An LLM privacy gateway is middleware between an application and an external model provider. It creates a repeatable control point before prompts, retrieval results, or tool output leave the application's boundary.
Why centralize it?
Without a shared boundary, different services can implement different sanitization rules. A gateway makes common checks reusable infrastructure.
Keep the application in control
Authorization, business permissions, tool access, provider choice, and provider contracts remain application responsibilities. NullTrace stays focused on inspection and transformation.