FlipScan 📷→💶

Snap a vintage item on your phone → Claude IDs it (brand, type, era, flaws, fake-flags) → it pulls comparable resale prices and gives you a range + one-tap search links into eBay (sold), Vinted and Depop.

Built to run on Vercel (one static page + one serverless function). Your API keys live as Vercel env vars — they never touch the browser.

flipscan/
  index.html      # the phone UI (camera, resize, results)
  api/scan.js     # serverless fn: photo -> Claude -> eBay comps -> JSON
  package.json    # Node 18+, ESM, zero dependencies
  .env.example    # the env vars to set in Vercel

Works in two stages (so you're never blocked)

• With just the Anthropic key: identifies the item + gives tap-through search links. Useful immediately.
• Add eBay keys: also shows an automatic price-band (median + low/high + example listings).

Setup (10 min)

1. Get an Anthropic API key — https://console.anthropic.com → API Keys. (Required.)
2. (Optional, for the price-band) Get eBay keys — https://developer.ebay.com → create an app → copy the Production Client ID and Client Secret. Free.
3. Deploy to Vercel:
   • Push this flipscan/ folder to a Git repo and Import it in Vercel, or run vercel in this folder with the CLI.
   • In Vercel → Settings → Environment Variables, add the values from .env.example: ANTHROPIC_API_KEY (required), and EBAY_CLIENT_ID / EBAY_CLIENT_SECRET / EBAY_MARKETPLACE (optional).
   • Redeploy. Open the URL on your phone and add it to your home screen.

Prefer Firebase? Same code works with one Cloud Function (port api/scan.js) + Firebase Hosting for index.html. Vercel is the least fiddly.

How it works

• The browser shrinks the photo to ~1024px before upload (fast + cheap + under Vercel's body limit).
• api/scan.js sends it to Claude Haiku (cheap vision; model id in the file — swap if you like), which returns a strict JSON identity incl. a search_query.
• If eBay keys are set, it hits the eBay Browse API for ~50 comparable listings and returns the 10th/50th/90th-percentile prices + 4 examples.

Honest limitations (and the upgrade path)

• Comp range, not an exact match — every used piece is unique. That's the right answer for reselling anyway.
• v1 uses eBay active listings (asking prices), not SOLD. Still a strong signal, and the eBay "sold" link in the UI lets you verify real sold prices in one tap. To get true SOLD comps automatically, replace the getComps() function in api/scan.js with eBay's Marketplace Insights API (approval-gated) or a sold-comps provider (e.g. SoldComps / Soldgraph) — nothing else changes.
• No Vinted/Depop scraping — those are ToS-grey and brittle; the UI deep-links you into them to eyeball instead.

Rough running cost

• Anthropic: fractions of a cent per photo (Haiku).
• eBay API: free tier is plenty for personal use.
• Vercel: free Hobby tier is fine.

Note

This is Yan's personal reselling tool — separate from the Let's Get Nessie project it happens to sit next to on disk.