GPT-5.6 Terra Pro is the same underlying model as [GPT-5.6 Terra](https://openrouter.ai/openai/gpt-5.6-terra), 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
Details
| Field | Value |
|---|---|
| id | openai/gpt-5.6-terra-pro |
| family | gpt-terra |
| modality | text+image+pdf->text |
| context_length | 1050000 |
| max_input_tokens | 922000 |
| max_output_tokens | 128000 |
| knowledge_cutoff | 2026-02-16 |
| release_date | 2026-07-09 |
| is_open_weights | no |
| supports_tool_call | yes |
| supports_reasoning | yes |
| supports_structured_output | yes |
| supports_attachment | yes |
| input_modalities | text, image, pdf |
| output_modalities | text |