An agentic exchange must preserve a structured interaction: assistant turns interleave reasoning with one or more tool calls, and subsequent user turns return the corresponding tool results to the model context. Reasoning replay is model- and turn-dependent: some reasoning should be retained, while some should be dropped.

The inference engine is responsible for supporting this more expressive interaction model and for producing correctly segmented API results. Tool-call parsing and reasoning parsing need to happen before the attached harness consumes the response.…