Remember reinforcement fine-tuning? We’ve been working away at it...

Remember reinforcement fine-tuning? We’ve been working away at it since last December, and it’s available today with OpenAI o4-mini! RFT uses chain-of-thought reasoning and task-specific grading to improve model performance—especially useful for complex domains. Take @AccordanceAI, which used RFT to fine-tune a model that’s SOTA for their tax and accounting purposes.

And in supervised fine-tuning news: you can now fine-tune GPT-4.1 nano. Get even more from our fastest, cheapest model by training it specifically for your use-case.
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RFT is available to verified organizations today. Share your datasets with us to receive a 50% discount and help improve future OpenAI models.

Get started with our reinforcement fine-tuning guide: platform.openai.com/docs/guides/rf…