Add Mcp Server

Add any workspace dependencies the server needs (e.g., "@proto-portal/design-tokens": "workspace:*").

tsconfig.json

{
  "compilerOptions": {
    "target": "ES2022",
    "lib": ["ES2023"],
    "module": "NodeNext",
    "moduleResolution": "NodeNext",
    "skipLibCheck": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": false,
    "declaration": true,
    "declarationMap": true,
    "outDir": "./dist",
    "rootDir": "./src",
    "strict": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noFallthroughCasesInSwitch": true,
    "esModuleInterop": true
  },
  "include": ["src/**/*.ts"],
  "exclude": ["node_modules", "dist"]
}

src/index.ts

export { createServer } from "./server.js";

src/server.ts

import { Server } from "@modelcontextprotocol/sdk/server/index.js";

export function createServer(): Server {
  const server = new Server(
    { name: "proto-portal-{server-name}", version: "1.0.0" },
    { capabilities: { tools: {}, resources: {}, prompts: {} } }
  );

  // Register your handlers here:
  // - server.setRequestHandler(ListToolsRequestSchema, ...)
  // - server.setRequestHandler(CallToolRequestSchema, ...)
  // - server.setRequestHandler(ListResourcesRequestSchema, ...)
  // - server.setRequestHandler(ReadResourceRequestSchema, ...)
  // - server.setRequestHandler(ListPromptsRequestSchema, ...)
  // - server.setRequestHandler(GetPromptRequestSchema, ...)

  return server;
}

2. Add to root workspaces

In the root package.json, add the new package to workspaces:

"workspaces": [
  ...existing...,
  "shared/mcp-servers/{server-name}"
]

3. Add CLI dependency

In shared/mcp-cli/package.json, add a workspace:* dependency:

"dependencies": {
  "@proto-portal/mcp-server-design-tokens": "workspace:*",
  "@proto-portal/mcp-server-{server-name}": "workspace:*"
}

4. Register in the CLI

In shared/mcp-cli/src/registry.ts, add an entry to serverRegistry:

{
  name: "{server-name}",
  description: "Short description of what this server provides",
  packageName: "@proto-portal/mcp-server-{server-name}",
  createServer: async () => {
    const mod = await import("@proto-portal/mcp-server-{server-name}");
    return mod.createServer;
  },
},

5. Register with Claude Code (optional)

Add to .mcp.json at the repo root:

{
  "mcpServers": {
    "{server-name}": {
      "command": "node",
      "args": ["shared/mcp-cli/dist/cli.js", "start", "{server-name}"]
    }
  }
}

6. Build and test

yarn install
yarn build:mcp
node shared/mcp-cli/dist/cli.js list
node shared/mcp-cli/dist/cli.js info {server-name}

MCP Server Design Guidelines

• Tools are for computed/parameterized data (queries with arguments)
• Resources are for static/semi-static data (token values, config snapshots)
• Prompts are for reusable prompt templates with optional arguments
• All output to stdout is reserved for MCP protocol — use console.error() for diagnostics
• Import from existing workspace packages — never duplicate data
• Use @modelcontextprotocol/sdk's InMemoryTransport for unit testing