[mewpmewp2]

I think you should be able to do it out of the box if you just keep sending the tokens, and after that ask the GPT "is there a mistake? Respond with just "yes" or "no". Why does there have to be something like a "null" token?

However it might seem expensive yes, but at least it only has to respond with one token.

[edgyquant]

There’s a null token because the question was about you not having to ask if there was a mistake. It would just default to constantly producing a null token until it had a real response