Cross-Shard Composability: atomic swaps of assets, inter-shard contracts
Harmony’s shards are similar to Cosmos’s zones and Polkadot’s parachains, but our shards offer simpler interface and more uniform security for developers. We are developing cross-shard transactions, comparable to Cosmos’s Inter-Blockchain Communication (IBC) and Polkadot’s Cross-Chain Message Passing (XMCP) but specialized for uniform shards.
Thanks to the nature of Harmony's FBFT consensus, blocks can be finalized as long as the 2/3 majority quorum is reached on the block. On Harmony mainnet, it now takes 2 seconds to finalize a newly proposed block and the transactions inside.
We are working with François-René Rideau from https://mukn.io for the implementation of cross-shard smart contract transactions. They are still in the design proposal phase and will soon update us with the proposal and an implementation timeline.
- Draft design is being reviewed and iterated: https://gitlab.com/mukn/harmony1-proposal/-/blob/main/README.md
- Mukn wrote a analysis on the cross-shard smart contract design: https://mukn.io/2021/09/09/safe-cross-chain-contract-interactions/
- We are working on the full design proposal for cross-shard smart contract support.