TL;DR
We propose to open HRMP communication between Shiden Network and Crab Network. This will require actions on both chains.

Summary
We propose to open a bi-directional channel between Shiden Network and Crab Network. The primary use cases will be:

1. To support Crab Network’s light-client cross-chain messaging protocol (LCMP) via XCM-LCMP rounter. Shiden ecosystem devs will be able to use LCMP to communicate with Ethereum, BNB Chain, etc. on Shiden Network.
2. $CRAB can be transferred to Shiden to be used in the ecosystem of Shiden Network and the protocols build on top of the network.

Proposal
There is no on-chain proposal. The proposal created in this forum acts as an official proposal between Crab Network and Shiden Network.

Technical details (WIP)
The procedure for opening the channels is as follows:

1. Crab Network initializes a proposal to open Crab Network to the Shiden Network HRMP channel via the Astar forum.
2. Wait until the proposal on step 1 gets approved & enacted.
3. Onboard your testnet on the Rococo relay chain and exchange public endpoints and parachain-ids.
4. Wait until onboarding was successful on testnet.
5. Shiden Network proposes to accept the Crab Network to Shiden Network HRMP channel and open a Shiden Network to Crab Network HRMP channel via [Astar MuliSig Governance Batch call].
6. Wait until the proposal on step 5 gets approved & enacted.
7. Crab Network accepts the Shiden Network to Crab Network HRMP channel.
8. Wait for another session on Kusama/or/Polkadot for the change to be effective.

These extrinsics need to be called with the parachain’s sovereign account as the origin. To achieve this, on the Crab Network side we will use polkadot-xcm pallet to send XCM message to the relay chain, by executing the following extrinsic from the parachain. Shiden Network should make an open request call and an accept request call with its pallet.

As a prerequisite, the parachain’s sovereign account must contain at least 10 KSM to be locked as collateral (5 for each channel direction), plus some KSM to pay for XCM execution fees.

Discussion
https://forum.astar.network/t/open-hrmp-channel-between-shiden-network-and-crab-network/4043