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OpenAI's Decisions API does not charge for output, at $0.10 per million input tokens

2026/10/19

OpenAI released the Decisions API in beta on 6 October 2026⁠[1]. Given text or images, it returns typed answers: the probability that a condition is true, one option from a fixed set, or a score against a rubric⁠[2].

According to OpenAI, it answers about 10 times faster than the Responses API⁠[1,2]. gpt-6-luna is currently the only model, and the endpoint is POST /v1/decisions⁠[2]. OpenAI expects general availability in the coming weeks⁠[2].

Only input tokens are billed, at $0.10 per million⁠[2]. There are no charges for output, cache reads or cache writes⁠[2]. Used normally, gpt-6-luna costs $0.50 per million output tokens⁠[1].

Regional processing premiums and long-context input multipliers still apply to this API⁠[2]. Zero Data Retention and HIPAA use are supported for eligible customers⁠[2].

There are three question types⁠[2]. predicate returns the probability from 0 to 1 that a condition is true, choice returns one of the supplied options, and score returns the probability-weighted average of the indices of ordered levels⁠[2].

choice and score also return the probability of each option and a confidence value⁠[2]. Independent questions can be combined in one request⁠[2]. When a question depends on an earlier answer, send separate requests⁠[2].

For extracting data into your own JSON schema or generating an explanation, OpenAI points to Structured Outputs in the Responses API⁠[2].

On 15 October, GPT-Live gained the ability to call Decisions directly⁠[1]. An application can act on what a user says while the user is still speaking⁠[1].