About GPT 5.1
GPT 5.1 is an LLM that excels in adaptive reasoning and reliably following instructions, dynamically allocating computational effort based on task complexity. It automatically routes requests to either a fast, conversational model (Instant) or a more analytical, deeper reasoning model (Thinking), depending on the nature of the prompt, which improves both speed and response quality for a wide range of tasks.
Some other noteworthy features of GPT 5.1 include expanded controls for personalizing tone and style, as well as improved performance in coding and math-related queries.
| Metric | Value |
|---|---|
| Context Length | 400,000 tokens |
| Multilingual | Yes |
Ready to build with GPT 5.1?
Try GPT 5.1 in the Workbench to prompt it, compare outputs, and iterate on prompts without writing any code. When you're ready to ship, call the same model from our API and build your own apps on top of it.
curl -sSf -X POST https://hub.oxen.ai/api/ai/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $OXEN_API_KEY" \
-d '{
"model": "gpt-5-1-2025-11-13",
"messages": [
{
"role": "user",
"content": "Try sending a message."
}
]
}'API endpoint
See the API reference for request and response formats.
https://hub.oxen.ai/api/ai/chat/completions