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

# Overview

> Reduce failed deliveries with in-checkout and post-checkout address validation for Shopify. Set rules, block risky addresses, tag orders, and automate follow-up flows.

## What AddressPill does

AddressPill helps you avoid shipping errors in Shopify.

It checks customer addresses at two moments:

* **In-checkout validation**: before the order is placed
* **Post-checkout validation**: after the order is placed

This means you can catch problems early, reduce manual work, and protect fulfillment quality.

## Start here

<CardGroup cols={2}>
  <Card title="General walkthrough" icon="circle-play" href="/get-started/addresspill-shopify-walkthrough">
    See the full app flow and understand every area in the sidebar.
  </Card>

  <Card title="In-checkout setup" icon="cart-shopping" href="/get-started/in-checkout-address-validation-setup">
    Enable checkout validation and stop invalid addresses before payment.
  </Card>

  <Card title="Post-checkout setup" icon="receipt" href="/get-started/post-checkout-address-validation-setup">
    Enable Thank You and Order Status validation after purchase.
  </Card>

  <Card title="Feature overview" icon="sliders" href="/features/in-checkout-validation">
    Understand what each feature does in plain language.
  </Card>
</CardGroup>

## How to use this documentation

1. Start with **Get Started**.
2. Read **Features** to understand what each module does.
3. Use **Settings** pages when you configure your store.
4. Open **FAQ & Troubleshooting** if something does not work.

<Info>
  AddressPill is designed to be simple. If you are not technical, follow the setup steps exactly in order.
</Info>

## FAQ

### What is AddressPill for Shopify?

AddressPill is a Shopify app that validates shipping addresses before and after checkout to reduce delivery errors.

### What is the difference between in-checkout and post-checkout validation?

In-checkout runs before payment. Post-checkout runs after payment on Thank You and Order Status pages.

### Which page should I read first?

Start with the Get Started walkthrough, then follow the two setup pages for in-checkout and post-checkout.