LLM Integration Basics

pip install anthropic openai python-dotenv

# .env file
ANTHROPIC_API_KEY=sk-ant-...
OPENAI_API_KEY=sk-...

Never hardcode API keys. Load them from environment variables using python-dotenv.

import anthropic
import os
from dotenv import load_dotenv

load_dotenv()

client = anthropic.Anthropic(api_key=os.environ["ANTHROPIC_API_KEY"])

message = client.messages.create(
    model="claude-haiku-4-5-20251001",
    max_tokens=1024,
    messages=[
        {
            "role": "user",
            "content": "Analyze this job description and list the top 5 required skills."
        }
    ]
)

print(message.content[0].text)

with client.messages.stream(
    model="claude-haiku-4-5-20251001",
    max_tokens=1024,
    messages=[{"role": "user", "content": prompt}]
) as stream:
    for text in stream.text_stream:
        print(text, end="", flush=True)

import time
from anthropic import RateLimitError, APIError

def call_with_retry(client, prompt, max_retries=3):
    for attempt in range(max_retries):
        try:
            return client.messages.create(
                model="claude-haiku-4-5-20251001",
                max_tokens=1024,
                messages=[{"role": "user", "content": prompt}]
            )
        except RateLimitError:
            wait = 2 ** attempt  # exponential backoff
            time.sleep(wait)
        except APIError as e:
            raise e  # don't retry on non-rate-limit errors
    raise Exception("Max retries exceeded")