DeepSeek V4.1 Flash as a Labs experiment, open for a short test window: temporary, not a permanent id. DeepSeek's latest flash model, served from the official DeepSeek-V4.1-Flash open weights: a 552B mixture-of-experts (8B active per token on prefill, 16B on decode) built for fast agentic coding, with native image understanding and a 1M-token context. Reasoning has four modes: non-think (none), think low (low), think high (high, the default) and think max (max). Access is seat-gated through the Labs page while an experiment is live. It is offered at limited capacity and low availability, so expect it to be flaky and to go down under load: crash it, give it a moment, and try again. For production work we recommend umans-coder or umans-deepseek-v4-pro-0813.