Meituan

Meituan LongCat has open-sourced LongCat-2.5, a natively multimodal model with 1.6 trillion total parameters, roughly 48 billion activated per token, and one-million-token context, released under the MIT license for commercial inference and retraining. It encodes visual signals as multi-level discrete tokens sharing the same backbone as text, and uses a W4A4 4-bit quantization scheme tuned for domestic AI chips constrained by memory and bandwidth.