Snow Editor

Markdown and Org-mode editor with live preview. Multiple local drafts in localStorage. Shared docs via link + SQLite backend.

Pablo Murad — pablomurad@pm.me

Highlights (0.0.2)

• CodeMirror editor for both Markdown and Org (highlight, checklist click-toggle).
• Multiple local drafts — drafts menu in the toolbar (list, create, delete). Imports open as a new draft.
• Outline sidebar for Markdown and Org on wide screens.
• Dark mode (follows prefers-color-scheme).
• Write/Read tabs on mobile; draggable split divider on desktop (double-click resets).
• Syntax highlighting in preview code blocks (highlight.js, lazy-loaded).
• Editor → preview scroll sync; capped preview line width for readability.
• Print styles: Ctrl+P prints only the rendered document.
• Exported filenames derive from the document title.
• Server: version snapshots coalesce (5 min window); expired documents are purged hourly.

Requirements

• Node.js 22.5+
• Docker + Compose (optional)

Quick start

cp .env.example .env
docker compose up -d --build

• Frontend: http://localhost:41737
• API: http://localhost:41738/api/health
• DB file: ./data/snow.db

Local dev

Terminal 1:

npm install
npm run dev

Terminal 2:

cd backend && npm install && npm run dev

Vite proxies /api to port 41738.

npm run build
npm run preview

Tests

cd backend && npm test   # API unit tests
npm test                 # Org pipeline unit tests
npm run test:e2e         # Playwright smoke (starts backend + Vite dev)

First e2e run needs npx playwright install chromium. CI (GitHub Actions) runs unit tests, build, and e2e on every push/PR.

Config

See .env.example. Main vars:

• SHARE_ALLOWED_ORIGINS — who may POST /api/documents (default includes localhost:41737)
• VITE_PUBLIC_ORIGIN — base URL for share links
• VITE_ALLOW_SEARCH_INDEXING — true/false (rebuild after change)
• DATABASE_PATH — SQLite path

Routes

• / — local editor
• /v/:token — read-only shared view
• /e/:token — shared edit (lock required to save)

Share from /: pick title and expiry, get view + edit URLs.

POST /api/documents needs a browser Origin on the allowlist. No origin → 403.

Edit lock: one editor per doc, 2 min TTL, refreshed every 30s while tab is open. Released on pagehide (re-acquired when restored from bfcache).

Versions: saving snapshots the previous content, coalesced to at most one snapshot per 5 minutes (restores always snapshot). Up to 50 versions per doc. Expired documents (and their locks/versions) are purged at boot and hourly.

API

GET    /api/health
POST   /api/documents
GET    /api/documents/view/:token
GET    /api/documents/edit/:token
POST   /api/documents/edit/:token/lock
POST   /api/documents/edit/:token/lock/refresh
DELETE /api/documents/edit/:token/lock
PUT    /api/documents/edit/:token
GET    /api/documents/edit/:token/versions?clientId=&lockToken=
POST   /api/documents/edit/:token/versions/:versionId/restore

Limits: 60 req/min per IP on /api, 10 req/min on POST /api/documents, 1 MB max body.

Health returns { ok, db, uptime, version }. DB down → 503.

Stack

React, Vite, Express, SQLite (node:sqlite), marked, Orga, CodeMirror 6, DOMPurify, highlight.js, Playwright.

Org-mode

Parser: Orga. Editor: CodeMirror (highlight, fold, checklist toggle, outline on wide screens).

Works: headings, lists, tables, TODO keywords, SRC/QUOTE blocks, basic inline markup, #+TITLE.

Does not work: babel, agenda, LaTeX, full Emacs export. Not a replacement for Emacs.

Backup

Manual only. Stop backend first if copying live.

./scripts/backup-db.sh          # or backup-db.ps1
docker compose stop backend
./scripts/restore-db.sh <file>  # or restore-db.ps1 -Backup <file>
docker compose start backend

Or copy data/snow.db yourself.

Notes

• No accounts. Edit links are capability tokens — anyone with the link can edit when unlocked.
• Token leak mitigation: Referrer-Policy: no-referrer (nginx + meta) and noindex on /v/ and /e/ routes.
• No realtime collab.
• Preview HTML is sanitized.
• Monitor production with GET /api/health.
• Rebuild Docker after changing VITE_* or SHARE_ALLOWED_ORIGINS.

License

Use freely for personal projects and learning.