OpenAI GPT-5.1 - Box Dev Docs

According to OpenAI, OpenAI GPT-5.1 is a multimodal model designed for coding and agentic tasks with configurable reasoning effort.

Model details

Item	Value	Description
Model name	GPT-5.1	The name of the model.
Model category	Premium	The category of the model: Standard or Premium.
API model name	`openai__gpt_5_1`	The name of the model that is used in the . The user must provide this exact name for the API to work.
Compliance	N/A	Government compliance frameworks and authorizations applicable to this model.
Hosting layer	OpenAI	The trusted organization that securely hosts the LLM.
Model provider	OpenAI	The organization that provides this model.
Release date	November 13th, 2025	The release date for the model.
Knowledge cutoff date	September 30th, 2024	The date after which the model does not get any information updates.
Input context window	400k tokens	The number of tokens supported by the input context window.
Maximum output tokens	128k tokens	The number of tokens that can be generated by the model in a single request.
Empirical throughput	Not specified	The number of tokens the model can generate per second.
Open source	No	Specifies if the model’s code is available for public use.