AI Observatory / Model Radar
OpenAI / openai/gpt-5.1-codex-max
OpenAI: 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...
400,000
Context
128,000
Max output
$1.25 / 1M
Prompt price
2025-12-04
Created
01 / Snapshot
Pricing, context, modalities, and parameters.
Model Radar detail pages stay neutral and operator-readable: core metadata first, then workflow fit.
| Provider | OpenAI | Input modalities | text, image |
|---|---|---|---|
| Output modalities | text | Prompt price | $1.25 / 1M |
| Completion price | $10.00 / 1M | Request price | N/A |
| Context length | 400,000 | Max completion tokens | 128,000 |
| Supported parameters | include_reasoning, max_completion_tokens, max_tokens, reasoning, response_format, seed, structured_outputs, tool_choice, tools | ||
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openai/gpt-5.1-codex-max
OpenAI: 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...
Deep analysis
Coding workflows
Cross-modal work
Long context
vision
tool-capable
long-context
low-cost
03 / Colophon
Routes and exits.
Each model page stays simple: overview, compare, related models, then back to the public hub.