Blockchain, NFT, Crypto Basics

Alchemy.io

What's Alchemy? Alchemy Basics

Avalanche (blockchain)

What's Avalanche? Avalanche Basics

Brave browser, BAT token

"Brave is a free and open-source web browser developed by Brave Software, Inc. based on the Chromium web browser. Brave is a privacy-focused browser, which automatically blocks online advertisements and website trackers in its default settings. It also provides users the choice to turn on optional ads that pay users for their attention in the form of Basic Attention Tokens (BAT) cryptocurrency. Users can then send contributions to websites and content creators, which support BAT in the form of tips along with the ability to keep the cryptocurrency they earned.[7][8]" -wikipedia The founder of Brave (CEO Brendan Eich) also co-founded Mozilla.

Blockchain

What is Blockchain?

"Blockchain is the innovative database technology that’s at the heart of nearly all cryptocurrencies." - Forbes

A blockchain is a public, distributed ledger, effectively a database. It can store data of any kind, usually texts and numbers, URLs in a block. A blockchain is a chain of blocks. Each block has a hard-to-tamper-with reference to the previous block.

Blockchain technology is often used to launch cryptocurrency and tokens. It is a public, relatively secure, distributed database (ledger, account of transactions).

Blockchain tech is often thought to be trustless - no need to entrust a 3rd party, a middle man. The code executes exactly as expected, consistently.

There are 5 layers of technology in blockchain tech stacks. The blockchain base layer for example is layer 0. For example Alchemy supports L1 and Atrium Layer 2. Polkadot is layer 1, connects the blockchains.

Consensus

Consensus mechanism, voting. todo e.g. stellar consensus

Development environment

Brownie

Ganache

A local blockchain for development. Faster, no need for test tokens, or chains.

Hardhat

"Hardhat, a development environment that facilitates building on Ethereum. It helps developers manage and automate the recurring tasks that are inherent to the process of building smart contracts and dApps, as well as easily introducing more functionality around this workflow. This means compiling and testing at the very core." hardhat documentation

Developer tool (tooling) for smart contract development. Smart contract development environment. Requires npm.

Hardhat: Why is hardhat library popular? public view

Hardhat may be considered newer and more hip than truffle.

DEX decentralized exchanges

Many DEX functionalities are not available for USA 🇺🇸 users. USA regulations generally requires Know your customer (KYC) and tax reporting. Currently most DEXs don't provide that.

DeFi Decentralized Finance

Related to DEX. DeFi providers include: swaps such as uniswap, Sushiswap, borrowing Aave and Chainlink

ERC-20

Ethereum-based tokens, hence Ethereum compatible. EVM code potentially compatible or with minimum code change. Example $MATIC token has an ERC-20 compatible token. It also has a polygon chain version, which can be bridged. Currently ERC-20 tokens all have high gas fees because ethereum has high gas fees.

You can easily send ERC-20 tokens to your compatible Ethereum wallets. It also means you will have to pay fees comparable to Ethereum gas fee for transactions and that’s high ranging from $8 to $200 depending on congested the network is.

Ether

Native currency of the ethereum blockchain.

ENS

If you see people using names such as .eth, they are using ENS service. Example Yourname.eth. Read more trivia like this on our blockchain landing page. You bet one of our staff has a .eth name. It's hyped right now. ENS is "Decentralised naming for wallets, websites, & more." If you see people using names such as .eth, they are using ENS service. Example Yourname.eth.

IPFS

What is IPFS? IPFS defined.

Gas Fee

gas = same amount for the compute size. gas cost = how you pay, priority. There are two parts to the gas total costs : gas and gas cost. disclaimer: our interpretation may contain mistakes or limited technical understanding. Use caution. Read full disclaimer.

Transaction costs can be very high on ethereum. Gas helps run the blockchain, e.g. incentivse miners to compute.

Metamask

An ethereum wallet, a virtual wallet, in the browser, as a chrome extension. The most popular ethereum wallet in the browser. Its logo is a fox. It holds ETH. It can connect to mainnet as well as testnets. Can be used to authenticate into websites (use caution!! read more about it, potential security risk), hold ether. Anything under the mainnet is a testnet. Do not experiment or develop with your mainnet. Warning newbies have lost all tokens and NFTs in their wallet (any kind of wallet, not just limited to metamask) after clicking on malicious links or signing smart contracts that are shady. Warning! It's a live blockchain wallet.

Metamask is a crypto wallet, the gateway to the blockchain, metaverse, NFT world, and many decentralized apps (dapps).

Mini project: work with metamask wallet in the browser Mini project : metamask wallet for ethereum

Metaverse

The word meta is made famous by facebook recently, but the word is about so much more. There are already great companies and apps built on metaverse: gamefi, play-to-earn P2E, in-game economy, game algorithms / design. Metaverse include Facebook which is changing to Meta, game world, imaginary world. Some companies and tokens in-play include : $MANA, $SAND. There has been speculative land sale, real estate, office space residency even an embassy established in metaverses. Metaverse often has some kind of in-game economy, tokens, in-game currency etc. We have seen NFTs being used as avatars, playable assets, even land and real estate in game. They can be bought and sold at in-game marketplaces. Even convert to in-game tokens such as $SAND, which can be converted to dollars minus a lot of gas fees.

