How we built a virtual filesystem for our Assistant

Mintlify replaced RAG-based doc retrieval in their AI assistant with a virtual filesystem (ChromaFS) that lets agents use grep, cat, ls, and find on live documentation. The approach cut session creation time from ~46 seconds to under 2 seconds and reduced infrastructure costs from $70k+/year to near zero. The key insight: agents treat filesystems as a native interface, making exact-string search and multi-page traversal trivially solvable.