E-commerce Warranty Card NFT System

Project Introduction

Many products come with Warranty Cards. Currently Warranty is determined by some physical Warranty Cards which posses several issues: -

• Warranty Document can be easily falsified
• A bad acting seller could create duplicate warranty cards or warranty Cards of expired products.
• Product Ownership and authenticity cannot be proven through physical warranty Cards.

This project tokenized the Warranty Cards in Blockchain world which eradicates the above problems. Features of the Project :-

• Warranty Cards are converted to Decaying NFTs.
• It proves authenticity and ownership of product.
• It eradicates the possibility of false or duplicate Warranty Cards.
• Warranty Card decays after the warranty period is over.
• Warranty Cards can be transaferred on resale of the product.

The Project consists of 3 Elements:

1. ERC721 Solidity Contract for Warranty Card
2. GUI to interact with Contract
3. Node Server for minting API and Burn Bot

Libraries and Open Source projects used

• openzeppelin ERC21 for ERC721 standard contract
• openzeppelin ERC721URIStrorage for tokenURI storage of Warranty Card
• openzeppelin E721Enumerable for Enumerability of Warranty Card.
• openzeppelin ERC721Burnable for burnable compatible Warranty Card.
• openzeppelin Ownable for Ownable Warranty Cards.
• openzeppelin Counters for genrating token ids for Minting Warranty Cards.
• openzeppelin AccessControl for Roles in contract.
• ethers.js for interacting with contract thorough javascript.
• react.js for UI
• Hardhat for devlopment and deployment of contract.
• Node.js and Express.js for Node server for catering minting API and Burn Bot.

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ERC721 Solidity Contract

• Contract can be used to mint Warranty Card.
• We cannot mint multiple warranty Cards with same SerialNo.
• By default, the owner of contract is approved for all Warranty Cards.
• Contract can check authenticity and ownership of the Warranty Card.
• Contract can burn the warranty Cards.

Roles in contract

• MINTER_ROLE - Address with this role can mint Warranty Card.
• SERVICE_PROVIDER - Address with this role can increase service count of Warrnty Card.
• MINTER_ROLE_ADMIN - Address with this role can assign or revoke MINTER_ROLE and MINTER_ROLE_ADMIN.
• SERVICE_PROVIDER_ADMIN - Address with this role can assign or revoke SERVICE_PROVIDER and SERVICE_PROVIDER_ADMIN.

Payable functionalities

• Any address with MINTER_ROLE can mint Warranty Card with serial number, warranty end and tokenUri.
• Warranty Card can burn after expiry by the owner of contract or by owner of Warranty Card.
• Warranty Card can be transferred to any address by the owner of Contract or ower of Warranty Card.
• Warranty Card's Service count can be increased by address with SERVICE_PROVODER role.

Non Payable functionalitites

• Contract can check ownership and authenticity of Warranty Card.
• Contract can return expiry date of Warranty Card
• Contract can return tokenId by the serial No of Warranty Card.
• We can get total number of active Warranty Cards.
• Contract can return Warranty Card tokenUri by it's tokenId.

Access Modifiers

• onlyMinters - Checks for MINTER_ROLE
• onlyServiceProviders - Checks for SERVICE_PROVIDER_ROLE

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Graphical User Interface

• We can interact with Contract with Web Based UI.
• UI connects with Metamask wallet using metamask extension.

Non Payable Functions

• We can get total active number of the Warranty Cards.
• It can use to check the authenticity and ownership of Warranty Card and thereby proving authenticity of the product using tokenID, serialNo and owner wallet address.
• It can be used to check expiry of the Warranty Card using token ID.
• We can also view our Warranty Card.
• We can also get our tokenID with serialNo of product.

Payable Functions

• Address with MINTER_ROLE can issue warranty card with necessary required information.
• Owner of contract or Owner of Warranty Card can transfer warranty card.
• Address with SERVICE_PROVIDER can increase service count of warranty card.
• Address with MINTER_ROLE_ADMIN and SERVICE_PROVIDER_ADMIN can grant or revoke their respective roles.

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Node Server

• It runs Minting API that can help to mint the Warranty Card.
• It runs Burn Bot that checks for expired tokens and burns them.
• Node server connects with owner's wallet address from metamask private key.
• It connects with the Blockchain network Provider with Provider URL.

Minting API

• Endpoint: POST /api/mint/warrantyCard
• Mint Warranty Card with requires headers and body.
• headers: Wallet-Authorization : metamask private key
• body: address, serialNo, warrantyEnd, name, description, product_id, inovice_no, payment_gateway, platform, purchase_date, transaction_id, transaction_method

Burn Bot

• Everyday bot checks for expired warranty cards off-chain.
• Bot burns the expired Warranty Cards if present.

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Setup Project

1. Perform npm install in main folder and client folder.
2. Rename .env.example to .env
3. Put values in .env
4. Perform above steps for /client/src/utils/constants.example.js
5. To deploy contract run:

npx hardhat run scripts/deploy.js --network fuji/polygon_mumbai

6. Paste contract address in env and constants.js
7. Start Node server

npm run start

8. Start React Server

npm run build
npm run preview