Facebook changed its name to META, but the metaverse concept is not created by Facebook. Despite that, Facebook attracted some great metaverse talents. Follow their best design practice at Design at Meta. Facebook is also the home of Oculus, Augmented Reality (AR). Also check out its design best practice.

Examples of metaverse: Sandbox, Decentraland, and Axie Infinity. Metaverse is where crypto meets gaming.

NFT

• Examples of NFT: Bored Ape Yacht Club, Crypto Punks, Azuki etc.
• ERC-721 non-fungible token on ethereum blockchain Example interface: each token has property tokenId of type uint256, and contract address. The pair of tokenId and contract address must be globally unique.
• Everyone can see it, just not own it. Even if you can't afford NFTs, you can still enjoy it.
• Check out our smart tutorial on Non Fungible Tokens (NFT) explained in plain English
• pfp: profile picture, avatar,
• Alchemy tutorial how to mint NFT in testnet. public view
  Note production net is called main net. Testnet as the name implies is for testing purpose only.
• OpenSea is future: it's the no.1 NFT market place in the United States. web3 intersects art/NFT, blockchain. It creates a new generation of consumers of digital art and commerce.
• Axie Infinity (game) popularized the concept of borrowing and lending NFT for game purpose. Axie Infinity is not available for US players.
• NFT collections can be as large as 10,000 items.
• NFT is only digitally made to be scarce, traits have different drop rates. Certain traits are made digitally rare such as golden crown or golden fur in BAYC.
• ERC1155 semi-fungible
• Minting an ERC 721 NFT is creating and publishing an unique instance of the token onto the ethereum blockchain.

Node

What's a node in blockchain [flash card, node, public]

Pinata

The n has a tilda, and is pronounced "knee". "Pi-nya-ta". Pinata is the a multimedia hub for NFT creators, builders, and artists in web3.

Polygon $MATIC

"Polygon, ... a sidechain scaling solution for Ethereum that cuts down on transaction fees. " - decrypt What is polygon (blockchain)? Polygon + Alchemy.io

Proof of Work

Miners have the burden of verifying transactions - a high computation power task. Associated with high energy cost. Each transaction needs to contribute to rewarding miners, hence transactions can be expensive.

Number of transactions processed per minute can be low.

Proof of Stake

Smart Contracts

Smart contract development

How to program smart contracts? Smart contracts are programmed using a Java class, object oriented programming (OOP), syntax like language called Solidity. Here's what Patrick Collins said about solidity. The file extension is dot sol (.sol). Check out their hackathons, documentation, and developer advocates Chainlink learning resources. Chainlink provides Price Feeds, Any-API, VRF for use in smart contracts. Smart contracts in Solana are written in Rust. Ethereum smart contracts are written in solidity.

Some say the smart contracts are neither smart nor are they contracts. They just faithful execute codes as the codes are written. It is public, every one can see the smart contract, and its codes are public.

This is great for transparent, however, it is also great for hackers to exploit, as the inner workings of the contracts are public. For this season, smart contracts must be thoroughly tested, audited and reviewed by security experts.

Anatomy of a Smart Contract : Line by line walkthrough of a Solidity smart contract coming soon ... todo

• What's a smart contract? Blockchain tech explained. A simple introduction to smart contract
• What's ABI [pro, smart contract]
• Solidity is the language of smart contracts on ethereum.

Testnet development environment

Development blockchain, test blockchain, testnet. Example of Ethereum testnets : Rinkbey, Roposten? todo

You can get test Ether (Ethereum) from faucets. Be sure to always check you are using a legitimate faucet.

If you are participating in a hackathon, please ask the organizer, tutorial author for official test faucet. Generally you will enter your address to the test faucet, await a bit of time to get the test tokens in your wallet.

Tezos

Claims to be an energy efficient blockchain (probably because of use of proof-of-stake instead of proof-of-work). Partners with Cambridge on climate change NFTs.

Vocabulary

Vitalik Buterin: founder of ethereum. Once donated $SHIB to India COVID relief.

Web3

Web3 is the next iteration of the internet. It is the future of web. It has javascript libraries like web3.js, ether.js which supports blockchain functionalities that web2 cannot handle. For example send ethereum to address ends with .eth . Utility libraries are in JavaScript. Python, Ruby and other SDKs are also available.

• web3.js basics public view

Web Development Skills

(web2 skills that are still important)

Common front end development tools : npm, webpack, babel. For example, Babel transcomile or "translates" JSX (used in React) to JavaScript.

Next section: we discussion new and upcoming technology

Innovation in the blockchain, decentralized app space

Chainlink : chainlink provides the on-demand tech, software, infrastructure to decentralized oracle networks. Test link URL

"What is Chainlink? Chainlink is the industry standard for building, accessing, and selling oracle services needed to power hybrid smart contracts on any blockchain. Chainlink oracle networks provide smart contracts with a way to reliably connect to any external API and leverage secure off-chain computations for enabling feature-rich applications." -official documentation

Avalanche : offers DeFi, yield

What is Avalanche? What is Moralis?. Moralis support for Avalanche.

uniswap

City of Miami using Internet of Things (IoT) sensors on Algorand for monitoring air pollution.