Files
greyhaven-design-system/mcp/server.ts
2026-04-16 13:04:38 -05:00

455 lines
14 KiB
JavaScript

#!/usr/bin/env node
/**
* Greyhaven Design System MCP Server
*
* Provides programmatic access to design tokens, component specs, and
* validation tools for any MCP-compatible AI agent.
*/
import { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js'
import { StdioServerTransport } from '@modelcontextprotocol/sdk/server/stdio.js'
import { z } from 'zod'
import * as fs from 'fs'
import * as path from 'path'
import { fileURLToPath } from 'url'
import {
COMPONENT_CATALOG,
getTokens,
type ComponentSpec,
} from '../lib/catalog.js'
const __filename = fileURLToPath(import.meta.url)
const __dirname = path.dirname(__filename)
const ROOT = path.resolve(__dirname, '..')
// ---------------------------------------------------------------------------
// Server setup
// ---------------------------------------------------------------------------
const server = new McpServer({
name: 'greyhaven-design-system',
version: '1.0.0',
})
// Tool: get_tokens
server.tool(
'get_tokens',
'Returns design token values. Optionally filter by category: color, typography, spacing, radii, shadows, motion.',
{ category: z.string().optional().describe('Token category to filter by') },
async ({ category }) => {
const tokens = getTokens(ROOT, category)
return {
content: [
{
type: 'text' as const,
text: JSON.stringify(tokens, null, 2),
},
],
}
},
)
// Tool: get_component
server.tool(
'get_component',
'Returns the full spec for a named component: props, variants, usage example, and when to use it.',
{ name: z.string().describe('Component name (case-insensitive)') },
async ({ name }) => {
const component = COMPONENT_CATALOG.find(
(c) => c.name.toLowerCase() === name.toLowerCase(),
)
if (!component) {
return {
content: [
{
type: 'text' as const,
text: `Component "${name}" not found. Use list_components to see available components.`,
},
],
isError: true,
}
}
let source = ''
try {
source = fs.readFileSync(path.join(ROOT, component.file), 'utf-8')
} catch {
source = '(source file not readable)'
}
return {
content: [
{
type: 'text' as const,
text: JSON.stringify({ ...component, source }, null, 2),
},
],
}
},
)
// Tool: list_components
server.tool(
'list_components',
'Lists all available design system components, optionally filtered by category.',
{
category: z
.string()
.optional()
.describe(
'Category filter: primitives, layout, overlay, navigation, data, feedback, form, composition',
),
},
async ({ category }) => {
let components = COMPONENT_CATALOG
if (category) {
components = components.filter(
(c) => c.category.toLowerCase() === category.toLowerCase(),
)
}
const summary = components.map((c) => ({
name: c.name,
category: c.category,
file: c.file,
description: c.description,
}))
return {
content: [
{
type: 'text' as const,
text: JSON.stringify(summary, null, 2),
},
],
}
},
)
// Tool: validate_colors
server.tool(
'validate_colors',
'Checks if a code snippet uses valid design system colors. Returns warnings for raw hex values that should use tokens instead.',
{ code: z.string().describe('Code string to validate') },
async ({ code }) => {
const hexRegex = /#[0-9a-fA-F]{3,8}/g
const matches = code.match(hexRegex) || []
const validHexValues = new Set([
'#f9f9f7', '#F9F9F7', '#161614', '#d95e2a', '#D95E2A',
'#b43232', '#B43232', '#f0f0ec', '#F0F0EC', '#ddddd7', '#DDDDD7',
'#c4c4bd', '#C4C4BD', '#a6a69f', '#A6A69F', '#7f7f79', '#7F7F79',
'#575753', '#2f2f2c', '#2F2F2C',
'#fff', '#FFF', '#ffffff', '#FFFFFF', '#000', '#000000',
])
const warnings: string[] = []
const seen = new Set<string>()
for (const hex of matches) {
const lower = hex.toLowerCase()
if (seen.has(lower)) continue
seen.add(lower)
if (validHexValues.has(hex)) {
warnings.push(
`${hex} -- valid Greyhaven primitive, but prefer semantic CSS variables (e.g., var(--primary)).`,
)
} else {
warnings.push(
`${hex} -- NOT a Greyhaven design token. Use semantic tokens: bg-primary, text-foreground, border-border, etc.`,
)
}
}
if (warnings.length === 0) {
return {
content: [{
type: 'text' as const,
