OpenAI GPT-5.5 - Box Dev Docs

According to OpenAI, OpenAI GPT-5.5 is a frontier model for the most complex professional work. It raises the baseline for complex production workflows. It is a strong fit for coding use cases, tool-heavy agents, grounded assistants, long-context retrieval, product-spec-to-plan workflows, and customer-facing workflows where execution quality and response polish are critical.

Model details

Item	Value	Description
Model name	GPT-5.5	The name of the model.
Model category	Premium	The category of the model: Standard or Premium.
API model name	`openai__gpt_5_5`	The name of the model that is used in the . You 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	April 23, 2026	The release date for the model.
Knowledge cutoff date	December 01, 2025	The date after which the model does not get any information updates.
Input context window	1m 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.

Additional documentation

For additional information, see .

Last modified on May 27, 2026

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Model details

Additional documentation