
Semantic Caching for LLMs: $0 Cache Hits, PII-Safe by Default
Traditional caching keys on an exact match: same input, same cached output. That works for HTTP and falls apart for language, because two prompts can be worded completely differently and mean exactly the same thing. "What's your refund policy?" and "How do I get my money back?" would miss an exact-match cache every time — and you'd pay to generate the same answer twice.
Semantic caching keys on meaning instead of bytes. But a cache that stores prompts and responses is also a governance surface: it can quietly hold raw PII, and it can quietly keep charging you for calls that never happened. Both are failure modes a governance platform has to close by default — which is why, in DVARA, the semantic cache lives inside the same governed path as Policy-as-Code and PII redaction, not off to the side.

