# Introduction

Verified purchase data for your application—automatically.

***

## What You Get

Connect your users to **15+ major retailers** and receive their verified purchase data:

| Feature               | Description                                                            |
| --------------------- | ---------------------------------------------------------------------- |
| **Verified Orders**   | Product names, prices, dates—directly from retailers                   |
| **15+ Retailers**     | Amazon, Walmart, Target, Costco, Kroger, and more                      |
| **Automatic Sync**    | Weekly auto-sync keeps data fresh                                      |
| **Portable Identity** | One phone number = one secure account, connect once and stay connected |
| **Privacy-First**     | No payment info, no addresses—just purchase data                       |

***

## How It Works

| Step                 | What Happens                                  | Details                                           |
| -------------------- | --------------------------------------------- | ------------------------------------------------- |
| **1. Integrate**     | Add widget to your app                        | 5 min setup. Web, React, Mobile WebView supported |
| **2. User Connects** | User signs in with phone & connects retailers | Amazon, Walmart, Target, etc.                     |
| **3. You Get Data**  | Receive orders via API or callbacks           | Line-item level purchase data                     |

***

## Quick Start

```html
<div id="sync-widget"></div>

<script src="https://sync-api.stackline.com/sync-sdk/latest/sdk.umd.js"></script>
<script>
  SyncSDK.init({
    clientId: "bc_your_app_id",
    environment: "sandbox",
    container: document.getElementById("sync-widget"),
    onSync: (result) => {
      console.log(`Synced ${result.ordersFound} orders`);
    },
  });
</script>
```

That's it. The widget handles authentication, retailer connection, and syncing.

***

## Use Cases

| Industry                  | Use Case                                      |
| ------------------------- | --------------------------------------------- |
| **Rewards & Loyalty**     | Award points for qualifying purchases         |
| **Personal Finance**      | Categorize spending by retailer/brand         |
| **Healthcare/HSA**        | Identify eligible health purchases            |
| **Purchase Verification** | Validate purchases for rebates/reimbursement  |
| **Analytics**             | Track purchase patterns and brand preferences |

***

## Environments

| Environment  | API URL                       | Use For                 |
| ------------ | ----------------------------- | ----------------------- |
| `sandbox`    | `sync-api-beta.stackline.com` | Development and testing |
| `production` | `sync-api.stackline.com`      | Live production apps    |

***

## Get Your Client ID

Contact Sync As A Service with your **app name** and **redirect URI** to receive your Client ID.

***

## Documentation

| Document                                                                             | Description                                  |
| ------------------------------------------------------------------------------------ | -------------------------------------------- |
| [Getting Started](https://docs-sync.stackline.com/overview/getting-started)          | 5-minute integration walkthrough             |
| [Integration Guides](https://docs-sync.stackline.com/integration/integration-guides) | Web, React, Mobile WebView, Backend examples |
| [Widget Reference](https://docs-sync.stackline.com/integration/widget-reference)     | All widget states, events, and customization |
| [API Reference](https://docs-sync.stackline.com/api-and-data/api-reference)          | REST API endpoints                           |
| [Data Reference](https://docs-sync.stackline.com/api-and-data/data-reference)        | Order data structure and fields              |
| [Security](https://docs-sync.stackline.com/reference/security)                       | How we protect user data                     |
| [Troubleshooting](https://docs-sync.stackline.com/reference/troubleshooting)         | Error codes and common issues                |