massCode

massCode provides a local, offline‑first workspace where developers can store and organize code snippets, markdown notes, and quick calculations. Snippets are edited with a CodeMirror‑based editor, formatted by Prettier, and can be previewed in real time for HTML, CSS, and JSON, while notes support live markdown rendering, Mermaid diagrams, and mind‑maps generated from headings.

The application groups content using folders, tags, and fragments, and includes a set of built‑in developer utilities such as converters, encoders, hash generators, and helpers for JSON, Base64, URLs, colors, passwords, and UUIDs. These tools let users perform small tasks without leaving the app. Integration points include a VS Code extension for searching and inserting snippets and a Raycast extension for quick access.

All data is saved as plain markdown files on the user’s machine, making synchronization with services like iCloud, Dropbox, or Git straightforward. massCode is open source, free to use, and offers a localized interface in fifteen languages.