[SOLVED] Realtime SIP calls: /accept returns 200, WebSocket returns 404

API Bugs
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1

Is anyone else seeing Realtime SIP incoming calls fail today?

Since around 2026-05-23 16:41 UTC, we receive realtime.call.incoming, call /v1/realtime/calls/{call_id}/accept, and get 200 OK. But immediately after, connecting to:

wss://api.openai.com/v1/realtime?call_id={call_id}

fails with:

Error during WebSocket handshake: Unexpected response code: 404

This has affected dozens of calls for us. Status page looks fine, we haven’t updated anything in our code, and the same setup has been working well for months. Is anyone else experiencing this?

2

Hi,

we’ve just been hit by the same issue. You’ve marked this as solved, can I ask what was the cause and how did you fix it?

Thanks

3

For anyone interested, it turned out to be a billing issue, the automated account recharge failed for some reason, and we ran out of credits, which resulted in websocket rejecting the connection with a 404, most likely due to SIP Invite getting rejected because of lack of credits.

4

Hi @sect2k, great you were able to find out quickly, and sorry I didn’t include a proper edit in the original post explaining it.

It was the same for us. We were suddenly on negative balance because the auto-recharge didn’t trigger. There was no invoice, no payment attempt from OpenAI. Once we added balance manually, everything returned to normal. The auto-recharge has been triggering normally since then, but we’re now monitoring the balance more closely just in case it fails again.

5

@OpenAI_Support maybe look into the automated recharge logic, as @victorm750 also mentioned, it seems as if the recharge never occurred, not that the payment failed. Looks like under the “right” conditions it never triggers.