Works On My Machine Certificate

"Works on my machine" is the oldest defense in software. The code runs locally, where the right runtime, environment variables, cached dependencies, and test data happen to exist, and fails everywhere else. Containers and CI were invented largely to retire the phrase. It survives anyway.

The generator draws a certificate of local functionality on a canvas in your browser: parchment, a double gold border, a seal, a signature line, a certificate number, and fine print disclaiming staging, production, CI, Docker, and any machine belonging to another person. Nothing is uploaded. The file is a 1600 by 1130 pixel PNG, large enough to print and pin above your desk.