The open source AI world just got a new heavyweight and it's a big one. Moonshot AI just dropped Kimi K3, a 2.8 trillion parameter model they're calling the world's first open "3T class" model, and it's punching well above its weight class. - First open model to hit 2.8T parameters, setting a new bar for open model size - Built on two new architecture pieces (Kimi Delta Attention and Attention Residuals) that change how info flows through the model - Uses a sparse Mixture of Experts setup, only activating 16 out of 896 experts per token instead of the whole model - Native vision built in, plus a 1 million token context window - Claims a 2.5x jump in scaling efficiency over their last model, Kimi K2 - Still trails the top closed models (Claude Fable 5 and GPT 5.6 Sol) on raw performance, but the gap is shrinking - In one demo, it designed a working computer chip in a single 48 hour autonomous run with no human help - In another, it finished astrophysics research in about 2 hours that would normally take a human researcher 1 to 2 weeks - API pricing starts at $0.30 per million tokens for cached input, noticeably cheap for something this size - Full model weights are set to release by July 27 Open models are starting to close the gap on the closed frontier labs! Link: https://www.kimi.com/blog/kimi-k3