NotesChain

NotesChain is a decentralized note-taking application (dApp) built on the Solana blockchain. It empowers users to own their data by removing centralized databases and traditional login systems, ensuring that every note is immutable, private, and permanently stored on-chain.

🚀 Live Demo: noteschain.vercel.app

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✨ Features

• Decentralized Storage: Notes are stored as Program Derived Addresses (PDAs) on the Solana blockchain.
• Wallet Authentication: No passwords or emails. Connect your Phantom or any Solana-compatible wallet to manage your data.
• Full CRUD Operations:
  • Create: Generate new notes with titles and content.
  • Read: Fetch and display all notes associated with your specific public key.
  • Update: Edit existing notes directly on-chain.
  • Delete: Remove notes and reclaim rent from the Solana account.
• Data Integrity: Enforced constraints for titles (max 100 chars) and content (max 1000 chars) via the Anchor framework.

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🛠️ Tech Stack

Frontend

• Framework: Next.js 15 (App Router)
• Styling: Tailwind CSS
• Animations: Framer Motion
• Wallet Integration: @solana/wallet-adapter-react

Blockchain / Backend

• Language: Rust (Anchor Framework)
• Network: Solana Devnet / Mainnet
• Program ID: nJiToJCPGNjxQ3Q6ySWgLqEX1AybLhaJu6niQdBxosK
• Client Library: @project-serum/anchor

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🏗️ Architecture

The DApp interacts with a custom-deployed Solana program. Every note is its own account, derived using a seeds-based PDA (Program Derived Address) strategy.

Data Structure (The Note Account)

struct Note {
    author: PublicKey,      // 32 bytes
    title: String,          // Variable
    content: String,        // Variable
    createdAt: i64,         // 8 bytes
    lastUpdated: i64,       // 8 bytes
}

🚀 Getting Started

Follow these steps to get a local copy of the project up and running.

Prerequisites

• Node.js (v18+)
• A Solana Wallet (e.g., Phantom)
• Devnet SOL (Use the Solana Faucet to fund your wallet)

🛠️ Installation & Setup

1. Install dependencies:

   npm install
   

2. Run the Development Server:

   npm run dev
   

3. Access the application: Open http://localhost:3000 in your browser

🔒 Security & Constraints

To ensure data integrity and security on the blockchain, the following rules are enforced within the smart contract:

• Unauthorized Access: Only the author who created the note has the permission to update or delete it. Access control is verified on-chain via signer checks.
• Input Validation:
  • Titles: Must be between 1–100 characters.
  • Content: Must be between 1–1000 characters.

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🤝 Contributing

Contributions are welcome! If you have suggestions for new features, bug fixes, or security enhancements, please follow these steps:

1. Fork the Project.
2. Create your Feature Branch (git checkout -b feature/AmazingFeature).
3. Open an Issue or submit a Pull Request.

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📄 License

This project is licensed under the MIT License.