IAP response code 4 and receipt null with Amazon Appstore DevTest

[dyang-fubo]

Bug Description

---

1. Summary

I’m trying to test IAP with Amazon Appstore DevTest.

When I’m trying to purchase an item, I have the expected screens that takes me through the purchase flow. But in the end, when redirected to my app, I have no receipt and return code stating “failed”.

App Name: Molotov UAT
App Link on Amazon Appstore: https://www.amazon.com/gp/product/B0FPMQL765

Bug Severity
Select one that applies

• Impacts operation of app
• Blocks current development
• Improvement suggestion
• Issue with documentation (If selected, please share the doc link and describe the issue)
• Other

2. Steps to Reproduce

1. Build the app in debug
2. Resign the app with the certificate setup for Amazon Appstore DevTest
3. Purchase an item

3. Observed Behavior

IAP flow ends with success but returns a failure response and no receipt.

{
  "receipt": null,
  "requestId": {
    "requestIdStr": "580ac8c4-66b9-4c46-977c-23cf04bacd5e"
  },
  "responseCode": 4,
  "userData": {
    "userId": "5dccA8n2qgKSeTWsKSfpkqKTdrVUAbURmR5gYNeC8qA=",
    "marketplace": "FR",
    "lwaConsentStatus": 1,
    "userProfileAccessConsentStatus": 1
  }
}

4. Expected Behavior

Response Code should be 0 and receipt not null.

4.a Possible Root Cause & Temporary Workaround

N/A

5. Logs or crash report

N/A

6. Environment

• SDK Version: 0.22.5875

• App State: Foreground

• OS Information:

NAME="OS"
OE_VERSION="4.0.0"
OS_MAJOR_VERSION="1"
OS_MINOR_VERSION="1"
RELEASE_ID="14"
OS_VERSION="1.1"
BRANCH_CODE="TV Ship day60"
BUILD_DESC="OS 1.1 (TV Ship day60/101)"
BUILD_FINGERPRINT="4.0.249302.0(3072cab629675a74)/101N:user/release-keys"
BUILD_VARIANT="user"
BUILD_TAGS="release-keys"
BUILD_DATE="Sat Mar 14 22:24:12 UTC 2026"
BUILD_TIMESTAMP="1773527052"
VERSION_NUMBER="1401010010120"

[amen]

Hi @dyang-fubo,

Thank you for the detailed bug report on the IAP response code 4 issue with Amazon Appstore DevTest.

Our team is investigating this issue and will provide an update as soon as we have more information. Could you please share the relevant logs from your app to help us diagnose the issue further?

Thanks for helping us improve the Vega platform.

Warm regards,
Aishwarya

[amen]

Hi @dyang-fubo,

Could you please provide the relevant device logs (journalctl/syslog) that cover the timeframe when you encountered this issue?

Additionally, it would be helpful if you could share:

• The exact timestamp when the purchase failure occurred

• Any app-level logs showing the IAP transaction flow

This information will help our team diagnose why the purchase flow is completing successfully but returning a failure response with no receipt.

Thanks for your patience as we work to resolve this.

Best regards,
Aishwarya

[dyang-fubo]

Here are our app logs showing the IAP transaction flow.

 (NOBRIDGE) DEBUG   🐞 IAPManager: Purchasing AMAZON_UAT_2_KITCHEN_MANIA_TBCC_7J_1_99_TERMS
 (NOBRIDGE) DEBUG   🐞 IAPManager: Handling Purchase response... {
  "receipt": null,
  "requestId": {
    "requestIdStr": "f0ccf0e9-ae09-4599-be88-40dfc7f89e36"
  },
  "responseCode": 4,
  "userData": {
    "userId": "5dccA8n2qgKSeTWsKSfpkqKTdrVUAbURmR5gYNeC8qA=",
    "marketplace": "FR",
    "lwaConsentStatus": 1,
    "userProfileAccessConsentStatus": 1
  }
}
 (NOBRIDGE) DEBUG   🐞 IAPManager: Could not purchase AMAZON_UAT_2_KITCHEN_MANIA_TBCC_7J_1_99_TERMS: Purchase failed
 (NOBRIDGE) WARN   ⚠️  1776158898148 IAB: Error purchasing product Purchase failed

The exact timestamp after the failure is logged as : 1776158898148 (Tue Apr 14 2026 11:28:18 GMT+0200 (Central European Summer Time)).

To add more info about the issue, I’m receiving an email confirmation from Amazon about the subscription, so it looks like the purchase is ok on Amazon Appstore DevTest… But I’m not getting a successful response status code or any receipt.

[amen]

Hi @dyang-fubo,

Thank you for sharing the detailed app logs and timestamp information. I’ve passed these details on to our team for investigation.

Could you please provide the complete device logs (journalctl/syslog) that cover the timeframe around 04/14/2026 11:28:18 GMT+0200? This will help us diagnose why the purchase is completing on Amazon Appstore DevTest but returning response code 4 with a null receipt.

Thanks for your patience as we work to resolve this.

Best regards,
Aishwarya

[dyang-fubo]

Hello @amen

I don’t have access to those logs anymore, but I reproduced the issue. Here are some fresh logs from the app and from the device.

Item SKU : AMAZON_UAT_2_EXPLORE_3_99_TERMS
Purchase initiated at timestamp 1776256742974 : ‘Wed Apr 15 2026 14:39:02 GMT+0200 (Central European Summer Time)’
Purchase failure response at timestamp 1776256759399 : ‘Wed Apr 15 2026 14:39:19 GMT+0200 (Central European Summer Time)’

app_logs.txt (910 Bytes)
device_logs.txt (400.7 KB)

[amen]

Hi @dyang-fubo,

Thanks for sharing the fresh logs. Our investigation confirms the subscription was successful on the server side - the issue appears to be on the client/SDK side, which is why the receipt is coming back as null.

The attached logs are incomplete and don’t include the full IAP process flow. Could you please share the complete logs in fresh terminal session covering the entire purchase journey?

Thanks for your patience.

Best regards,
Aishwarya

[dyang-fubo]

Please let me know what you expect as “complete logs”.

I used loggingctl log -f and shared the logs before and after the IAP purchase.

[amen]

Hi @dyang-fubo,

Thanks for the clarification. By “complete logs,” we mean logs captured from a fresh terminal session (not from an IDE terminal or iTerm) that cover the entire purchase journey from start to finish - including initialization, the purchase attempt, and the response.

Using loggingctl log -f is fine, but please make sure the session is started fresh before initiating the purchase so no log entries are missed.

Best regards,
Aishwarya

[dyang-fubo]

Hello.

Here a more logs, starting before the app is even launched.

SKU: AMAZON_UAT_2_SOCIETY_PLUS_4_90_TERMS
Purchase initiated at 2026-04-22T13:14:18.056Z
Purchase failure at 2026-04-22T13:14:32.295Z (no receipt id received)

I received an email confirmation that the purchase was successful.

device_logs_20260422.txt (1.4 MB)
app_logs_20260422.txt (829 Bytes)