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

Try GPT 5.1 in the Workbench

​Example request

​Fetch model details

​Request parameters

Example request

Fetch model details

Request parameters