Guides for running a developer Mac

Find the process holding port 3000 with lsof, stop it without kill -9, and handle servers that come straight back. Then the one-click version.

Fan noise is a symptom. Find the swift-frontend, tsc, or webpack process behind it with top and ps, trace it to a project, and stop it without losing work.

Find uncommitted changes, unpushed branches, stashes, and repos with no remote across every project, plus the keys and .env files Git never had.

Rotate the key, remove it from history with git filter-repo, find the others across your repos, and keep .env values out of the tree for good.

What Claude Code, Codex, and Cursor can do with a shell, how to limit it in each tool, and how scoped MCP tools that ask first replace rm -rf.

Find your Mac’s LAN address, bind Vite, Next, or Expo to all interfaces, get past the macOS firewall, and scan a QR code instead of typing the URL.

Folder by folder: what Xcode and Docker Desktop keep on a Mac, which parts come back on their own, which do not, and the command for each.