fix(kosong): omit reasoning_effort instead of sending null when thinking is off#2476
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fix(kosong): omit reasoning_effort instead of sending null when thinking is off#2476logicwu0 wants to merge 1 commit into
logicwu0 wants to merge 1 commit into
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…ing is off
OpenAILegacy.with_thinking("off") maps to a Python None, which was passed straight
to client.chat.completions.create(). The OpenAI SDK serializes an explicit None as
"reasoning_effort": null, which is invalid in the chat-completions schema: strict
validators reject it with HTTP 400 (driving a retry/rate-limit loop) and lenient
backends treat null as "reasoning on by default", so thinking is not actually disabled.
Normalize a None reasoning_effort to the SDK omit sentinel in generate() so the field
is dropped from the payload. Adds a snapshot test asserting reasoning_effort is absent
from the request body when thinking is off.
Closes MoonshotAI#2465
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| if reasoning_effort is None: | ||
| reasoning_effort = omit |
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🚩 Kimi provider may have the same null reasoning_effort serialization issue
The Kimi provider's with_thinking("off") also sets reasoning_effort=None (kimi.py:199), and this value is passed via **generation_kwargs to self.client.chat.completions.create() at kimi.py:170-177. Unlike OpenAILegacy, there is no None → omit guard, so "reasoning_effort": null will appear in the Kimi API request payload. This may be acceptable because the Kimi API endpoint handles it differently (and the extra_body.thinking.type: "disabled" already signals the intent), but it is an inconsistency with the fix applied here.
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This was referenced Jun 27, 2026
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Summary
OpenAILegacy.with_thinking("off")maps to a PythonNone(thinking_effort_to_reasoning_effort("off")), which was passed straight toclient.chat.completions.create(reasoning_effort=...). The OpenAI SDK serializes an explicitNoneas"reasoning_effort": null— only theomitsentinel is dropped from the payload.That
nullis wrong in two ways (per #2465):nullbut treat it as "reasoning on by default", so thinking is not actually disabled.The existing auto-enable guard only handled
Omit, so aNonefromwith_thinking("off")flowed straight through.Fix
In
generate(), normalize aNonereasoning_effortto theomitsentinel before the API call, so the field is dropped from the payload entirely when thinking is off.Test
Added
test_openai_legacy_with_thinking_off_omits_reasoning_effortassertingreasoning_effortis absent from the request body afterwith_thinking("off"). It fails before the fix (body containsreasoning_effort: null) and passes after. Fulltest_openai_legacy.pysuite green;ruffclean.Closes #2465