ISMP (Interoperable State Machine Protocol) is designed to improve and secure cross-chain communication and operations by facilitating "GET-like" and "POST-like" requests between all substrate based chains under the security of the Polkadot Relay chain. By leveraging state proofs, it relieves the relay chain of the burden of message passing, contributing significantly to the scalability of parachains, especially with async backing on the horizon. It’s GET-like request protocol facilitates for the first time in the ecosystem state reads of sibling parachains, as well as the relay chain, unlocking new kinds of applications.

Inspired by HTTP, aiming to become a similar standard for interoperability in the multi-chain environment. It's designed as a substrate-based pallet to ease integration with parachains and standalone chains, Following a successful w3f grant delivery for the preliminary functionally which enables Parachain interoperability.

You can find a link to ISMP repository here: https://github.com/polytope-labs/ismp-substrate.

Relevant discussion links:

• Polkadot Forum discussion
• Polkadot decoded devrel stream
• The Kusamarian Interview
• Polkadot interoperability keynote at ParisDotComm

We have fully extended ISMP to facilitate messaging between; standalone chains, standalone chains and Parachains & relay chains. It is EVM compatible, enabling cross chain solidity smart contract communication among EVM compatible substrate based chains.

This submission is to propose a retroactive payment by Polkadot Treasury to cover development costs incurred.

You can find the details of the proposal here.

Please let us know what you think in the comments.

Thank you for reading!