This repository contains a suite of Solidity smart contracts implementing an on-chain identity and reputation system using soulbound (non-transferable) NFTs and tokens on Base Sepolia.
This project showcases a robust, fully on-chain identity system using soulbound (non-transferable) NFTs and ERC20 tokens to track user achievements and reputation.
It includes contracts for:
- Awarding achievements as NFTs for key milestones.
- Awarding reputation points as soulbound ERC20 tokens.
- Preventing transfers of both NFTs & reputation points (soulbound).
- Managing user registration and automatically awarding registration achievements.
This project was developed as a portfolio demonstration of an on-chain identity and reputation system using soulbound tokens.
The repository includes:
- SoulboundNFT: Non-transferable ERC721 tokens used to represent user achievements.
- SoulboundReputation: Non-transferable ERC20 tokens used to track reputation points.
- UserRegistration: A contract that registers users and automatically awards a registration achievement.
All contracts were written in Solidity and deployed to the Base Sepolia test network.
| Contract | Description |
|---|---|
| SoulboundNFT.sol | ERC721 soulbound NFT contract awarding unique achievements per user. |
| SoulboundReputation.sol | ERC20 soulbound reputation point system where users rate each other. |
| UserRegistration.sol | Handles user registration and mints a registration achievement. |
✅ Soulbound NFTs (non-transferable) to record achievements.
✅ Soulbound ERC20 reputation points (non-transferable).
✅ Awards users for their first rating and for registering.
✅ Prevents self-rating and duplicate ratings.
✅ Fully verified on Base Sepolia block explorer.
✅ Uses OpenZeppelin security primitives (Ownable, AccessControl, ReentrancyGuard).
This Soulbound Identity Suite architecture is flexible and can be integrated into various on-chain and hybrid systems, such as:
- 🎮 Web3 games — award players for key milestones, leaderboards, or contributions.
- 🛒 Marketplaces — track reputation & contributions of buyers/sellers.
- 🏦 DAOs — measure contributions to governance and community engagement.
- 👨🏫 Learning platforms — reward learners with certificates & points for achievements.
- 🧩 Any dApp — where on-chain identity & reputation enhance trust and engagement.
You can adapt the achievement types, reputation mechanisms, and registration flow to fit specific business needs — supporting ERC20, ERC721, ERC1155, or even hybrid on/off-chain logic.
Contracts Owner:
0xB94503C6a717BDD677ad9dAB7B450AF86d3Aa3F5
| Contract | Address |
|---|---|
| SoulboundNFT | 0xc3BAa93807F505dD3adDDAaa29Eb795EE4f8f4f0 |
| SoulboundReputation | 0x8a72B2205dc5C5a1DD9dD0E8110639ed9e2E6B71 |
| UserRegistration | 0xA7842Ac2C2B01f620285294e6c2A0EaF5e8f9acd |
Personal portfolio project demonstrating a decentralized identity and reputation system using soulbound tokens.
Dantis Minurland Constantin
Full-Stack Software Developer
🌐 https://mdantis.dev
✉️ hello@mdantis.dev
This repository is licensed under the MIT License.
If you are interested in similar smart contract development or blockchain integrations, feel free to get in touch.