CapiNet

This project is a social tech ecosystem designed to connect people in the real world through digital experiences powered by NFC-enabled accessories. Our goal is to make networking more meaningful, playful, and frictionless by combining physical objects (pins and rings) with on-chain rewards and digital identity.

What the project is about

We are creating a new way for people to share who they are, connect with others, and build community. Users can wear a pin or ring with an embedded NFC chip, and when someone taps it with their smartphone, it instantly opens a customizable digital profile. This profile can include social links, personal info, portfolio, contact details, or any content the user wants to share.

How it works

Instant Interaction: Tapping the NFC pin or ring with a phone opens the user’s profile—no app installation required to view it.

Gamified Social Exchange: Each interaction generates points for both users involved.

On-chain Rewards: Points can be converted into NFTs, which users can collect, trade, sell, or keep as digital assets that represent their social activity.

Community Growth: The more users connect and interact, the more value they unlock within the ecosystem.

Why this project is different

We merge physical social interactions with digital value creation. Instead of networking being limited to exchanging names or social media handles, this system turns real-world interactions into collectible, memorable, and valuable digital moments.

Business Model

Accessory Sales: Revenue from selling NFC pins and rings.

Micro-transactions: A small fee is applied when users convert their points into NFTs.

Brand & Event Partnerships: We will collaborate with brands, creators, and events to expand reach and create exclusive collectible drops tied to real-life experiences.

Premium Services: Users can access advanced profile customization and exclusive features through a paid tier.

Target Audience

People who value technology, networking, community, and digital identity—especially across Latin America (Argentina, Uruguay, Brazil). Our early adopters include tech-savvy users, creators, students, professionals, and event-goers who enjoy meeting new people and building social capital both offline and online.

Impact

Our aim is to enable authentic human connections while empowering users to create digital value from their interactions. By merging web3, NFC tech, and social dynamics, we are building a community where every “hello” has value—both socially and digitally.

You can see our deck here: https://docs.google.com/presentation/d/176Xyplacc9VDtkw-Vg_gCxOA_z2369Oa49pvJUU8tfo/edit?usp=sharing

We built this project using a full-stack approach that combines web, NFC and blockchain technologies.

For design, you can access the MVP prototype here: https://www.figma.com/proto/LY1F6jTMfaGYEUeq0Uqe8J/Capi-app?page-id=11%3A252&node-id=49-2927&viewport=149%2C253%2C0.14&t=Bc0mqvubraMloZG1-1&scaling=scale-down&content-scaling=fixed&starting-point-node-id=49%3A2620

On the frontend, we used React with Material UI to rapidly create a clean, responsive interface for user profiles and interactions. The UI is optimized for mobile-first usage since most interactions come from scanning the NFC accessories. It uses Reown AppKit for smooth wallet connections, transactions, and social logins

For the backend, we used Node.js + Express.js to manage user profiles, interaction logs, and point tracking. The backend serves as the bridge between the NFC-triggered profile views and the on-chain reward logic.

On the blockchain side, we developed our smart contracts using Hardhat, enabling users to convert their social interaction points into NFTs. Hardhat allowed us to iterate fast, test contracts locally, and deploy efficiently.

We also integrated NFC functionality to trigger unique profile URLs when the pins/rings are scanned with a smartphone. A “hacky but effective” part of our build was generating dynamic profile links mapped to NFC tag IDs so each accessory acts as a unique gateway to the user’s digital identity.

This combination of physical NFC hardware, a Web2 backend, and Web3 smart contracts will enable us to create a seamless experience where real-world interactions are transformed into digital value. Backend Architecture Context: This is a backend API for the project, it manages user authentication (including SIWE), user profiles, friend requests (via wallet, referral code, or NFC), a points system, and profile picture uploads.

The API is designed for secure, scalable deployment, with integration to Google Cloud services for secrets and file storage. Its technology Stack:

Language: JavaScript (ES6+) Runtime: Node.js (18+) Framework: Express.js Database: MongoDB (with Mongoose ODM) Authentication: JWT, SIWE (Sign-In With Ethereum) File Uploads: Multer (with Google Cloud Storage for storage) Secrets Management: Google Cloud Secret Manager Cloud/Deployment: Google Cloud Run (Dockerized) Linting/Formatting: ESLint, Prettier API Documentation: Swagger (OpenAPI) Other: Uses modular folder structure for controllers, routes, models, helpers, and services Smart Contract Architecture Overview Project Context This documentation provides a theoretical overview of the blockchain smart contract infrastructure that powers our NFC-enabled social tech ecosystem. The smart contracts serve as the backbone for converting real-world social interactions into digital value through tokenization and on-chain rewards.

1. Introduction to the Smart Contract Layer Purpose The smart contract layer bridges the physical and digital worlds by: Creating verifiable links between physical NFC accessories (pins/rings) and digital NFT assets Managing the lifecycle of "phygital" (physical + digital) assets Tracking social interactions and converting them into blockchain-based rewards Enabling a decentralized economy around social networking Technology Stack Blockchain Framework: Hardhat development environment Smart Contract Language: Solidity 0.8.24 Token Standards: ERC721, ERC721A, ERC1155, ERC2981 (Royalty), ERC4907 (Rental)

2. Core Contract Architecture 2.1 Phygital NFT Contracts The system employs two primary phygital contract variants: Phygital Contract (Standard ERC721) This contract manages individual phygital assets with the following characteristics:

Key Features: One-to-One Minting: Each NFC tag corresponds to a unique NFT token Immutable Physical Linkage: NFC chip IDs are permanently registered to prevent duplication Lifecycle Management: Tracks item status (OWNED, DAMAGED, REPAIRED, DESTROYED, etc.) Whitelist System: Controlled early access minting for community building Public Sale Mechanics: Time-gated public minting after whitelist period Registration Process: Physical NFC chip is embedded in accessory (pin) User purchases/mints an NFT associated with that unique chip ID Chip ID is permanently stored on-chain, creating tamper-proof linkage Digital profile becomes accessible via NFC tap PhygitalA Contract (Batch-Optimized ERC721A)

An optimized variant designed for high-volume minting: Key Features: Gas-Efficient Batch Minting: Can mint up to 10,000 tokens at the cost of minting one ERC20 Payment Integration: Uses project tokens instead of native cryptocurrency Reveal Mechanism: Supports hidden/unrevealed metadata for surprise launches Post-Mint Registration: Allows minting first, NFC registration later Delegated Minting: Operators can mint on behalf of users Use Cases: Large event drops (conferences, festivals) Brand partnerships requiring bulk distribution Community rewards programs Creator collaboration campaign