$lice

Imagine trying to split a bill with friends from different countries. How do you settle it? Each country has their own banking system and payment apps. International transfers are costly and can take days. Not everyone has a crypto wallet and there are high gas fees to send funds on Ethereum. That's why we created $lice.

$lice is a frictionless P2P crypto payments dapp, designed to simplify the way we interact with digital currencies.

Our mission is to make day-to-day crypto payments, including bill splitting, as simple, efficient, and secure as possible, paving the way for web3 mass adoption.

With $lice, you can send crypto for free, using just a phone number, and complete transactions in under a minute. We've harnessed the power of ERC-4337 and account abstraction to enable gasless transactions, reducing barriers to entry and making cryptocurrency payments accessible to everyone.

By combining the simplicity of a phone number with the security and decentralization of blockchain technology, $lice creates a seamless and friendly user experience. This perfect blend of innovation and familiarity makes $lice the go-to solution to split bills with friends and family.

Key benefits of $lice include:

1. Effortless bill splitting: Split a bill with anyone, using just a phone number.
2. Free transactions: $lice leverages account abstraction to enable gasless payments.
3. Speedy payments: With under 10 seconds to pay and under 1 minute to split a bill, $lice ensures a smooth and efficient experience.
4. Enhanced security: $lice offers safer transactions by initiating them from the receiver's end, avoiding human error.

At $lice, our focus is to simplify day-to-day crypto transactions and foster connections between friends and family. By prioritizing ease of use and a user-centric approach, we aim to create a platform that instills confidence, security, and value for our users. $lice envisions a future where P2P crypto payments seamlessly integrate into our everyday lives, making digital currency interactions both accessible and enjoyable.

Together, let's make cryptocurrency payments a piece of cake! 🍰

In order to build Slice during the EthGlobal Lisbon hackathon we employed a range of technologies and tools to build an innovative P2P crypto payment and bill splitting platform. Here's a comprehensive overview of the technologies we used and how they were integrated:

🟢 - Implemented

🟡 - Partial Implementation

🔴 - Planned but not implemented

1. 🟢 Web3Auth: In order to make the onboarding process as easy as possible we took advantage of Safe’s AuthKit together with Web3Auth as a way to provide non-web3 users an easy and smooth way to create their first account.
2. 🟡 Associate a Phone Number: Our goal is to be able to associate Phone Numbers with wallet address so that payments are streamline and can be done with just using a phone number. We didn’t have time to build it completely - we did include asking for a Name + Phone number during the onboarding process but currently are not storing them.
3. 🟡 Find your friends: We used the Lens SDK (and in the future, the ContactPickerAPI) in order to enable users to search for friends using multiple ways. This feature queries these integrations and returns matching results for seamless bill slicing.
4. 🔴 Currency conversion: To handle currency conversions, we wanted to integrate the Chainlink Price Feeds API. This would allow us to access accurate and reliable real-time exchange rates for fiat currencies and USDC, providing users with up-to-date conversion information.
5. 🟢 Gasless transactions: To enable gasless transactions, we incorporated the SafeRelaySDK and leveraged Gelato. This allowed us to sponsor gas fees on behalf of users, making transactions more cost-effective, less friction to onboard users and accessible to a wider audience.
6. 🟢 Account abstraction with Safe{Core}: For secure and efficient transaction management, we implemented Safe{Core}, a smart contract-based account abstraction layer. We set up 1:1 Safes for each user, which handle transactions and bill splitting processes securely and efficiently.
7. 🟢 Fiat on-ramping with Safe Onramp Kit: To support fiat payments, we integrated the Safe Onramp Kit with Stripe, a popular payment processing platform. This allows users to pay their share of the bill using either crypto or fiat currencies, providing flexibility and convenience.
8. 🟢 Deployed on Polygon, Gnosis Chain, Optimism, Scroll, Linea, and Goerli: To ensure scalability and reliability, we deployed our smart contracts and dApp across multiple networks, including Polygon, Gnosis Chain, Scroll, and Linea. This multi-chain approach provides redundancy and broadens the reach of our platform.
9. 🔴 Data storage and querying with TheGraph: For efficient data storage and querying, we wanted to use TheGraph in order to store our on-chain data and make it easily accessible for users through a performant and decentralized query layer.

Throughout the development process, we focused on building a robust, scalable, and user-friendly platform for P2P crypto payments and bill splitting. By integrating various sponsor technologies and innovative tools, we have created a powerful and accessible platform that simplifies the management of digital assets and shared expenses.