Initial commit: Daily tech newsletter worker

A Node.js/TypeScript worker that sends daily AI-generated summaries
of tech news from X/Twitter via Nitter RSS feeds.

Features:
- Fetches tweets from 40+ curated tech accounts via Nitter RSS
- Filters and categorizes by topic (AI/ML, SWE, General Tech)
- Generates AI summaries using OpenRouter (Claude/GPT-4)
- Sends professional HTML email via Brevo SMTP
- Runs on cron schedule inside Docker container
- Instance rotation for Nitter reliability
- Graceful degradation if AI fails

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.ts

@@ -0,0 +1,94 @@
+import { config } from './config/index.js';
+import { logger } from './utils/logger.js';
+import { NewsletterPipeline } from './core/NewsletterPipeline.js';
+import { CronScheduler } from './services/scheduler/CronScheduler.js';
+import { EmailService } from './services/email/EmailService.js';
+
+async function main() {
+  const args = process.argv.slice(2);
+  const runNow = args.includes('--run-now');
+  const dryRun = args.includes('--dry-run');
+
+  if (dryRun) {
+    process.env.DRY_RUN = 'true';
+  }
+
+  logger.info(
+    {
+      runNow,
+      dryRun: config.features.dryRun || dryRun,
+      cronSchedule: config.scheduler.cronExpression,
+      timezone: config.scheduler.timezone,
+      recipients: config.email.recipients.length,
+    },
+    'X-Newsletter starting'
+  );
+
+  const pipeline = new NewsletterPipeline();
+
+  if (runNow) {
+    logger.info('Running newsletter pipeline immediately');
+
+    const result = await pipeline.run();
+
+    if (result.success) {
+      logger.info('Newsletter sent successfully');
+      process.exit(0);
+    } else {
+      logger.error({ errors: result.errors }, 'Newsletter pipeline failed');
+      process.exit(1);
+    }
+  }
+
+  // Verify email connection on startup
+  const emailService = new EmailService();
+  const emailConnected = await emailService.verifyConnection();
+
+  if (!emailConnected) {
+    logger.warn('Email service connection could not be verified - will retry on send');
+  }
+
+  // Set up scheduled execution
+  const scheduler = new CronScheduler();
+
+  scheduler.schedule(
+    'daily-newsletter',
+    config.scheduler.cronExpression,
+    async () => {
+      const result = await pipeline.run();
+
+      if (!result.success) {
+        logger.error({ errors: result.errors }, 'Scheduled newsletter failed');
+      }
+    },
+    { timezone: config.scheduler.timezone }
+  );
+
+  scheduler.start();
+
+  logger.info(
+    {
+      schedule: config.scheduler.cronExpression,
+      timezone: config.scheduler.timezone,
+    },
+    'Newsletter scheduler started. Waiting for next scheduled run...'
+  );
+
+  // Handle graceful shutdown
+  const shutdown = () => {
+    logger.info('Shutting down...');
+    scheduler.stop();
+    process.exit(0);
+  };
+
+  process.on('SIGTERM', shutdown);
+  process.on('SIGINT', shutdown);
+
+  // Keep the process running
+  await new Promise(() => {});
+}
+
+main().catch((error) => {
+  logger.error({ error }, 'Fatal error');
+  process.exit(1);
+});