## TL:DR
Similar to other HRPM channel proposals, we propose to open an HRMP channel between Moonriver and Bifrost (Kusama).

## Summary
We propose to open a bi-directional channel between Moonriver and Bifrost. Initially, the main use case will be to transfer MOVR and BNC between the two chains, but it can be further expanded to other use cases.

## Proposal
Proposal #14 with the following hash: *0x60dcde86369363b52e4ec67c013ff56b26c4086724cfb5964e96920992fd0530*

## Technical details:
The procedure for opening the channels is as follows:

 - Bifrost: democracy proposal to open Bifrost to Moonriver HRMP channel
 - Moonriver: democracy proposal to open Moonriver to BifrostHRMP channel
 - Wait until the proposals on step 1 & 2 get approved & enacted
 - Bifrost: democracy proposal to accept Moonriver to Bifrost HRMP channel
 - Moonriver: democracy proposal to accept Bifrost to Moonriver HRMP channel
 - Wait until proposals on step 3 & 4 get approved & enacted
 - Kusama: wait one session after each acceptance for each channel to be opened

XCM based cross-chain transfer will be possible at this stage. The extrinsics that need to be executed on the relay chain , are:

 - For step 1: hrmp.hrmpInitOpenChannel(recipient: 2023, proposedMaxCapacity: 1000,  - proposedMaxMessageSize: 102400) , which its hex-encoded call data is 0x3c00e7070000e803000000900100
 - For step 2: hrmp.hrmpInitOpenChannel(recipient: 2001, proposedMaxCapacity: 1000, proposedMaxMessageSize: 102400), which its hex-encoded call data is 0x3c00d1070000e803000000900100
 - For step 4: hrmp.hrmpAcceptOpenChannel(sender: 2023) , which hex-encoded call data is 0x3c01e7070000
For step 5: hrmp.hrmpAcceptOpenChannel(sender: 2001), which its hex-encoded call data is 0x3c01d1070000
The *proposedMaxCapacity *and *proposedMaxMessageSize *are set to the values of Kusama’s *configuration.activeConfig.hrmpChannelMaxCapacity* and *configuration.activeConfig.hrmpChannelMaxMessageSize* values, respectively.

These extrinsics need to be called from the parachain’s sovereign account as origin, via a democracy proposal. The proposal will use polkadotXcm pallet to send XCM message to the Relay Chain with the following items:

 - Withdraw asset: take funds out of the Sovereign Account of the origin parachain (in the relay chain) to a holding state
 - Buy execution: buys execution time from the relay chain, to execute the XCM message
 - Transact: provides the call data to be executed
 - Deposit asset (optional): refunds the leftover funds after the execution. If this is not provided, no refunds will be carried out

If you are interested, the hex-encoded call data for both the hrmpAcceptOpenChannel and hrmpInitOpenChannel for [Moonriver](https://polkadot.js.org/apps/?rpc=wss%3A%2F%2Fwss.api.moonriver.moonbeam.network#/extrinsics/decode) are:

**Accept Channel:** 0x67000101000210000400000000070010a5d4e81300000000070010a5d4e8010700f2052a01060002286bee183c01d10700000d0100040001010070617261e7070000000000000000000000000000000000000000000000000000

**Open Channel:**
0x67000101000210000400000000070010a5d4e81300000000070010a5d4e8010700f2052a01060002286bee383c00d1070000e8030000009001000d0100040001010070617261e7070000000000000000000000000000000000000000000000000000

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.

- They want to open a channel between Moonriver and Bifrost.
- They need to go through a process of proposals and approvals.
- They will use XCM to transfer assets between the two chains.
- They need to call specific extrinsics from the parachain's sovereign account.
- They need to have enough KSM for collateral and execution fees.

#74 Open HRMP channel between Moonriver and Bifrost (Kusama)