I've seen this called "agentic RAG" by some people. The easiest way to get a local demo is with Claude Code or Codex CLI. They know how to use grep, and you can set them loose on a folder full of text files and tell them to use grep to answer questions - it can work really well.

I just tried this in "claude --dangerously-skip-permissions":

> Use Python and AppleScript to find Apple Notes that mention UPS

... and fell down a rabbit hole of optimizations because my Notes collection is HUGE, but it got there in the end!