Claude Haiku 4.5 (Thinking) API
claude-haiku-4-5-20251001-thinkingClaude Haiku 4.5 with extended thinking capability for complex reasoning tasks.
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-haiku-4-5-20251001-thinking",
"stream": true,
"max_tokens": 1024,
"messages": [...]
}Function Calling (Tools)
Enable Claude to use tools and call functions.
{
"model": "claude-haiku-4-5-20251001-thinking",
"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-haiku-4-5-20251001-thinking",
"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-haiku-4-5-20251001-thinking",
"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-haiku-4-5-20251001-thinking",
"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-haiku-4-5-20251001-thinking) |
| 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
Extended Thinking
Step-by-step reasoning
Fast Response
Quick with deep analysis
Cost Effective
Affordable reasoning
Complex Tasks
Handle multi-step problems
About Claude Haiku 4.5 (Thinking)
Claude Haiku 4.5 (Thinking) is a Large Language Model API provided by Anthropic. Claude Haiku 4.5 with extended thinking capability for complex reasoning tasks. Through APIMODELS platform, you can access this model via a unified API with transparent pay-as-you-go pricing. Current pricing: Input: $0.353, Output: $1.765 per 1M tokens.
Key Features
- Extended Thinking -- Step-by-step reasoning
- Fast Response -- Quick with deep analysis
- Cost Effective -- Affordable reasoning
- Complex Tasks -- Handle multi-step problems
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 APIMODELS
- Unified API -- One API key to access all models, no need to register on multiple platforms
- Transparent Pricing -- Pay-as-you-go with per-call pricing published on every model page, 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 Haiku 4.5 (Thinking) cost?
Claude Haiku 4.5 (Thinking) is available through APIMODELS at: Input: $0.353, Output: $1.765 per 1M tokens. Billing is pay-as-you-go — you only pay for what you generate.
How to use Claude Haiku 4.5 (Thinking) API?
Sign up at APIMODELS, 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 APIMODELS and the official Anthropic API?
APIMODELS offers the same Claude Haiku 4.5 (Thinking) model 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.
How does Claude Haiku 4.5 (Thinking) compare to other Large Language Model models?
On APIMODELS, Claude Haiku 4.5 (Thinking) runs alongside 60+ models on one API key and one balance, so choosing is about fit, not lock-in. It supports Extended Thinking, Fast Response, Cost Effective, and you can weigh it on price and capability against other Large Language Model models, then switch by changing a single model-name string — no new account or integration. Browse every Large Language Model option with live pricing at apimodels.app/models.
What can Claude Haiku 4.5 (Thinking) do?
Claude Haiku 4.5 (Thinking) supports: Extended Thinking, Fast Response, Cost Effective. See the APIMODELS docs for full parameters and call examples.
Can I access the Claude Haiku 4.5 (Thinking) API from anywhere (incl. China)?
Yes. APIMODELS exposes Claude Haiku 4.5 (Thinking) through a single unified API and one key — no separate provider accounts, and no need to handle each provider's regional network access yourself.
What payment methods are supported?
We support Stripe (Visa, Mastercard, and other international cards) and Alipay. Credits are available instantly after payment.