> ## Documentation Index
> Fetch the complete documentation index at: https://upstash-bulkdlqdelete.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Getting Started

QStash is an HTTP-based messaging and scheduling solution, designed for serverless
and edge computing environments, guaranteeing **at-least-once delivery**.

## Use Cases

<CardGroup cols={2}>
  <Card title="Background Jobs" icon="share-all" href="/qstash/features/background-jobs">
    Run long-running tasks in the background, without blocking your application
  </Card>

  <Card title="Schedules" icon="calendar-days" href="/qstash/features/schedules">
    Schedule messages to be delivered at a time in the future
  </Card>

  <Card title="Fan out" icon="arrow-up-to-dotted-line" href="/qstash/features/topics">
    Publish messages to multiple endpoints, in parallel, using topics
  </Card>

  <Card title="Callbacks" icon="phone" href="/qstash/features/callbacks">
    Get a response delivered to your API when a message is delivered
  </Card>

  <Card title="Retry Failed Jobs" icon="repeat" href="/qstash/features/dlq">
    Use a Dead Letter Queue to have full control over failed messages
  </Card>

  <Card title="Deduplication" icon="copy" href="/qstash/features/deduplication">
    Prevent duplicate messages from being delivered
  </Card>
</CardGroup>

## Quick Start

Check out these Quick Start guides to get started with QStash in your application.

<CardGroup cols={2}>
  <Card title="Next.js" icon="node-js" href="/qstash/quickstarts/vercel-nextjs">
    Build a Next application that uses QStash to start a long-running job on your platform
  </Card>

  <Card title="Python" icon="python" href="/qstash/quickstarts/python-vercel">
    Build a Python application that uses QStash to schedule a daily job that clean up a database
  </Card>
</CardGroup>

Or continue reading to learn how to send your first message!

## Send your first message

<Check>
  **Prerequisite**

  You need an Upstash account before publishing messages, create one
  [here](https://console.upstash.com).
</Check>

### Public API

Make sure you have a publicly available HTTP API that you want to send your
messages to. If you don't, you can use something like
[requestcatcher.com](https://requestcatcher.com/) or
[webhook.site](https://webhook.site/) to try it out.

For example, you can use this URL to test your messages: [https://firstqstashmessage.requestcatcher.com](https://firstqstashmessage.requestcatcher.com)

### Get your token

Go to the [Upstash Console](https://console.upstash.com/qstash) and copy the
`QSTASH_TOKEN`.

<Frame>
  <img src="https://mintlify.s3-us-west-1.amazonaws.com/upstash-bulkdlqdelete/img/qstash/rest_token.png" />
</Frame>

### Publish a message

A message can be any shape or form: json, xml, binary, anything, that can be
transmitted in the http request body. We do not impose any restrictions other
than a size limit of 1 MB (which can be customized at your request).

In addition to the request body itself, you can also send HTTP headers. Learn
more about this in the [message publishing section](/qstash/howto/publishing).

<CodeGroup>
  ```bash cURL
  curl -XPOST \
      -H 'Authorization: Bearer <QSTASH_TOKEN>' \
      -H "Content-type: application/json" \
      -d '{ "hello": "world" }' \
      'https://qstash.upstash.io/v2/publish/https://<your-api-url>'
  ```

  ```bash cURL RequestCatcher
  curl -XPOST \
      -H 'Authorization: Bearer <QSTASH_TOKEN>' \
      -H "Content-type: application/json" \
      -d '{ "hello": "world" }' \
      'https://qstash.upstash.io/v2/publish/https://https://firstqstashmessage.requestcatcher.com/test'
  ```
</CodeGroup>

Don't worry, we have SDKs for different languages so you don't
have to make these requests manually.

### Check Response

You should receive a response with a unique message ID.

<Frame>
  <img src="https://mintlify.s3-us-west-1.amazonaws.com/upstash-bulkdlqdelete/img/qstash/reqcatcher.png" />
</Frame>

### Check Message Status

Head over to [Upstash Console](https://console.upstash.com/qstash) and go to the
`Logs` tab where you can see your message activities.

<Frame>
  <img src="https://mintlify.s3-us-west-1.amazonaws.com/upstash-bulkdlqdelete/img/qstash/log.png" />
</Frame>

Learn more about different states [here](/qstash/howto/debug-logs).