We're going to help you build your first blockchain using Substrate

How to create your own blockchain

Introduction to Substrate, course content, prerequisites and setting up - all under this section!

Hey fam,&nbsp;This is Aswin here again.&nbsp;Today we are going to launch a blockchain using Substrate. It's going to be so much fun because not many platforms (or any) have attempted to teach how to launch a blockchain.&nbsp;But but but… will not only be building a blockchain, rather we'll simultaneously dive deep into blockchain concepts as well. &nbsp;I cannot put more emphasis on how important this course is for your career as a web3 engineer, so study and study closely.&nbsp;<figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://metaschool.s3-ap-southeast-1.amazonaws.com/images/Mq6kqEvKg4mm2bSZTG4Rx91A0kSKAwa2OZvYRe1X.png" data-origin="," alt="" data-proportion="true" data-align="none" data-index="0" data-file-name="Mq6kqEvKg4mm2bSZTG4Rx91A0kSKAwa2OZvYRe1X.png" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div></figure><h3>&nbsp;</h3><h3>So, what is Substrate?</h3>It's the main blockchain SDK (software development kit) used by programmers to build the parachains that make up the Polkadot network.Polkadot is a Layer-0 protocol, built by Ethereum’s co-founder Gavin Wood citing Ethereum’s inability to scale. Wood wanted to solve this problem by introducing a proof-of-stake (POS) validation system since PoS consensus is used by most modern blockchains.Polkadot makes the development of a Layer-1 blockchain easier by providing a built-in infrastructure for developers to build upon.Now let’s understand,<h4>Why do we need Substrate?</h4>Blockchain development is a very complex and resource consuming task. It involves many sophisticated technologies including advanced cryptography and distributed computing. The development also involves a lot of problem statements like scalability, interoperability, upgradability, etc.So, substrate is an SDK that provide that framework to build a blockchain, so rather than focusing on developing a framework from scratch like the application layer, network layer, RPC, etc, you could focus on developing the business logic or its runtime logic.<h4>Substrate has the following advantages</h4><ul><li>It's an open source SDK so you can customize your blockchain according to your needs. Plus they have a very strong builder community to help you with the development</li><li>The blockchain created using substrate are highly interoperable as it can communicate with other substrate blockchains using Cross Consensus Messaging or XCM</li><li>Substrate frameworks are upgradable and composable as the state transition logic of the blockchain or the runtime is stored as a WebAssembly object which gives the blockchain nodes the ability to perform “forkless” upgrades</li></ul>Hope I could help you understand the basics of Substrate and why we should use it.&nbsp; Let’s move to the next lesson where we will setup the environment to run the Substrate template node locally 🔥

⚡ Introduction

Before we get started, let’s familiarize ourselves with all that we'll be learning.&nbsp;<h3>This course on how to launch your own blockchain will cover</h3><ul><li>Using Substrate SDK</li><li>Understanding Polkadot environment and Layer-0 protocol</li><li>Key blockchain concepts and working principles</li><li>What is relay chain</li><li>What are parachains</li><li>How to run your substrate based blockchain locally</li></ul><h3>Prerequisites before building your own blockchain</h3><ul><li>A good Internet connection and access to your CLI</li><li>Basic understanding of&nbsp;<a href="https://hackr.io/blog/basic-linux-commands" target="_blank" rel="noopener noreferrer">how to use Linux terminal</a></li><li>Rust Environment (walkthrough in the next lesson)</li></ul>Let’s move to the next lesson now where we will set up the environment finally!<h3>🛠 Contribute to our projects!</h3>Don’t forget to star ⭐️ our repository and start contributing to our projects on Github! We will be very thankful! ♥️Github: <a href="https://github.com/0xmetaschool" target="_blank" rel="noopener noreferrer">https://github.com/0xmetaschool</a>&nbsp;Are you excited? How about a cherry on the top?You’ll get a very special NFT upon completion of this course. Lezzz go!!!&nbsp;<figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh5.googleusercontent.com/svAxhAAcaAhNuyiXlCR5ODORbfWrW2KR8-PLeXFFHewI1jxMz54Fd9DqPCKylyJ_x6RsX0aRhCFGaIXik_ebvK0RTU5v0zxyaLA1CK3cDuOxAstT8ltm4t9c8mGwU17dtpocoKemxCa9WHBBYUyZCdWxbc8ey-cziLq3FsbKdQgaNxl59wheZY-n0ssGvQ" alt="journey" data-origin="," data-proportion="true" data-align="none" data-index="0" data-file-name="svAxhAAcaAhNuyiXlCR5ODORbfWrW2KR8-PLeXFFHewI1jxMz54Fd9DqPCKylyJ_x6RsX0aRhCFGaIXik_ebvK0RTU5v0zxyaLA1CK3cDuOxAstT8ltm4t9c8mGwU17dtpocoKemxCa9WHBBYUyZCdWxbc8ey-cziLq3FsbKdQgaNxl59wheZY-n0ssGvQ" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div></figure>

