syncpayment

• 

  Where fiat meets crypto, seamlessly

Inspiration

We noticed that despite crypto's potential, everyday payments remain stuck in traditional systems. The friction between fiat and crypto – volatility, slow conversions, and complexity – prevents real-world adoption. We were inspired to create a seamless bridge that lets people spend crypto as easily as swiping a card, without thinking about conversions or gas fees.

What it does

Sync enables instant fiat-to-token and tone-to-fiat payments on StarkNet. Users maintain both a local currency wallet (Naira, USD, EUR) and a crypto wallet. When paying merchants, if fiat runs low, the system automatically taps into token reserves, swaps them instantly via liquidity pools, and completes the payment – all in seconds. Merchants receive settlements in their preferred currency, while users enjoy the flexibility of crypto-backed spending.

How we built it

We built Sync on StarkNet's rollup infrastructure for low-cost, high-speed transactions. The architecture includes: smart contracts for automated funding and liquidity management, a P2P liquidity bridge for instant fiat-crypto swaps, integrated wallet layer managing dual balances, and merchant payment interfaces with QR code support. We leveraged StarkNet's ZK-proofs for privacy and security while maintaining compliance standards.

Challenges we ran into

Still working on a solution to manage liquidity imbalance, ensuring the liquidity remains evenly distributed and doesn’t get exhausted on one side.

Accomplishments that we're proud of

We created a truly hybrid payment system that doesn't compromise on decentralization or user experience. The automated liquidity bridge works seamlessly without user intervention.

What we learned

Designing for real-world payments requires thinking beyond pure DeFi mechanics. User experience matters more than technical sophistication – if it's not simple, it won't be adopted. StarkNet's capabilities are perfect for payment systems needing speed and low costs. Liquidity management is crucial for hybrid systems. Regulatory considerations must be built in from day one, not retrofitted.

What's next for syncpayment

Launch beta with select merchants and early adopters to gather real-world feedback. Introduce the sync token with staking rewards for liquidity providers. Expand currency support beyond initial markets. Build partnerships with local payment processors and businesses. Conduct comprehensive security audits. Develop merchant dashboard and analytics tools. Explore cross-chain bridges to expand beyond StarkNet. Scale liquidity pools through community governance and incentives.

Built With

• apibara
• cairo
• javascript
• nest
• react
• react-native