text: 'No raw hex colors found. The code uses design system tokens correctly.',
}],
}
}
return {
content: [{
type: 'text' as const,
text: `Found ${matches.length} hex color(s):\n\n${warnings.join('\n')}`,
}],
}
},
)
// Tool: suggest_component
server.tool(
'suggest_component',
'Suggests the best Greyhaven component(s) for a described UI need.',
{ description: z.string().describe('Natural language description of what UI you need') },
async ({ description }) => {
const desc = description.toLowerCase()
const suggestions: ComponentSpec[] = []
const keywords: Record<string, string[]> = {
button: ['button', 'click', 'action', 'submit', 'cta'],
card: ['card', 'container', 'box', 'panel', 'tile'],
dialog: ['dialog', 'modal', 'popup', 'overlay', 'confirm'],
input: ['input', 'text field', 'textbox', 'form field'],
table: ['table', 'grid', 'data', 'list', 'rows', 'columns'],
navbar: ['navbar', 'navigation bar', 'header', 'top bar', 'nav'],
hero: ['hero', 'banner', 'landing', 'splash', 'headline'],
'cta-section': ['cta', 'call to action', 'signup', 'sign up'],
footer: ['footer', 'bottom', 'copyright'],
form: ['form', 'registration', 'login', 'sign in', 'contact'],
select: ['select', 'dropdown', 'choose', 'pick'],
tabs: ['tabs', 'tab', 'sections', 'switch between'],
accordion: ['accordion', 'expandable', 'collapsible', 'faq'],
alert: ['alert', 'warning', 'error', 'notification', 'message'],
badge: ['badge', 'tag', 'label', 'status', 'chip'],
avatar: ['avatar', 'profile', 'user image', 'photo'],
tooltip: ['tooltip', 'hint', 'hover info'],
progress: ['progress', 'loading', 'bar', 'percentage'],
skeleton: ['skeleton', 'loading', 'placeholder', 'shimmer'],
drawer: ['drawer', 'sheet', 'bottom sheet', 'slide'],
popover: ['popover', 'floating', 'popup content'],
separator: ['separator', 'divider', 'line', 'hr'],
breadcrumb: ['breadcrumb', 'trail', 'path'],
pagination: ['pagination', 'pages', 'next', 'previous'],
section: ['section', 'content block', 'area'],
'page-layout': ['layout', 'page', 'shell', 'scaffold', 'template'],
logo: ['logo', 'brand', 'greyhaven'],
calendar: ['calendar', 'date', 'date picker'],
}
for (const [componentName, kw] of Object.entries(keywords)) {
if (kw.some((k) => desc.includes(k))) {
const match = COMPONENT_CATALOG.find(
(c) => c.name.toLowerCase() === componentName.toLowerCase() ||
c.name.toLowerCase().replace(/\s+/g, '-') === componentName,
)
if (match) suggestions.push(match)
}
}
if (suggestions.length === 0) {
return {
content: [{
type: 'text' as const,
text: `No strong match for "${description}". Use list_components() to browse all ${COMPONENT_CATALOG.length} components.`,
}],
}
}
return {
content: [{
type: 'text' as const,
text: JSON.stringify(
suggestions.map((s) => ({
name: s.name,
category: s.category,
description: s.description,
example: s.example,
})),
null, 2,
),
}],
}
},
)
// ---------------------------------------------------------------------------
// Brand tools & resources
// ---------------------------------------------------------------------------
const BRAND_SKILL_PATH = path.join(ROOT, 'skill', 'BRAND.md')
function readBrandSkill(): string {
try {
return fs.readFileSync(BRAND_SKILL_PATH, 'utf-8')
} catch {
return '(skill/BRAND.md not found — hand-curated brand skill is missing)'
}
}
server.tool(
'get_brand_rules',
'Returns the Greyhaven brand voice, tone, and messaging rules. Use this BEFORE generating any user-facing marketing copy, CTAs, landing page content, or product explanations. Covers positioning, brand axes, tone, writing rules, reasoning patterns, CTA guidance, logo usage, and a self-check list.',
{
section: z
.enum([
'all',
'positioning',
'axes',
'tone',
'writing-rules',
'reasoning-patterns',
'cta',
'logo',
'self-check',
])
.optional()
.describe('Optional section filter. Default returns the full brand skill.'),
},
async ({ section }) => {
const full = readBrandSkill()
if (!section || section === 'all') {
return {
content: [{ type: 'text' as const, text: full }],
}
}
// Section anchors in BRAND.md (markdown H2 headings)
const anchors: Record<string, RegExp> = {
