---

name: claude-api-reference description: "Claude API development reference guide. Use when developing Claude API applications for Messages API, Vision, PDF processing, Tool Use, Streaming, and more. Triggers: (1) Claude API integration development, (2) Image or PDF file processing, (3) Tool Use or Function Calling implementation, (4) Streaming or Batch processing setup, (5) Any Claude SDK development questions"

Claude API Reference Skill

This skill provides essential knowledge and best practices for Claude API development.

Quick Start

Copyfrom anthropic import Anthropic

client = Anthropic()  # Automatically reads ANTHROPIC_API_KEY from environment
message = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello, Claude"}]
)
print(message.content[0].text)

Core API Endpoints

Required Headers

Copyx-api-key: YOUR_API_KEY
anthropic-version: 2023-06-01
content-type: application/json

Model Selection

File Handling

For detailed specifications, see:

• PDF/Image processing: references/file_handling.md
• Tool Use: references/tool_use.md
• Advanced features: references/advanced_features.md

PDF Quick Example

Copyimport base64

with open("document.pdf", "rb") as f:
    pdf_data = base64.standard_b64encode(f.read()).decode("utf-8")

message = client.messages.create(
    model="claude-sonnet-4-5-20250929",
    max_tokens=4096,
    messages=[{
        "role": "user",
        "content": [
            {
                "type": "document",
                "source": {
                    "type": "base64",
                    "media_type": "application/pdf",
                    "data": pdf_data
                }
            },
            {"type": "text", "text": "Analyze the key points of this document"}
        ]
    }]
)

Image Processing

Copy# Base64 method
{
    "type": "image",
    "source": {
        "type": "base64",
        "media_type": "image/png",  # image/jpeg, image/gif, image/webp
        "data": image_base64
    }
}

# URL method
{
    "type": "image",
    "source": {
        "type": "url",
        "url": "https://example.com/image.jpg"
    }
}

Limits

Official Resources

• Documentation: https://docs.claude.com
• Python SDK: https://github.com/anthropics/anthropic-sdk-python
• Cookbook: https://github.com/anthropics/anthropic-cookbook
• Quickstarts: https://github.com/anthropics/anthropic-quickstarts