A bot is just a program that sends a prompt to Claude and does something with the reply.

Install Python and the SDK

Windows steps

powershell

winget install Python.Python.3.12
py -m pip install anthropic

Store your key (never in code)

Windows steps

powershell

setx ANTHROPIC_API_KEY "sk-ant-...your key..."

Close and reopen PowerShell so it takes effect.

hello_bot.py

python

import anthropic

client = anthropic.Anthropic()  # reads ANTHROPIC_API_KEY
reply = client.messages.create(
    model="claude-haiku-5-5",
    max_tokens=300,
    system="You are a friendly assistant. Answer in 3 short sentences.",
    messages=[{"role": "user", "content": "Give me one tip to save time at work."}],
)
print(reply.content[0].text)

Run it: py hello_bot.py (Windows) or python3 hello_bot.py (Mac/Linux).

Cost tip: set max_tokens low and use Haiku for simple jobs. Add a monthly spend limit in the Anthropic Console.

Build Your First AI Bots

Your first Claude API call

Install Python and the SDK

Store your key (never in code)

hello_bot.py

Quick quiz

Quick assignment