PayPal Hub

Find it. Pay with PayPal. Let the Guardian watch your subscriptions.

Inspiration

Online subscriptions are easy to start and surprisingly easy to forget. Streaming platforms, cloud storage, design tools and other digital services can create recurring expenses that become difficult to track, especially when people no longer remember when they last used a service.

We wanted to build a single place where users could manage subscription records, understand recurring spending and get help deciding which services deserve their attention. PayPal provides the payment foundation, while AI helps make the information more useful.

What PayPal Hub does

1. PayPal payments and subscriptions

Users can go through a PayPal checkout flow for a one-time payment or a recurring subscription. The prototype uses PayPal Sandbox, so no real money is transferred.

2. Subscription tracking

The Hub maintains a ledger of subscriptions created through PayPal Hub and associated with the signed-in user. It displays service names, monthly costs, PayPal status and manually recorded usage information. Users can mark an eligible PayPal subscription as used, updating its usage record on the backend.

3. Guardian AI

Guardian reviews eligible subscription records against an illustrative monthly planning limit. It considers recorded costs and days since use, then returns one of three recommendations: Keep, Cancel or Review, with an explanation.

Guardian uses Groq for AI-powered recommendations and ExchangeRate-API to convert supported currencies into USD estimates. These recommendations support user decisions; Guardian does not cancel subscriptions or access usage data directly from third-party providers.

4. Discover

Users can describe what they need and explore relevant product results. Groq helps formulate the search, while Channel3 supplies product results. The Discover directory also provides comparisons of familiar services. Country selection is a reference for the user's market, not a guarantee that a provider accepts PayPal in that country.

How we built it

The frontend was built with React, React Router and Vite. AG Grid Community powers the subscription table, including sorting, filtering and pagination. The responsive interface provides desktop table and mobile card views.

The backend uses Node.js and Express. Firebase Authentication handles email/password and Google sign-in, while Cloud Firestore stores user-associated records. The backend integrates PayPal Sandbox for checkout and subscriptions, Groq for Guardian and Discover, Channel3 for product search, and ExchangeRate-API for currency conversion.

The frontend is deployed on Vercel and the backend on Render.

Challenges we faced

One of our main challenges was connecting several services into one coherent experience. Payment approval, authenticated user records, AI recommendations, product search and currency conversion each have different data formats and requirements.

We also had to distinguish between information the application actually knows and information it cannot access. For example, the Hub can track subscriptions created through its own PayPal flow, but it cannot automatically import every subscription a user has elsewhere or verify how often a user uses an external service.

Another challenge was making AI recommendations useful without presenting them as automatic financial decisions. Guardian explains its suggestions and leaves the final decision with the user.

What we learned

We learned that an AI-powered product is only as useful as the information supplied to it. Reliable authentication, structured records, clear currency handling and honest limitations matter just as much as the AI model.

We also learned to use AI as decision support rather than pretending it can independently see or control data held by other providers.

What's next

We would like to expand provider integrations, improve product matching and retailer data quality, and explore ways to make subscription usage records easier to maintain. We also see an opportunity to support more currencies and additional subscription-management workflows.

PayPal Hub is a hackathon prototype using PayPal Sandbox. It is not affiliated with PayPal, and its test checkout does not process real payments.