Briq

Problem Statement

Briq is a revolutionary rental platform that creates an immutable trust layer between landlords and tenants using signature-based agreements and NFT-powered reputation systems. Built on Hedera Hashgraph, Briq eliminates traditional rental friction while establishing verifiable rental histories that benefit both parties.

Solution

Briq is built as a full-stack decentralized application combining cutting-edge blockchain technology with practical real-world rental market solutions. The project leverages React 18 with TypeScript for the frontend, providing type safety and modern component architecture, while Tailwind CSS handles the responsive design system that adapts seamlessly across desktop and mobile devices. The core blockchain infrastructure runs on Hedera Hashgraph, chosen for its low transaction fees and fast finality, with smart contracts written in Solidity and deployed using Hardhat for property management and rental agreements.The most innovative aspect of Briq is its signature-based rental system that bypasses traditional payment-first approaches. When a tenant wants to rent a property, instead of requiring upfront payments that often fail due to smart contract complexities, Briq uses EIP-712 compliant wallet signatures to create legally-binding rental agreements. These signatures are generated using ethers.js v6 and contain structured data including property details, rental terms, and agreement hashes. This approach eliminates the "bad deposit" errors that plagued traditional smart contract rentals while maintaining cryptographic proof of agreement.The trust layer architecture is perhaps the most technically sophisticated component. Each user has an updatable NFT profile managed through Hedera Token Service (HTS), where rental history and behavioral data are stored as on-chain metadata. The system implements a burn-and-mint pattern to update NFT metadata, ensuring immutable rental history while allowing trust scores to evolve. Trust calculations use custom algorithms inspired by credit scoring systems - tenants get scores from 0-850 (CIBIL-style) while landlords get 0-100 ratings, with real-time updates based on payment behavior, property maintenance, and communication patterns.The tenant management system for landlords is built as a comprehensive dashboard with three modal-based action systems: payment recording (on-time, late, missed), behavioral actions (noise complaints, property damage, maintenance issues), and query management (maintenance requests, complaints, compliments). Each action immediately updates the tenant's trust score using weighted algorithms that consider payment history (35% weight), tenancy stability (30%), property care (20%), financial capacity (10%), and dispute resolution (5%). The UI uses React hooks for state management and implements optimistic updates for immediate feedback.Integration with Hedera's SDK required sophisticated error handling due to account setup complexities, leading to the implementation of robust fallback mechanisms. The NFT creation process uses a burn-and-mint strategy because Hedera NFTs are immutable by default - when trust data updates, we burn the old NFT and mint a new one with updated metadata, maintaining a single active trust profile per user. This required careful handling of NFT references and implementing a cleanup system to prevent orphaned tokens.The rental agreement generation uses structured data signing where the signature message contains human-readable rental terms alongside machine-readable agreement hashes. This creates both legal validity (users can read exactly what they're signing) and technical integrity (cryptographic proof of specific terms). The agreement hash incorporates property ID, user addresses, rental amounts, and timestamps to ensure uniqueness and prevent replay attacks. The mock tenant system stores these signed agreements with full cryptographic verification, creating an auditable trail of rental commitments.One notable technical implementation was developing a development testing framework that generates realistic rental scenarios instantly. This system creates mock rental agreements with proper trust data initialization, allowing immediate demonstration of the tenant management features without requiring actual blockchain transactions. The testing framework proved essential for rapid iteration and feature validation, as it eliminates the time and cost barriers of continuous blockchain interaction during development cycles.The project uses Vite for lightning-fast development builds and TypeScript strict mode throughout for type safety. State management relies on React's built-in hooks rather than external libraries, keeping the bundle size minimal while maintaining reactivity. The trust scoring algorithms are implemented as pure functions that can be easily tested and audited, with clear separation between data fetching, score calculation, and UI updates. The mock data systems use the same interfaces as production blockchain calls, ensuring seamless transition between development and production environments.The most innovative technical decision was treating rental agreements as immutable records while keeping property and user states mutable. Once a signature-based rental is created, the agreement terms are frozen in both NFT metadata and the mock tenant registry, but ongoing rental performance (payments, behavior, communication) continues to update trust scores. This hybrid approach creates an auditable trail of rental relationships while allowing reputation to evolve based on actual performance. The mock system demonstrates how decentralized rental agreements can solve the cold-start problem that plagues traditional rental platforms, providing a foundation for users to build verifiable rental history from their first transaction.