Certificate NFT

A non-transferable NFT smart contract for issuing certificates on the Mandala Chain. This contract allows authorized entities to mint certificate NFTs with metadata and images stored on IPFS.

Features

Non-transferable NFTs (Soul-bound tokens)
IPFS integration for metadata and images
Fully compliant with ERC721 standard
Transfer and approval blocking
Gas-efficient operations

Contract Architecture

The contract inherits from:

```
ERC721URIStorage
```
: For storing token metadata
```
Ownable
```
: For access control

Key components:

Minting functionality
Transfer blocking
Approval blocking
Metadata generation
Event emission

Prerequisites

Foundry
Access to Mandala Chain RPC
IPFS for storing certificate images

Installation

    
 bash 
 # Clone the repository:
git clone <your-repo-url>
cd certificate-nft

# Install dependencies: 
forge install

# Set up environment variables:
# Create .env file with your configuration
RPC_URL="https://mlg1.mandalachain.io"
PRIVATE_KEY="your-private-key" 

# Deployment

    
 bash 
 # Compile the contract:
forge build

# Deploy to Mandala Chain:
forge create src/CertificateNFT.sol:CertificateNFT \
  --rpc-url "https://mlg1.mandalachain.io" \
  --private-key $PRIVATE_KEY \
  --broadcast 

# Minting Certificates

    
 bash 
 # To mint a new certificate NFT:

# Export contract address
export NFT_CONTRACT="your-contract-address"

# Mint NFT
cast send $NFT_CONTRACT "mintNFT(address,string)" \
  $RECIPIENT_ADDRESS \
  "https://ipfs.io/ipfs/your-image-hash" \
  --rpc-url $RPC_URL \
  --private-key $PRIVATE_KEY 

Contract Details

Latest Deployment:

Network: Mandala Chain

Contract:

0xcDCf9295EB880C166E73Ef9D42f07eD9c2E1B7Ee

Explorer: https://niskala.mandalachain.io

Testing

Run the test suite:

forge test

The tests cover:

Basic minting functionality
Transfer blocking
Approval blocking
Owner-only access

Security Features

Non-transferable tokens
- All transfer functions are blocked
- NFTs cannot be moved once minted
Access Control
- Only contract owner can mint certificates
- All approval functions are blocked
Metadata Integrity
- On-chain metadata storage
- Base64 encoded JSON structure
- IPFS integration for immutable storage