MCP Production Playbook

// mcp-server.ts  — minimal production skeleton (~25 lines)
// Must be the FIRST code that runs. Redirect stdout before any import
// so dep banners and console.log calls don't corrupt the JSON-RPC frame.
const _write = process.stdout.write.bind(process.stdout);
process.stdout.write = ((chunk, ...rest) => {
  const s = typeof chunk === "string" ? chunk : Buffer.from(chunk).toString();
  if (s.startsWith("{") || s.startsWith("Content-Length:"))
    return _write(chunk, ...rest);
  process.stderr.write(chunk);
  return true;
}) as typeof process.stdout.write;
const log = (...a: unknown[]) => process.stderr.write(a.join(" ") + "
");

import { Server } from "@modelcontextprotocol/sdk/server/index.js";
import { StdioServerTransport } from "@modelcontextprotocol/sdk/server/stdio.js";
import { ListToolsRequestSchema, CallToolRequestSchema }
  from "@modelcontextprotocol/sdk/types.js";

const server = new Server({ name: "my-server", version: "0.1.0" },
  { capabilities: { tools: {} } });

server.setRequestHandler(ListToolsRequestSchema, async () => ({
  tools: [{ name: "ping", description: "Returns pong.", inputSchema:
    { type: "object", properties: {}, required: [] } }],
}));
server.setRequestHandler(CallToolRequestSchema, async (req) => {
  if (req.params.name === "ping")
    return { content: [{ type: "text", text: "pong" }] };
  return { content: [{ type: "text", text: `unknown tool: ${req.params.name}` }], isError: true };
});

const transport = new StdioServerTransport();
await server.connect(transport);
process.on("SIGINT",  () => server.close().then(() => process.exit(0)));
process.on("SIGTERM", () => server.close().then(() => process.exit(0)));
log("[mcp] server ready");

#!/usr/bin/env bash
# .claude/hooks/pre-commit  — runs before every Claude Code commit.
#
# Pattern: always resolve to the repo root so the hook works from any
# worktree or linked checkout (absolute path, never relative).
set -euo pipefail

# Resolve repo root from THIS script's location, not cwd.
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(git -C "${SCRIPT_DIR}" rev-parse --show-toplevel)"

# All yarn commands run from root so node_modules is always found.
cd "${REPO_ROOT}"

# Gate 1: env registry — blocks if code references an undeclared env var.
yarn env:check

# Gate 2: lint + types — fast; skips next build so dev server stays up.
yarn verify:dev

echo "[hook] pre-commit passed"