GPT 5.1 - Oxen.ai

Try GPT 5.1 in the Workbench

Run this model interactively, tune parameters, and compare outputs.

Model ID: gpt-5-1-2025-11-13 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
Parameter Count	Unknown
Mixture of Experts	No
Context Length	Unknown
Multilingual	Yes
Quantized*	Unknown

*Quantization is specific to the inference provider and the model may be offered with different quantization levels by other providers.

Example request

Use the Workbench as a request builder: configure parameters for this model in the UI, then open the API tab to copy the exact cURL or Python call.

Minimal
Basic parameters
All parameters

curl -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": "Hello, what can you do?"
    }
  ]
}'

curl -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": "Hello, what can you do?"
    }
  ],
  "temperature": 0.7,
  "max_tokens": 1024,
  "stream": false
}'

curl -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": "Hello, what can you do?"
    }
  ],
  "temperature": 0.7,
  "max_tokens": 1024,
  "stream": false,
  "top_p": 1.0,
  "frequency_penalty": 0,
  "presence_penalty": 0
}'

Fetch model details

The models endpoint returns the full model object, including its json_request_schema.

curl -H "Authorization: Bearer $OXEN_API_KEY" https://hub.oxen.ai/api/ai/models/gpt-5-1-2025-11-13

Request parameters

This model follows the standard OpenAI chat completions request body. See the chat completions reference for the full parameter list.

Inference API

Documentation Index

Try GPT 5.1 in the Workbench

​Example request

​Fetch model details

​Request parameters

Example request

Fetch model details

Request parameters