The Anthropic API and your first script

The concept

Claude is available over an API billed per token, with a large context window and native support for tool use and long documents. The idea is simple: the same model you have been chatting with also answers a web request, so you can put it inside a script, a spreadsheet or a page. A key identifies you; a request sends the text; a response comes back as data.

The reason to try it once, even if you never build anything: it makes the chat version less mysterious. You see that the whole conversation is text in and text out, that your instructions are literally lines of a request, and that "the model" is one parameter among several.

A first call looks like this:

import anthropic

client = anthropic.Anthropic()   # reads ANTHROPIC_API_KEY

msg = client.messages.create(
    model="claude-sonnet-4-5",
    max_tokens=300,
    messages=[{
        "role": "user",
        "content": "In three sentences, what is a data analyst? Be concrete.",
    }],
)

print(msg.content[0].text)