---
title: Server-to-Server (S2S) Postback Integration
slug: server-to-server-s2s-postback-integration
icon: ↩️
docTags:
createdAt: 2025-11-15T20:12:54.493Z
---
# Overview
Server-to-Server (S2S) Postback integration allows advertisers to send measurement and conversion events directly to MomentScience from their server. This method provides a reliable way to track conversions without requiring client-side implementation on conversion pages.
When MomentScience sends traffic to your landing pages, we include an `adpx_click_id`parameter in the URL. You store this identifier with the user session, then send it back to us via postback when conversions occur.
## Key Benefits
- **No client-side dependencies:** Track conversions without JavaScript, ideal when browser-based tracking is restricted or unreliable
- **Multi-event attribution:** Record multiple conversion actions per user session with dynamic payout values
- **Privacy-compliant:** Meet GDPR/CCPA requirements with server-side data handling
- **Cross-platform support:** Works with mobile apps, backend systems, and any environment that can make HTTP requests
## Prerequisites
Before you begin, ensure you have:
- Technical capability to capture URL parameters from incoming traffic
- Server infrastructure to store click identifiers and trigger postbacks
# How S2S Postback Works
1. **MomentScience sends traffic** to your landing page with `adpx_click_id` parameter
2. **Your system captures** the `adpx_click_id` and stores it with the user session
3. **User completes an action** (purchase, signup, etc.)
4. **Your server sends a postback** to MomentScience with conversion details
# Integration Steps
## Step 1: Capture the Click ID from Incoming Traffic
When MomentScience sends traffic to your landing page, capture the `adpx_click_id` parameter from the URL and store the `adpx_click_id` value with the user's session. The method depends on your technology stack.
The `adpx_click_id` must be stored reliably. If this value is lost, you won't be able to attribute conversions back to MomentScience.
Example Landing Page URL
:::BlockQuote
https\://yourdomain.com/landing-page?adpx\_click\_id=abc123def456\&other\_param=value
:::
## Step 2: Configure Your Postback URL
Configure your system to send postbacks to the MomentScience tracking endpoint.
Examples:
Track a measurement event
:::BlockQuote
https://trk.pubtailer.com/track/?click-id={ADPX_CLICK_ID}&measurement=1&event={EVENT}
:::
Track a payable event (CPA only)
:::BlockQuote
https://trk.pubtailer.com/track/?click-id={ADPX_CLICK_ID}&measurement=1&event={EVENT}&payout={PAYOUT}
:::
Track a payable event with sale value (ROAS)
:::BlockQuote
https://trk.pubtailer.com/track/?click-id={ADPX_CLICK_ID}&measurement=1&event={EVENT}&payout={PAYOUT}&sale_amount={AMOUNT}
:::
:::hint{type="info"}
For the event parameter, you can use any event identifier that your offer supports. Common choices include `mosci`, `conversion`, `purchase`, or any custom event name.
:::
### URL Parameters Reference
| **Parameter** | **Type** | **Required** | **Description** |
| ------------- | -------- | ------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `click-id` | String | Yes | The `adpx_click_id` value received from incoming traffic |
| `measurement` | Integer | Conditional | Must be set to `1`. Required whenever you send an `event`, with or without a `payout`. |
| `event` | String | Conditional | Event type identifier (e.g., `purchase`, `signup`, `conversion`). Required for event-based and variable payout tracking; can be sent without `payout` for no-payout event tracking. |
| `payout` | Decimal | Conditional | Payout amount for the conversion in USD (e.g., `25.50`). Only required when the event carries a payout, omit it for no-payout event tracking. |
| `sale_amount` | Decimal | No | Sale amount for CPS goal tracking. |
## Step 3: Trigger Postbacks on Conversion Events
When a user completes a conversion action, send a postback to MomentScience with the stored `adpx_click_id`.
### Example Postback URLs
Signup Event (No Payout)
:::BlockQuote
curl -X GET "https\://trk.pubtailer.com/track/?click-id=abc123def456\&measurement=1\&event=signup"
-H "Accept: */*"
-H "Cache-Control: no-cache"
:::
Purchase Event with Payout
:::BlockQuote
curl -X GET "https\://trk.pubtailer.com/track/?click-id=abc123def456\&measurement=1\&event=conversion\&payout=25.00"
-H "Accept: */*"
-H "Cache-Control: no-cache"
:::
Lead Generation
:::BlockQuote
curl -X GET "https\://trk.pubtailer.com/track/?click-id=abc123def456\&measurement=1\&event=lead\&payout=5.00"
-H "Accept: */*"
:::
Subscription with Payout and Sale Amount (for CPS)
:::BlockQuote
curl -X GET "https\://trk.pubtailer.com/track/?click-id=abc123def456\&measurement=1\&event=subscription\&payout=29.99\&sale\_amount=149.99"
-H "Accept: */*"
:::
:::hint{type="warning"}
Use lowercase event names with underscores (e.g., `profile_complete`, `trial_start`). Keep names descriptive but concise, avoid special characters except underscores, and limit to 50 characters maximum.
:::
:::hint{type="success"}
You can send multiple postbacks for the same `adpx_click_id` if multiple conversion events occur. For example, a user might sign up (first event) and then make a purchase (second event) within your defined conversion window.
:::
# Postback Response Codes
MomentScience returns HTTP status codes to indicate the result of your postback request:
| **Status Code** | **Meaning** | **Action Required** |
| ---------------- | -------------------------------- | ------------------------------------------ |
| `200 OK` | Conversion successfully recorded | No action needed. Do not resend. |
| Any other status | Request failed or error occurred | Retry the request with exponential backoff |
:::hint{type="warning"}
Only retry postbacks that receive a non-200 status code. If you receive a `200 OK` response, the conversion has been recorded successfully and should not be sent again.
:::
***
If you encounter any issues during integration or have questions about S2S postback tracking, contact us [help@momentscience.com](mailto\:help@momentscience.com).