[09366768] OpenAI Ads API "503: Authentication backend failure"

API Bugs
,
1

Using POST endpoint /v1/events?pid=PIXEL_ID with proper API key (from conversions page, with ads_third_party_events scope) is throwing the following 503 error:

{
    "error": {
        "message": "503: Authentication backend failure",
        "type": "server_error",
        "param": null,
        "code": null
    }
}

Already tried with multiple correctly-formatted payloads.

Looks like a backend issue on your side. Is this a known issue?

Thank you

2

Hey @andrei-akiflow :waving_hand:

Thanks for reaching out!

We’re looking into this. 503: Authentication backend failure on POST /v1/events points to the auth/backend path for the Ads Events API, so this may be on our side rather than an issue with your payload.

Could you share:

  • the approximate timestamp of a failing request, including timezone

  • whether it is still reproducing

  • the endpoint host you called

  • any x-request-id or trace/request ID returned in the response headers

Please don’t post API keys, full payloads, or anything account-sensitive here. If you need to share sensitive details, email ads-support@openai.com and include this forum thread.

3

It is still happening as of now (29-05-2026 16PM EEST), but also since this morning 9AM EEST.
Endpoint POST bzr[dot].openai[dot].com (cannot post urls, but it’s the same exact one from docs and mentioned in OP)

Response headers:

  • openai-version: 2020-10-01
  • x-request-id: 9e58f4f0-d4f5-95b7-a695-7682cfec212a

Let me know if you need anything else

4

Hey @andrei-akiflow — thanks, that was enough to trace this.

I checked the request ID you shared, and the request did reach our Ads Events API backend. The 503 came from our auth/dependency path, so this is not looking like a payload-format issue on your side.

We’re investigating this internally now. No need to post any more details publicly for the moment. If we need account-specific information, I’ll ask you to move that to ads-support@openai.com.

5

Looks like something changed on your backend, and now I’m getting:
{
“error”: {
“message”: “Unauthorized”,
“type”: “invalid_request_error”,
“param”: null,
“code”: null
}
}

x-request-id: dab411fb-f62b-4203-82f5-8056b0aeb498

6

@siddhant any news? thanks

7

Hey @andrei-akiflow :waving_hand:

Thanks for following up, and apologies for the delay in response, we had a bank holiday here yesterday.

I checked the newer request ID you shared, and this latest request is reaching our backend but being rejected as Unauthorized rather than failing with the earlier 503.

At this point, the main thing to verify is that the Authorization header is using a Conversions API key from the Conversions page, not a pixel/client-data-source key. Please don’t post the key here.

If you’re already using a Conversions API key and still seeing this, please email ads-support@openai.com with the x-request-id, the pid used in /v1/events?pid=…, and a note confirming which key type you used, and send me the case ID here so that we can continue from there.

8

Using the api key prior the fix didn’t work. I’ve regenerated the key and it’s now working.

Thank you