positioning: /## 2\. Core Positioning[\s\S]*?(?=\n## |\n---)/,
axes: /## 3\. The Three Brand Axes[\s\S]*?(?=\n## |\n---)/,
tone: /## 4\. Tone of Voice[\s\S]*?(?=\n## |\n---)/,
'writing-rules': /## 5\. Writing Rules[\s\S]*?(?=\n## |\n---)/,
'reasoning-patterns': /## 6\. Patterns for Reasoning[\s\S]*?(?=\n## |\n---)/,
cta: /## 7\. CTA Guidance[\s\S]*?(?=\n## |\n---)/,
logo: /## 10\. Logo Usage[\s\S]*?(?=\n## |\n---)/,
'self-check': /## 11\. Self-check[\s\S]*?(?=\n## |\n---)/,
}
const re = anchors[section]
const match = re ? full.match(re) : null
if (!match) {
return {
content: [{
type: 'text' as const,
text: `Section "${section}" not found. Returning full brand skill instead.\n\n${full}`,
}],
}
}
return {
content: [{ type: 'text' as const, text: match[0] }],
}
},
)
server.tool(
'validate_copy',
'Checks a piece of user-facing copy against Greyhaven brand rules. Flags hype words, sales language, vague superlatives, and other brand violations. Use on marketing copy, CTAs, headlines, product descriptions before shipping.',
{ text: z.string().describe('The copy to validate') },
async ({ text }) => {
const lower = text.toLowerCase()
const bannedWords = [
'unleash', 'transform', 'revolutionary', 'revolutionize',
'seamless', 'seamlessly', 'game-changing', 'cutting-edge',
'next-gen', 'next-generation', 'leverage', 'synergy', 'unlock',
'supercharge', 'empower', 'empowered', 'unprecedented',
'best-in-class', 'industry-leading', 'world-class',
'lightning-fast', 'blazing fast',
]
const vagueSuperlatives = [
'amazing', 'incredible', 'awesome', 'stunning', 'beautiful',
'powerful', 'robust', 'cutting edge', 'state-of-the-art',
]
const urgencyPhrases = [
'limited time', 'act now', "don't miss out", 'hurry',
'last chance', 'today only',
]
const findings: string[] = []
for (const w of bannedWords) {
if (lower.includes(w)) {
findings.push(`⚠ Banned hype/sales word: "${w}"`)
}
}
for (const w of vagueSuperlatives) {
if (lower.includes(w)) {
findings.push(`⚠ Vague superlative: "${w}" — replace with specifics`)
}
}
for (const p of urgencyPhrases) {
if (lower.includes(p)) {
findings.push(`⚠ Urgency framing: "${p}" — Greyhaven does not use urgency`)
}
}
// Exclamation marks
const exclamations = (text.match(/!/g) || []).length
if (exclamations > 0) {
findings.push(`⚠ Found ${exclamations} exclamation mark(s) — Greyhaven copy does not use them`)
}
if (findings.length === 0) {
return {
content: [{
type: 'text' as const,
text: 'No obvious brand violations found. Still run the self-check list from get_brand_rules({section: "self-check"}) before shipping.',
}],
}
}
return {
content: [{
type: 'text' as const,
text: `Found ${findings.length} potential brand violation(s):\n\n${findings.join('\n')}\n\nFor detailed guidance, call get_brand_rules() or get_brand_rules({section: "tone"}).`,
}],
}
},
)
// ---------------------------------------------------------------------------
// Resources
// ---------------------------------------------------------------------------
server.resource('brand://guidelines', 'brand://guidelines', async (uri) => {
return {
contents: [{
uri: uri.href,
mimeType: 'text/markdown',
text: readBrandSkill(),
}],
}
})
server.resource('tokens://all', 'tokens://all', async (uri) => {
const tokens = getTokens(ROOT)
return {
contents: [{
uri: uri.href,
mimeType: 'application/json',
text: JSON.stringify(tokens, null, 2),
}],
}
})
for (const component of COMPONENT_CATALOG) {
const uri = `component://${component.name.toLowerCase()}`
server.resource(uri, uri, async (resourceUri) => {
let source = ''
try {
source = fs.readFileSync(path.join(ROOT, component.file), 'utf-8')
} catch {
source = '(source not readable)'
}
return {
contents: [{
uri: resourceUri.href,
mimeType: 'application/json',
text: JSON.stringify({ ...component, source }, null, 2),
}],
}
})
}
// ---------------------------------------------------------------------------
// Start
// ---------------------------------------------------------------------------
async function main() {
const transport = new StdioServerTransport()
await server.connect(transport)
}
main().catch(console.error)