feat: add mcp package

package.json

@@ -3,6 +3,8 @@
   "private": true,
   "workspaces": [
     "packages/rollup-plugin-import-css",
+    "packages/react",
+    "packages/mcp",
     "packages/*",
     "examples/*"
   ],

packages/mcp/package.json

@@ -0,0 +1,49 @@
+{
+  "name": "@primer/mcp",
+  "version": "0.0.0",
+  "private": true,
+  "type": "module",
+  "exports": {
+    "./transports/stdio": {
+      "types": "./dist/transports/stdio.d.ts",
+      "default": "./dist/stdio.js"
+    }
+  },
+  "files": [
+    "dist",
+    "src",
+    "README.md"
+  ],
+  "scripts": {
+    "clean": "rimraf dist",
+    "build": "rollup -c",
+    "type-check": "tsc --noEmit",
+    "watch": "rollup -c -w"
+  },
+  "dependencies": {
+    "@babel/runtime": "^7.27.0",
+    "@modelcontextprotocol/sdk": "^1.12.0",
+    "@primer/primitives": "^8.2.3",
+    "@primer/react": "^37.24.0",
+    "cheerio": "^1.0.0",
+    "turndown": "^7.2.0",
+    "zod": "^3.23.8"
+  },
+  "devDependencies": {
+    "@babel/core": "^7.27.1",
+    "@babel/plugin-transform-runtime": "^7.27.1",
+    "@babel/preset-env": "^7.27.2",
+    "@babel/preset-typescript": "^7.27.1",
+    "@modelcontextprotocol/inspector": "^0.13.0",
+    "@rollup/plugin-babel": "^6.0.4",
+    "@rollup/plugin-commonjs": "^25.0.8",
+    "@rollup/plugin-json": "^6.1.0",
+    "@rollup/plugin-node-resolve": "^15.2.3",
+    "@types/turndown": "^5.0.5",
+    "concurrently": "^9.1.2",
+    "rimraf": "^6.0.1",
+    "rollup": "^4.30.1",
+    "rollup-plugin-typescript2": "^0.36.0",
+    "typescript": "^5.8.3"
+  }
+}

packages/mcp/rollup.config.js

@@ -0,0 +1,51 @@
+import {defineConfig} from 'rollup'
+import babel from '@rollup/plugin-babel'
+import json from '@rollup/plugin-json'
+import nodeResolve from '@rollup/plugin-node-resolve'
+import commonjs from '@rollup/plugin-commonjs'
+import typescript from 'rollup-plugin-typescript2'
+import packageJson from './package.json' with {type: 'json'}
+
+const external = [
+  ...Object.keys(packageJson.peerDependencies ?? {}),
+  ...Object.keys(packageJson.dependencies ?? {}),
+  ...Object.keys(packageJson.devDependencies ?? {}),
+].map(name => {
+  return new RegExp(`^${name}(/.*)?`)
+})
+
+const config = defineConfig({
+  input: ['./src/transports/stdio.ts'],
+  external,
+  plugins: [
+    nodeResolve(),
+    commonjs(),
+    babel({
+      extensions: ['.js', '.cjs', '.mjs', '.ts', '.tsx'],
+      presets: [
+        [
+          '@babel/preset-env',
+          {
+            targets: {
+              node: 'current',
+            },
+          },
+        ],
+        '@babel/preset-typescript',
+      ],
+      plugins: ['@babel/plugin-transform-runtime'],
+      babelHelpers: 'runtime',
+    }),
+    typescript({
+      tsconfig: './tsconfig.build.json',
+    }),
+    json(),
+  ],
+  output: {
+    dir: 'dist',
+    format: 'esm',
+    importAttributesKey: 'with',
+  },
+})
+
+export default config

packages/mcp/src/primer.ts

@@ -0,0 +1,73 @@
+import componentsMetadata from '@primer/react/generated/components.json' with {type: 'json'}
+
+type Component = {
+  id: string
+  name: string
+  importPath: string
+}
+
+const components: Array<Component> = Object.entries(componentsMetadata.components).map(([id, component]) => {
+  return {
+    id,
+    name: component.name,
+    importPath: component.importPath,
+  }
+})
+
+function listComponents(): Array<Component> {
+  return components
+}
+
+type Pattern = {
+  id: string
+  name: string
+}
+
+const patterns: Array<Pattern> = [
+  {
+    id: 'data-visualization',
+    name: 'Data Visualization',
+  },
+  {
+    id: 'degraded-experiences',
+    name: 'Degraded Experiences',
+  },
+  {
+    id: 'empty-states',
+    name: 'Empty States',
+  },
+  {
+    id: 'feature-onboarding',
+    name: 'Feature Onboarding',
+  },
+  {
+    id: 'forms',
+    name: 'Forms',
+  },
+  {
+    id: 'loading',
+    name: 'Loading',
+  },
+  {
+    id: 'navigation',
+    name: 'Navigation',
+  },
+  {
+    id: 'notification-messaging',
+    name: 'Notification message',
+  },
+  {
+    id: 'progressive-disclosure',
+    name: 'Progressive disclosure',
+  },
+  {
+    id: 'saving',
+    name: 'Saving',
+  },
+]
+
+function listPatterns(): Array<Pattern> {
+  return patterns
+}
+
+export {listComponents, listPatterns}