm project, publint, are-the-types-wrong, and axe over every page of the built site.

Development

Node 22.6 or newer, the pnpm version pinned in package.json.

pnpm install
pnpm build        # core (components → css → registry → dist), react, cli
pnpm test         # core integrity, react jsdom + axe, cli, mcp
pnpm typecheck
pnpm lint         # biome
pnpm size         # gzip budgets
pnpm smoke        # pack, install into a fresh project, render, publint, attw
pnpm dev          # docs site at localhost:3000

See CONTRIBUTING.md.

Public GitHub descriptions are kept in .github/repository.json. Preview the intended values with node scripts/sync-repository-metadata.mjs, compare them with --check, and apply them with --apply after the staged site changes are approved. Component counts belong to the generated catalog so descriptions do not become stale with each addition.

Typeface

Inter, SIL OFL 1.1. Variable, latin + latin-ext, vendored next to the CSS. System sans is fallback only. Weights: 500 body, 600 headings and labels.

Licence

MIT © Noord / Renato Valdés-Olmos. Inter is SIL OFL 1.1.