What is keystrokes?

Keystrokes is a small JavaScript project that turns your typing into music. Instead of choosing which sounds to play, your keystrokes steer a generative lofi engine that always stays in key and on the beat. Typing supplies rhythm and energy while the underlying music theory runs automatically in the background. There are two ways to use it. A browser version runs entirely on a web page: you type into it and it plays sampled piano notes, swung drums, and vinyl crackle, with nothing saved or sent anywhere. A local version, started with a single script, listens to your keystrokes across any application on your computer, and adds a second melodic voice built from text generated by AI coding assistants such as Claude Code and Codex, played back panned to one side. The local setup runs a small system: a program watches your keystrokes, a lightweight local server coordinates everything, and a browser tab renders the actual sound using the Web Audio API. Getting started is a single script that checks for git, node, and python, then opens a local hub in your browser. On a Mac, you need to grant your terminal permission to monitor keystrokes before the tap can work, the other pieces also run on Linux and Windows, sometimes with a few manual steps instead of the one-command install. You can choose from several musical styles, from lofi tape to arcade chiptune to a slower rainy day mood, and adjust how busy the melody gets. The local version also reacts to your actual coding work: running a terminal command, hitting an error, a test passing or failing, and making a git commit each trigger their own small musical cue. Every session is automatically recorded as a set of sound events rather than text or keystrokes, and can be replayed later from a saved list, either in the browser or on your own machine. This is a personal, playful tool rather than a productivity app, built for people who want ambient music that responds to the act of typing and working.