How to use Claude API Python

The Claude API, developed by Anthropic, allows developers to integrate the powerful Claude language model into their applications. To use the Claude API in Python:

1. Install the Anthropic Python package: `pip install anthropic`[1][2]

2. Obtain an API key from the Anthropic console (console.anthropic.com) and set it as an environment variable `ANTHROPIC_API_KEY`.[1][2]

3. Create a client object using the API key:

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

4. Use the client object to generate text completions:

python
completion = client.completions.create(
    model="claude-2.1",
    max_tokens_to_sample=300,
    prompt=f"{anthropic.HUMAN_PROMPT} What is the Matthew effect? {anthropic.AI_PROMPT}"
)
print(completion.completion)

The newer Claude 3 model uses the Messages API instead of the Completions API, so the usage is slightly different.[2]

The Anthropic API also supports asynchronous requests for more efficient and scalable performance.[1]

Additionally, there is an unofficial Claude API Python package available on GitHub that provides a simple interface to interact with the Claude AI model.[4]