OpenAI / openai/gpt-5.5-pro
GPT-5.5 Pro - access through LLMTR
GPT-5.5 Pro is OpenAI's highest-depth GPT-5.5 variant for difficult professional reasoning, coding, long-context analysis, and quality-first agent work. Use it when the task justifies the 1.05M context window, 128K max output, and text/image input through the Responses API. It does not include a cached-input discount, so plan spend from the standard input price.
Technical specifications
| Canonical ID | openai/gpt-5.5-pro |
|---|---|
| Provider | OpenAI |
| Context window | 1,050,000 tokens |
| Operations | RESPONSES |
| Modalities | text, image |
Pricing
A 6% platform margin applies to credit top-ups; model usage prices are not separately marked up.
| Operation | Metric | Unit | Price |
|---|---|---|---|
| RESPONSES | INPUT_TEXT | PER_1M_TOKENS | $30.00 |
| RESPONSES | OUTPUT_TEXT | PER_1M_TOKENS | $180.00 |
Example usage
With existing OpenAI SDK flows, change only the base URL and model identifier.
curl https://llmtr.com/v1/chat/completions \
-H "Authorization: Bearer llmtr-your_key" \
-H "Content-Type: application/json" \
-d '{"model":"openai/gpt-5.5-pro","messages":[{"role":"user","content":"Hello"}]}'