Vercel Cron Digest Email with Rovela (2026): CRON_SECRET + POST /emails + Idempotency-Key
Secure a Vercel Cron App Router route with CRON_SECRET, build a fresh daily/weekly digest or ops report from your DB, and send it via Rovela POST /emails with Idempotency-Key scoped to the UTC run window. Secrets in project env. Distinct from Cloudflare Workers transactional, AI-agent HTTP send, and Rovela scheduled_at.