QStash is Upstash's serverless message queue for when you need to make HTTP calls later, reliably. Send a message via HTTP, it gets delivered to your endpoint with retries, signature verification, and optional callbacks. Great for scheduling webhooks, running cron jobs without servers, or ensuring delivery when downstream services are flaky. The skill emphasizes signature verification (always check both keys), warns against localhost endpoints, and pushes you toward fast acknowledgment patterns. If you're reaching for a heavyweight queue but really just need "call this URL in 5 minutes" or "retry this webhook until it works," this is the simpler path.
npx skills add https://github.com/davila7/claude-code-templates --skill upstash-qstash