Mixlayer
An independent technical analysis of Qwen3.5-397B-A17B published on InferenceX confirms the model as the first open-weights release in Alibaba's Qwen3.5 series, explicitly naming the variant with 397B total parameters and 17B activated per forward pass. The page documents the February 2026 announcement by the Qwen team The same InferenceX entry details that Qwen3.5-397B-A17B unifies thinking and non-thinking behavior in a single checkpoint, operating in thinking mode by default with `...` tags before the answer and dropping the `/think` and `/nothink` soft switches used in Qwen3, so non-thinking responses are controlled via API param