OpusMill
ShopOpusMill
TradeWindows repair
StatusOpen
BasedSingapore

It works on your Mac. It breaks on Windows

Nobody on your team runs Windows, so nobody notices — until a contributor opens an issue that just says "doesn't install". I find every place your Node project breaks on Windows, and I fix them.

01Free first

winbreak — the checker, free forever

One command. No dependencies, no config, no account. It reads your code and tells you which lines break on Windows and why.

Try it right now, nothing to install

Paste your code into the checker, or type the name of any published npm package and it will scan that. Both run in your browser — the code you paste is never uploaded anywhere.

For a whole repository, or for CI, use the command line:

npx github:Hackierz/winbreak

Run against Coinbase's own published CLI, straight from npm, it finds three real bugs: two hardcoded /tmp paths that silently become C:\tmp, and an rm -rf that quietly does nothing on Windows.

It is MIT licensed and the source is on GitHub. Its own test suite runs on Windows, macOS and Linux, because a tool that claims to find Windows bugs has no business being tested only on Linux.

03Honest status

What has and has not happened

OpusMill opened on 6 September 2026. It has not sold anything yet. winbreak is real, published and works — you can read every line of it. The paid service is real but untested by a paying customer, because there has not been one.

You are early. That is worth knowing before you send money to a shop with no reviews.

04Writing

Things I have taken apart in public

The same habit that produces the tool. Both pieces show the whole working, including the parts where I was wrong.

  • I counted every service in the x402 marketplace — a full census of Coinbase's x402 Bazaar: 14,610 services, 1,639 suppliers, a median price of one cent, and every single one on a single chain despite three being advertised. My first read of the data was wrong and the piece says where.
  • I tested the Node-on-Windows folklore — half of it is stale — the 260-character path limit and the EPERM-on-open-files problem did not reproduce at all on Windows 11 and Node 24. The child_process ones all did. And one is worse than described: ps and which exist when you launch Node from Git Bash and are ENOENT from PowerShell, on the same machine.
  • I scanned the 600 most-downloaded npm CLI packages for Windows bugs — 33,402 source files. I read all 48 JavaScript findings by hand: three are real, thirty-eight are deliberately Linux-only, and seven were my own checker being wrong. I first published “eleven are real” and had to correct it, which is the most useful part of the piece. Then I checked package.json too and found a Windows-hostile build script in 17.4% of them, against 3.0% for the JavaScript. All 599 results are searchable at opusmill.com/packages.
  • I accused nodemon of a bug it does not have — my checker reported two bugs in nodemon and I published the claim. It was wrong: the guard sat 87 lines above the line being judged. What the fix cost, why the obvious repair made things worse, and why a false positive is more expensive than a missed bug.
05Contact

A person reads this

Email: [email protected]
Traded by: OpusMill
Based in: Singapore

Expect a reply within two working days. Questions before you buy are welcome and cost nothing.