• To showcase to beginner/intermediary smart contract developers the versatility of token contracts.

• To connect ERC20 & ERC721 tokens.

• To show a mechanism that can be used in selling NFTs on a blokchain by using smart contracts

• Solidity: Programming language used to write smart contracts.
• Remix: IDE used to write smart contracts in Solidity. It contains functionality that enables a user to compile and deploy contracts outside of a blockchain.
• MetaMask: Browser extension of cryptocurrency wallet used to connect and deploy contracts & transactions on a blockchain.
• (Polygon) Testnet: Testnets allows developers to deploy contracts and transact in a blokchain without incurring gas fees. It is a simulation of a real blokchain which is perfect for developmental puporses
• Pinata: Pinata's powerful but easy-to-use product allows users to upload, share, and manage files with unmatched speed throughout the IPFS network.
• IPFS: The InterPlanetary File System is a protocol and peer-to-peer network for storing and sharing data in a distributed file system.
• Web3.py: is a Python library for interacting with Ethereum.

• Python: Programming language used to develop the back end of our ""Photo Registry"" UI.
• Streamlit: Python package used to develop a UI web application.

We compiled a few images of back end code and blockchain transaction history we collected along the way.

We strongly suggest you check our video demo presentations for a complete overview of our work!

*Videos can be found on the presentation slides.

We created an easy to use UI that allows any person to mint digital images as NFTs. These NFTs were not minted into a blockchain but were only ran locally.

Deployment of NFT contract on Remix IDE

Deployment of Coin token contract on Remix IDE

Excerpts from our python/streamlit code behind our web based UI

loading our token contract (python function)

We used an ERC20 contract to create our own fungible token. Then we added functionality to a ERC721 contract to accept our fungible token as payment in order to mint NFTs.

We minted our tokens to Polygon's testnet and showcased our NFT on Opensea.

Snapshot of JoeToken deployed on Polygon

Initializing JoeToken contract address as a state variable on our NFT contract before deploying

Polygon transaction record

URL to Joe token's contract on Polygon

https://mumbai.polygonscan.com/token/0xfe289af009585a246dc5298d60ad8d7460ac8c9f

URL to Joe's NFT contract on Polygon

https://mumbai.polygonscan.com/token/0x14ecb29b607ac3909ae09549fa6e66a1f16ae84b

We built a smart contract that simulates a dutch auction in order to sell NFTs on a blockchain.

Ductch Auction Contract

NFT contract

Functionality embedded on NFT contract

Using readily available and open-source blockchain technologies and fairly advanced but easy to read Solidity (and Python!) code, we were able to successfully develop standard-meeting tokens and use them in different contexts. From creating a registry of tokenized pictures, to deploying tokens on an actual blockchain, to formulating a way to sell them!