Claude Python SDK Guides First API Calls and Streaming on Python 3.9+
Updated
Updated · KDnuggets · Jul 3
Claude Python SDK Guides First API Calls and Streaming on Python 3.9+
3 articles · Updated · KDnuggets · Jul 3
Summary
Python 3.9+ developers can start using the Claude API with the anthropic SDK, a Console account, an API key, and as little as $5 in credits.
The guide centers on client.messages.create(), showing a first request with model="claude-sonnet-5", max_tokens=256, and a user message list that must begin with a user turn.
Response handling focuses on the typed Message object, where response.content[0].text extracts output, stop_reason shows whether generation ended naturally or hit max_tokens, and usage reports input and output tokens for billing and context tracking.
System prompts are passed as a top-level parameter rather than inside messages, letting developers enforce persistent roles or formatting constraints across a conversation.
Streaming uses client.messages.stream() as a context manager, yielding text chunks in real time and allowing stream.get_final_message() to recover the full response with token counts after completion.