How to Create Smart Contracts on Polkadot

Blockchain evolution is necessary to improve the functionality of specific blockchain networks for different use cases. While many second-generation blockchains, such as Ethereum, can address the limitations of first-generation blockchains, interoperability remains a significant issue.

Polkadot addresses this interoperability problem by allowing various heterogeneous blockchains, known as parachains, to connect with each other and external blockchains like Ethereum through bridges. In addition to facilitating interoperability, these bridges also act as a linking layer that allows businesses to interact with and access non-blockchain databases in the real world.

The ability to connect and interoperate with multiple blockchains and external databases makes Polkadot well-suited for diverse dApp development and ecosystem building. Smart contracts, which are essential for regulating blockchain and dApp operations, can be deployed on the Polkadot network.

Why Should You Choose Polkadot For Smart Contract Development?

Polkadot is a blockchain protocol that allows for interoperability between different blockchains. dApps built on the Polkadot ecosystem as Parachains are able to communicate and interact with other parachains within the network seamlessly.

These parachains are advanced layer-1 blockchains that form a diverse ecosystem of independent blockchains, improving upon the traditional, isolated approach of individual blockchains.

Polkadot offers a number of benefits, including the ability for smart contract developers to take advantage of the shared security, governance, consensus, and scalability of the Polkadot relay chain.

Its high level of flexibility and the ability to develop parachains make it easier to optimize use cases and provide fully optimized and secure services with no downtime. In addition, developers can perform regular upgrades on smart contracts to keep them functioning effectively and up to date with the latest technologies.

Smart contracts created for Parachains also benefit from the strong security the underlying blockchain provides, eliminating the need to set up a network of miners or gather validators from scratch.

Tools And Technology Stack A Polkadot Development Company Uses To Build Smart Contracts

Polkadot provides a range of tools, including software development kits (SDKs), Parachain development kits (PDKs), a testnet, and a blockchain framework, to support the creation of next-generation web 3 solutions and decentralized applications (dApps).

The network continually updates these resources to make the Polkadot ecosystem more powerful and relevant. Here is a concise list of some of the essential tools and resources that are commonly used for development.


  1. Substrate
  2. Substate developers docs
  3. Substrate VSCode plugin
  4. Substrate debug kit
  5. Diener
  6. Polkadot Launch
  7. Halva
  8. Fork-off Substrate
  9. SRtool
  10. sub-bench
  11. substrate-devhub-utils
  12. sub-flood

Programming languages

  1. Rust
  2. Ruby
  3. Go
  4. C++
  5. Typescript
  6. AssemblyScript
  7. Haskell
  8. Java
  9. Python

Testnet & SDKs

  1. Kusama- testnet for ensuring the optimization of the smart contract before mainnet deployment.
  2. Rococo- Polkadot’s testnet for the Parachian.

How To Create A Smart Contract On Polkadot?

Before we begin developing on Polkadot, it is important to understand how the Polkadot and parachains work together. While the relay chain coordinates all the parachains on the Polkadot network, it does not support the execution of smart contracts on decentralized applications.

Instead, substrate developers on the Polkadot network use the Substrate framework, which includes a web assembly interpreter and allows for the creation of network logic and the implementation of essential elements like token balances and transaction history. Here are the steps for creating a smart contract on the Polkadot network.

Installing Pre-requisites

The first step in developing a Polkadot smart contract using Rust as Polkadot smart contract language is to install the necessary prerequisites. Prerequisites can be installed for the following operating systems:


  1. Arch Linux
  2. Fedora
  3. OpenSUSE
  4. macOS
  5. Windows

After installing the necessary prerequisites, it is important to test your setup to ensure your computer is ready for Substrate development.

Install the contract node

You will need to install the built-in contract pallets to continue with Substrate development. The ink! CLI is also an important tool for developing Polkadot smart contracts using Substrate. It is recommended to download the ink! command-line utility to make Substrate development easier and more streamlined.

 1. Create a project with ink!

To begin developing smart contracts in Substrate, you will need to use ink! to generate the necessary files. Here are the steps to create an ink! project:

  • Construct the source code: Ink! simplifies the process of building the source code for your smart contract.
  • Test the compiled code: Testing the code is important to ensure its robustness and functionality. Ink! provides simple test cases to make testing and optimizing your contract code easier.
  • Create the contract: To build your contract, you will need to compile it in the Flipper project directory and deploy it on the chain.

2. Run smart contract nodes for the Substrate

After installing the Substrate contract node, you can run it to begin local development on the Polkadot ecosystem.

Smart Contract Deployment On The Polkadot

To deploy a smart contract on Polkadot using Substrate, you will need to follow these two steps:

Step 1: Uploading the compiled contract code to the blockchain

Step 2: Creating instances of the smart contract

Upload The Contract On The Blockchain

According to the Substrate-based deployment strategies for smart contracts, you only need to upload the contract code to the blockchain once, but it can be initiated multiple times without the need to upload it again. This saves space on the blockchain and avoids unnecessary duplication. To upload the contract code and initiate it on the blockchain, you can follow these steps:

  1. Go to the “Add New Contract” section in the sidebar.
  2. Click the “Upload New Contract” button.
  3. Select an instantiation account (e.g., ALICE).
  4. Give the contract a descriptive name (e.g., Flipper contract).
  5. Drag and drop the flipper.contract file into the drag & drop section. This area holds the bundled Wasm blob and metadata information. The UI will parse the metadata and activate the next button.
  6. Click the “Next” button to move on 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 extension of an account, so you will need to create an instance of the contract to generate an AccountId for storing and managing balances and allowing users to interact with the contract on the blockchain. Once you create the instance, the information for the smart contract will be displayed on the screen. To create a replica of the contract, you can follow these steps:

  1. Accept the default parameters in the contract deployment constructor.
  2. Accept the default maximum gas amount limit of 20000.
  3. Click “Next.”
  4. After completing these steps, the transaction will be queued. You can then review the data and make any necessary changes. When you are ready, click “Upload and Instantiate.”


The Polkadot network is expanding, and interoperability is becoming increasingly important in blockchain development. Any blockchain-based solution or decentralized application built as a parachain on the Polkadot network will automatically be interoperable with the other parachains.

Additionally, even non-parachains can interact with each other using Polkadot interoperability bridges. This is why many new blockchain projects are being built on the Polkadot network, and others are migrating their existing infrastructure to this platform.