DeepSeek V4.1 Flash is live on the public API for two days only, under a model ID that expires September 10
r/LocalLLaMA (corroborated by TechNode and Vercel AI Gateway)·high signal
DeepSeek opened an intermediate V4.1 Flash build to all API users on September 8 at about 3pm Beijing time via the model ID deepseek-v4.1-flash-expires-on-0910, with no beta application, the same base_url, V4 Flash pricing and 20 concurrent requests per account. The company describes a new architecture with multimodal support built into the model rather than bolted on as with V4-Flash-Vision-Exp, handling text, image and speech in one pass. Developer measurements put output above 300 tok/s with a peak of 507 tok/s.