Kaffeelisten

Kaffeelisten is a live digital coffee and snack log for shared campus spaces. It replaces the paper sheet on the wall with a fast PWA flow for members and a PIN-protected admin panel for monthly reporting.

Built by HuggyWuggies for the B4Y3RW4LD Hackathon at ITC1 Deggendorf.

Live app: kaffeelisten.vercel.app
Pitch deck: arudaev.github.io/kaffeelisten

What It Does

Members use the wall-mounted iPad or any browser:

1. Pick a company.
2. Pick their name.
3. Pick coffee, drinks, snacks, or food.
4. Confirm the entry.

No account. No password. No app store. The target interaction is under 15 seconds from cup to saved transaction.

Admins use /admin:

• View month-to-date transactions.
• Filter and inspect entries.
• Manage companies, members, and items.
• Export CSV.
• Send the monthly report manually.
• Let Vercel Cron send the report automatically at month end.

The report flow generates a PDF and Excel workbook, emails them via Resend, archives the live transactions, and resets the current-month table.

Screenshots

Landing

Member Flow

Company	Member	Items	Confirmation

Admin Panel

PIN login	Dashboard
Transaction log

Stack

Layer	Tech
Frontend	React 18, TypeScript, Vite, Tailwind CSS
PWA	vite-plugin-pwa, Workbox
Database	Supabase, PostgreSQL, RLS
Hosting	Vercel, Serverless Functions, Cron
Reports	Puppeteer, ExcelJS
Email	Resend

Project Structure

apps/web/
  src/                 React app: member flow, admin panel, privacy page
  api/                 Vercel functions: PIN check, report send, cron
  public/              App icons, illustrations, PWA assets
docs/
  index.html           Pitch deck
  design-*.md          Visual system and design notes
  prd.md               Product requirements
  roadmap.md           Future phases
supabase/
  migrations/          Schema, grants, RLS policies
  seeds/               ITC1 seed data
scripts/, tools/       Utility scripts

Local Development

Requires Node.js 24 or newer.

npm install
cp apps/web/.env.example apps/web/.env.local
# fill apps/web/.env.local using the table below
npm run dev

The Vite app runs at http://localhost:5173.

For local API testing, run Vercel from the web app directory:

cd apps/web
npx vercel dev

Useful root commands:

npm run build
npm run typecheck
npm run lint

Environment Variables

Client-side variables must use the VITE_ prefix. Server-only variables must not use that prefix.

Variable	Used by	Notes
VITE_SUPABASE_URL	client + server	Supabase project URL
VITE_SUPABASE_ANON_KEY	client	Public anon key for RLS-protected reads/inserts
SUPABASE_SERVICE_ROLE_KEY	server	Required for reports, archive, and reset
RESEND_API_KEY	server	Sends monthly report email
ADMIN_EMAIL	server	Report recipient
ADMIN_PIN	server	PIN for /admin
CRON_SECRET	server	Bearer token for /api/cron/monthly-report
CHROMIUM_PATH	server, optional	Local/custom Chromium path for PDF rendering

Database Setup

Create a Supabase project, then apply the SQL files in supabase/migrations/ in numeric order.

Current migrations:

001_initial_schema.sql
002_grant_table_permissions.sql
003_anon_read_transactions.sql
004_anon_insert_members.sql
005_admin_crud_policies.sql
006_service_role_grants.sql
007_member_work_email.sql
009_fix_member_rls_update.sql

Optional seed data lives in supabase/seeds/002_demo_data.sql.

Data Model

companies
members
items
transactions
transactions_archive

The browser uses the Supabase anon key with RLS. Service-role access is limited to Vercel serverless functions for admin-only reporting, archiving, and monthly reset behavior.

Reporting

Manual report:

POST /api/send-report
Header: x-admin-pin: <ADMIN_PIN>
Body: { "month": "YYYY-MM" }    # optional

Automatic report:

GET /api/cron/monthly-report
Header: Authorization: Bearer <CRON_SECRET>

Vercel schedules the cron on days 28-31 at 22:00 UTC. The function only runs the report when that day is the actual last day of the month.

Deployment

The production app is designed for Vercel with apps/web as the project root.

1. Create/configure Supabase.
2. Apply migrations.
3. Add the environment variables in Vercel.
4. Deploy apps/web.

The app is a PWA, so the live URL can be installed on an iPad and used as the wall-mounted member terminal.

Documentation

• Product requirements
• Domain model
• Design foundation
• Design system
• Roadmap
• Pitch deck

License

Copyright 2026 HuggyWuggies. Licensed under the Apache License 2.0.

This license applies to the source code in this repository. Third-party names, logos, and event or campus branding, including ITC1 Deggendorf and B4Y3RW4LD Hackathon references, remain the property of their respective owners.