basketch

This week's grocery promotions from seven Swiss supermarkets, side by side.

basketch is a free web page that shows this week's promotions from Migros, Coop, LIDL, ALDI, Denner, SPAR and Volg. It compares the stores by category and lets you build a shopping list, grouped by store with an estimated total, that you can share. No app and no account are needed.

Live: https://basketch.vercel.app (German by default, English at /en).

---

What it does today

• Home. For each of Fresh, Long-life and Household, names the store with the highest average discount this week, or says it is tied.
• Deals. Every collected promotion, grouped by sub-category, with filters by type, category, storage and store, and a search.
• My list. Add deals to a list that is kept only in your browser. The list is grouped by store, with a total per store and an estimated overall total. Share it by WhatsApp, email or link.
• Honest prices. Each deal shows its validity dates and a link to where the price came from. Prices that apply only from a certain date or when buying several are labelled, and they never decide a winner.

basketch compares weekly promotions, not regular shelf prices. It does not choose the cheapest store for each item. You pick the deals; routing each item to its cheapest store is a long-term goal that has not been built. Details, known gaps and open questions are in the PRD.

Where the data comes from

Retailer	Source
Denner	denner.ch
Volg	volg.ch weekly offers
LIDL, ALDI, SPAR	the retailer's public weekly flyer
Migros	the public weekly flyer (Issuu, Zurich edition), read with free OCR
Coop	aktionis.ch, a public Swiss deal site, because coop.ch blocks automated access

A scheduled pipeline collects all seven retailers on Monday, Tuesday and Thursday. Products are sorted into basketch's own category list by an AI model (Google Gemini, free tier), and a second AI model (via OpenRouter) checks the answers. basketch never works around a technical block.

Tech stack

Layer	Technology
Frontend	Next.js 16 (App Router), TypeScript, Tailwind, next-intl (German and English)
Pipeline	TypeScript, with Python for Migros OCR, on GitHub Actions
Database	Supabase (PostgreSQL)
Hosting	Vercel

Cost: free tiers, plus one paid AI checker capped at USD 5 per month.

Case-study documents

Document	What it covers
PRD v4.0	Problem, goal vs. what ships, product rules, data, status, risks, open product questions
Use cases v3.0	Live and parked use cases with acceptance criteria and known defects
Technical architecture v2.0	System design, modules, data flow
Business model canvas v2.0	The nine blocks, competition, assumptions to validate
Competitive analysis v2.0	13 tools (6 Swiss, 7 international), sourced

Running it locally

Requires Node.js and Python 3.

./setup.sh                      # installs pipeline + frontend deps, Python OCR deps, creates .env from .env.example
cd web-next && npm run dev      # frontend at http://localhost:3000

Tests (three separate suites):

cd pipeline && npm test
cd shared   && npx vitest run
cd web-next && npm test && npm run lint

Type-check each package from its own folder: ./node_modules/.bin/tsc --noEmit -p tsconfig.json. See CLAUDE.md for conventions.

Built with

Built with Claude Code, from PRD through implementation, as part of the product process.

Author

Kiran Dommalapati, Senior Product Manager, Bern, Switzerland. LinkedIn | Email