Learn the bjs command-line tool for the BabylonJS Market and the create-arcade scaffolder. Across seven short lessons you log in from your terminal with a device-code flow, scaffold a running BabylonJS project and choose its kind and renderer, browse the catalog in the terminal BBS, download marketplace assets with bjs download, eject the arcade package's own component source into your project as code you own and can edit, shape a component into the marketplace folder format, and inject it back for curator review — then track it from pending to merged. Every lesson stays on the real commands you run and the marketplace loop they drive — how each step works and why, without wading into the tool's internals. The course stays on the CLI workflow and the marketplace loop, and links out to the Arcade ECS and TypeScript courses for the framework and toolchain underneath. By the end you have moved code both ways: community code into your project, and your own component into the catalog.