AlphaFold gave us the fold of one protein. But biology runs on contact — a protein grips another, a drug settles into a pocket, a transcription factor clamps onto DNA. Co-folding models like AlphaFold3 predict the joint structure of the whole complex in one shot; the open-source Boltz line then democratized it, and Boltz-2 took the next step no structure model had — predicting how tightly two molecules bind, approaching physics-based accuracy about a thousand times faster. It’s the wiring, and the weights, a virtual cell needs — and the scoring half of an agent that designs its own drugs.
