Design systems, readable by people and machines.

Browse

Search by name or idea and filter by theme. Open a style to explore its palette, typography, spacing, components and guidelines. Expand the preview for a closer look, then copy a design guide or download a file. Related styles help you keep exploring. No account needed.

Four ways to take a style with you

Every style exports in four formats, on its detail page or through the MCP server. Each comes in a compact and an extended variant; the compact one leaves out the type scale, surfaces, elevation and components.

• DESIGN.md

  A brief in prose and tables, written for a coding agent to follow.

  design-md

• Tailwind theme

  A Tailwind v4 @theme block with colours, fonts, spacing and radii.

  tailwind

• CSS variables

  Custom properties on :root, ready to drop into any stylesheet.

  css

• Design tokens

  W3C design tokens as JSON, for a pipeline that consumes them.

  tokens

Connect your AI

The catalogue is available to Claude Code, Codex, Cursor, Windsurf and VS Code through the endpoint /mcp. Requests need a personal API key, and a key works while its owner has an active Pro subscription. Three steps:

1. Create an account

   Sign up with your email. Favourites work right away; the MCP server needs the next two steps.

   Sign up

2. Get Pro

   €9 a month or €84 a year, paid through Stripe. Change or cancel at any time from the billing page.

   Open billing

3. Create a key

   Up to five active keys, each shown once. The setup for every client is on the same page, already filled in.

   Open API keys

Then add the server to your client. For Claude Code that is one line in the terminal:

claude mcp add --transport http musterlab https://musterlab.space/mcp --header "Authorization: Bearer <api-key>"

Codex, Cursor, Windsurf and VS Code each spell the config a little differently. Your keys page has the exact snippet and the steps for every one of them.

What your assistant can do

There are 10 tools. Answers come back as readable Markdown unless you ask for JSON, and the tools that name a style take up to ten at once, so comparing several costs one call instead of ten. A Pro key is good for 10,000 calls a month.

• search_styles

  Searches website design systems: the public catalogue, plus any you have measured yourself in the Musterlab Studio. Your own come first and are marked `source: yours`; use scope to narrow to one side. Free text matches name, essence, description and domain. Filters: theme (light, dark, mixed), industry, font family. Returns short summaries with ids for the other tools.

  { "query": "editorial", "theme": "light" }

• search_sites

  Searches the websites in the catalog by company name or domain, each with the styles measured from it. Use this when you know the company but not the style, e.g. 'stripe' or 'linear.app'.

  { "query": "linear" }

• get_style

  Returns the full design system of a style: colors with roles, typefaces, type scale, spacing, surfaces, elevation, layout, components, do/avoid principles and media URLs. Reaches your own Studio styles as well as the catalogue, and prefers yours when a domain is in both. Reference one style by id or domain, or up to 10 at once with ids or domains to compare them in a single call.

  { "domain": "linear.app" }

• get_style_export

  Generates a ready-to-use file from a style: design-md (DESIGN.md for AI agents), tailwind (Tailwind v4 @theme), css (CSS custom properties) or tokens (W3C design tokens JSON). Variant compact leaves out the extended sections. Accepts up to 10 styles, which returns one file per style.

  { "domain": "linear.app", "format": "design-md" }

• find_similar_styles

  Finds styles with the same theme, preferably the same industry, ordered by how many palette colors they share.

  { "domain": "linear.app", "limit": 5 }

• get_style_image

  Returns one picture of a style as an image, for looking at rather than reading about. thumbnail (default) is the small card image, screenshot the top of the page as it appears on opening, poster a still from the preview video, and screen a numbered screenful — screen 1 is the top, each one after that is a screen further down. get_style_screens returns several at once. Read these for layout, rhythm and feel; the design system is what to build from.

  { "domain": "linear.app", "image": "screenshot" }

• get_style_screens

  Returns several screenfuls of a page as images in one call, top to bottom, so the whole layout can be seen rather than just the part above the fold. Screen 1 is the top; each one after that is a screen further down, ending at the foot of the page. Read these for layout, rhythm and feel — what a section looks like, how things are arranged, where the page breathes. Build from the design system, not by copying what is in the picture.

  { "domain": "linear.app" }

• get_style_metrics

  Returns the raw measurements taken from the live website (computed colors, font sizes, spacing values and similar). Large and technical, only useful when the curated design system from get_style is not detailed enough.

  { "domain": "linear.app" }

• list_fonts

  Lists the font families used across the catalog with the number of styles using each, most common first.

  { "limit": 20 }

• list_industries

  Lists the industry labels used in the catalog with the number of styles for each.

  { "response_format": "json" }

Every argument of every tool is listed at https://musterlab.space/mcp/docs. It is plain text and needs no key, so you can paste the link into a prompt and let your assistant read it before it calls anything.

Your account

The library needs no account: every style, its design system and all four exports are open to anyone. An account adds favourites. Mark a style with the heart on a card or on its detail page and find it again under Favourites. Your API keys and subscription live in the account area.