Originally published at kalyna.pro
Streaming sends Claude's response token by token as it's generated, instead of waiting for the full completion before showing anything. For a chat UI this is the difference between a user staring at a spinner for several seconds and seeing the first words appear within a few hundred milliseconds. The Claude API Tutorial introduces the basic stream.text_stream helper — this guide covers the full picture: the raw event stream, async streaming, error handling, and a complete FastAPI endpoint that streams Claude's output to a browser.
Prerequisites
pip install anthropic
# for the API endpoint example later:
