fonts.customFonts

Your own fonts: the same bag FontRegistry.registerCustomFont() takes. Your own fonts are never gated. customFonts (a URL you serve or bytes you hold) works under every license, and so do the fonts embedded in the documents you open. The license governs where _our_ fonts come from, not which fonts you use. A viewer's fonts are the ones customFonts names when it is created; there is no method to add one to a running viewer. FontRegistry is exported for loading fonts outside a viewer — fonts you register with one you construct yourself are not seen by any viewer.

// Register a custom font from URL
fonts: {
  customFonts: [
    {
      id: 'my-serif',
      displayName: 'My Serif',
      ttfUrl: 'https://cdn.example.com/fonts/MySerif-Regular.ttf',
      category: 'serif',
    },
  ],
}