📖 Course Learnings & Prerequisites

Let's get to the most important part which is setting up the Rust environment.Please follow the steps carefully.&nbsp;If you are on Mac, please scroll down the follow that. If you are on Linux, set up is the same as Windows but you don’t need WSL.&nbsp;<h3>For Windows</h3>You need to install Linux Subsystem for Windows as this development needs Linux kernel.&nbsp;So if you have a Linux or Mac environment it's great, but if you have a Windows environment we need to setup up Linux on it.&nbsp;You could either install Linux on your system as dual boot or use virtualization tools like Vmware or Install Windows Subsystem for Linux (WSL).For this course, I will go with WSL.<ul><li>Start by running your Windows terminal in administrator mode &nbsp;</li><li>In your CMD or Powershell run the following command</li></ul><pre><code>wsl --install</code></pre>It will take some time to install as it will install an Ubuntu distort of Linux on your Windows.<ul><li>Restart your computer, after your installation is complete &nbsp;</li><li>After restarting your computer, an Ubuntu shell will popup automatically installing some required feature. If it doesn’t popup after restarting your computer, open Ubuntu on Windows from start menu</li></ul>The Ubuntu terminal will now ask for the unix username as shown here👇🏼<div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh4.googleusercontent.com/m-O7y15I0HYCvPzMLVds0fzZXSged__8OxxySP33wQKq2JZZi1IVLo-p_9ckIUfuScwJbC50F9RgPpeGqARRhsMS93tmFMxpiJiREYmmKuh_Gi7aBHWmzdT-FA76Xpg3LgWqOSFmV4ofOWi_8sqi3fMw4TKoQsdyHAmK5TUychc5zJezgVkSOU-a37sXeA" data-origin="," alt="" data-proportion="true" data-align="none" data-index="0" data-file-name="m-O7y15I0HYCvPzMLVds0fzZXSged__8OxxySP33wQKq2JZZi1IVLo-p_9ckIUfuScwJbC50F9RgPpeGqARRhsMS93tmFMxpiJiREYmmKuh_Gi7aBHWmzdT-FA76Xpg3LgWqOSFmV4ofOWi_8sqi3fMw4TKoQsdyHAmK5TUychc5zJezgVkSOU-a37sXeA" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> <ul><li>Now enter a username and press enter, then it will prompt you to enter a password &nbsp;</li><li>Enter a password and note whenever you enter a password in any Linux terminal, no feedback (like any bullets)&nbsp;when entering a character, just keep typing your password and then press enter</li></ul>After your Ubuntu setup is complete, your terminal will show up like this 👇🏼<div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh5.googleusercontent.com/WPEdNI5c6cClHK_gzv0604nHilvV_72G0ClmXE8c8EJ9mPArGMEOu45RGWRb5Jr1AGYRtmcZrAuMDXaK9Y0Dq5UzTJLfEqH4LMyRI98Th9NXLDqb53E2aVcAzUnlIw_ncwtgffZUR6mwVc_Xkxja9iJgoRxDr5HyGuzlo54-tcKm07iBTtdmeT4eOfLqvQ" data-origin="," alt="" data-proportion="true" data-align="none" data-index="1" data-file-name="WPEdNI5c6cClHK_gzv0604nHilvV_72G0ClmXE8c8EJ9mPArGMEOu45RGWRb5Jr1AGYRtmcZrAuMDXaK9Y0Dq5UzTJLfEqH4LMyRI98Th9NXLDqb53E2aVcAzUnlIw_ncwtgffZUR6mwVc_Xkxja9iJgoRxDr5HyGuzlo54-tcKm07iBTtdmeT4eOfLqvQ" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> Now… let’s move forward and install Rust toolchain on WSL<ul><li>First, download the latest updates for your Ubuntu distribution by running the following command 👇🏼</li></ul><pre><code>sudo apt update</code></pre>Note: Sudo will allow the terminal to run in administrator mode on any Linux distort and whenever you use sudo, you need to type your password. Again, no feedback will be shown as usual so keep entering your password and press enter<ul><li>Add the required package for our Ubuntu distribution by running the following command 👇🏼</li></ul><pre><code>sudo apt install --assume-yes git clang curl libssl-dev llvm libudev-dev make protobuf-compiler</code></pre>Note: If a prompt comes up for allowing the installation of package, enter yes or y to continueAfter that let’s curl Rustup installation program 👇🏼<pre><code>curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh</code></pre>Follow the instructions and proceed with the default installationNote: These installations take up some space so keep at