TL;DR — Can an outsider verify that an LLM was "trained from scratch"? In 2026, largely yes. Using only public Hugging Face artifacts — config.json , tokenizer.json , and embedding weights — you can fingerprint a model's lineage and place it on a spectrum from fully original to a straight port of a foreign base. This guide explains the method, what it can and cannot prove, and the open-weight debate that made it a 2026 talking point. Key takeaways Three public signals —...