[pcbtracer]

PCB Tracer reads and writes over a dozen different file types — including images, schematics, datasheets, netlists, and revision history. It also provides an AutoSave feature, to prevent losing your work. Every file is saved to your project directory during a session. Doing all of this without constant interruptions to get user permissions requires the File System Access API, which is not yet available in all browsers. The Firefox developers have explicitly stated that this API will not be supported.

The File System Access API has security precautions built-in. For example, it requires users to explicitly grant permission to access a specific directory (once) per session. Also, the API never allows access to root or to system-related directories.