Summary

Cross chain messaging between parachains are implemented via HRMP. HRMP has several disadvantages:

• HRMP puts message payloads in the consensus path.
• HRMP does not scale well for high-volume cross-chain traffic.
• HRMP latency is bounded by relaychain/parachain.
• HRMP is expensive to implement on JAM Parachain Service.

Replacing HRMP has become a blocker for JAM Parachain Service. The Snowfork Team has been working with the Offchain Messaging design team since May and we believe we can implement an MVP for the design they have specified.

Git Hub issues

Offchain Message Spec
Offchain Message for JAM

Proposal

Full Proposal Document