gpt-5.5-pro

Overview

GPT-5.5 Pro is OpenAI’s high-capability model optimized for deep reasoning and accuracy on complex, high-stakes workloads. It features a 1M+ token context window (922K input, 128K output) with support for text and image inputs, and is designed for long-horizon problem solving, agentic coding, and precise execution across multi-step workflows.

• Model type: Text generation
• Input: Text / Image
• Output: Text
• Endpoints: chat / chat_completion

Code example

Call with gpt-5.5-pro :

curl https://www.starunion.net/v1/chat/completions \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "gpt-5.5-pro",
    "messages": [{ "role": "user", "content": "Hello" }]
  }'