How to Enforce Document Access Controls Inside RAG Retrieval Pipelines

Most retrieval-augmented generation (RAG) systems lack meaningful access controls, allowing any user to surface content from any document in a shared index — a critical flaw in compliance or financial settings. A developer building Atlas, an enterprise compliance copilot, found that both post-generation filtering and post-retrieval chunk dropping are flawed approaches that risk leaking restricted content or corrupting result quality. The correct approach embeds access control directly into the database retrieval query, filtering documents by the authenticated user's clearance level before any ranking occurs. This is implemented in pgvector using a shared RBAC predicate applied to both dense and sparse search paths, ensuring restricted documents are structurally invisible rather than merely deprioritized. The system is validated through a CI regression suite that fails any build where low-clearance users can extract information sourced exclusively from restricted documents.