> ## Documentation Index
> Fetch the complete documentation index at: https://quartr.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Backlog audio
> The backlog audio dataset
## Overview
The backlog audio dataset provides access to audio files from past events. Each event includes two URLs to allow for both streaming and downloading.
## How it works
Each audio record in the API response includes URLs that point directly to audio files hosted on our CDN, so you can stream or download them without any additional authentication. Audio is served in both **MPEG** format for downloading and **M3U8** format for HLS streaming.
Audio records are linked to events through `eventId`. Use the `expand` parameter to include event metadata directly in the response.
## Chapters
Audio files can be divided into structured segments using [chapters](/datasets/chapters). Use the [chapters endpoint](/api-reference/backlog-audio/list-audio-chapters) to retrieve hierarchical sections with titles and timestamps for a given audio record.
## How to access this data
Query audio by ticker, ISIN, event ID, and more.
Subscribe to webhooks for real-time updates.
Query the data using SQL.
### Streaming example
Example using [HLS.js](https://github.com/video-dev/hls.js) to play the `streamUrl` in a browser.
```html theme={null}
```
## Overview
The backlog audio dataset provides access to audio files from past events. Each event includes two URLs to allow for both streaming and downloading.
## How it works
Each audio record in the API response includes URLs that point directly to audio files hosted on our CDN, so you can stream or download them without any additional authentication. Audio is served in both **MPEG** format for downloading and **M3U8** format for HLS streaming.