Initial deliverable of the architecture phase: 16 ADRs (stack, CRDT collaboration, plugin sandbox, import/export, backups, CI/CD), data model, permission model, real-time collaboration and plugin concepts, deployment/operations/security documentation, and the milestone roadmap that the implementation issues are derived from. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2.1 KiB
2.1 KiB
ADR 0016: Self-hosted Google Fonts, per-pond font configuration
- Status: accepted
- Date: 2026-07-04
Context
The vision: Pond Admins choose fonts for headings, body text, and monospace from a set of free Google Fonts; fonts must be served from the instance itself (never from Google's CDN) to avoid GDPR issues. Defaults: Roboto 400 (headings), Roboto 200 (body), Fira Code (monospace).
Decision
- Curated font catalog: the repo contains a maintained list (~15–25
families) of OFL/Apache-licensed families with the needed weights. A build
step (
deploy/fonts/) downloads the WOFF2 files at image build time from google-webfonts-helper/upstream sources and bakes them into thewebimage under/fonts/<family>/. No runtime download, no third-party requests from visitors' browsers — CSP allowsfont-src 'self'only. - Per-pond configuration: pond settings store three font slots
(
heading,body,mono), each referencing a catalog entry + weight. The app applies them as CSS custom properties (--font-heading,--font-body,--font-mono) on the pond's root element;@font-facerules for the catalog are generated once. - Defaults per vision: Roboto 400 / Roboto 200 / Fira Code. (Roboto 200 is
provided via the variable font or the 200 static weight; fallback stack
system-uichain.) - Licensing: each catalog entry records its license (OFL/Apache); the catalog page in the app shows attribution.
- Exports: the PDF renderer (ADR 0009) inlines the pond's fonts so PDFs match the on-screen look.
Consequences
- Adding a font is a catalog PR + image rebuild — no runtime font management surface (deliberately small attack/complexity surface).
- Image size grows by a few MiB per family (WOFF2, subset to latin/latin-ext by default) — negligible.
Alternatives considered
- Runtime font download by the server on admin selection: flexible but adds an outbound dependency, cache invalidation, and licensing bookkeeping at runtime; rejected for v1.
- Arbitrary font upload by Pond Admins: licensing risk and file-format attack surface; may become a Site-Admin-level feature later.