Models/Claude Opus 4

Claude Opus 4

claude-opus-4-20250514

Most capable model with superior reasoning and analysis capabilities.

Most CapableSuperior ReasoningComplex Tasks

Input$5.405

Output$27.023

per 1M tokens

Most Capable

Top-tier intelligence

Superior Reasoning

Best-in-class logic

Complex Tasks

Handle any challenge

Premium Quality

Highest output quality

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": "claude-opus-4-20250514",
  "stream": true,
  "max_tokens": 1024,
  "messages": [...]
}

Function Calling (Tools)

Enable Claude to use tools and call functions.

{
  "model": "claude-opus-4-20250514",
  "max_tokens": 1024,
  "tools": [{
    "name": "get_weather",
    "description": "Get current weather for a location",
    "input_schema": {
      "type": "object",
      "properties": {
        "location": {"type": "string", "description": "City name"}
      },
      "required": ["location"]
    }
  }],
  "tool_choice": {"type": "auto"},
  "messages": [{"role": "user", "content": "What's the weather in Tokyo?"}]
}

PDF Support

Analyze PDF documents by sending them as base64 encoded content.

{
  "model": "claude-opus-4-20250514",
  "max_tokens": 1024,
  "messages": [{
    "role": "user",
    "content": [{
      "type": "document",
      "source": {
        "type": "base64",
        "media_type": "application/pdf",
        "data": "<base64_encoded_pdf>"
      }
    }, {
      "type": "text",
      "text": "Summarize this document."
    }]
  }]
}

Structured Output (JSON Schema)

Get structured JSON responses that match your schema.

{
  "model": "claude-opus-4-20250514",
  "max_tokens": 1024,
  "output_format": {
    "type": "json_schema",
    "schema": {
      "type": "object",
      "properties": {
        "name": {"type": "string"},
        "age": {"type": "integer"}
      },
      "required": ["name", "age"]
    }
  },
  "messages": [{"role": "user", "content": "Extract info: John is 30 years old"}]
}

Web Search

Enable Claude to search the web for up-to-date information.

{
  "model": "claude-opus-4-20250514",
  "max_tokens": 1024,
  "tools": [{
    "type": "web_search_20250305",
    "name": "web_search",
    "max_uses": 5
  }],
  "messages": [{"role": "user", "content": "What's the latest news about AI?"}]
}

API Parameters Reference

Parameter	Type	Required	Description
model	string	Yes	Model identifier (e.g., claude-opus-4-20250514)
messages	array	Yes	Array of message objects with role and content
max_tokens	integer	Yes	Maximum tokens in the response (1 - 128000)
system	string	No	System prompt to set context
stream	boolean	No	Enable streaming responses (SSE)
temperature	number	No	Sampling temperature (0.0 - 1.0)
top_p	number	No	Nucleus sampling threshold (0.0 - 1.0)
top_k	integer	No	Top-k sampling (0 - infinity)
stop_sequences	array	No	Sequences that stop generation
tools	array	No	Function calling tools definition
tool_choice	object	No	Tool selection strategy (auto/any/tool)
thinking	object	No	Enable extended thinking mode
output_format	object	No	Structured output with JSON schema

Full API Documentation

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

View Documentation

Pricing

Input

$5.405

per 1M tokens

Output

$27.023

per 1M tokens

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

About Claude Opus 4

Claude Opus 4 is a Large Language Model API provided by Anthropic. Most capable model with superior reasoning and analysis capabilities. Through API Models platform, you can access this model via a unified API at prices significantly lower than official rates. Current pricing: Input: $5.405, Output: $27.023 per 1M tokens.

Key Features

Most Capable -- Top-tier intelligence
Superior Reasoning -- Best-in-class logic
Complex Tasks -- Handle any challenge
Premium Quality -- Highest output quality

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 Claude Opus 4 cost?

Claude Opus 4 is available through API Models at: Input: $5.405, Output: $27.023 per 1M tokens. This is up to 95% cheaper than official pricing.

How to use Claude Opus 4 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 Anthropic API?

API Models offers the same Claude Opus 4 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.