How to build your first blockchain on Substrate?

When Ethereum launched in July 2015, the world was introduced to the concept of smart contracts that hoped to revolutionize the blockchain space, allowing everyone from developers to enthusiasts to deploy decentralized applications (DApps) on the Ethereum mainnet.

With various DApps currently in use across different blockchains such as Ethereum, they offer many use cases including banking, gaming, finance, e-commerce and social media, with an ever-growing user base worldwide.

However, after providing the infrastructure needed for developers to create innovative digital applications, Ethereum has limitations such as limited scalability and high gas fees, factors that now prevent developers from building specialized solutions that can compete with popular centralized platforms such as Twitter, Facebook and Netflix .

To overcome these challenges and explore the possibilities of blockchain technology, Ethereum co-founder and its first chief technology officer Gavin Wood left the Ethereum Foundation and founded Parity Technologies to build blockchain infrastructure that could help create the foundation of a decentralized web, or Web3 as it is known.

Related: Five major challenges in the blockchain industry

Armed with vast industry experience and deep understanding of creating blockchains, he went on to build Substrate as an open-source and future-proof blockchain framework for developers to build upon, allowing them to fine-tune the blockchain architecture in line with changing customer preferences.

Substrate-based blockchains can be integrated as parachains on networks such as Polkadot or Kusama and provide a high level of interoperability, helping to bring to market truly decentralized real-world solutions that are faster, cheaper and more secure than ever before.

What is substrate blockchain and how does it work?

The vision of Web3 being a decentralized blockchain-based version of the internet relies on developers being able to create various blockchain applications that can interact with each other and with networks like Ethereum and Bitcoin.

Typically, a blockchain framework is used by blockchain developers to create such applications, and by using built-in templates, they can save a lot of development time at the cost of limited adaptability.

This is where Substrate, an open source blockchain framework for building custom blockchains, enables developers to quickly build blockchains based on field-tested code that powers a large ecosystem of blockchain projects worldwide.

Comprised of an extensive collection of tools and libraries, Substrate is the primary blockchain software development kit (SDK) used to build the Polkadot layer-0 protocol and can be used by developers to create any type of blockchain.

Related: What is the difference between blockchain layers L0 and L1?

The primary block of any blockchain is the node and relies on a decentralized network of these nodes or computers communicating with each other to maintain a current ledger of the most recent transactions. Each node in a blockchain network acts as both client and server, requesting and responding to requests for data according to its requirements.

What makes a Substrate node unique is the way these operational responsibilities are divided horizontally to provide a modular framework for building blockchains. Each Substrate node uses two main elements: an outer node that handles network activity and a runtime that determines transaction validity and is responsible for handling changes in the blockchain’s state transition function.

The outer node is responsible for communicating with other nodes, managing the transaction pool, peer discovery, and responding to remote procedure calls (RPC) or browser requests using the Substrate’s RPC Application Programming Interface (API). By querying the substrate’s runtime or by providing it with information, the outer node uses specialized runtime APIs to handle this communication.

With the Substrate runtime handling everything that happens on-chain, it is the core component of the node for building blockchains and controls how transactions are included in blocks, how blocks are returned to the outer node, or how the chain state changes in response to transactions.

Using host functions to communicate with the outer node, the Substrate runtime enables runtime validity checking and cross-platform compatibility, provides proof of validation for relay chain consensus mechanisms, and offers support for fork-free upgrades to the node architecture.

How does Substrate allow you to create a custom blockchain?

Substrate offers greater freedom, flexibility and optimization capabilities than building on top of a general smart-contract blockchain like Ethereum. Also, substrate-based blockchains can exist as “solo chains” or integrate into Polkadot or Kusama to become parachains.

Developers can choose to first start with a Substrate node template, which is the basic unit in building a blockchain using Substrate and provides a lot of pre-built functionality with standard implementations for aspects such as account management, consensus, privileged access and peer-to-peer (P2P ) network.

These Substrate node templates are maintained in the Substrate Developer Hub, and developers can also access Substrate’s large, active and helpful community of builders who continuously contribute to the ecosystem.

However, for more complex projects, developers will want a higher degree of freedom to determine the logic of the blockchain, and this is where the Substrates Framework for Runtime Aggregation of Modularized Entities (FRAME) comes into play.

FRAME is one of the most powerful tools offered by Substrate and consists of a number of modules and support libraries to simplify runtime development. Also known as Substrate pallets, these modules represent customizable business logic for use cases such as staking, governance, consensus, and other important activities that developers may want to include in the runtime.

In addition, developers can use the system, support, and executive platforms to provide a wide variety of services for the runtime environment. While one can build a Substrate-based blockchain without using FRAME, the various platforms and libraries enable developers to compose custom runtime logic using the predefined components as a starting point.

By combining pre-built and custom pallets to infinitely control the features and functionality offered by the Substrate blockchain, developers can achieve specific results with a high degree of flexibility and convenience.

How to create your first blockchain on a substrate?

Whether you’re a beginner developer or someone with previous experience using a blockchain framework, Substrate offers tutorials that focus on providing hands-on experience and Substrate Playground for those who want to experiment without much guidance.

Underlay tutorials are suitable even for absolute beginners, and cover all steps without going too much into the coding details. Apart from these tutorials, Substrate provides a number of tutorials on specific topics and also provides access to many open source projects built using Substrate.

However, it is important to understand how to work with pallets on Substrate to adapt each node’s logic so that it can be used in conjunction with smart contracts to incorporate even more functionality into the resulting blockchain.

Thus, Substrate offers all the necessary support right from installation to the successful operation of your own custom blockchain. Although it does not have a native crypto-token, the Polkadot (DOT) token is most widely used considering its compatibility with other parachains in the Substrate and Polkadot ecosystem, reflecting its focus on interoperability and scalability.