least 50 GB free in your Windows DriveNow update your current shell with cargo environment by running the following command 👇🏼<pre><code>source ~/.cargo/env</code></pre>If you have Rust installed in your environment, check the installed version using the following command 👇🏼<pre><code>rustc --version</code></pre>Configure the rustup to use the latest stable version of the toolchain by running the following command 👇🏼<pre><code>rustup default stablerustup update</code></pre>Add the nightly version of the toolchain and the nightly WebAssembly (WASM) target to the development environment by running the following command 👇🏼<pre><code>rustup update nightlyrustup target add wasm32-unknown-unknown --toolchain nightly</code></pre>Now, we have almost finished setting up the environment. Let’s check our toolchain specs and if we have installed everything correctly ⚡️<pre><code>rustup showrustup +nightly show</code></pre><div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh5.googleusercontent.com/SY6tV50R5nMuMejeUQiTFCx3Uim4DZJBtdGCb85KSRRBaxsqOBX1efbMtNOCkb9TWOqVKPQrfq3upEO7q1TYKvwbYI4AK75hHD-7jmidFJfpLTFM0vsXsrXZR8rV89P4GySt9QT-gXh0ESM_g2JK3b2Ylkmj6OBBrDHbVLdcWanizxBkmiKDFCi4S_CPAQ" data-origin="," alt="" data-proportion="true" data-align="none" data-index="2" data-file-name="SY6tV50R5nMuMejeUQiTFCx3Uim4DZJBtdGCb85KSRRBaxsqOBX1efbMtNOCkb9TWOqVKPQrfq3upEO7q1TYKvwbYI4AK75hHD-7jmidFJfpLTFM0vsXsrXZR8rV89P4GySt9QT-gXh0ESM_g2JK3b2Ylkmj6OBBrDHbVLdcWanizxBkmiKDFCi4S_CPAQ" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> As you can see, we have installed everything perfectly so we are good to go forward!If you are using a Mac or Linux, you can skip setting up the Linux environment as both of these support UNIX terminals by default.&nbsp;If you're using Windows, you can skip the next part about Mac and move to the next lesson. 💻&nbsp;<h3>For MAC</h3>Start by installing homebrewOpen terminal and run the following command 👇🏼<pre><code>/bin/bash -c "$(curl -fsSL&nbsp;https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"</code></pre>Verify your installation by running 👇🏼<pre><code>brew --version</code></pre>If you are using an M1 Mac or any ARM processor, you must have Rosetta installed to run protoc tools. Install Rosetta by running the following command in your terminal 👇🏼<pre><code>softwareupdate --install-rosetta</code></pre>Install OpenSSL and rust toolchain for Mac. We need to install openSSL to provide support for cryptography which a blockchain needs. Run the following command to install it 👇🏼<pre><code>brew install openssl</code></pre>Let’s download the rustup installation program 👇🏼<pre><code>curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh</code></pre>Follow the installation instructions and proceed with the default installation.&nbsp;Now go ahead and update your current shell with cargo environment by running the following command 👇🏼<pre><code>source ~/.cargo/env</code></pre>If you have Rust installed in your environment, check the installed version using the following command 👇🏼<pre><code>rustc --version</code></pre>Configure the rustup to use the latest stable version of the toolchain by running the following command 👇🏼<pre><code>rustup default stablerustup update</code></pre>Add the nightly version of the toolchain and the nightly WebAssembly (WASM) target to the development environment by running the following command 👇🏼<pre><code>rustup update nightlyrustup target add wasm32-unknown-unknown --toolchain nightly</code></pre>Now, we have almost finished setting up the environment. Let’s check our toolchain specs and if we have installed everything correctly,<pre><code>rustup showrustup +nightly show</code></pre>So this was the whole process for all you frens using mac or linux. You don’t need any special instructions, it’s pretty simple - just follow the Windows one if you don’t need to set up any environment.Let’s move on to the next lesson and where we will start building our blockchain ✨💻

