Models/GPT-5.1 (2025-11-13)

GPT-5.1 (2025-11-13)

gpt-5.1-2025-11-13

Snapshot version of GPT-5.1 for reproducible outputs.

StableReproducibleProduction

Input$0.265

Output$2.206

per 1M tokens

Stable

Pinned model version

Reproducible

Consistent results

Production

Ready for deployment

Reliable

Predictable behavior

API Documentation

View complete API reference with all parameters and examples.

View Docs

Advanced Features

Streaming

Enable real-time streaming responses with Server-Sent Events.

{
  "model": "gpt-5.1-2025-11-13",
  "stream": true,
  "messages": [...]
}

Function Calling (Tools)

Enable the model to use tools and call functions.

{
  "model": "gpt-5.1-2025-11-13",
  "tools": [{
    "type": "function",
    "function": {
      "name": "get_weather",
      "description": "Get current weather for a location",
      "parameters": {
        "type": "object",
        "properties": {
          "location": {"type": "string", "description": "City name"}
        },
        "required": ["location"]
      }
    }
  }],
  "messages": [{"role": "user", "content": "What's the weather in Tokyo?"}]
}

JSON Mode

Get structured JSON responses from the model.

{
  "model": "gpt-5.1-2025-11-13",
  "response_format": {"type": "json_object"},
  "messages": [{"role": "user", "content": "Extract info as JSON: John is 30 years old"}]
}

API Parameters Reference

Parameter	Type	Required	Description
model	string	Yes	Model identifier (e.g., gpt-5.1-2025-11-13)
messages	array	Yes	Array of message objects with role and content
max_tokens	integer	No	Maximum tokens in the response
stream	boolean	No	Enable streaming responses (SSE)
temperature	number	No	Sampling temperature (0.0 - 2.0)
top_p	number	No	Nucleus sampling threshold (0.0 - 1.0)
tools	array	No	Function calling tools definition
response_format	object	No	Output format (e.g., json_object)

Full API Documentation

View complete API reference with streaming, thinking, and more.

View Documentation

Pricing

Input

$0.265

per 1M tokens

Output

$2.206

per 1M tokens

Billing: Cost = (input_tokens * input_price + output_tokens * output_price) / 1,000,000

About GPT-5.1 (2025-11-13)

GPT-5.1 (2025-11-13) is a Large Language Model API provided by OpenAI. Snapshot version of GPT-5.1 for reproducible outputs. Through API Models platform, you can access this model via a unified API at prices significantly lower than official rates. Current pricing: Input: $0.265, Output: $2.206 per 1M tokens.

Key Features

Stable -- Pinned model version
Reproducible -- Consistent results
Production -- Ready for deployment
Reliable -- Predictable behavior

Use Cases

Chatbot & Customer Support

Build intelligent conversational systems to automatically answer user queries and improve service efficiency.

Content Generation

Automatically write articles, emails, ad copy, and other text content to boost productivity.

Code Assistant

Assist with code writing, debugging, and code review to accelerate software development.

Data Analysis

Understand and analyze unstructured data, extract key insights, and generate summary reports.

Why API Models

Unified API -- One API key to access all models, no need to register on multiple platforms
Cost Savings -- 60-95% cheaper than official pricing, ideal for indie developers and startups
Instant Access -- Start using immediately after signup, supports Stripe and Alipay payments
Full Documentation -- Detailed API docs with code examples in cURL, Python, and Node.js

Frequently Asked Questions

How much does GPT-5.1 (2025-11-13) cost?

GPT-5.1 (2025-11-13) is available through API Models at: Input: $0.265, Output: $2.206 per 1M tokens. This is up to 95% cheaper than official pricing.

How to use GPT-5.1 (2025-11-13) API?

Sign up at API Models, get your API key, and call our unified API endpoint. We provide detailed API documentation with code examples in cURL, Python, and Node.js.

What is the difference between API Models and the official OpenAI API?

API Models offers the same GPT-5.1 (2025-11-13) model at 60-95% lower cost through our aggregation platform. We provide a unified API interface so you do not need separate accounts for each provider - one API key to access all models.

What payment methods are supported?

We support Stripe (Visa, Mastercard, and other international cards) and Alipay. Credits are available instantly after payment.