Since version 96, Microsoft announced that users can use Protocol Handlers in Microsoft Edge. This latest feature will allow installed web apps (or PWAs) to browse pre-set or custom protocols. Installed network applications will also be able to register with the operating system as protocol handlers and start when a specific protocol is invoked.
If your web application has the ability to register as a protocol handler, it integrates better with the operating system and can be set to open specific protocols. It can also be set as the default handler, which means that if you’re developing a web app that acts as an email client, you can give users the option to make it the default app for generating new emails.
Additionally, you can generate custom schemes that your web application can manage by registering protocols prefixed with web+. It can be a useful resource if you need to browse a “safelist scheme set not suitable” URL.
According to the press release, in order to register your installed web application as a protocol handler, you need to use the protocol_handlers field in your manifest file. If the protocol-handlers field in the manifest is available, in this case, the web app will be registered as the protocol handlers defined in the collection during installation.
Protocol handlers provide support for Windows, Linux, and Mac. The press release mentions that Microsoft has “contributed this work to the Chromium open source project” and that the feature is also available in other Chromium-based browsers.