Building a Small App with the Claude API

Project: Code Review Bot

Let's build a simple application that uses the Claude API to review code. This example demonstrates API integration, streaming, and practical Claude usage.

Setup

# Install the Anthropic SDK
pip install anthropic

# Set your API key
export ANTHROPIC_API_KEY="your-key-here"

Implementation

import anthropic

def review_code(code: str, language: str) -> str:
    client = anthropic.Anthropic()
    
    response = client.messages.create(
        model="claude-3-5-sonnet-20241022",
        max_tokens=2048,
        system="You are an expert code reviewer. 
Provide constructive feedback on code quality, 
bugs, and improvements.",
        messages=[{
            "role": "user",
            "content": f"Review this {language} code:\n\n{code}"
        }]
    )
    return response.content[0].text

Adding Streaming

def review_code_streaming(code: str, language: str):
    client = anthropic.Anthropic()
    
    with client.messages.stream(
        model="claude-3-5-sonnet-20241022",
        max_tokens=2048,
        system="You are an expert code reviewer.",
        messages=[{"role": "user", "content": code}]
    ) as stream:
        for text in stream.text_stream:
            print(text, end="", flush=True)

Key Points

• Install the Anthropic SDK with pip install anthropic.
• Use system prompts to set Claude's role and behavior.
• Streaming provides real-time output to the user.
• Handle API errors gracefully in production code.
• Start simple and add features incrementally.