Streaming responses

Why does ChatGPT feel snappy and your beginner script feel slow? Streaming. This lesson upgrades your apps from "AI wait" to "AI flow".

Watching a video buffer vs streaming. Same content, totally different feel. You will never want non-streaming UX after this lesson.

Set stream=True. The SDK returns an iterator of token chunks. You print them as they arrive. The user sees instant feedback. Perceived latency drops dramatically even if total time is identical.

OpenAI streaming:

stream = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Tell me a 3-sentence story."}],
    stream=True,
)
for chunk in stream:
    delta = chunk.choices[0].delta.content
    if delta:
        print(delta, end="", flush=True)
print()

Gemini and Anthropic have analogous patterns.