GPT-5.5 Pro

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.

ChatOpenAI1M tokens$32.7018 / $196.2107 · 1M

openai/gpt-5.5-pro

Context
1M tokens
Completion cap
128,000
Tools
Yes
JSON
Yes
Released
2026-04-24

Call it from Geek Hub

Same OpenAI SDK. Change the base URL and the model id.

curl https://api.geekhub.mx/v1/chat/completions \
  -H "Authorization: Bearer $GEEKHUB_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-5.5-pro",
    "messages": [{"role": "user", "content": "Hola"}]
  }'
Get an API key

Frequently asked questions

What is GPT-5.5 Pro?
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. GPT-5.5 Pro runs on the Geek Hub API (OpenAI-compatible). Model id: openai/gpt-5.5-pro.
Is GPT-5.5 Pro free?
No. Input is $32.7018 per 1M tokens and output is $196.2107 per 1M tokens on Geek Hub (markup included).
What is the context length of GPT-5.5 Pro?
GPT-5.5 Pro has a 1M tokens context window. It supports up to 128,000 completion tokens.
Does GPT-5.5 Pro support tool calling and structured outputs?
GPT-5.5 Pro accepts tools and tool_choice for function calling. It also supports structured outputs via a JSON schema in response_format.
When was GPT-5.5 Pro released?
GPT-5.5 Pro was released on 2026-04-24.

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