A type design tool that teaches as you draw. Sketch glyphs with a pencil, trace to Bézier, ship OpenType — and learn from a 102-code audit module with plain-English fixes for everything from spacing to OpenType invariants.
patens.design · Latin: lying open — root of patent, before lawyers got there.
Patens is a browser-native, open-source SvelteKit app for designing type. Every project lives in the browser's IndexedDB; nothing leaves your machine unless you choose to export. The differentiator isn't that it's browser-native — it's that the audit module is a citizen of the editor, not an afterthought. Every glyph, every metric, every kern pair has a teaching surface: "your sidebearings drift across the stem class" or "this contour winds the wrong way for OpenType" — with the rule, the why, and a one-click fix where one exists. (Why audit-as-teaching →)
The demo project ships 162 drawn glyphs across Latin (uppercase + lowercase, numerals, punctuation, currency, math, brackets, composite ligatures), a partial Cyrillic set (17 look-alike letters reusing Latin builders + bespoke Я Ж Ф), and a partial Greek set (14 uppercase look-alikes) — enough to set a UI, a price table, or a Bulgarian legal footer without falling back to system fonts.
- Marketing site: patens.design — long-scroll editorial with the audit's worldview, an annotated specimen of the demo OTF, an interface mock of the editing surface, the 101 codes by family, and a comparison vs every other tool in the field (FontLab, Glyphs, Robofont, Fontra, Glyphr Studio, typlr, BirdFont, FontForge, Lipi, Fontish).
- Compare table: patens.design/compare — 11 tools × 26 distinguishing features.
- The Method (the 101 codes): patens.design/audit — what each family checks, what's plain-English-explained, what's one-click-fixable.
- Canonical references on every rule page: patens.design/audit/self-intersecting — each of the 101 dedicated audit-rule pages now surfaces the primary literature where the rule is established (OpenType spec, TrueType reference, FEA spec, UFO 3 spec, Unicode 16, Adobe Glyph List, Stop Stealing Sheep, OpenType Cookbook, Knuth Metafont papers, variablefonts.io primer). 89 of 101 codes covered in the open MVP corpus per
docs/research/canonical-library.md; the remaining 8 require licensing the craft canon (Tracy 1986, Smeijers 1996, Noordzij 1985, Cheng 2006).
The app itself is in private alpha at an unlisted URL — invitees only. Public launch is scheduled for TypeCon Portland, August 6–8, 2026. Sign up for an invite at patens.design; the waitlist endpoint persists to Vercel Blob.
| Capability | Notes |
|---|---|
| Audit | 101 codes covering contour shape, vertical metrics, OpenType invariants, brief completeness, multi-script coverage; teaching prose on every code + one-click fixes for the fixable ones. The headline feature — runs continuously alongside the editor, not as a separate lint step. |
| Pressure-sensitive sketch | Drawn input with stroke weight + pressure; trace to cubic-Bézier contours via boolean union + Schneider curve fitting |
| Direct contour editing | Smooth ↔ corner points, nudge, multi-select, transform |
| Variable fonts | Multiple masters at distinct axis locations + named instances + a 2D variation explorer for ≥2-axis projects |
| OpenType features | Auto-detected from glyph-name suffixes (.ss01, .smcp, .onum); real ligature substitution (f_i → fi); live HarfBuzz preview |
| Kerning + classes | Pair editor, class system, silhouette-distance auto-kern, family-wide kerning resolution |
| Color fonts | COLR v0/v1 + CPAL palettes; live color-plan rendering |
| Anchors + composites | Mark-positioning rig (top / _top anchor convention) + component composites with offset resolution |
| Export | OTF + WOFF2 (in-browser), TTF (Pyodide + ttfautohint), UFO, designer-bundled .zip, portable .font.json |
| Specimen | Print stylesheet that strips chrome and emits a PDF-ready specimen sheet |
| PWA | Service worker for real offline; manifest + 192/512 icons for install |
| Accessibility | WCAG 2.0 + 2.1 + 2.2 A/AA enforced via axe-core in CI across 31 routes |
v1.5.2 — production code-grade, private alpha by invitation. The marketing surface and OG cards are live at patens.design; the editor sits at an unlisted URL handed out to alpha invitees. Public launch at TypeCon Portland, August 6–8, 2026 (~10 weeks). Three optional integrations gracefully degrade when not configured:
- Vercel Blob — cloud share (recipients in other browsers)
- GitHub OAuth — sign-in via GitHub
- Anthropic API key — AI presets (audit explanations, consistency, kerning suggestions; user-provided key, no shared cost surface)
Setup per host (Vercel, Cloudflare Pages, Netlify, self-host): see docs/setup.md.
For what's deferred: ROADMAP.md. For release history: CHANGELOG.md (also at patens.design/changelog · RSS).
pnpm install
pnpm dev # http://localhost:5173
pnpm test # vitest (722 unit tests + 6 perf benches)
pnpm test:e2e # Playwright + axe-core a11y (66 e2e tests across 7 files)
pnpm check # svelte-check / TypeScript strict
pnpm build # production build
pnpm profile # cold-load CDP trace (any URL)Audit a .font.json project without opening the editor — useful for
CI, foundries lint-checking client deliverables, or scripted batch
work. The CLI is a thin shell around the same 102-code audit module
the editor uses, packaged for Node 22+.
pnpm run cli:build # bundles cli/dist/index.mjs (one-time)
pnpm patens audit my.font.json
pnpm patens audit my.font.json --severity=error # CI-friendly
pnpm patens audit my.font.json --json | jq '.' # machine output
pnpm patens audit my.font.json --github # PR annotations
pnpm patens describe self-intersecting # explain a code
pnpm patens helpExit code is 0 when no error-severity issues, 1 when there are,
2 on usage / parse failure. Drop-in CI:
- run: pnpm run cli:build
- run: pnpm patens audit fonts/*.font.json --github --severity=warnEvery project is a single JSON blob (typed as Project in src/lib/font/types.ts) stored under a UUID key in IndexedDB via idb-keyval. The editor reads through a projectStore reactive store; mutations re-emit + auto-save. The share page is ssr=false and loads from the local IndexedDB — its only network dependency is the static SvelteKit build itself. Export is dual-path: OTF/WOFF2 via opentype.js in the browser, TTF + ttfautohint via Pyodide running as WASM. The audit module is the spine: 101 codes feeding five teaching surfaces (edit panel, audit page, release pre-flight, family hub, home page) through a single describeAuditCode() dictionary. Cloud share uses Vercel Blob with token-based auth (constantTimeEqual for token comparison); sign-in uses HMAC-signed session cookies (safeReturnTo against open-redirect). Full setup details in ARCHITECTURE.md.
See CONTRIBUTING.md. PRs welcome. Run pnpm check && pnpm test && pnpm test:e2e before submitting.
For security issues: see SECURITY.md or email security@patens.design.
MIT. The demo project's glyph data is part of the codebase under the same license; export an OTF and use it however you'd license your own work.
Made by Alejandro Vizio — @patenstype on X, @patens.design on Bluesky, hi@patens.design for everything else.