Streaming

Pass stream: true to receive standard chat.completion.chunk SSE, terminated by data: [DONE]. Because agent turns can run for minutes, streaming is the recommended mode for every integration — a stream is unambiguous about liveness where a long POST is not.

What the stream contains

An immediate first chunk (delta: {"role": "assistant", "content": ""}) — fast first byte even while the agent environment spins up.
SSE comment lines (: keepalive) during silent agent work. Every OpenAI SDK ignores them per the SSE spec — but don’t buffer the stream through proxies that time out on first-byte silence.
One or more delta.content chunks carrying the reply.
The final chunk with finish_reason — always carries the x_ravchat block, even without stream_options.
With stream_options.include_usage — one extra chunk before [DONE] with choices: [] and populated usage (including usage.cost). All other chunks carry usage: null.

In v1 the reply currently arrives as a single content chunk (whole-message), not token-by-token; finer-grained incremental deltas are a planned fast-follow. Write your client to consume any number of delta.content chunks — as every OpenAI SDK already does — and rely on finish_reason (not chunk count) for completion. Nothing changes when incremental deltas land.

Reading credits from a stream

Streaming responses can’t carry usage.cost in a header — headers are sent before the turn runs. Read credits from the final chunk’s x_ravchat.credits or from the include_usage usage chunk.

stream = client.chat.completions.create(
    model="ravchat",
    messages=[{"role": "user", "content": "Explain bitachon in two sentences."}],
    stream=True,
    stream_options={"include_usage": True},
)
text, cost = "", None
for chunk in stream:
    if chunk.choices and chunk.choices[0].delta.content:
        text += chunk.choices[0].delta.content
    if chunk.usage:  # final usage chunk
        cost = (chunk.usage.model_extra or {}).get("cost")
print(text, "\ncredits:", cost)

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Core concepts

What the stream contains

Reading credits from a stream

​What the stream contains

​Reading credits from a stream

What the stream contains

Reading credits from a stream