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OpenAI: GPT-5.1-Codex-Max
openai/gpt-5.1-codex-max
VisionTool useJSONReasoningStreaming
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...
Pricing
Input
$1.25 / 1M
Output
$10.00 / 1M
Specs
Context
400,000 tokens
Input
text, image
Output
text
Released: 2025-12
Supported parameters
include_reasoningmax_completion_tokensmax_tokensreasoningresponse_formatseedstructured_outputstool_choicetools