# Reasoning\_effort not working

**URL:** <https://community.openai.com/t/reasoning-effort-not-working/1144107>\
**Category:** API\
**Tags:** api\
**Created:** [March 15, 2025, 11:47pm UTC](https://community.openai.com/t/reasoning-effort-not-working/1144107 "2025-03-15T23:47:03Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![mgbcsw13](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/mgbcsw13/32/565235_2.png) [@mgbcsw13](https://community.openai.com/u/mgbcsw13)\
**Post date:** [March 15, 2025, 11:47pm UTC](https://community.openai.com/t/reasoning-effort-not-working/1144107/1 "2025-03-15T23:47:03Z")

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am getting the following error when giving the reasoning\_effort parameter to o1-preview: {‘error’: {‘message’: “Unknown parameter: ‘reasoning\_effort’.”, ‘type’: ‘invalid\_request\_error’, ‘param’: ‘reasoning\_effort’, ‘code’: ‘unknown\_parameter’}}  
attached is a screenshot of my code. is it not supported for structured output or something?

 ![Screenshot 2025-03-15 at 4.46.33 PM](https://us1.discourse-cdn.com/openai1/original/4X/3/2/d/32dbb170aa47460c9e0cf0536b6aa9a8b785f010.png)

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**Author:** ![\_j](https://sea2.discourse-cdn.com/openai1/user_avatar/community.openai.com/_j/32/766292_2.png) [@\_j](https://community.openai.com/u/_j)\
**Post date:** [March 16, 2025, 2:09am UTC](https://community.openai.com/t/reasoning-effort-not-working/1144107/2 "2025-03-16T02:09:55Z")

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o1-preview and o1-mini do not support reasoning effort as an input.

It is only on the newly-released ‘o1’ and ‘o3-mini’ that have that.

These models also have a smaller feature set. You’ll also have to stick to chat completions and not sending system messages, among others, like _no structured outputs_…