---
title: Identifying the parameters in a postback
framework: adattributionkit
role: article
role_heading: Article
path: adattributionkit/identifying-the-parameters-in-a-postback
---

# Identifying the parameters in a postback

Interpret postback properties to understand the attribution report.

## Overview

Overview The lists in this article describe all the possible parameters you can get in a postback. To verify that Apple signed the postback, see Verifying a postback. Understand the JSON stanza the framework sends The JSON stanza your servers receive resembles the following: {   "jws-string": "eyJraWQiOiJhcHBsZS1kZXZlbG9wbWVudC1pZGVudGlmaWVyXC8xIiwiYWxnIjoiRVMyNTYifQ.eyJwb3N0YmFjay1pZGVudGlmaWVyIjoiODU1NDZFQjctRkQzOS00NEJDLTg5OTAtQzk4QTRBQzM2QTQ5IiwicHVibGlzaGVyLWl0ZW0taWRlbnRpZmllciI6MCwibWFya2V0cGxhY2UtaWRlbnRpZmllciI6ImNvbS5hcHBsZS5BcHBTdG9yZSIsImltcHJlc3Npb24tdHlwZSI6ImFwcC1pbXByZXNzaW9uIiwiYWQtbmV0d29yay1pZGVudGlmaWVyIjoiZGV2ZWxvcG1lbnQuYWRhdHRyaWJ1dGlvbmtpdCIsImRpZC13aW4iOnRydWUsInBvc3RiYWNrLXNlcXVlbmNlLWluZGV4IjowLCJjb252ZXJzaW9uLXR5cGUiOiJyZS1lbmdhZ2VtZW50Iiwic291cmNlLWlkZW50aWZpZXIiOiIxMjM0IiwiYWR2ZXJ0aXNlZC1pdGVtLWlkZW50aWZpZXIiOjEwNzM4MDI3NzU2fQ.bAdNwKd6OfHK9tofvjjua4X_JPcFTxXPQSspD9gZkinw97pY7R1aI-LSjl-oxZZF3_K2H5JK5TSEBee4_1U4oQ",   "conversion-value": 24,   "ad-interaction-type": "click",   "country-code": "US" } The keys in this stanza may include: Examine the JWS header for the encryption algorithm and key identifier The JWS header of the postback consists of two parameters and resembles the following structure: {   "kid": "apple-development-identifier/1",   "alg": "ES256" } The keys for this structure are: Examine the JWS payload of the postback The JWS decoded payload of the postback resembles the following structure: {   "postback-identifier": "85546EB7-FD39-44BC-8990-C98A4AC36A49",   "publisher-item-identifier": 0,   "marketplace-identifier": "com.apple.AppStore",   "impression-type": "app-impression",   "ad-network-identifier": "development.adattributionkit",   "did-win": true,   "postback-sequence-index": 0,   "conversion-type": "re-engagement",   "source-identifier": "1234",   "advertised-item-identifier": 10738027756 } The keys the framework delivers in this structure may include the following: Examine the postback’s JWS signature The signature is a combination of the JSON Web Signature (JWS) header and payload components that Apple signs using its private key. For more information about verifying the postback’s signature, see Verifying a postback. For more information about receiving postbacks, see Receiving postbacks in multiple conversion windows. Understand the crowd anonymity controlled properties To help ensure crowd anonymity, Apple assigns a postback data tier to app downloads. The postback data tier determines whether certain parameters appear in the postback, as well as the number of digits in the hierarchical source identifier. The following postback parameters are subject to the postback data tier: coarse-conversion-value conversion-value source-identifier (affects the number of digits the postback returns) publisher-item-identifier marketplace-identifier country-code

## See Also

### Postback verification and parameter identification

- [Verifying a postback](adattributionkit/verifying-a-postback.md)