OpenAI model

GPT-5.1-Codex-Max API

The Model id is openai/gpt-5.1-codex-max. It is OpenAI: GPT-5.1-Codex-Max. It has an input price of $1.25 / 1M tokens, an output price of $10 / 1M tokens, and a context window of 400000 tokens.

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OpenAIPlatform curatedCatalog
ThinkingFunction CallingVision
Input price$1.25 / 1M tokens
Output price$10 / 1M tokens
Context length400k tokens
Max output8.2k tokens

What is GPT-5.1-Codex-Max API in NextModel?

The Model id is openai/gpt-5.1-codex-max. It is OpenAI: GPT-5.1-Codex-Max. It has an input price of $1.25 / 1M tokens, an output price of $10 / 1M tokens, and a context window of 400000 tokens.

GPT-5.1 Codex Max via NextModel: 400k-token context; $1.25 / 1M tokens in / $10 / 1M tokens out per 1M tokens. Capabilities: streaming, tool, json.

Best use cases

  • Call this id for vision, long-context, or agent work.
  • Call this id when you need streaming, tool, json, vision, and long capabilities in one model.
  • Call this id when an unpublished CacheSafety score is acceptable.

When not to use

  • Do not call this id if you require a first-party CacheSafety score, because the catalog has no CacheSafety row for this exact model.
  • A required number is unpublished in the catalog snapshot.
  • You need a first-party CacheSafety score and this model does not have one.

OpenAI-compatible code example

request.sh
curl https://api.nextmodel.app/v1/chat/completions \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $NEXTMODEL_API_KEY" \
  -d '{"model":"openai/gpt-5.1-codex-max","messages":[{"role":"user","content":"Reply with OK."}]}'

Switching models only changes the model field.

Try it in the playground

Similar alternatives

OpenAICatalog

GPT-5.2

GPT-5.2 via NextModel: 400k-token context; $1.75 / 1M tokens in / $14 / 1M tokens out per 1M tokens. Capabilities: streaming, tool, json.

$1.75 / 1M tokensInput$14 / 1M tokensOutput400kContext
Best forimage understanding, multimodal chat
StreamingTool callingJSON modeVision
Platform curatedCurated and maintained in the NextModel catalog
View details
OpenAICatalog

GPT-5.1

GPT-5.1 via NextModel: 400k-token context; $1.25 / 1M tokens in / $10 / 1M tokens out per 1M tokens. Capabilities: streaming, tool, json.

$1.25 / 1M tokensInput$10 / 1M tokensOutput400kContext
Best forimage understanding, multimodal chat
StreamingTool callingJSON modeVision
Platform curatedCurated and maintained in the NextModel catalog
View details
OpenAICatalog

GPT-5.1 Codex

GPT-5.1 Codex via NextModel: 400k-token context; $1.25 / 1M tokens in / $10 / 1M tokens out per 1M tokens. Capabilities: streaming, tool, json.

$1.25 / 1M tokensInput$10 / 1M tokensOutput400kContext
Best forimage understanding, multimodal chat
StreamingTool callingJSON modeVision
Platform curatedCurated and maintained in the NextModel catalog
View details

Compare GPT-5.1 Codex Max

GPT-5.1 Codex Max vs GPT-5.2GPT-5.1 Codex Max vs GPT-5.1GPT-5.1 Codex Max vs GPT-5.1 CodexGPT-5.1 Codex Max vs GPT-5.1 Codex MiniGPT-5.1 Codex Max vs GPT-5.2 Codex

Reading

Articles that explain GPT-5.1 Codex Max

FAQ

GPT-5.1 Codex Max API questions

What model id do I send for GPT-5.1-Codex-Max?

Send openai/gpt-5.1-codex-max to https://api.nextmodel.app/v1 with your OpenAI SDK. If that id is missing from /v1/models, the page is stale.

What does the catalog list for price and context?

GPT-5.1-Codex-Max is listed at $1.25 / 1M tokens input and $10 / 1M tokens output. Context window: 400000 tokens.

What should I treat as unverified?

Do not call this id if you require a first-party CacheSafety score, because the catalog has no CacheSafety row for this exact model.

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