The Anti-Zelle

What it does The Anti-Zelle lets people create a circle with a shared vault. They chat, propose expenses, vote, split costs, and move money from personal accounts into the group vault using a sandbox bank API. There’s a simple financial summary and AI to help suggest ideas. This ensures everyone has committed to the trip so no one can back out leaving others to cover their cost.

How we built it Website: React + Vite. Server: Python + FastAPI. Login & database: Supabase. Fake bank: Nessie. AI: Google Gemini.

Challenges we ran into The sandbox bank often didn’t update balances even when calls “succeeded,” so the app could look broken. We tracked balances in our database so the UI still made sense.

Accomplishments that we’re proud of A full flow: create a group → propose → vote → move money → get a booking-style confirmation, plus chat and deposits into the vault.

What we learned APIs don’t always do what you expect; you have to test the real behavior. Good group rules (voting, splits) matter as much as the code.

What’s next for The Anti-Zelle Clear history of who paid what, notifications, and someday real bank connections if we take it beyond a demo.

Built With

• cors
• docker
• fastapi
• gemini
• jwt
• nessie
• postgresql
• pydantic
• python
• react
• supabase
• typescript
• vite