OpenAI: GPT-5.1 Codex Max
Chat-20%openai/gpt-5.1-codex-maxGPT-5.1 Codex Max is OpenAI's agentic coding model, released on 2025-12-04 and 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 workflows spanning software engineering, mathematics, and research. Capabilities include reasoning, tool use, prompt caching, web search, and multimodal input covering images, audio, and video. Context window: 256K tokens, output: 128K. Cached input is billed at $0.13/M tokens against $1.25/M for standard input, which keeps long agent sessions that reuse the same repository context affordable. Accessible via the OpenAI-compatible protocol through Ofox.
Context Window
256K
Max Output Tokens
128K
Released
2025-12-04
Capabilities
VisionFunction CallingReasoningPrompt CachingWeb SearchAudio InputVideo Input
Available Providers
Azure
Supported Protocols
openai
Providers
Azure
-20%Input Tokens
$1/M
$1.25/M
Output Tokens
$8/M
$10/M
Cache Read
$0.104/M
$0.13/M
Web Search
$0.035/R
Protocols
openai
/v1/chat/completions/v1/responsesCode Examples
from openai import OpenAIclient = OpenAI(base_url="https://api.ofox.ai/v1",api_key="YOUR_OFOX_API_KEY",)response = client.chat.completions.create(model="openai/gpt-5.1-codex-max",messages=[{"role": "user", "content": "Hello!"}],)print(response.choices[0].message.content)
Related Models
Frequently Asked Questions
OpenAI: GPT-5.1 Codex Max on Ofox.ai costs $1.25/M per million input tokens and $10/M per million output tokens. Pay-as-you-go, no monthly fees.
OpenAI: GPT-5.1 Codex Max supports a context window of 256K tokens with max output of 128K tokens, allowing you to process large documents and maintain long conversations.
Simply set your base URL to https://api.ofox.ai/v1 and use your Ofox API key. The API is OpenAI-compatible — just change the base URL and API key in your existing code.
OpenAI: GPT-5.1 Codex Max supports the following capabilities: Vision, Function Calling, Reasoning, Prompt Caching, Web Search, Audio Input, Video Input. Access all features through the Ofox.ai unified API.