• As the final week for project submission approaches, development was strictly based on successful deployment of contracts and testing the development environment.

• Implementation of CarbonCreditMarketplace contract which includes the following functionalities :

  • Initialization the Carbon Credit Marketplace contract with the NFT contract address.

  • Creates a listing for a Carbon Credit NFT.

  • Removes a listing for a Carbon Credit NFT.

  • Buys a Carbon Credit NFT from a listing.

• Tested all the contracts in local node and written deployment scripts in Hardhat.

Challenges I ran into

✅ Duplicate Unique IDs The possibility of duplicate unique IDs could undermine the credibility of carbon credits traded on the platform.

Solution : Implemented secure hashing algorithms and a mapping to store and verify unique IDs. This approach successfully addressed the issue and ensured the uniqueness and integrity of each carbon credit NFT.

✅ Data Integrity Ensuring the accuracy and reliability of the carbon credit data is critical to the platform's success.

Solution: Introduced validation checks for the information associated with each carbon credit before minting the NFT. This process included verifying the origin, eligibility, and carbon reduction impact of the project or activity, ensuring the credibility of the carbon credits.

✅ Unauthorized Access Limiting access to critical functions in the smart contracts was necessary to prevent unauthorized minting or modifications of carbon credits.

Solution: Implemented proper access control using OpenZeppelin's Ownable contract or Role-Based Access Control (RBAC) to restrict access to critical functions. This measure helped maintain the integrity of the platform and prevented unauthorized actions.

✅ User Interface Challenges in having a smooth frontend deployment due to technical difficulties.

Checkout my project proposal here.

• Resubmitted the project proposal with analysis of similar products existing and how’s carbon trace is different.

• Analysis with similar products :

  1. Pachama is a platform that employs satellite imagery and machine learning to measure and verify carbon offsets. It also focuses on carbon offsetting and uses technology to verify carbon credits. CarbonTrace, on the other hand, utilizes blockchain technology to establish a transparent and secure market for carbon credit trading.

  2. AirCarbon is a carbon trading platform that uses blockchain technology for trading carbon credits. Unlike CarbonTrace, AirCarbon does not tokenize carbon credits into NFTs. CarbonTrace's unique feature of tokenizing carbon credits into NFTs creates a more transparent and secure market for carbon credit trading.

  3. CBL Markets is a carbon and environmental commodity trading platform that utilizes blockchain technology. Unlike AirCarbon, CBL Markets does not tokenize carbon credits into NFTs. CarbonTrace's use of NFTs creates a more unique and innovative approach to carbon credit trading.

  4. Nori is a carbon removal marketplace that enables individuals and companies to fund carbon removal projects. Unlike CarbonTrace, which focuses on carbon credit trading through NFTs, Nori focuses solely on carbon removal.

• Exploring different NFT contracts and its implementation strategies.

• Started working on the smart contract infrastructure.

• Implementation of CarbonCredit NFT contract which includes the following functionalities :

  • Mints a new Carbon Credit NFT with the provided hashed unique ID and metadata.

  • Marks a Carbon Credit NFT as used.

  • Verifies if a hashed unique ID matches the expected hash for a given token ID.

Checkout my project proposal here.

• Researched into protocols and platforms to get a project idea. We had a brainstorming session where i got many ideas surrounding my R&D on NFTs.

• Started doing research on carbon offset and tokenization of carbon credits.

Project Idea : Carbon Trace

CarbonTrace is a platform that leverages the power of blockchain and NFTs to create a more transparent and secure market for carbon credits. The platform allows companies and individuals to tokenize their carbon credits.

CarbonTrace's objective is to tackle carbon emissions and climate change by developing a platform to tokenize carbon credits into NFTs. This platform will facilitate easy trading and selling of carbon credits on a decentralized marketplace, motivating individuals and organizations to reduce carbon emissions and adopt sustainable practices.

Checkout my project proposal :

https://thoughtful-citron-84a.notion.site/CarbonTrace-An-NFT-Based-Carbon-Credits-Platform-87beaf815fda4bfdbafa263826257f6a

• For the current week, we started exploring different project ideas for building over the course of next 3-4 weeks.

• Defi presentations were scheduled for each where each fellow was assigned a Defi protocol to research and then give a 4-minute presentation on it. I was asked to research on Zapper.

• Zapper.fi is a social web3 explorer which allows users to follow the blockchain journey of other people in NFTs, DeFi and DAOs.

• Explored on different functionalities of Zapper and tried to implement and interact with their APIs, however, i was unable to get it since Zapper provide API keys to selected few only and not for educational or research purposes.

• It was overall a good experience to learn in depth on Zapper and on different protocols presented by fellow colleagues.

Check out my Presentation deck :

https://docs.google.com/presentation/d/1Mgx-BbVipFkAp05qe4F6ROr1jIsLAs-vWRdDs_VsVYk/edit?usp=sharing

1. Challenge : Multisig Wallet

   The challenge helped to understand the concept of Multisig mechanism where multiple signers need to sign the transaction to make it complete. The contract will keep track of transactions in an array of structs and owners will confirm or reject each one.

   The contract uses recover() to retrieve the public addresses and verify the signatures. It also has duplicateGuard which avoid any duplicate entries from the signers.

