Claude Opus 4.5
claude-opus-4-5-20251101Latest Opus model with enhanced capabilities and improved reasoning.
Latest Opus
Most recent flagship
Best Performance
Top-tier capability
Premium
Highest quality outputs
Improved Pricing
Better value than Opus 4
API Documentation
View complete API reference with all parameters and examples.
Advanced Features
Streaming
Enable real-time streaming responses with Server-Sent Events.
{
"model": "claude-opus-4-5-20251101",
"stream": true,
"max_tokens": 1024,
"messages": [...]
}Function Calling (Tools)
Enable Claude to use tools and call functions.
{
"model": "claude-opus-4-5-20251101",
"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-4-5-20251101",
"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-4-5-20251101",
"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-4-5-20251101",
"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-4-5-20251101) |
| 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.
Pricing
Billing: Cost = (input_tokens * input_price + output_tokens * output_price) / 1,000,000
About Claude Opus 4.5
Claude Opus 4.5 is a Large Language Model API provided by Anthropic. Latest Opus model with enhanced capabilities and improved reasoning. Through API Models platform, you can access this model via a unified API at prices significantly lower than official rates. Current pricing: Input: $1.802, Output: $9.008 per 1M tokens.
Key Features
- Latest Opus -- Most recent flagship
- Best Performance -- Top-tier capability
- Premium -- Highest quality outputs
- Improved Pricing -- Better value than Opus 4
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 4.5 cost?
Claude Opus 4.5 is available through API Models at: Input: $1.802, Output: $9.008 per 1M tokens. This is up to 95% cheaper than official pricing.
How to use Claude Opus 4.5 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 4.5 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.