RTB API: Reasons for UNKNOWN_ID and BAD_COOKIE

[Bharath Maroli]

Hey team,

I am using this API for bulk upload as per this document. document.

This is the API that i am trying to use

curl --location 'https://cm.g.doubleclick.net/upload?nid=adnear_ddp' \
--header 'Content-Type: application/json' \
--data '{
  "UserDataOperation":[{
    "user_id":"137C651C-2771-4AC0-AA10-4AFC378E063E",
    "user_id_type":"ANDROID_ADVERTISING_ID",
    "user_list_id":"9200941806"
  },
  {
    "user_id":"1531C099-5885-4D35-B8E6-4EE3F8611DB1",
    "user_id_type":"IDFA",
    "user_list_id":"9200941806"
  }],
  "send_notifications": false,
  "process_consent": true
}'

The payload for the curl is sent as a byte array serialized using the proto file provided in the document.

As a sample I have sent 100 IDs (in the curl only 2 are provided). And the response for the request was "Partial Success" as mentioned in the document.

In the response body while traversing the error list (which I believe you return for those IDs which were not successful) for the individual IDs I am getting the error_code as  `unknown_id` and `bad_cookie`. sample error list response provided below.

[user_id: "137C651C-2771-4AC0-AA10-4AFC378E063E"
error_code: BAD_COOKIE
user_id_type: ANDROID_ADVERTISING_ID
, user_id: "1531C099-5885-4D35-B8E6-4EE3F8611DB1"
error_code: UNKNOWN_ID
user_id_type: IDFA
]

we know that IDs which have an error_code as `UNKNOWN_ID`, the IDs are not present in your system.

Wanted to know for which situation does the ID get the error_code as BAD_COOKIE ?

also needed your assistance for the following
1) is there any way to recognize those IDs for whom the status was UNKNOWN_ID ?
2) For the IDs which return as BAD_COOKIE is there anything that I should pass extra in the payload for it to be successful ?

Regards
Bharath Maroli

[Authorized Buyers API Forum Advisor]

Hello Bharath,

Thanks for reaching out.

In your first example, the ID 137C651C... is an iOS IDFA, but the user_id_type was sent as ANDROID_ADVERTISING_ID. This format mismatch is the likely cause of the BAD_COOKIE error.

For your second example, the UNKNOWN_ID error most commonly occurs when there is no matching user ID in our system.

Could you confirm if cookie matching has been performed for all the IDs you are sending?

 

Thanks,
 

Joshua Authorized Buyers API Team

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[2025-09-30 16:46:21Z GMT] This message is in relation to case "ref:!00D1U01174p.!500Ht01u7iK7:ref" (ADR-00333845)