Curio — website prototype

One word, one origin story, once a day — now as a website instead of the original React Native app. See website-pivot-brief.md (in the project) for the reasoning behind the pivot; this README covers what's actually built here.

What's implemented

• Today (/) — shows the date-math-determined word of the day. No backend sync needed to compute it; same logic that powered the app's notification timing, minus the notification.
• Story view (/story/[slug]) — Origin / Journey / Related Words sections, favorite (heart) and share (Web Share API, falls back to copy-link) actions. Reachable from Today, History, Collection, or an emailed link.
• Collection (/collection) — the words you've favourited, newest first, with a language band drawn from them. Static, and no account is needed: favourites live in localStorage (and sync to the account when signed in). It loads their word data from /api/words.
• History (/history) — the archive. Signed in, "My days" and "All words"; signed out, just "All words". Linked from Today ("Past words") and Collection, not the nav. Favourites aren't here: that's Collection.
• Onboarding — a first-visit modal (tagline + short pitch) with an inline email + delivery-hour signup, skippable. Replaces the app's notification-permission step.
• Email digest — /api/subscribe takes {email, source?}; anonymous signups confirm by email (double opt-in: a signed 7-day link, and a button on the page it opens adds the address). /api/cron/send-daily runs once a day at 09:00 UTC (vercel.json; the Hobby plan allows one run a day) and sends every subscriber the day's shared word through Resend's batch endpoint. It's idempotent per UTC day (?resend=failed, ?force=1 and ?force=1&bluesky=1, all with CRON_SECRET, for deliberate re-sends; see handover.md). Every digest carries a signed unsubscribe link plus List-Unsubscribe / one-click headers; opening the link shows a confirm page, and only its button (or a mail app's one-click) unsubscribes.
• Light/dark mode — follows system preference by default; the header toggle cycles System → Light → Dark, stored in localStorage.
• Attribution (/attribution) — the CC BY-SA notice for Wiktionary / Wiktextract content, linked from the footer. This was an open compliance item on the mobile app too — it's included from the start here rather than left for later.
• Bluesky (@curiodaily.bsky.social) — the same daily cron posts the word: a teaser, then word · lineage arrows, then #etymology #wordoftheday (format (a)), with the story link moved out of the text into a link card (the story's own title, a fixed description, and its Open Graph image as a thumbnail). npm run bluesky:preview -- [days] [from] prints what the next days' posts will look like, read-only, for review before anything goes out.
• Threads + Instagram — a separate daily cron, /api/cron/social at 10:00 UTC, posts the same word to Threads (a text post with a link card) and to Instagram (a 4–6 slide 1080×1350 carousel, built only from the word's stored fields and served as JPEG from /social/carousel/<slug>/<n>). Each channel is idempotent per UTC day, with ?repost=threads|instagram (CRON_SECRET) for a deliberate re-post. Nothing posts until the four THREADS_* / INSTAGRAM_* env vars are set — without them the cron only logs, and removing a token turns its channel off again — and the tokens are refreshed weekly into Redis in production. npm run social:preview -- [days] [from] prints the next days' posts and slide URLs, read-only, for review. Setup and operations are in handover.md.
• Traffic sources — first-party, counts-only tracking of where visits and signups come from (email, Bluesky, Threads, Instagram, search, share and so on), production writes only. /admin shows it; npm run traffic:report -- [days] prints it, read-only. See "Measuring growth" in handover.md.
• Language facts — an "About {language}" panel on Collection (map, timeline, speakers, family path, origin), built only from owner-reviewed sheets in lib/languages/data.ts. The sheets come from an offline pipeline, run in this order (details and checks in handover.md, "Language panel"): npm run languages:facts -- [--only "A,B"] [--limit N] [--refresh] fetches Wikipedia and Wikidata facts; npm run languages:draft -- [--only] [--limit] has Claude draft a sheet from those facts (needs ANTHROPIC_API_KEY in .env.local); npm run languages:review writes the git-ignored review.html; npm run languages:approve -- --all-valid | --only "A,B" validates and writes data.ts and sheetIndex.ts (never hand-edit either). npm run languages:map regenerates the dev-only map dots. data.ts is empty until the first reviewed batch, so no "About" link shows yet.

Content

lib/words.ts has 8 seed entries, written in Curio's voice from general etymological knowledge. This is a stand-in for the real content pipeline — port over the offline Wiktextract + Haiku rewrite pass from the mobile project to generate a full word bank, then replace the WORDS array (or swap lib/words.ts to read from wherever that pipeline writes its output).

Datastore & email — real vs. fallback

Both lib/db.ts (subscribers) and lib/email.ts (sending) check for credentials and fall back to something dev-friendly if they're missing:

	Configured	Fallback (no env vars)
Datastore	Upstash Redis	Local JSON file at .data/subscribers.json
Email	Resend	Logs to console instead of sending

This means npm run dev works out of the box with zero setup — subscribing writes to a local file, and the cron route logs what it would send. Add real credentials (see .env.example) whenever you're ready to actually send mail.

Getting started

```bash npm install cp .env.example .env.local # optional for local dev — works without it npm run dev ```

Visit http://localhost:3000. To test the send flow locally:

```bash curl http://localhost:3000/api/cron/send-daily ```

Deploying

The natural fit is Vercel (matches Next.js, and vercel.json already configures the two daily crons: the digest at 09:00 UTC and the Threads/Instagram posts at 10:00 UTC):

1. Push this to a git repo, import it into Vercel.
2. Set the environment variables from .env.example in the Vercel project settings — at minimum RESEND_API_KEY, CURIO_FROM_EMAIL, UPSTASH_REDIS_REST_URL, UPSTASH_REDIS_REST_TOKEN, CURIO_SITE_URL (your production domain), CRON_SECRET, and UNSUBSCRIBE_SECRET (required: without it the daily send refuses to run). Optionally, the four THREADS_* / INSTAGRAM_* vars: without them the social cron only logs, so they're what switches those posts on.
3. Vercel Cron picks up vercel.json automatically on deploy — no extra configuration needed.
4. Create a free Upstash Redis database and a Resend account/domain to get the real credentials.

Open items / next stage

• Port the real word bank over from the mobile project's content pipeline (currently only 8 placeholder entries).
• Wire up real Upstash + Resend credentials and send a real test digest.
• Decide on a production domain for CURIO_SITE_URL and sender address.
• No automated tests yet.