💻 Environment Setup

Substrate and its basics

So, now we are on to the fun part, so hold on to your seats tightly.&nbsp;Follow the instructions carefully as you are developing a sophisticated system and any mistake will cost you to redo the whole process again!To begin, we need the Substrate node template, which will act as a framework for us to build our blockchain on as we will not be coding anything from scratch.&nbsp;Download the Substrate node template from&nbsp;<a href="https://github.com/substrate-developer-hub/substrate-node-template" target="_blank" rel="noopener noreferrer">here</a> &nbsp;If you are using git, clone it using the following command 👇🏼git clone&nbsp;<a href="https://github.com/substrate-developer-hub/substrate-node-template" target="_blank" rel="noopener noreferrer">https://github.com/substrate-developer-hub/substrate-node-template</a>&nbsp;If you have downloaded the template, open the terminal in the root directory of the folder or if you have cloned it, then run 👇🏼<pre><code>cd substrate-node-template</code></pre>So now you can type ls to view the content of the folder and you can explore the files and use use the default text editor of Linux nano to edit files if needed via the terminal itself<h3>Default structure of the Substrate framework</h3><h4>Node folder 📁</h4>It is the most important folder as it contains all the Layers of the blockchain, the runtime, executor and the CLI.Inside the Node folder you will find three folders, CLI, runtime, executor.&nbsp;Today we will only compile the basic framework for you to understand the environment and how it works.The CLI folder contains the terminal framework and the chain spec files which contains the configurations of your blockchain. This folder contains files which help users of your blockchain to interact with the it using CLI and JSON RPC.The next important folder is the Runtime folder which contains files which handle the working logic of the blockchain as well its consensus that it uses when implementing the principle of distributed computing. &nbsp;<div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh3.googleusercontent.com/8l5xJLErdQWGjaWbMm1YG_Gs1LZSYeb0_lbdV2uRxziTArOrg6XiOSfHUNDmkoo6kAQCvjnCikbg-S3sjmm-GxwnvtUK-HR9xAB1X1E1MnbBaJks5MdN6scyHCM0Kix3rRfzJlSqTxO4xhNmnn5asSL5VjRH2scADtQDXaquB4TR0avSL8CLw-f3BGSNRg" data-origin="," alt="" data-proportion="true" data-align="none" data-index="0" data-file-name="8l5xJLErdQWGjaWbMm1YG_Gs1LZSYeb0_lbdV2uRxziTArOrg6XiOSfHUNDmkoo6kAQCvjnCikbg-S3sjmm-GxwnvtUK-HR9xAB1X1E1MnbBaJks5MdN6scyHCM0Kix3rRfzJlSqTxO4xhNmnn5asSL5VjRH2scADtQDXaquB4TR0avSL8CLw-f3BGSNRg" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> <h4>The Consensus 🤝</h4>It is an algorithm that sets a certain set of rules and regulations for the participants of the network on how they should and could interact with the blockchain, i.e, PoW, PoS, PoH.The consensus is a practical version of the Byzantine fault tolerance theorem which is a mathematical theorem that helps the components of a system reach a mutual agreement with each other to defend against any failure in the system&nbsp;<figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh4.googleusercontent.com/UGrB19K48SFDNBcLRsnwDyZo7kgNQ0Rpw4EdJfgN2Poq7KQd6F4zLgOA_zmCz4My76rk-tVxIPTuO5dFKoldBLA8ehlWxoIlcADscC2hXnKniHxxM8UNsTQlBcMFiWfmnkOPSLH25mtXcb9LsMmNwR8uLp_T2edRSfjdwC_hzLJK5QDkXK6eW8WYWKgCfw" data-origin="," alt="" data-proportion="true" data-align="none" data-index="1" data-file-name="UGrB19K48SFDNBcLRsnwDyZo7kgNQ0Rpw4EdJfgN2Poq7KQd6F4zLgOA_zmCz4My76rk-tVxIPTuO5dFKoldBLA8ehlWxoIlcADscC2hXnKniHxxM8UNsTQlBcMFiWfmnkOPSLH25mtXcb9LsMmNwR8uLp_T2edRSfjdwC_hzLJK5QDkXK6eW8WYWKgCfw" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div></figure><h4>The Blockchain Trilemma ⛓</h4>There is a rule of thumb blockchain system design termed by Vitalik Buterin called the blockchain trilemma. It refers to a widely held belief that decentralized networks can only provide two or three benefits at any given time with respect to decentralization, security, and