GPT 5.1 Codex Max
openai/gpt-5.1-codex-maxGPT 5.1 Codex Max (openai/gpt-5.1-codex-max) is an AI model from OpenAI with a 272,000-token context window and 128,000 max output tokens, priced at $1.25/1M input and $10.00/1M output tokens. Available via the haimaker.ai OpenAI-compatible API.
Overview
OpenAI's highest-capacity Codex model with maximum context and compute for large-scale code generation and agentic software engineering.
Features & Capabilities
| Mode | responses |
| Context Window | 272,000 tokens |
| Max Output | 128,000 tokens |
| Function Calling | Supported |
| Vision | Supported |
| Reasoning | Supported |
| Web Search | Supported |
| Url Context | - |
API Usage
from openai import OpenAI
client = OpenAI(
base_url="https://api.haimaker.ai/v1",
api_key="YOUR_API_KEY",
)
response = client.chat.completions.create(
model="openai/gpt-5.1-codex-max",
messages=[
{"role": "user", "content": "Hello, how are you?"}
],
)
print(response.choices[0].message.content)Frequently Asked Questions
What is the context window of GPT 5.1 Codex Max?
GPT 5.1 Codex Max (openai/gpt-5.1-codex-max) has a 272,000-token context window and supports up to 128,000 output tokens per request.
How much does GPT 5.1 Codex Max cost?
GPT 5.1 Codex Max is priced at $1.25 per 1M input tokens and $10.00 per 1M output tokens when accessed via the haimaker.ai OpenAI-compatible API.
What features does GPT 5.1 Codex Max support?
GPT 5.1 Codex Max supports function calling, vision, reasoning, web search.
How do I use GPT 5.1 Codex Max via API?
Send requests to https://api.haimaker.ai/v1/chat/completions with model "openai/gpt-5.1-codex-max" using any OpenAI-compatible SDK. Authentication uses a Bearer API key from https://app.haimaker.ai.
Use GPT 5.1 Codex Max with the haimaker API
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