sde-meeting-toolkit/server.js

/*
 * Local server for the SDE meeting toolkit.
 * Serves the static tool files.
 * Proxies AI draft requests to the Anthropic API, so the API key
 * stays on the server and never appears in the browser.
 */
const http = require('http');
const fs = require('fs');
const path = require('path');

const ROOT = __dirname;
const PORT = process.env.PORT || 5173;
const ANTHROPIC_VERSION = '2023-06-01';

const MIME = {
  '.html': 'text/html; charset=utf-8',
  '.js': 'text/javascript; charset=utf-8',
  '.css': 'text/css; charset=utf-8',
  '.json': 'application/json; charset=utf-8',
  '.svg': 'image/svg+xml',
  '.png': 'image/png',
  '.skill': 'application/zip'
};

function loadEnvFile() {
  const envPath = path.join(ROOT, '.env');
  let content;
  try {
    content = fs.readFileSync(envPath, 'utf8');
  } catch (err) {
    return; // no .env file; that is allowed, the AI draft route will report it
  }
  content.split('\n').forEach((line) => {
    const trimmed = line.trim();
    if (!trimmed || trimmed.startsWith('#')) return;
    const idx = trimmed.indexOf('=');
    if (idx === -1) return;
    const key = trimmed.slice(0, idx).trim();
    const value = trimmed.slice(idx + 1).trim().replace(/^["']|["']$/g, '');
    if (key && !(key in process.env)) process.env[key] = value;
  });
}
loadEnvFile();

function sendJson(res, status, obj) {
  const body = JSON.stringify(obj);
  res.writeHead(status, { 'Content-Type': 'application/json; charset=utf-8' });
  res.end(body);
}

/* ===== Access control =====
 * Set APP_USERNAME and APP_PASSWORD (in .env or the container environment)
 * to require a login for the whole app. Leave both unset for solo local use
 * with no login prompt. This is a simple shared-credential gate, meant to sit
 * behind the company VPN and internal network, not to replace them. */
function checkBasicAuth(req) {
  const user = process.env.APP_USERNAME;
  const pass = process.env.APP_PASSWORD;
  if (!user || !pass) return true;
  const header = req.headers['authorization'] || '';
  const expected = 'Basic ' + Buffer.from(`${user}:${pass}`).toString('base64');
  return header === expected;
}
function requireAuth(res) {
  res.writeHead(401, {
    'WWW-Authenticate': 'Basic realm="SDE Meeting Toolkit"',
    'Content-Type': 'text/plain'
  });
  res.end('Authentication required.');
}

/* ===== Rate limiting for the AI proxy =====
 * A shared company API key means one leaked link or one runaway script can
 * generate real cost. This caps AI draft calls per source IP. It resets if
 * the process restarts; that is an accepted tradeoff for a small internal tool. */
const RATE_LIMIT_MAX = parseInt(process.env.RATE_LIMIT_MAX || '20', 10);
const RATE_LIMIT_WINDOW_MS = parseInt(process.env.RATE_LIMIT_WINDOW_MS || String(5 * 60 * 1000), 10);
const rateLimitHits = new Map();
function isRateLimited(ip) {
  const now = Date.now();
  const hits = (rateLimitHits.get(ip) || []).filter((t) => now - t < RATE_LIMIT_WINDOW_MS);
  hits.push(now);
  rateLimitHits.set(ip, hits);
  return hits.length > RATE_LIMIT_MAX;
}

function proxyToClaude(req, res) {
  if (!process.env.ANTHROPIC_API_KEY) {
    sendJson(res, 500, {
      error: 'ANTHROPIC_API_KEY is not set. Add it to the .env file in this folder, then restart the server.'
    });
    return;
  }
  let body = '';
  req.on('data', (chunk) => { body += chunk; });
  req.on('end', async () => {
    try {
      const upstream = await fetch('https://api.anthropic.com/v1/messages', {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          'x-api-key': process.env.ANTHROPIC_API_KEY,
          'anthropic-version': ANTHROPIC_VERSION
        },
        body
      });
      const text = await upstream.text();
      res.writeHead(upstream.status, { 'Content-Type': 'application/json; charset=utf-8' });
      res.end(text);
    } catch (err) {
      sendJson(res, 502, { error: 'Could not reach the Anthropic API: ' + err.message });
    }
  });
}

function serveStatic(req, res) {
  const urlPath = decodeURIComponent(req.url.split('?')[0]);
  if (urlPath === '/') {
    const index = `<!doctype html><html><body style="font:14px system-ui;padding:2rem">
      <h1>SDE Meeting Toolkit</h1>
      <ul>
        <li><a href="/tools/field-problem-workshop.html">Field Problem Workshop</a></li>
        <li><a href="/tools/scope-lock-meeting-suite.html">Scope Lock Meeting Suite</a></li>
      </ul>
    </body></html>`;
    res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });
    res.end(index);
    return;
  }
  const filePath = path.normalize(path.join(ROOT, urlPath));
  if (!filePath.startsWith(ROOT)) {
    res.writeHead(403);
    res.end('Forbidden');
    return;
  }
  fs.readFile(filePath, (err, data) => {
    if (err) {
      res.writeHead(404, { 'Content-Type': 'text/plain' });
      res.end('Not found: ' + urlPath);
      return;
    }
    const ext = path.extname(filePath);
    res.writeHead(200, { 'Content-Type': MIME[ext] || 'application/octet-stream' });
    res.end(data);
  });
}

const server = http.createServer((req, res) => {
  if (!checkBasicAuth(req)) {
    requireAuth(res);
    return;
  }
  if (req.method === 'POST' && req.url === '/api/claude') {
    const ip = req.socket.remoteAddress || 'unknown';
    if (isRateLimited(ip)) {
      sendJson(res, 429, { error: `Rate limit reached (${RATE_LIMIT_MAX} AI drafts per ${Math.round(RATE_LIMIT_WINDOW_MS / 60000)} min). Wait a bit and try again.` });
      return;
    }
    proxyToClaude(req, res);
    return;
  }
  if (req.method === 'GET') {
    serveStatic(req, res);
    return;
  }
  res.writeHead(405, { 'Content-Type': 'text/plain' });
  res.end('Method not allowed');
});

server.listen(PORT, () => {
  console.log(`SDE meeting toolkit running at http://localhost:${PORT}`);
  console.log(process.env.ANTHROPIC_API_KEY ? 'ANTHROPIC_API_KEY loaded: AI draft button is live.' : 'No ANTHROPIC_API_KEY found: AI draft button will return an error until you add one to .env.');
  console.log((process.env.APP_USERNAME && process.env.APP_PASSWORD) ? 'Login required: APP_USERNAME/APP_PASSWORD are set.' : 'No login required: APP_USERNAME/APP_PASSWORD are not set.');
});