I've been sticking with the chat completion endpoint because of this same behavior. OAI has been subtly pushing users away from chat completion and toward the endpoints that are possible to obfuscate (responses API).

With chat completion, the reasoning process is entirely under your control. You can build a reasoning agent that uses custom MCTS techniques with GPT5.6 models today if you are willing to get your hands just a little bit dirty. You have to enable experimental flags and set options in slightly confusing ways, but it still works.

You can use models up to gpt5.5 with custom API tokens and model configuration in VS Copilot. gpt5.6 family (currently) no longer work in this setup. Presumably, because we aren't explicitly forcing reasoning_effort to none to satisfy the new moat expansion behavior.

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Dangeranger an hour ago | parent | next [-]

Definition provided below for others like myself who abhor acronyms:

MCTS -> Monte Carlo Tree Search

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dannyw 2 hours ago | parent | prev | next [-]

> MCTS techniques

what does that mean?

> the reasoning process is entirely under your control

you're still dealing with summarised thinking, no, which is kinda useless as it's way too high level?

	▲	bob1029 2 hours ago \| parent [-]
		https://arxiv.org/abs/2503.04412

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ATMLOTTOBEER 3 hours ago | parent | prev | next [-]

Can you not abuse “mcts” as a buzzword like this

The thing you’re gesturing at isn’t mcts in any real sense

	▲	bob1029 2 hours ago \| parent \| next [-]
		You can absolutely apply most of the meaningful principles of MCTS to this problem. LLMs do violate certain "strict" properties but I still see a lot of practical value in this kind of thinking.
	▲	next_xibalba 2 hours ago \| parent \| prev [-]
		You could replace “gesturing at” with “describing,” then explain why the description is technically wrong.

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gizmodo59 4 hours ago | parent | prev [-]

responses api provided many benefits over chat completions https://developers.openai.com/api/docs/guides/migrate-to-res.... Any reasoning model which is all the new models these days should use responses as per the recommendation

	▲	bob1029 4 hours ago \| parent [-]
		I'm well aware of what the official propaganda states but this is simply not a fair characterization of reality. Responses integration will lock you into OAI much more deeply than chat completion integration will. I can easily swap my inference provider right now. The business is not interested in a form of integration that is difficult to swap.