Datachain to Build Bridge Between Cosmos and Harmony

4 min readJan 11, 2022


Datachain has received a grant from Harmony to construct a bridge between Cosmos (Tendermint-based blockchain) and Harmony. The bridge will make it possible to move assets on Harmony to IBC-enabled blockchains such as Cosmos, Terra, JUNO and Osmosis and vice versa. With the IBC protocol, the bridge is built using trustless intermediaries to achieve interoperability.

Cosmos is now one of the largest interoperability ecosystems in the world, and IBC is the communication protocol developed by Cosmos and Interchain Foundation, which enables various chains to be interconnected. After the release of IBC in April 2021, it has made a huge progress. According to Map of zones, there are 27 active chains and over 3 million IBC transfers in 30 days.

Harmony is one of the latest EVM-compatible blockchain platforms. Harmony’s mainnet runs Ethereum applications with 2-second transaction finality and 1,000 times lower fees, as well as secure bridges to Ethereum and other chains. There is an increasing number of applications built on Harmony, such as DeFi Kingdom,, Mars Colony, Unite Finance and Euphoria (Olympus fork). You can see more on Harmony Universe and Defi Llama.

Datachain has contributed to the Cosmos community, including the implementation of IBC-Solidity granted by Interchain Foundation. We are delighted to contribute to both the Cosmos and Harmony community by building a bridge between them. The Cosmos <> Harmony bridge will make Harmony to be connected to Tendermint-based blockchains such as Cosmos, Terra, JUNO, Secret Network, Osmosis and Akash Network. We believe that it will be an important milestone for both ecosystems.

Scope of This Grant

What We Achieve

With the funding, we will connect Harmony and Cosmos (Tendermint-based) blockchain via IBC (on a private testnet) and transfer the HRC-20 token on Harmony to the Cosmos blockchain as an ICS-20 token.

What We Build

We will build these components below:

  • Harmony light client on Tendermint-based blockchain
  • Tendermint light client on Harmony
  • Communication module for Harmony, an extension for yui-relayer
  • Sample application of token transfer

* Light client and relayer are words defined in IBC Protocol. Learn more about those concepts here.
* Some of the implementations will be done while referencing the previous works.

In this project, we use IBC-Solidity, which Datachain has led the development under a grant from the Interchain Foundation. Those components above will be provided as OSS.

Future Initiatives

After this grant project, we are considering the mainnet launch of Cosmos <> Harmony bridge, adding the cross-chain atomic swap feature (Harmony support in Cross Framework) and connecting Harmony to other chains such as Hyperledger Fabric.

Datachain is also considering supporting other EVM-compatible blockchains such as Binance Smart Chain and Polygon so that those blockchains can communicate to other chains using IBC.

If you have any questions or are interested in our projects, please feel free to contact us on Twitter.

Comment from Li Jiang, the COO of Harmony

Web3 is growing in all areas but particularly NFT infrastructure, DAO tooling, and inter-protocol bridges. We know trustless and secure bridges to all chains is the core of open platforms. We are excited to connect the Cosmos and Harmony ecosystems.

Datachain has strong experience with building interoperability solutions connecting public blockchains. We gave them a grant to connect Harmony and Cosmos and look forward to working with them to build a multi-chain future.

We started the project 4 years ago with a mission of scaling trust and creating a radically fair economy. Looking forward the next 4 years, Harmony is scaling Web3 infrastructure of DeFi and NFT. Our strategy is bringing the best results of Zero-Knowledge Proofs to production and decentralizing governance through thousands of DAOs.

(Li Jiang, the COO of Harmony)

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Core Contributor of LCP and Hyperledger Lab YUI, cross-chain interoperability solutions using the IBC protocol.