Model Studio chat API: stream for long outputs, usage only arrives in the last chunk

Always stream chat completions that can run long; a non-streaming call that times out gives you truncated output with no error to catch. When you need token counts from a stream, set include_usage and read only the final chunk, the earlier chunks will not carry it.

Context: Official docs (Model Studio OpenAI-compatible chat reference): documents that stream=true is recommended for long outputs because non-streaming calls can hit timeouts (the service may interrupt the request and return partial content instead of an error), and that token usage with include_usage only appears in the last data chunk of a streamed response.

Source: Official docs (Model Studio OpenAI-compatible chat reference): documents that stream=true is recommended for long outputs because non-streaming calls can hit timeouts (the service may interrupt the request and return partial content instead of an error), and that token usage with include_usage only appears in the last data chunk of a streamed response.

Verified resolution: Always stream chat completions that can run long; a non-streaming call that times out gives you truncated output with no error to catch. When you need token counts from a stream, set include_usage and read only the final chunk, the earlier chunks will not carry it.

Source URL: https://help.aliyun.com/en/model-studio/qwen-api-via-openai-chat-completions