> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cabinspress.com/llms.txt
> Use this file to discover all available pages before exploring further.

# ARC Download

> Delivers a personalized, watermarked EPUB through a one-time-use link.

## Who this is for

ARC readers downloading their copy.

## Overview

Delivers a personalized, watermarked EPUB through a one-time-use link.

## How it works

### Each ARC reader gets a unique link

* Generated per reader, not a shared URL
* Author can copy-share from the Book Readers tab
* Also delivered via email (when included in a cadence template using `{{book_arc_download_url}}`)

### Reader experience

* Opens a download page showing the book cover, description, and a **Download** button
* Single click downloads the EPUB with a progress bar showing preparation and byte-level download progress
* Download status shown: Available, Already Used, Invalid, or Not Available (outside window)

### Download mechanics

* **One-time use** — second attempt returns "ARC link already used"
* **Watermarked** — the EPUB carries the reader's identity invisibly so leaked copies can be traced back
* **Window-gated** — link only works during the configured download window (independent of signup window)
* For books in EPUB-import mode, the uploaded EPUB is delivered as-is; for editor-built books, a fresh EPUB is generated with the watermark embedded

**Cleanup:** Used tokens for published books are removed periodically to prevent token table bloat.

## **Leak detection:** Authors can submit a suspicious EPUB through admin tools to identify the original recipient.

## Next steps

[**Public Shop Catalog**](/readers/public-shop-catalog)