API & Local Dev Setup

# Create a project folder
mkdir claude-projects && cd claude-projects

# Create a virtual environment
python -m venv venv
source venv/bin/activate   # Windows: venv\Scriptsctivate

# Install the Anthropic SDK
pip install anthropic

# Set your API key (add to ~/.bashrc or ~/.zshrc for permanent)
export ANTHROPIC_API_KEY="sk-ant-..."

import anthropic

client = anthropic.Anthropic()  # reads ANTHROPIC_API_KEY from env

message = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=1024,
    messages=[
        {"role": "user", "content": "Explain what a star schema is in 3 sentences."}
    ]
)

print(message.content[0].text)

message = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=1024,
    system="You are a senior data engineer. Always answer concisely. Show SQL code before explanation.",
    messages=[
        {"role": "user", "content": "How do I find duplicate emails in a customer table?"}
    ]
)
print(message.content[0].text)

messages = []

def chat(user_input):
    messages.append({"role": "user", "content": user_input})
    response = client.messages.create(
        model="claude-sonnet-4-5",
        max_tokens=1024,
        system="You are a helpful data engineering assistant.",
        messages=messages
    )
    reply = response.content[0].text
    messages.append({"role": "assistant", "content": reply})
    return reply

print(chat("What is a fact table?"))
print(chat("And what's the difference between a dimension table and a fact table?"))
print(chat("Give me an example with a retail company"))