scalability. So when you achieve one of the benefits, you have to let go off the other two!I know that's a lot of theory but I imagined it would be fun to learn about important concepts while we are building the blockchain.So, going back to the terminal where we were in the root directory of the substrate node template,Let’s compile our node template by running the following command 👇🏼<pre><code>cargo build --release</code></pre>Make sure you have an active internet connection as this process will download all the dependencies needed for our blockchain as mentioned in the cargo.toml file which you will find under every folder.This process will take up a lot of time as Rust will download these dependencies as cargo crates which are similar to npm packages. Then we will compile it on our local system.So, while it compiles let’s go back to learning some concepts of the blockchain ⛓Make sure you keep making notes on these concepts as these are important for your journey as a web3 engineer.&nbsp;Since we've already covered consensus, there is a term associated with it called distributed computing.<h4>Distributed computing 🖥</h4>It is a concept of running the nodes of a network on different computers or systems with computational power, thus distributing the computer power needed among the participants of the network. There are different types of distributed computing and blockchain uses a peer-to-peer model or p2p.These participants of the network interact with each other based on a set of rules called consensus which makes sure that,<ul><li>Each participant of the network gets fair chances&nbsp;</li><li>Each participant of the network is true to the network</li><li>Incentivize each participant of the network if they are true to the network</li><li>Penalize each participant of the network if they conduct an activity which goes against the consensus of the network</li></ul><div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh5.googleusercontent.com/j_jo4UasCTkbLzNzqq73V2YqyRlF6oeEpQfnCl7c8h5A_x39mcec50Osqgvs-EfI0P6O8EBT7SIkLbBxvycJCS9iINCG6KLDwwGu4BZO74YCSepqh_y1hOFBF61si18FDkmLgyDL24d9zQ0_Y0I7I2YeIqN2rsPW0ztNP0JAF5wruPIP8JSgAxjEMbkZZA" data-origin="," alt="" data-proportion="true" data-align="none" data-index="2" data-file-name="j_jo4UasCTkbLzNzqq73V2YqyRlF6oeEpQfnCl7c8h5A_x39mcec50Osqgvs-EfI0P6O8EBT7SIkLbBxvycJCS9iINCG6KLDwwGu4BZO74YCSepqh_y1hOFBF61si18FDkmLgyDL24d9zQ0_Y0I7I2YeIqN2rsPW0ztNP0JAF5wruPIP8JSgAxjEMbkZZA" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> <h4>Some more blockchain 🟥 🟦 🟦 🟦</h4>The blockchain stores the data as blocks and each block consist of previous hash, block height, parent hash, etcThe first block produced by any blockchain is called the genesis block, which will have a hash and the block. The block succeeding the genesis block will have the hash of the genesis block and its previous hash. This way the chain will continue - thus the term blockchain.These blocks are produced by a block authoring algorithm or node which processes transactions and submits them &nbsp;into the validating queue to be included in the blockchain.The block authoring node will process the transaction locally in a transaction pool which is like a cache memory.The valid transactions from the pool enters a transaction queue which will have two queues: the ready queue and the future queue.The ready queue contains the transactions which will enter the pending block, that is, the block which will be produced once the node gets the chance to be the block authoring node.The future queue contains the transaction which will be valid for the future blocks like suppose if the nonce of the current transaction is too high when compared to the existing transactions in the pending block. These transactions will wait in the future queue for its turn to be included in the pending block.The blocks produced are then gossiped (a way to signal the consensus that the node is ready to submit its block into the chain) and the consensus will listen to these blocks from all the nodes and verify