Official model documentation
Fields: model identity
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…
- Context
- 400K
- Max output
- 128K
- Input
- $1.25
- Output
- $10
Recommended use cases
Strengths in this dataset
- 400,000-token context window
- text, image input
- 9 supported API parameters listed
Limits and caveats
- Provider behavior and pricing can change; verify the linked sources before production use.
Capability
Model-native facts
Model- Reasoning
- Supported
- Open weights
- Unknown
Provider endpoint facts
Provider endpoint- Tool calling
- Supported
- Structured output
- Supported
- Streaming
- Unknown
- Prompt cache
- Supported
- Batch
- Unknown
- Fine-tuning
- Unknown
GPT-5.1-Codex-Max Provider pricing
Provider endpoint: openai/gpt-5.1-codex-max
- Input
- $1.25 per 1M tokens
- Output
- $10 per 1M tokens
- Cached input
- $0.125 per 1M tokens
- Image output
- Unknown per 1M tokens
Sources and verification
OpenRouter Models API
Fields: identity, description, modalities, context window, maximum output, pricing, supported parameters
Frequently asked questions
Answers are generated from the same sourced model and provider facts shown above.
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…
Model specifications and prices may vary by provider and change over time. AIToolly displays sources and verification dates so users can confirm critical details before production use.