Need a card without the commitment? Whether you're an international traveler or tired of being rejected by credit card companies, Kardle makes it easy for you to make the payments you need.

What it does

If you don't/can't have a credit or debit card, but want to make a purchase which requires one, Kardle can use your digital wallet funds to make that purchase! There are two types of users on Kardle: Requesters and Providers. Requesters will request a card to make an online purchase and then Kardle will match them with an anonymous provider who has agreed to allow their card to be used by requesters.

Once Kardle has found a provider for a requester,

  1. Funds from the requester's digital wallet are transferred to the provider's digital wallet, then
  2. The provider's credit card information is autofilled securely (so nobody but the vendor can see their information) on the purchase form, then
  3. The requester can make their purchase using the provider's card!

The provider is compensated in the form of credit card spending perks, such as air miles or cashback.

How we built it

Kardle's user interface was was built with a chrome extension made in javascript, as well as a web application made wth Bootstrap. Transactions between Card-Providers and Requesters are handled using the Stellar blockchain and the SDF's transaction and account creation APIs. A backend flask server was used to connect the many parts of this application, such as sending information to and from the user's browser to the web application and sending transaction details to the Stellar blockchain (with Ajax). We used the Nomics API to keep track on the real-time USD exchange rate of Stellar.

Challenges we ran into

We attempted to use the google payments api in order to send secure payments tokens to users' browsers. However, this was very challenging to set up in the short amount of time we had, so we are sending information to the browser using http requests for this demo version of our solution. We have included our work setting up google pay in our repo because we did dedicate time to it this weekend, and plan to implement it soon to ensure that transactions on our platform are secure.

Accomplishments that we're proud of

Creating a working prototype of our idea! We're also excited to work on something that our team would be really interested in using ourselves.

What we learned

A lot about blockchain transactions and the Stellar API. We also gained valuable experience in back-end web development, including working with asynchronous functions and resolving CORS errors.

What's next for Kardle

Implement the google pay API for secure transactions, add other digital wallets to our platform, integrate the PLAID api to allow real-time credit card transaction balance information to be displayed in our web app.

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