the block by listening to what the majority of the nodes are saying.Each block has a hash right, so these hashes are produced by SHA256 algorithm. Hence whenever a node gossips about its block, the consensus verifies the hash with the other nodes if 2/3 nodes have the same hash. &nbsp;<figure class="image"><div class="se-component se-image-container __se__float-none" contenteditable="false"><figure class="image" style="margin: 0px;"><img src="https://lh6.googleusercontent.com/U5iwQfSPJLuxpSPg4qtIKQDdwFtfIFl1uXTF1iU0XVf-hB86-0H27myjaAKBgHn8dn-RiaDgBm75buTbtTR99xi0d0aTSOp9pqGcuJESUNCYPaLTOXynj8NH6CuJ3Z7Bt0MoNQWpVr_ZPpP6uEyulX_rd7ZdfzOSTaOJUY5sJDYsPoeFaO6LA7ed1rgrhw" data-origin="," alt="" data-proportion="true" data-align="none" data-index="3" data-file-name="U5iwQfSPJLuxpSPg4qtIKQDdwFtfIFl1uXTF1iU0XVf-hB86-0H27myjaAKBgHn8dn-RiaDgBm75buTbtTR99xi0d0aTSOp9pqGcuJESUNCYPaLTOXynj8NH6CuJ3Z7Bt0MoNQWpVr_ZPpP6uEyulX_rd7ZdfzOSTaOJUY5sJDYsPoeFaO6LA7ed1rgrhw" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div></figure>So, these blocks come together to produce a chain in the order of their inclusion in the chain and linked with a hash so if anyone tries to change a transaction in the queue, the hash of the whole block will change due to a concept called avalanche effect in cryptography.&nbsp;Doing so will lead to the breaking the chain so nodes will not be a part of the consensus algorithm and would not be allowed to participate in the network until it restore its database back to the original stateSo if I summarize the whole process,<ul><li>A transaction happens</li><li>The transaction enters the transaction pool and some checks are performed locally like if they have enough balance to pay, the gas, the size, etc.</li><li>If the transaction is invalid, it is dropped from the pool</li><li>If the transaction is valid, the transaction moves into the transaction queue in the order of their validity</li><li>The node waits for its chance to be the next block authoring node&nbsp;</li><li>Once the node is a block authoring node, it calls a separate execution function to produce blocks with the ready queue and gossips the production of the block for the other nodes to listen</li><li>2/3 check is done - if true the block is included in to the blockchain</li></ul>This summarizes the whole transaction cycle of a blockchain. It is one of the most important concepts when it comes to designing the runtime logic.&nbsp;<h3>What is the relay chain in Polkadot? 🔗</h3>Polkadot is a relay chain, that is, a central chain which creates a multichain architecture for other chains to communicate.Parachains, on the other hand, are specialized chains that connect to the relay chain in a shared security architecture - or in layman terms, a shared consensus.In short. a relay chain is the cpu and parachains are the cores. Each core has their own computational power and they come together to form a multicore system.&nbsp;That summarizes the whole Polkadot Layer-0 architecture.I hope while we discussed so much about blockchain, you are done with your compilation.&nbsp;Let’s go back and check our terminal 👇🏼<div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh6.googleusercontent.com/38ObM2BfZPUeCMi5SYA0ClHGeg4Y8Gdx4ih0DAX6x3t1EUkbNC-Gm81jBKP0V-hzGi3lkwGQA36h0dA9G1grwmdRhTUMq8YBP-u32jQbZUSB1ZLKDkDQMDHPiDUKChksc9eRQxhrTdIMUGKMeROKHpJ7GIkCo3NlKoxo_mmonwPajHjSGJ7zXWK99H4E6w" data-origin="," alt="" data-proportion="true" data-align="none" data-index="4" data-file-name="38ObM2BfZPUeCMi5SYA0ClHGeg4Y8Gdx4ih0DAX6x3t1EUkbNC-Gm81jBKP0V-hzGi3lkwGQA36h0dA9G1grwmdRhTUMq8YBP-u32jQbZUSB1ZLKDkDQMDHPiDUKChksc9eRQxhrTdIMUGKMeROKHpJ7GIkCo3NlKoxo_mmonwPajHjSGJ7zXWK99H4E6w" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> If everything went well this is the prompt you will be getting! ☝🏼Congratulations, we have compiled our blockchain as well as learned a lot about blockchain.&nbsp;I can say with confidence that you guys are ready to explain this sophisticated system design to your friends and teachers - if you want to show off 😉

