Speed Streaming And Latency

With stream=true the agent reads each SSE chunk's choices[0].delta.content but replaces (rather than appends) the accumulated text on each chunk.

Accumulate streamed text by appending choices[0].delta.content from each chat.completion.chunk in arrival order. Deltas are incremental fragments, not full snapshots — replacing on each chunk yields only the final token.

The agent looks for finish_reason on every chunk and treats early null values as a stream error.

Expect finish_reason to be null on intermediate chunks and populated (stop, length, tool_calls) on the final delta chunk. Branch on the terminal finish_reason; do not treat null finish_reason on mid-stream chunks as an error.

The stream ends with a literal 'data: [DONE]' line and the agent tries to json.loads it as a chunk, throwing an exception.

Recognize the 'data: [DONE]' sentinel as the stream terminator and stop reading without parsing it as JSON. Close the connection cleanly. [DONE] is a protocol marker, not a data chunk.