Every AI search tool makes you copy data out and sync a second source of truth forever. SemiLayer flips it: an intelligence layer that bolts onto the database you already run — point at a table, declare a lens, get a typed client. Your data never leaves. Stands out: 4 features in one client (semantic search, similarity, drillable dashboards, personal feeds) where most tools do one; cross-source joins across Postgres/Mongo/ClickHouse; zero vector infra; airgap-capable Runners.