Metadata Filtering

"There's no authentication or authorization through the security principal. The principal is just a string." Microsoft wrote that sentence about security filters in Azure AI Search, and it holds for every search engine and vector database a RAG assistant might use: the engine compares the strings it is handed. Whether those strings describe the person asking, and what happens when a chunk arrives without them, is decided by the code that builds the filter. That code is the access-control system of a RAG assistant, whether or not anyone designed it as one.