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openaiOpenAI: GPT-5.1-Codex-Max
GPT-5.1-Codex-Max is OpenAI’s latest agentic coding model, designed for long-running, high-context software development tasks. It is based on an updated version of the 5.1 reasoning stack and trained on agentic workflows spanning software engineering, mathematics, and research. GPT-5.1-Codex-Max delivers faster performance, improved reasoning, and higher token efficiency across the development lifecycle.
openai/gpt-5.1-codex-max
Context Size
400K
Input Price
7,687.5 Ks/M
Output Price
61,500 Ks/M
Architecture
Text
Image
Supported Parameters
include_reasoningmax_tokensreasoningresponse_formatseedstructured_outputstool_choicetools
Details
TokenizerGPT
Max Completion128,000 tokens
Provider Context400K tokens
ModeratedYes