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OpenAI: GPT-5.1-Codex-Max

OpenAI
openai/gpt-5.1-codex-max

About this model

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...

Make a request

OpenAI-compatible: set the base URL and your Promptix API key, keep your existing SDK.

curl https://promptix.tn/api/v1/chat/completions \  -H "Authorization: Bearer $PROMPTIX_API_KEY" \  -H "Content-Type: application/json" \  -d '{    "model": "openai/gpt-5.1-codex-max",    "messages": [      {"role": "user", "content": "Hello! What can you do?"}    ]  }'

Pricing

In TND per 1M tokens. VAT and the platform fee are added at top-up.

Input tokens

4.153 TND

per 1M tokens

Output tokens

33.226 TND

per 1M tokens

1,000 requests with 1K input and 500 output tokens cost about 20.766 TND.

Specifications

Provider
OpenAI
Context window
400,000 tokens
Input modality
Text
Added
Dec 4, 2025
Supported parameters
include_reasoningmax_completion_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choice