Klayr SDK


The Klayr SDK is an open-source software development kit that enables developers to build scalable blockchain applications in JavaScript & TypeScript.


The most important highlights and features of the Klayr SDK:

  • One blockchain per app: Each Klayr application runs on its own customized blockchain.

  • Programming language: JS logo (JavaScript) & TS logo (TypeScript)

  • Consensus algorithm: Klayr PoS & Klayr BFT

  • Completely modular: Configure, exchange, or extend any of the blockchain-related logic in the application with Modules and Commands and Plugins.

  • Convenient development tools:

    • Klayr Commander:

      • Bootstrap a complete, default Klayr client with a single command.

      • Generate skeletons for modules, commands, and plugins.

      • Use the Klayr SDK libraries directly in the terminal via the interactive Klayr console.

      • Many other convenient CLI tools such as creating accounts, encrypting passphrases/messages, and more. Dashboard Plugin: Communicate conveniently with the blockchain during development via a dashboard.

    • SDK testing utilities: simplifies the testing of all components of a blockchain client by providing dedicated fixtures, mock-ups, and utility functions.

  • Interoperable: Make your blockchain interoperable with other Klayr applications, by registering it as a sidechain on the Klayr mainchain. For more information see Klayr Interoperability.

Klayr SDK overview

Klayr SDK ecosystem diagram
Figure 1. Klayr SDK ecosystem

As shown in the image above, Klayr Framework is built on top of Klayr Elements and uses a lot of its functions to complement its logic. Developers can use Klayr Commander to generate a default blockchain client that is based on the Framework components, and add their specific business logic on top.

The Klayr SDK operates on the Node.js. Its three components Klayr Framework, Klayr Elements, and Klayr Commander each provide specific utilities to blockchain developers, as described in the following section.

Hardware requirements

Below are the recommended hardware requirements to run applications built with the SDK.


4 core fast CPU




SSD: 50GB+

Klayr SDK components

Component Description

Klayr Framework

Klayr Framework is an application framework responsible for establishing and maintaining the interactions between the different components of a blockchain client.

Klayr Elements

Klayr Elements is a collection of libraries, each of which implements a certain type of blockchain functionality such as cryptography, transactions, p2p, etc. Each library of Klayr Elements is also published as an NPM package, and can be installed separately if needed. For more information about Klayr Protocol, see Klayr Improvement Proposals.

Klayr Commander

Klayr Commander is a command line tool that provides various commands to simplify the development and management of Klayr apps. For example, it allows the user to bootstrap a complete blockchain client with just one command.