Building Cross-Platform CLI Tools That Work Everywhere: macOS, Linux, and Windows

Building Cross-Platform CLI Tools That Work Everywhere: macOS, Linux, and Windows Your CLI tool works perfectly on your MacBook. You push it to npm. Then the bug reports roll in: "crashes on Windows," "wrong path separator," "colors don't show up in PowerShell." You've just learned the hard way that building a CLI tool for your machine and building one for everyone's machine are two very different things. After shipping over 30 npm CLI tools — from websnap-reader (a headless page snapshot utility) to ghbounty (a GitHub bounty scanner) to pricemon (a price monitoring daemon) — I've catalogued every cross-platform pitfall worth knowing about. This guide is the distilled playbook: the problems you'll hit, the solutions that work, and the libraries that save you hours of debugging. The Cross-Platform Challenge Node.js promises "write once, run anywhere." And for pure computation, it delivers. But CLI tools aren't pure computation. They touch the file system, spawn child processes, read env