SpliX

SpliX is a bill splitting application designed to make group payments transparent, efficient, and verifiable using blockchain technology. Users can upload receipts, automatically extract item details via AI, and create a bill-splitting group on-chain. Each item is recorded and tracked on a smart contract, allowing group members to pay for their share directly using USDC with cross-chain composability.

Receipts become immutable digital records, while the contract tracks payment status per item. Though the owner can edit or delete items, the blockchain maintains a historical record of all changes. Members can join via invite links or QR codes and settle payments either directly through the smart contract or allow the owner to claim funds.

Designed with cross-chain compatibility and a seamless UX in mind, SpliX also includes AI-enhanced receipt processing, automated payment reminders, and future plans for privacy features, bridging, and token swaps.

SpliX is built as a full-stack decentralized application (dApp) with the following components:

• Smart Contracts: Written in Solidity and foundry framework, the core contract stores groups, items, prices, ownership, and payment status. Functions include creating/editing groups and paying for selected items. The structure supports auditing changes due to blockchain’s immutability. The most important part is we integrated circle’s CCTPV2 to mint and transfer USDC token atomically and securely in the function.
• Frontend: The UI allows users to upload receipt photos, which are then itemized through our powerful backend. Users can edit items, invite members, and track payment status—all within a simple, intuitive interface.
• Backend & Indexer: A custom backend indexes on-chain data and manages user-related operations like QR invite handling and push notifications. We also integrate outstanding LLM model (favoring gemma2.0flash) for AI-powered OCR and item classification from receipt photos.
• Database: Used for off-chain metadata indexing and temporary caching for faster UI updates.
• Crosschain & Payments: Circle’s CCTP v2 (Enables cross-chain USDC transfers)
• RPC: We leverage Nodit to maximize the speed and experience for interacting with the blockchain.
• Hacky/Notable Additions
  • OCR via AI (gemini-2.0-flash) instead of traditional model.
  • Editable smart contract records with transparent versioning.
  • We ignore edge cases that occur doing our demo and mainly focused on building the happy path
  • We ignore any security concern