How to create smart contracts on Polkadot?

The evolution of the blockchain is essential to allow the creation of improved, more efficient, and innovation-rich blockchain protocols. Let’s look back to the origin of blockchain with Bitcoin and compare it with the third-generation blockchains. We realize the considerable changes that blockchain technology has experienced so far.

For instance, Ethereum brought the concept of integrated functionality and an open-source blockchain ecosystem to support the development of decentralized applications (dApps) and blockchain-based solutions for diverse industries. With such intrusive features, Ethereum gained overwhelming popularity. However, it cannot enable interoperability across the blockchain networks.

Polkadot emerged as an advanced blockchain network that can provide interoperability elements to any blockchain ecosystem and enable interaction between them to solve these interoperability issues. Polkadot currently powers a range of

How does Polkadot support the development of next-gen blockchain use cases?

Polkadot is one of the fastest-growing blockchain ecosystems, and it has constantly supported the development of cross-chain technology-enabled blockchain use cases. Besides the interoperability attribute, Polkadot strives to solve various issues related to the blockchain, such as low TPS, hard forks, high transaction costs, etc. Below are some key reasons Polkadot is a more feasible ecosystem for smart contract and dApp development.

How to create a smart contract on the Polkadot?

‘Before we start developing the Polkadot, we must understand the working mechanism and correlation of the Polkadot and the Parachain. While relay Parachains coordinate the entire Parachains live on the Polkadot network, it cannot support smart-contract functionality on the decentralized applications.

Now, developers on the Polkadot Network use the Substrate framework that enables network logic and web assembly interpreter, besides implementing the crucial elements like token balances and token history. Following are the steps to create a smart contract on the Polkadot Network.

Installing prerequisites

Installing prerequisites is the first step to developing the Polkadot smart contract using the Rust programming language. You can install prerequisites for the following operating systems:


  • Arch Linux

  • Fedora

  • OpenSUSE

  • macOS

  • Windows

Once you install the prerequisites, test the whole setup to ensure your computer is prepared for Substrate development.

Install the contract node

Install the built-in contract pallets required to support the Substrate development further.

Ink! CLI is another essential tool utilized for Polkadot smart contract development using Substrate. Download ink!Command-line utility as it makes Substrate development a lot easier and straightforward.

  1. Create a project with ink!

In the next step, you need to use ink! To generate files to support smart contract development in Substrate. Following are the steps to create the ink! Project.

  • Construct the source code: ink! Automatically builds the source code, simplifying the whole smart contract development process.

  • Test the compiled code: Testing the code is crucial to ensure the robustness of the code and to examine its functioning. For ink!, you will find the simplest test cases to test easily and optimize the contract code.

  • Create the contract: Building contract requires you to compile the contract in the Flipper project directory and deploy it on-chain.

     2. Run smart contract nodes for the Substrate

Once you install the Substrate contract node, run the contract node to begin with the local development on the Polkadot ecosystem.

Smart contract deployment on the Polkadot

Smart contract deployment on the Polkadot involves the following two steps (when you are using the Substrate):

Step1: Placing the compiled contract code on the blockchain

Step2: Creating instances for the smart contract

Upload the contract on the blockchain

Abiding by the Substrate-based smart contract deployment strategies, you only need to place the contract code once on the blockchain, but it can be seamlessly initiated multiple times. For instance, you can ERC20 contract code once on the blockchain and initiate as many times as you want without uploading the code multiple times, which prevents the blockchain from occupying extra space.

Following are the steps to upload the contract code and initiate it on the blockchain:

  1. Visit the Add New Contract section available in the sidebar.
  2.  A button saying Upload New Contract will appear on this page; click it.
  3. Select any instantiation account, i.e., ALICE.
  4. Now, add a descriptive name, i.e., Flipper contract.
  5. Drag and drop the flipper. Contract file across the drag&drop section. This area keeps the bundled Wasm blob and metadata information. Now, the UI parses the metadata, activating the button that allows you to explore the next phase.
  6. Click the Next Button to move to the next phase of smart contract deployment.

Instantiate the contract code on the blockchain

A smart contract on the Polkadot Network exists as an account extension. Therefore, you need to create an instance of the contract that can generate AcountId for storing and managing the balances and allowing the users to interact with the deployed on the blockchain.

Once you create the instance, the information corresponding to the smart contract appears on the screen. Next, create a replica of the contract using the following steps:

  • Accept default parameters on the contract deployment constructor.

  • Since the maximum gas amount limit allowed is 20000, accept the default settings for this.

  • Proceed with Next.

Upon completion of the above steps, the entire transaction is queued. As the next step, you need to investigate the data to make the required changes. Once done, click Upload and Instantiate.


Polkadot Network is growing, with interoperability becoming the most crucial aspect of blockchain development. Any blockchain-based solution and decentralized application built as Parachain on the Polkadot network automatically become interoperable with the rest of the Parachains. Even non-parachains can interact with each other using Polkadot interoperability bridges. Hence, many new blockchain projects are being built on the Polkadot Network, and others are migrating their current infrastructure to this platform.

By this, you complete this workshop successfully!!