Why I scrub AI prose with regex, not a second LLM

Written by Stephanie Dover, Software Engineer 10+ YOE, ex GitHub, Twitch, Microsoft. Creator of Klaussy. LinkedIn · GitHub · Klaussy Desktop · Klaussy Agents TL;DR klaussy-agents is a free, MIT-licensed CLI ( pip install klaussy-agents ) that makes the prose an AI coding agent writes, PR comments, review notes, commit messages, read like a person wrote them. It works in two layers: a humanization spec baked into the agent's skills so it writes clean prose up front, and a deterministic klaussy humanize pass that scrubs the output afterward. The scrubber is rule-based regex, not an LLM, and it never touches code. There's also a part I didn't expect going in: once the AI tells are gone, what's left can read curt and run long, so the spec also handles tone (don't be rude) and length (one sentence for a reply, one to five for a review comment). Repo: github.com/steph-dove/klaussy-agents. The problem You can spot AI-written text now. Everyone can. And the place it grates most is a code review comment or a commit message, where the prose sits next to your name in a thread your teammates read. The tells are consistent. The em-dash is the biggest one. Right behind it: filler openers like "It's worth noting that…" and "I wanted to point out that…", chatbot scaffolding like "Hope this helps!" and "Let me know if you have questions!", and stacked hedges like could potentially . An agent that leaves those in your PR reads like a bot, and people notice. The obvious fix is to tell the model not to do it. Add "don't sound like AI" to the prompt and move on. That helps, inconsistently, and it regresses silently the moment you change the model or the prompt drifts. Editing every comment by hand works too, but hand-editing every comment defeats the point of having an agent write them. I wanted something I could trust without rereading. Why "just tell the model" wasn't enough The honest answer to "why not just prompt for it" is: a prompt asks, it doesn't enforce. The model tries to com