The Orchestrator › Models › OpenAI
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...
Specifications
| Provider | OpenAI |
| Model ID | openai/gpt-5.1-codex-max |
| Context window | 400K tokens (400,000) |
| Modalities | text + image → text |
| Tokenizer | GPT |
| Router sources | OpenRouter, Vercel AI Gateway |
| Released | 2025-12-04 |
| Tracked since | 2026-11-14 |
| Popularity | Not in the ranked set |
| Reasoning | Mandatory |
Pricing (per million tokens)
| Variant | Source | API ID | Input | Output | Context |
|---|---|---|---|---|---|
| standard | OpenRouter | openai/gpt-5.1-codex-max | $1.25 | $10.00 | 400K |
| standard | Vercel AI Gateway | openai/gpt-5.1-codex-max | $1.25 | $10.00 | 400K |
Recorded price history
| Date | Input / 1M | Output / 1M | Context |
|---|---|---|---|
| 2026-11-14 | $1.25 | $10.00 | 400K |
| 2026-11-14 | $1.25 | $10.00 | 400K |
Capabilities
Vision (image input)Agentic tool useStructured outputsReasoning (always on)256K+ context windowControllable reasoningZero data retentionNo training on inputs (attested)
Trust flags come from TrustedRouter's per-provider attestations.
Supported parameters
include_reasoning, max_completion_tokens, reasoning, reasoning_effort, response_format, seed, structured_outputs, tool_choice, tools, verbosity