Design cross-shard communication and smart contract functionality

Name of Company

Mutual Knowledge Systems, Inc.

Application type


Proposal overview

Design of Harmony’s cross-shard communication and smart contract functionalities. The feature should be fully secure against all kinds of attacks so the user’s asset are not in danger when involved in cross-shard operations such as sending HRC20 across shards or making smart contract calls across shards. The feature should enable the composability of smart contracts across shards.

Harmony is a sharded blockchain where there are 4 shards each running consensus separately. Currently, harmony supports cross-shard ONE token transfer where users can send ONE tokens across shards. Smart contract runs in each individual shards separately as of now and is not able to communicate with smart contracts from other shards. For example, users can not send a HRC20 token that’s in shard 0 to shard 1 if the HRC20 contract only lives in shard 0.

Harmony described the initial design idea for the cross-shard smart contract feature here for reference: Transactions - Harmony. The final design will be worked together by the bounty hunter/grantee and the harmony team.

  • Successful delivery of the design of the cross-shard smart contract functionalities with full technical details and specifications, including protocol design change, security analysis, performance considerations, deployment strategies, etc.
  • The design should be reviewed by the Harmony core team and improved iteratively until final approval by the Harmony core team.

Proposal ask

$75k (50% upfront, 50% upon successful delivery)

External Links


the first 50% upfront has been funded.

1 Like

The design coming out of 3 months of close discussion and brainstorming with MuKn has finally arrived. We welcome any feedback or suggestions from the community. · main · MuKn / Harmony1 Proposal · GitLab


funded: 0x46f2c54ba0cdfede6b76ab344b2f541a0c99c30d82cb6dc0cbf007d6dbbd6e16