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

# Introduction

> What Knit Bundles is and which guide to follow

Knit Bundles is a Shopify app for product bundles, volume discounts, and mix-and-match offers. You create the offer in Shopify admin. Shoppers see it on the product page. The discount is applied at Shopify checkout.

How you **render** the widget depends on the storefront:

| Storefront                                    | What you use                                  |
| --------------------------------------------- | --------------------------------------------- |
| Shopify Liquid theme                          | Theme app extension (installed with the app)  |
| Tapcart mobile app                            | Knit Bundle block in App Studio               |
| Hydrogen, custom cart, or other headless host | [Headless Bundles API](/headless-bundles-api) |

All three use the **same bundles** from Knit admin and the **same checkout discount**.

<CardGroup cols={2}>
  <Card title="Getting started" icon="rocket" href="/getting-started">
    Install the app, create an active bundle, confirm it on the product page.
  </Card>

  <Card title="How discounts apply" icon="percent" href="/how-discounts-apply">
    Why cart lines must keep `__FB_ATC_UID` for the discount to fire.
  </Card>

  <Card title="Tapcart" icon="mobile" href="/tapcart">
    Add the Knit Bundle block to your Tapcart product page.
  </Card>

  <Card title="Headless Bundles API" icon="code" href="/headless-bundles-api">
    Embed the widget or consume the data API from any host.
  </Card>
</CardGroup>