Typography.kt resolved Fraunces, Inter and JetBrains Mono through the Play
Services font provider, which fetches them over the network on first use.
Same rule-164 problem the web client had, with a second failure mode on
top: the provider is absent entirely on devices without Play Services, so
the app fell back to the platform default and stopped looking like
Minstrel — quietly, with no error.
The five static instances now live in res/font, vendored by the same
tools/vendor-fonts.py that produces the web bundle. Both clients draw
from one list of faces so they cannot drift apart. Cost is ~0.86 MB of
APK; the runtime path is removed rather than kept as a fallback — the
ui-text-google-fonts dependency, its version-catalog entry and the
provider certificate hashes in font_certs.xml are all gone.
Two things about fetching TTFs that are worth writing down, because both
fail by succeeding:
Google Fonts picks the format from the User-Agent, and there is no
parameter to ask for one. A modern UA gets woff2, which res/font cannot
load. The obvious "use an old UA" fix gets EOT — an IE-only format that
downloads happily, has a plausible size, and is entirely useless here. An
Android 4.4 UA is what actually yields TrueType.
css2 also collapses a multi-weight request to 400 for legacy clients, so
asking for Medium silently returns Regular: a valid TrueType file that
renders at the wrong weight everywhere. Each weight is therefore fetched
on its own URL, and the script now asserts OS/2 usWeightClass on every
download — that field is the only thing distinguishing the two files.
Verified before wiring: all five carry TrueType magic, the 400/500 pairs
differ, and their usWeightClass reads 400/400/500/500/400 as declared
beside them in the FontFamily.
Not covered: there is no guard for this on the Android side. The web
equivalent is asserted by no-external-assets.test.ts, but the Android
tree has no source-inspection test pattern to follow and no way to
falsify one without a local Gradle run.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SQ31KQpYbStyK5y58UmPLH
app.html linked its stylesheet straight from fonts.googleapis.com, with
preconnects to that host and fonts.gstatic.com. A deployed instance has
no outbound network, so those requests never arrive and the whole UI
renders in fallback faces — Georgia for the display face, whatever the
system has for Inter and JetBrains Mono.
This is invisible in development, which is why it survived: the dev
machine has internet, so the fonts load and everything looks right. Only
a real deployment shows the failure.
tools/vendor-fonts.py fetches the three families once and writes them
under web/static/fonts with a generated stylesheet. static/ is copied
into the SvelteKit build, which Go embeds, so the faces travel inside the
binary. 32 woff2 files, 912K.
Two details that matter for correctness rather than size:
Urls in the generated CSS are relative (./Inter-400-latin.woff2), not
absolute. A url() resolves against the stylesheet's own address, so the
directory keeps working when the app is served under a base path;
/fonts/... would not.
Every subset Google slices is kept, with unicode-range intact. The
browser still fetches only the ranges a page uses, so this costs
repository bytes rather than request bytes — and a library full of
Cyrillic or Greek artist names renders instead of falling back mid-list.
The guard asserts the property, not the vendor: any absolute url in a
resource-loading attribute fails, whoever hosts it, since naming Google
would pass the day someone reached for a different CDN. It also checks
preconnect separately (those carry no fetch of their own, so the url
check misses them), strips HTML comments before asserting an absence so
prose describing the forbidden thing cannot satisfy the check, and pins
the font families to tokens.json rather than a hardcoded list.
Falsified against the pre-change app.html: it trips both the external-url
and preconnect assertions.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SQ31KQpYbStyK5y58UmPLH
bvandeusenandClaude Opus 5