Coding agents default to the same generic UI because they can't decide what it should look like — so they fall back to hero + 3 cards + a gradient. web-stylebook-mcp is a Model Context Protocol server that hands the agent design contracts — scored visual directions, UI-state plans, and design tokens — drawn from the same curated catalog as webstylebook.com. It returns evidence, not code. Your agent still writes the code — now it knows what to build.

No API key. No model call. No network. No filesystem access. Deterministic, read-only, fully local.

Without it / with it

Watch it decide

"High-density monitoring dashboard for SREs, watched all day on call. Calm, technical. Avoid cyberpunk."

// → recommend_design_direction  (input)
{
  "productDescription": "High-density monitoring dashboard for SREs, watched all day on call",
  "productType": "operational-saas",
  "tone": ["calm", "technical"],
  "density": "high",
  "usageFrequency": "daily",
  "avoid": ["cyberpunk"]
}

// ← result
{
  "confidence": "high",
  "candidates": [                      // all tied at 0.91 — ordering is NOT meaningful
    { "style": "notion-style",   "score": 0.91 },
    { "style": "platform-core",  "score": 0.91 },
    { "style": "quiet-utility",  "score": 0.91 },
    { "style": "runtime-signal", "score": 0.91 }
  ],
  "rejected": [
    { "style": "cyberpunk-glitch", "reasons": ["EXPLICITLY_AVOIDED", "DAILY_USE_OVERSTIMULATION"] },
    { "style": "aurora-gradient",  "reasons": ["PRODUCT_NOT_IDEAL", "DAILY_USE_OVERSTIMULATION"] }
  ],
  "pairing": "macos-liquid-glass + notion-style (quieter forms / nav)",
  "guidance": "Treat candidates as scored evidence; pick by product context. 4 are tied — ordering isn't meaningful; use differentiators."
}

Notice what it doesn't do: it doesn't pretend there's one winner. Four directions tie at 0.91, the rejects come with reason codes, and the guidance tells the model to make the final call. That honesty is the point — the server provides evidence, the agent decides.

Then turn the chosen direction into real tokens:

// → compose_design_tokens(style: "notion-style", format: "css-variables", theme: "light")
// 0 WCAG contrast warnings
:root {
  --color-canvas: #ffffff;
  --color-text:   #37352f;
  --color-accent: #2383e2;
  --color-border: #d3d3d1;
  /* … role-based color, type, spacing, radius, motion, density */
}

One request in — and the agent chose a direction, saw what was rejected and why, and got tokens that pass WCAG, without generating a line of code.

What an agent builds with it

A different brief — "a marketing landing page for Throughline, a B2B SaaS that turns scattered customer feedback (support tickets, sales calls, app reviews, Slack) into one prioritized roadmap." No layout, no hero, no styling was specified. Following the companion skill, the agent composed the opening from the product's core idea instead of reaching for a stock hero: the right half is a bespoke diagram of the product's actual mechanic — feedback sources converging into an auto-ranked roadmap — not a decorative card you could paste onto any other site.

How it works

flowchart LR
    A[AI coding agent] -->|product, tone,<br/>density, usage| B(web-stylebook-mcp)
    B --> C{Bundled catalog<br/>read-only · offline}
    C --> D[recommend_design_direction]
    C --> E[compare_design_directions]
    C --> F[get_ui_state_plan]
    C --> G[compose_design_tokens]
    D & E & F & G -->|design contracts<br/>scores · reason codes · tokens| A
    A -->|writes code<br/>from evidence| H[Your UI]

The agent describes the product; the server scores its curated catalog and returns structured evidence. No code is generated and nothing leaves your machine.

Install

Requires Node ≥ 20.

codex mcp add web-stylebook -- npx -y web-stylebook-mcp@latest

[mcp_servers.web-stylebook]
command = "npx"
args = ["-y", "web-stylebook-mcp@latest"]

claude mcp add web-stylebook -- npx -y web-stylebook-mcp@latest

{
  "mcpServers": {
    "web-stylebook": {
      "command": "npx",
      "args": ["-y", "web-stylebook-mcp@latest"]
    }
  }
}

{
  "mcpServers": {
    "web-stylebook": {
      "command": "npx",
      "args": ["-y", "web-stylebook-mcp@latest"]
    }
  }
}

Tools

Catalog: 48 styles · 20 components · 5 surfaces · 57 UI-state recipes · 29 motion profiles · 14 product archetypes.

Localized output

Every tool takes an optional locale. Reason codes, guidance, and labels come back in the requested language:

"en" | "ko" | "ja"     // English · 한국어 · 日本語

Resources

Browse the catalog directly over MCP resources:

webstylebook://manifest
webstylebook://styles · /styles/{id}
webstylebook://motion · /motion/{id}
webstylebook://components · /components/{id}
webstylebook://states/surfaces · /states/{surface} · /states/{surface}/{state}
webstylebook://products · /products/{id}
webstylebook://policies/anti-patterns · /policies/verification

Prompts

Ready-made MCP prompts for common workflows:

design-product · design-screen · complete-ui-states · redesign-with-style · audit-design-direction

CLI

web-stylebook-mcp                 # run the server over stdio (default)
web-stylebook-mcp --version
web-stylebook-mcp --catalog-info
web-stylebook-mcp --validate-catalog

Companion skill

A companion skill ships in skill/ so your agent reaches for these tools at the right moment — and uses the results well (compose, don't recolor; offer multiple candidates; earn trust, don't fake it; land on reusable components):

Codex

• Copy or symlink skill/web-stylebook-design/ into a Codex skill location such as .agents/skills/web-stylebook-design/ in your repo, or ~/.agents/skills/web-stylebook-design/ for your user profile.
• If you do not want to install the skill, copy skill/AGENTS.md into your project's AGENTS.md.

Claude Code and other agents

• Point your agent's skills directory at skill/web-stylebook-design/, or
• Copy skill/CLAUDE.md into your project's CLAUDE.md or equivalent rules file.

Privacy & security

The server reads from a catalog snapshot bundled in the package. Nothing is sent anywhere; the same inputs always yield the same contracts.

Compatibility

• Node: ≥ 20
• Transport: stdio (Model Context Protocol)
• Clients: Codex CLI / IDE extension, Claude Code, Claude Desktop, Cursor, Windsurf, and any MCP-compatible client

License

MIT — covers the code and the bundled catalog snapshot (free for commercial use).

The webstylebook.com website is licensed CC BY-NC. The same owner grants an MIT license for the catalog snapshot bundled in this package.