streaming

stream chat deltas

Set stream=True. The official SDK parses each server-sent event and yields typed chunks.

stream = client.chat.completions.create(
    model="brok-2.3-fast",
    messages=[{"role": "user", "content": "Explain SSE briefly."}],
    stream=True,
)

for chunk in stream:
    delta = chunk.choices[0].delta.content
    if delta:
        print(delta, end="", flush=True)

stream response events

with client.responses.stream(
    model="brok-2.3",
    input="Give me three product names.",
) as stream:
    for event in stream:
        if event.type == "response.output_text.delta":
            print(event.delta, end="", flush=True)

Key event types are response.created, response.output_text.delta, and response.completed.

connection behavior

For chat completions, read each data: line until [DONE]. For Responses, dispatch using the event: name. Do not buffer the entire HTTP body in a proxy. Streaming usage is finalized after the stream closes and then appears in Usage.