Imported from upstash/qstash-js (skills/SKILL.md). Install upstream with npx skills add upstash/qstash-js --skill skills. Copyright stays with the author.

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
• Schedules
• Queues and Flow Control
• URL Groups

For verifying incoming messages:

• Receiver Verification - Core signature verification with the Receiver class
• Platform-Specific Verifiers:
  • Next.js - App Router, Pages Router, and Edge Runtime

For advanced features:

• Callbacks
• Dead Letter Queue (DLQ)
• Message Deduplication
• Region migration & multi-region support
  • If needed, multi-region env variable setup verification script. 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