Three Claude tabs kept clobbering each other. So I built a guard.
TL;DR I run 3-5 parallel Claude Code sessions against the same homelab. One tab mid-refactor, one tab doing docs, one tab chasing a bug. They don’t know about each other, so every so often one tab “tidies up” a file another tab is actively editing — and Claude, being a dutiful little overwriter, just clobbers the work. I built a small Go binary that hooks into SessionStart / SessionEnd / PreToolUse, tracks file claims on disk, and injects a warning straight into the LLM’s context window when it’s about to step on another session’s toes. Optional Slack mirror so I can watch the timeline from my phone. MIT, single binary, no runtime deps. Repo: github.com/zolty-mat/claude-session-guard. ...