Show HN: Isartor – Pure-Rust prompt firewall, deflects 60-95% of LLM traffic

Isartor: pure‑Rust prompt firewall that claims to deflect 60–95% of LLM calls using semantic caching + an embedded SLM. Self‑hosted, air‑gapped. Read the repo: https://github.com/isartor-ai/Isartor (docs: https://isartor-ai.github.io/Isartor/) How it works: sits between agents and the cloud LLM, computes embeddings, checks a semantic cache, and either returns a cached answer or runs a tiny local SLM (Candle/HuggingFace). Pure Rust runtime — no external infra required. Where it wins: repetitive