FunPay

Screenshots

Problem Statement

InspirationWhen usingbanking applications and e-wallets, we found that the demand for payroll, recurring investments, and batch payments of users are relatively high. However, applications facemany barriers, such as international payment, transaction time, and high transaction feesto perform those operations.Therefore, we have invested time in researching and developing the application based on the blockchain platform,using crypto to overcome the limited problems.What it doesFunPay is an application that allows users to pay, invest and disburse using cryptocurrencies; the application is deployed on the FileCoin blockchain platform. Features include:•One-Time Payment:allows users to send money to many recipients simultaneously and supports paying directly to the wallet at that time or paying at a specific time in the future.•Recurring Payment: allows users to send money to multiple recipients based on a schedule. This schedule can be understood as a periodic disbursement. For example, the sender can configure thestart date, the number of unlock, unlock amount, the time between payments, and the amount that can be prepaid.•Invoice: Allows the user to create an invoice andsend it to the client, through which the client can use crypto to pay that invoice.•Address Book: allows users to manage the address book, making it easier to fill in payment information.•Balance Management: allows users to deposit tokens into a Smart Contract and manage it.•Upload CSV: allows senders to upload payment data for multiple recipients simultaneously.

Solution

How we built itTech stack:Solidity, Open Zeppelin, React, Redux, TypeScript, NodeJS, EthersJS, Truffle và Filecoin Hyperspace testnet.The development process is divided into stages:• Design Smart Contracts, write unit tests, and run tests on a local development environment.• Deploy SM to test net.• UI/UX Design.• Integrate UI with Smart Contract and Wallet.• Test & Improve.In development, to be easily expandable later. The source code has been designed to be divided into many modules and many interfaces, allowing you to easily change the interface while keeping the core logic and vice versa.Challenges we ran intoMost challenges are related to business problems and solutions. We have reviewed several products related to recurring payments using crypto. Some products require creating a new Smart Contract when there is a payment between the sender & recipient; the rest are handled by only one Smart Contract for all payments. Each solution has different strengths and weaknesses, but when evaluated based on the following criteria: cost-saving, time-saving, and ensuring user experience. We tested on the FileCoin Hyperspace Testnet; we carefully considered and selected the solution to handle payments on one Smart Contract.The next issue is to ensure security and fairness for both the recipient and the sender when participating in a payment. We have carefully designed Smart Contracts so no one can withdraw money from Smart Contracts other than the sender and recipient. We remove any right to outside interference. The calculation formulas are checked and tested repeatedly.Accomplishments that we're proud ofComplete an actual application, helpful business, and many supporting features in a short time of Hackathon.What we learnedUnderstand the strengths and limitations of FEVM and other characteristics of the FileCoin blockchain, such as transaction completion time, gas price, and transaction fee, and how to optimize it.What's next for FunPay• Improved UI and UX• Develop some more features related to invoice• Audit Smart Contracts• Deploy Beta Testing.• Prepare for deployment to mainnet.• Develop SDK/API to integrate with other products such as Game, DAO…