> For the complete documentation index, see [llms.txt](https://docs.sparkloop.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sparkloop.app/postbacks.md).

# Postbacks

How to confirm Action offers via postbacks

When you create an Action offer, conversions must be explicitly confirmed after the user completes the desired action on your website (e.g., signs up for a trial, makes a purchase, downloads a resource).\
​\
This guide explains how to confirm Action conversions using a postback.\
​\
**​How It Works**

1. User clicks offer link
2. User is redirected to your website → You capture the Click ID parameter
3. User completes the action -> Purchase/Signup/Download/etc..
4. You call the postback URL → Confirm the conversion with SparkLoop
5. Conversion is processed

***

### Step 1: Capture the Tracking Parameters <a href="#h_1639a94dd2" id="h_1639a94dd2"></a>

When SparkLoop redirects users to your website, we append a `sl_click_id` query parameter to your redirect URL.

If your offer URL is `https://example.com/signup`, the user will be redirected to:\
​\
​`https://example.com/signup?sl_click_id=ABC---submission_1234abcd`\
​\
​Important: You must capture and store the `sl_click_id` parameter when the user lands on your site. You'll need it to confirm the conversion later.

***

### Step 2: Confirm the Conversion <a href="#h_91e03547bb" id="h_91e03547bb"></a>

Once the user completes your desired action, send a call to your unique postback URL.

```
GET https://postbacks.sparkloop.app/{:UNIQUE_TOKEN}?sl_click_id={sl_click_id}
```

You'll find your unique postback URL under your offer's "Conversion Pixel" instructions.

Replace  `{sl_click_id}` with the `sl_click_id` parameter from Step 1.

***

Important Notes

* Action conversions expire after 45 days if not confirmed
* Make sure to confirm conversions as soon as the user completes your desired action