   The smart contract that acts as an off-chain signature-based shared wallet amongst different signers that showcases use of meta-transaction knowledge and ECDSA recover().

   Deployed App : Multisig Wallet

   Contract Address : Contract

2. Challenge : SVG NFT

The challenge helped to build a NFT where TokenURI is generated within the contract. Unlike normal implementation where we use IPFS or any centralized storage service to store metadata, we use MetaDataGenerator where we enforce randomness to customize the NFT image. The Loogies NFT is drawn within the contract from the svg and packaged together for us to see it.

The randomness is based on multiple factors like block hash , addresses , contract       address and an NFT will be minted.

Deployed App : SVG NFT

Contract Address : Contract

Minted NFT

1. Challenge : Build a Dex

   The challenge was to build a simple decentralized exchange with one token pair (ERC20 and ETH). It helped to understand the concept of Reserves , Automated Market Makers (AMM) where reserves will provide liquidity to swap between the tokens. Tutorial also helped to explore into the Constant formulae (x * y = K) used in Uniswap v2.

   x * y = k, Where x and y are the balance of the assets in the pool.

   Given Δx (Input value), to swap Δx for Δy, Uniswap V2 will perform the following calculation:

   **     (x + Δx ) * (y + Δy) = k**

   **     Δy = y - k/(x + Δx )**

   We wrote two functions for swapping from each asset to other, ethToToken() and tokenToEth().

   Deployed App : DEX Contract

   Verified contract address : Contract

2. Challenge : State Channel Application

   State channels is a scaling solution in cases where a fixed set of participants want to exchange value-for-service at high frequency.

   For the challenge, the service provider is a Guru who provides wisdom to each client Rube through a one-way chat box. Each character of text that is delivered is expected to be compensated with a payment in ETH. The Guru provides the service in exchange for signed vouchers which can later be redeemed on-chain.

   The challenge helped in understanding the signature and its onchain verification using ecrecover function.

Deployed App : State Channel Application

Verified contract address : Contract

1. Challenge 2 : Token Vendor

   The challenge required us to write a smart contract to Buy , Sell ERC20 tokens. Along the way, it helped to understand the usage of approve while interacting with smart contracts.

   Challenges :

   I was able to finish the contract and but the test cases were failing while trying to run it.

   Solution : Had to manage the validation added in the contract to be able to successfully pass the test cases.

   Deployed App : Token Vendor

   Verified contract address : Contract

2. Challenge 3 : Dice Game

   The challenge was to exploit the randomization feature of the Dice contract. Activity helped to under how to create random numbers using blockhash. This also led me to explore into Oracles and Chainlink.

   Deployed Contract : Dice Game

   Verified contract address : Contract

Challenge 0: Simple NFT Example

Third Party APIs

• Etherscan API key - To verify the contract

• Infura - To access the Goerli network

Steps to run the application

cd challenge-0-simple-nft
git checkout challenge-0-simple-nft
yarn install
yarn chain


cd challenge-0-simple-nft
yarn deploy 

cd challenge-0-simple-nft
yarn start


Deploy in Goerli network by updating the hardhat.config.js file. 
Change the targetNetwork to NETWORKS.goerli in Reactjs project. 

Generate a deployer address with yarn generate

yarn verify --network your_network

Run the tests : yarn test

Build frontend : yarn build

Upload the app to surge : yarn surge

Challenges faced :

openssl-legacy-provider error

Solution : Check for node version and get the latest stable node version.

nvm install 18

nvm use 18

Surge deployed link not working

Was unable to access the surge link after the initial deployment. Had to retry multiple times and switch between networks. It worked after 5 mins.

Contract deployment and Links

Deployed "YourCollectible" (tx: 0xb18c3f91c84e8f306dcf62ca01fd05393fdf292f0a9893b659084e55e036a1a2) : deployed at 0x314B161bDDEA7eBab756B73115fF984731347c0e

Explorer link :

https://goerli.etherscan.io/tx/0xb18c3f91c84e8f306dcf62ca01fd05393fdf292f0a9893b659084e55e036a1a2

Success! - Published to https://full-play.surge.sh

Challenge 1 : Decentralized Staking App

Steps to run the application

git clone https://github.com/scaffold-eth/scaffold-eth-challenges.git challenge-1-decentralized-staking

cd challenge-1-decentralized-staking

git checkout challenge-1-decentralized-staking

yarn install

yarn chain
yarn deploy 
yarn start


Update the contract Staker based on the Hints given in the challenge. 

Challenges faced :

Test cases were failing. Had to redeploy the contract with modifier to pass the test cases.

Goerli network was down and had to extend the deployment and testing in Goerli network later.

Contract deployment and Links

"ExampleExternalContract" at 0x51da68fA050a46E6B05EdCC8c67F759FA3F2908d

deploying "Staker" (tx: 0x9678c4d90d1518b0aaa5394143b763ad4ae6bc10fbfcea7c3738f1950bbf3186) deployed at 0x78E72aa7EdC4d11bDf233A571674e7A328Ee57Db

https://goerli.etherscan.io/address/0x78E72aa7EdC4d11bDf233A571674e7A328Ee57Db

Success! - Published to tawdry-snake.surge.sh