🧑‍💻 Compiling the Substrate framework using Cargo

Coding our first blockchain ⛓

So we are finally here and I hope you took notes of the things we talked about in the last lesson.If not I would ask you to go back, take the notes and come back because this is the starting point of blockchain development.&nbsp;We have a series of courses coming up to help you build full-fledged blockchains like Solana, Ethereum and launch it for the world - so you'll be needing all the knowledge you can have. &nbsp;Without further ado,&nbsp;Let’s open the terminal in the root folder of the substrate node template and run the following command which will trigger our blockchain’s CLI and execute the node 👇🏼<pre><code>./target/release/node-template --dev</code></pre>In this case release is the production version of our blockchain and node-template is the name of the file which helps us to interact with our blockchain, created as a result of the compilation.--dev is the CLI flag we are passing to our blockchain. This flag is defined in the CLI config and is associated with a chain spec config so whenever you run --dev, a particular chain setting is loaded into the runtime logic.You can add more flags as per your requirement. We will learn more about that in upcoming courses.&nbsp;If everything went well, your output will be like this 👇🏼<div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh3.googleusercontent.com/pSlMO4FiqRm3G6komdIeqWcs8L0iaKqNZsiMlK2u1Plmp3jhuIFGU_SkmeO0qViJQ0VXcGxU_d9hGhBrA6Xmb-QqUSktd3F1G13EfAhu7GoNkkNRgjkfmlBsT-silRH5CjLjkp9UN9fjo8fFva1UXjiQAb-CgoAyb70kupKdi9x2RVlXtzSAC-bX0X7lUQ" data-origin="," alt="" data-proportion="true" data-align="none" data-index="0" data-file-name="pSlMO4FiqRm3G6komdIeqWcs8L0iaKqNZsiMlK2u1Plmp3jhuIFGU_SkmeO0qViJQ0VXcGxU_d9hGhBrA6Xmb-QqUSktd3F1G13EfAhu7GoNkkNRgjkfmlBsT-silRH5CjLjkp9UN9fjo8fFva1UXjiQAb-CgoAyb70kupKdi9x2RVlXtzSAC-bX0X7lUQ" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> &nbsp;And JUST LIKE THAT you've launched a node of your blockchain. This was so fun, right?Now, what about we make a frontend or a blockchain explorer to see the stats of your blockchain node? I hear you guyssssss, let’s boot up a frontend then!👋🏼 Also, just a reminder do not close the terminal in which you are running your blockchain node or else the blockchain will stop workingYou wouldn't want that. So be super careful!&nbsp;Onto the next lesson we gooooo

