GPT-5.1-Codex-Max
by OpenAItext+image->text1 endpoint
Overview
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
Text generation
Image understanding
Tool use / Function calling
Structured output
Extended reasoning
Prompt caching
Long context
Deterministic seed
Modalities
Input
TextImage
Output
Text
Technical Specifications
Context Window
400K tokens
Max Output
128K tokens
Tokenizer
GPT
Uptime (24h)
10000.0%
Supported Parameters
include_reasoningmax_completion_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choicetools
Pricing
Per 1M tokens
Input$1.25
Output$10.00
Cache read$0.13
Added
December 4, 2025
Last synced 9/16/2026