In a new app
fliin init --preset c0000000000000
In an app already set up
fliin theme --preset c0000000000000
Fonts
Fliin writes the family name into the tokens; your app ships the font files. Download them from Google Fonts, then declare them in pubspec.yaml:
The tokens it writes
core/tokens/fliin.tokens.json after the command, in a fresh app on core 0.2.5, the version fliin init installs today. The command regenerates tokens.g.dart from it. An app on another version of core gets the tokens of that version.