Baidu just released ERNIE 5.5 Flash as a raw base model, and that's the interesting part 🧱
Most open model launches hand you a finished assistant. Baidu went the other way this weekend: it put ERNIE-5.5-Flash-Base on Hugging Face, the checkpoint taken at the very end of pre-training, before any mid-training, instruction tuning or reinforcement learning. In other words, the foundation, not the house. What was released According to the model card, ERNIE 5.5 Flash is a sparse Mixture-of-Experts model with 280B total parameters, of which only 14B are active per token. It was pre-trained from scratch on 33.5 trillion tokens with the Muon optimizer, at a training context of up to 128K, and the released config supports fine-tuning and inference up to 1M tokens. It is text-only, and Baidu publishes both FP8 and BF16 weights, with serving instructions for SGLang and vLLM (via a vLLM-ERNIE plugin). Why I like this A base checkpoint is the most useful thing a lab can give researchers and builders. Every chat model makes choices about tone, safety style and reasoning format. A base...