Juggling Claude Code, Codex, OpenCode, and Cursor across a dozen tabs means losing the thread. A session finishes, you move on, and coming back means re-reading everything to remember where it stood. ThreadVigil watches all four locally, pings you the moment one's actually waiting, and writes a paste-ready "catch me up" handoff so you're not re-explaining context to yourself. Nothing leaves your Mac. Free, with an optional way to chip in.