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

# Back-in-Stock

> Capture WhatsApp numbers from customers on out-of-stock product pages and automatically notify them the moment a variant is restocked.

The Back-in-Stock module converts inventory gaps into a recoverable revenue opportunity. When a product variant is out of stock, customers can subscribe through a storefront widget using their WhatsApp number. The moment that variant is restocked in Shopify, Galantis detects the inventory change and dispatches a WhatsApp notification automatically — no manual work, no delay, no missed restock window.

The module has two distinct parts that work together: the **storefront widget**, which captures subscriptions on your live store, and the **notification pipeline**, which listens for restock events and sends the message. Both must be configured for the full flow to work.

## How it works end to end

```
Customer visits out-of-stock product page
  → Widget appears on the variant
  → Customer submits their WhatsApp number
  → Subscription created with ACTIVE status
  → Variant restocked in Shopify
  → Shopify sends products/update webhook
  → Galantis detects inventory_quantity 0 → > 0
  → BACK_IN_STOCK automation trigger fires
  → WhatsApp notification sent to all ACTIVE subscribers
  → Subscription status moves to NOTIFIED
```

## What this section covers

* Installing and verifying the storefront widget
* Customizing widget appearance and branding
* How subscriptions move through their lifecycle
* The full notification pipeline from restock detection to message dispatch
* Per-variant product and inventory rules
* Analytics and conversion metrics

## Guides in this section

<CardGroup cols={2}>
  <Card title="Widget Installation" icon="code" href="./widget-installation">
    Script tag injection, verification steps, and troubleshooting widget display issues.
  </Card>

  <Card title="Widget Design" icon="palette" href="./widget-design">
    All branding and appearance settings — button, modal, colors, fonts, and form states.
  </Card>

  <Card title="Subscription Lifecycle" icon="arrows-rotate" href="./subscription-lifecycle">
    PENDING, ACTIVE, NOTIFIED, and CANCELLED — how subscriptions transition between states.
  </Card>

  <Card title="Notification Logic" icon="bell" href="./notification-logic">
    The full pipeline from Shopify restock webhook to WhatsApp message dispatch.
  </Card>

  <Card title="Product & Inventory Rules" icon="boxes-stacked" href="./product-inventory-rules">
    Per-variant subscription behavior, subscription limits, and eligibility rules.
  </Card>

  <Card title="Analytics" icon="chart-bar" href="./back-in-stock-analytics">
    Active subscriptions, notification volume, click rate, conversion rate, and revenue attribution.
  </Card>
</CardGroup>

## Prerequisites

Before the Back-in-Stock module can send notifications:

* Your WhatsApp Business Account must be connected — see [WhatsApp Connection](/whatsapp/getting-started/whatsapp-connection)
* An approved WhatsApp template must exist for the restock notification message — see [Templates](/whatsapp/templates/index)
* The `write_script_tags` Shopify permission must be granted — required for widget injection

Subscription capture (the widget) works independently of the notification template — customers can subscribe before the template is approved. But notifications will not send until an approved template is in place and assigned to the Back-in-Stock automation flow.

## Billing

Back-in-Stock is billed as a separate add-on with two components: a **monthly tier subscription** that determines how many subscribers you can hold (Starter \$19 / 250 subs → Enterprise \$149 / 10,000 subs), and **1 Conversation credit per delivered notification** drawn from the same credit pool as campaigns. **Enterprise core plan includes the Starter BIS tier (250 subscribers) by default.** See [Back-in-Stock Add-on Billing](/galantis/whatsapp/billing/add-ons/back-in-stock) for the full pricing breakdown.