Meta PrivacyLib: Privacy Controls at the Data Access Boundary

Meta detailed PrivacyLib, a common library embedded in the clients of hundreds of its data and processing systems that enforces privacy requirements at the point of data access, performing billions of checks per second. Systems integrate once, and new privacy capabilities ship as plug-in modules, replacing per-system implementations that could take months. An Agent Observability module tracks internal AI agent data access by carrying agent context to PrivacyLib.