When a RAG system confidently states last quarter's price, last year's policy, or a fact that stopped being true in March, the reflex is to blame the model. Often the model did exactly its job: it grounded its answer faithfully in what retrieval handed it, and what retrieval handed it was stale. Your vector index is a cache of the world, and like any cache it goes wrong not by erroring but by quietly serving the past. Here is how to keep an index built from scraped web data fresh, and why freshn...