OpenAI: GPT-5.6 Sol Pro
openai/gpt-5.6-sol-pro · OpenAINot yet established- Declared family
- GPT
- Evidence confidence
- Unknown
- Declared tokenizer tag
- GPT
- Entered catalogue
- 9 July 2026
- Last tested
- Not yet measured
- Measurement
- Awaiting measurement
| Signal | Result | Reference |
|---|---|---|
| Tokenizer signature | Not measured | – |
| API surface | Identical contract to 6 other entries | api_b333d4ee |
| Context and output | 1,050,000 context · 128,000 max output | declared |
| Reasoning contract | Optional · efforts max, xhigh, high, medium, low, none · default medium | declared |
| Serving providers observed | None recorded yet | – |
GPT-5.6 Sol Pro is the same underlying model as [GPT-5.6 Sol](https://openrouter.ai/openai/gpt-5.6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. Learn more in OpenAI's docs: https://developers.openai.com/api/docs/guides/reasoning#reasoning-mode
Supported parameters
include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choicetools
defaults: {"temperature":null,"top_p":null,"top_k":null,"frequency_penalty":null,"presence_penalty":null,"repetition_penalty":null}
Cite this page as the evidence record for OpenAI: GPT-5.6 Sol Pro: the URL is stable, measurements are dated, and revisions append to the history above. Method: tokenizer fingerprinting, v1, 50 strings. The raw data behind every figure is on the data page.