LimeChain develops Subsembly, a Substrate alternative supported by Web3 Foundation Grants


Earlier this year LimeChain built a Proof of Concept Substrate Runtime in AssemblyScript – a language similar to TypeScript. The PoC is now evolving into a full-blown framework for Substrate Runtime development – Subsembly.

LimeChain is excited to continue its push towards development empowerment and lowering the blockchain development barrier with Subsembly – an AssemblyScript runtime framework for the Polkadot community, supported by Web3 Foundation grants. Polkadot is a scalable, sharded chain, and the first protocol that provides a secure environment for cross-chain composability across multiple shards. Applications from DeFi to energy to gaming will thrive on Polkadot, challenging the centralized platforms of Web 2.0.

LimeChain has previously received and completed grants from Web3 Foundation for the development of an AssemblyScript SCALE codec library and a Substrate Proof of Concept Runtime written in AssemblyScript, both of which serving as a prelude to the Subsembly framework. The end goal is to provide the blockchain community of JavaScript and TypeScript developers with an alternative to Substrate.


Subsembly is a Runtime development framework, based on AssemblyScript. It provides the necessary foundation for anyone to be able to build Substrate runtimes.

Subsembly has a similar architecture to Substrate Runtime components. The framework will provide developers with the already familiar Substrate Pallets, a CLI tool for bootstrapping and compiling, as well as extensive documentation and recipes for development. All of the core components of a Substrate runtime will come out of the box with a simple and quick CLI command.

Having a framework for AssemblyScript Runtime development will benefit the community by providing developers with the opportunity to build runtimes in a language similar to TypeScript, which most blockchain developers are comfortable with.

The framework is based on several months of infrastructure development, building the necessary tools for the framework.

Currently, the LimeChain team has completed Milestone 1 of the Subsembly grant, which includes architecture design and improvements in the SCALE Codec library. There are 5 more milestones to go (total of 6), with Milestone 3 being a Subsembly CLI planned for release in Q1. Milestones 4,5 and 6 will include detailed documentation and recipes, as well as the implementation of various pallets.


Our Motivation

Since 2017, LimeChain has been working towards a better development infrastructure and enabling more success stories through blockchain and DLTs. Our Blockchain Solutions Architect and Polkadot Lead, Daniel shares his views on the Polkadot network and the importance of the Subsembly framework:

“Polkadot is one of the promising projects in the industry and I would say that after the successful launch that it had this year, a lot of developers are looking at it as the chain of choice for their projects. We are seeing more and more demand for Polkadot related development. Projects that are already supporting other chains want to have their apps deployed on Polkadot as-well. Subsembly provides more flexibility and options to those developers and we at LimeChain are very passionate about developer experience and tooling.”

About LimeChain

LimeChain is a leading blockchain & DLT solutions company pioneering the adoption of DLTs globally. Since 2017, LimeChain has worked with leading startups and Fortune 500 companies to bring tangible business results using blockchain. The team has worked on 80+ development and consulting projects on both public and private networks, with use cases including supply chain tracking, ERP integrations, asset tokenization, decentralized finance (DeFi), and developer tooling for some of the top blockchain protocols out there.