Demos are great to see examples of how an end user may interact with WebAuthn, but developers may be interested in the details of authenticator interaction. Check out these tools to help with your WebAuthn implementation.
SimpleWebAuthn is a collection of libraries created by @MasterKale to simplify WebAuthn integration. The demo implementation uses the server and client libraries and provides more detail on authenticator input and output. A debugger is also available that parses and displays authenticator output.
WebAuthn Playground by @opotonniee shows authenticator input and output details along with a parsed output for debugging.
The WebAuthn Viewer project, created by @inabajunmr, allows selecting various registration and authentication options. The site displays parsed authenticator output for both ceremonies.