⛓️ Running a Substrate node locally

Running your first blockchain node locally 🔗

In this lesson, again, we don’t need to do anything from scratch as we have a Substrate frontend template (yayyyy) 🫠Let's get to business, shall we?Download the substrate frontend template from&nbsp;<a href="https://github.com/substrate-developer-hub/substrate-front-end-template" target="_blank" rel="noopener noreferrer">here</a>Or clone the front-end template by running the following command 👇🏼<pre><code>git clone&nbsp;https://github.com/substrate-developer-hub/substrate-front-end-template</code></pre>&nbsp;But wait we need to set up NodeJS and Yarn right?&nbsp;Download and install the&nbsp;<a href="https://nodejs.org/" target="_blank" rel="noopener noreferrer">NodeJS</a>, run following commands to install NodeJS 👇🏼<pre><code>curl -sL https://deb.nodesource.com/setup_16.x -o /tmp/nodesource_setup.shsudo bash /tmp/nodesource_setup.shsudo apt install nodejsnode -v</code></pre>Make sure you install at least v14 for the frontend template to runInstall Yarn using NPM by running the following command 👇🏼<pre><code>sudo npm install --global yarn</code></pre>Let’s go to the root directory of the frontend by running the following command 👇🏼<pre><code>cd substrate-front-end-template</code></pre>Run the following command to install the dependencies needed for the frontend👇🏼<pre><code>yarn install</code></pre>Hope we are ready to start out frontend and connect it to our blockchain.Let’s run the frontend by using the following command 👇🏼<pre><code>yarn start</code></pre>If everything went perfectly, you will have this frontend opened in your browser 😍👇🏼 &nbsp;<div class="se-component se-image-container __se__float- __se__float-none" contenteditable="false"><figure style="margin: 0px;"><img src="https://lh5.googleusercontent.com/rINjA0PvxGPnOTqRZ5Bcw1LPAKry3FNVmbVPT2kTk8pd_osseGECHNRk39bixHU15Sjz6bB0wLfbwMlAbOMd57YpB5L-WAJDqEkI34k1Ha6PfWOYp_xzxl5RQ5mkltLh-e0QVjWyr-4Szq4oYMUj4Uw9IIo25G2K7MTMFajH2pDDDGZy3RK0eOmOOSW_Lw" data-origin="," alt="" data-proportion="true" data-align="none" data-index="0" data-file-name="rINjA0PvxGPnOTqRZ5Bcw1LPAKry3FNVmbVPT2kTk8pd_osseGECHNRk39bixHU15Sjz6bB0wLfbwMlAbOMd57YpB5L-WAJDqEkI34k1Ha6PfWOYp_xzxl5RQ5mkltLh-e0QVjWyr-4Szq4oYMUj4Uw9IIo25G2K7MTMFajH2pDDDGZy3RK0eOmOOSW_Lw" data-file-size="0" data-rotate="" data-rotatex="" data-rotatey="" style="" data-size="," data-percentage="auto,auto"></figure></div> Congratulations, you have successfully launched your own blockchain with a frontend. Yep, that's it - that's all. 🥳In the upcoming series of courses we will work on these templates and make necessary changes to build our runtime logic.I hope you enjoyed this course and learnt a lot.&nbsp;It’s time you help us by sharing this course with your friends and colleagues. Maybe share the screenshot of your blockchain on your social media and tag @<a href="https://twitter.com/0xmetaschool" target="_blank" rel="noopener noreferrer">oxmetaschool</a> we will follow and repost the best ones!

How to create your own blockchain

Project Curriculum

Substrate and its basics

Coding our first blockchain ⛓

Running your first blockchain node locally 🔗

Making a frontend for our blockchain 🖥

🎉 Completion

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