QStash JavaScript SDK

QStash is an HTTP-based messaging and scheduling solution for serverless and edge runtimes. This skill helps you use the QStash JS SDK effectively.

When to use this skill

Use this skill when:

• Publishing HTTP messages to endpoints or URL groups
• Creating scheduled or delayed message delivery
• Managing FIFO queues with configurable parallelism
• Verifying incoming webhook signatures from QStash
• Implementing callbacks, DLQ handling, or message deduplication

Quick Start

Installing the SDK

npm install @upstash/qstash

Basic Publishing

import { Client } from "@upstash/qstash";

const client = new Client({
  token: process.env.QSTASH_TOKEN!,
});

const result = await client.publishJSON({
  url: "https://my-api.example.com/webhook",
  body: { event: "user.created", userId: "123" },
});

Core Concepts

For fundamental QStash operations, see:

• [Publishing Messages](fundamentals/publishing-messages.md)
• [Schedules](fundamentals/schedules.md)
• [Queues and Flow Control](fundamentals/queues-and-flow-control.md)
• [URL Groups](fundamentals/url-groups.md)
• [Local Development](fundamentals/local-development.md) — automatic dev server via devMode: true

For verifying incoming messages:

• [Receiver Verification](verification/receiver.md) - Core signature verification with the Receiver class
• Platform-Specific Verifiers:

- [Next.js](verification/platform-specific/nextjs.md) - App Router, Pages Router, and Edge Runtime

For advanced features:

• [Callbacks](advanced/callbacks.md)
• [Dead Letter Queue (DLQ)](advanced/dlq.md)
• [Message Deduplication](advanced/deduplication.md)
• [Region migration & multi-region support](advanced/multi-region/summary.md)

- If needed, [multi-region env variable setup verification script](advanced/multi-region/verify-multi-region-setup.ts). Can be run without arguments

Platform Support

QStash JS SDK works across various platforms:

• Next.js (App Router and Pages Router)
• Cloudflare Workers
• Deno
• Node.js (v18+)
• Vercel Edge Runtime
• SvelteKit, Nuxt, SolidJS, and other frameworks

Note on Workflow SDK: For building complex durable workflows that chain multiple QStash messages together, consider using the separate QStash Workflow SDK (@upstash/workflow). The Workflow SDK empowers you to orchestrate multi-step processes with automatic state management, retries, and fault tolerance. This Skills file focuses on the core QStash messaging SDK.

Best Practices

• Always verify incoming QStash messages using the Receiver class
• Use environment variables for tokens and signing keys
• Set appropriate retry counts and timeouts for your use case
• Use queues for ordered processing with controlled parallelism
• Implement DLQ handling for failed message recovery