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

# subscription_initial_purchase Event

> Track first-time subscription purchases from new subscribers — automatically generated by Upstack.

<Info>
  **Automatically Generated** — This event is created by Upstack backend services for Shopify customers. You do not need to fire this event manually.
</Info>

## Overview

The `subscription_initial_purchase` event is generated when a customer signs up for a new subscription — the first order in a subscription sequence. It fires for stores using subscription apps like Recharge, Bold Subscriptions, Skio, Loop Subscriptions, or native Shopify Subscriptions.

## How It Works

When a subscription order is processed, Upstack analyzes the order metadata:

1. **Order received** — Shopify sends a purchase webhook to Upstack
2. **Subscription detection** — Upstack checks for subscription app tags and order properties
3. **Classification** — The order is classified as initial or recurring based on the subscription data
4. **Event generation** — The appropriate subscription event is generated
5. **Forwarding** — Events are sent to your configured destinations

Upstack identifies subscription orders through order tags from subscription apps (e.g., `subscription_first_order`, `recurring_order`), order and line item properties containing subscription metadata, and subscription app-specific identifiers in the order data.

## Use Cases

* **Measure subscriber acquisition** — Track how many new subscribers you're acquiring
* **Calculate subscriber CAC** — Understand the true cost to acquire a subscriber
* **Optimize acquisition campaigns** — Train ad algorithms to find subscription-likely customers
* **Attribution for LTV** — Attribute the full potential LTV to the acquiring campaign

## Properties

This event includes all properties from the original `purchase` event:

| Property | Type   | Description                              |
| -------- | ------ | ---------------------------------------- |
| orderId  | string | Shopify order ID                         |
| value    | number | Order total value                        |
| currency | string | ISO 4217 currency code (e.g., `USD`)     |
| items    | array  | Products purchased                       |
| email    | string | Customer email (hashed for destinations) |
| phone    | string | Customer phone (hashed for destinations) |

## Destination Mapping

This event is forwarded to destinations as:

| Destination           | Event Name        | Notes                                   |
| --------------------- | ----------------- | --------------------------------------- |
| **Meta CAPI**         | `Purchase`        | With `subscription_type` in custom data |
| **Google Ads**        | `purchase`        | Filterable by event name                |
| **TikTok Events API** | `CompletePayment` | Subscription flag included              |
| **Klaviyo**           | `Placed Order`    | Tagged with subscription type           |
| **GA4**               | `purchase`        | Custom dimension for subscription       |

## Metrics Available

| Metric                         | Description                    |
| ------------------------------ | ------------------------------ |
| Subscription Initial Purchases | New subscription sign-ups      |
| Cost per Subscription Initial  | CAC for new subscribers        |
| Subscription Initial Value     | Revenue from new subscriptions |

<Note>
  **E-commerce subscriptions only** — this event is for subscription boxes and recurring product purchases. For SaaS subscription lifecycle events (plan changes, trials), see [SaaS Events](/event-tracking/event-taxonomy/saas-events).
</Note>

## Related Events

* [purchase](/event-tracking/event-taxonomy/standard-events#purchase) — The base purchase event
* [subscription\_recurring\_purchase](/event-tracking/event-taxonomy/upstack-generated/subscription-recurring-purchase) — Recurring subscription renewals
* [nc\_purchase](/event-tracking/event-taxonomy/standard-events/nc-purchase) — New customer purchases