GPT-5.1-Codex-Max coding
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...
Capabilities
Context Window 400k tokens
Max Output 128k tokens
Inputs
Outputs
Pricing (per 1M tokens)
Input $1.25
Output $10.00
Cache Read $0.12
Cache Write -
Supported Parameters
include_reasoningmax_completion_tokensmax_tokensreasoningresponse_formatseedstructured_outputstool_choicetools