## TL:DR

This batched proposal is to Accept/Open an HRMP channel with Interlay and to register IBTC and INT tokens

## Summary

We propose to open a bi-directional channel between Moonbeam and Interlay. Initially, the main use case will be to transfer IBTC and INT between the two chains, but it can be further expanded to other use cases. The proposal also includes the IBTC and INT asset registration as xcIBTC and xcINT , with the following details:

IBTC:
 - Multilocation: *{ "parents": 1, "interior": {"X2": { "Parachain": 2032}, {"GeneralKey": 0x0001}}*
 - Decimals: *8*
 - Name: *interBTC*
 - Symbol: *xcIBTC*

INT:
 - Multilocation: *{ "parents": 1, "interior": {"X2": { "Parachain": 2032}, {"GeneralKey": 0x0002}}*
 - Decimals: *10*
 - Name: *Interlay*
 - Symbol: *xcINT*

xcIBTC will have the following asset ID and XC-20 address:
 - Asset ID: 120637696315203257380661607956669368914
 - XC-20 address: 0xffffffff5ac1f9a51a93f5c527385edf7fe98a52

xcINT will have the following asset ID and XC-20 address:
 - Asset ID: 101170542313601871197860408087030232491
 - XC-20 address: 0xffffffff4c1cbcd97597339702436d4f18a375ab

## Proposal
Proposal #2 with the following hash: *0xfff6d8fbb8b49126654aec50f05d3e77b1b887cfef0beb8bea5de8b25ad1aed5*

## Technical details:
The procedure for opening the channels is as follows:
 - Interlay: already proposed to open an HRMP channel to Moonbeam
 - Moonbeam: democracy batched proposal
     - Open Moonbeam to Interlay HRMP channel
     - Accept Interlay to Moonbeam HRMP channel
     - Register IBTC and INT assets as XC-20s 
 - Interlay: democracy proposal to accept Moonbeam to Interlay HRMP channel

Once the HRMP channels are ready, XCM based cross-chain transfer will be possible. The extrinsics that need to be executed on the relay chain, are:
 - To open the HRMP channel from Moonbeam: *hrmp.hrmpInitOpenChannel(recipient: 2032, proposedMaxCapacity: 1000, proposedMaxMessageSize: 102400)*, which its hex-encoded call data is *0x3c00f0070000e803000000900100*
 - To accept this HRMP channel: *hrmp.hrmpAcceptOpenChannel(sender: 2032)*, which hex-encoded call data is *0x3c01f0070000*

The *proposedMaxCapacity* and *proposedMaxMessageSize* are set to the values of Polkadot’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

The asset will be registered with the metadata described in the summary. The *setAssetUnitsPerSecond* was calculated using an estimated value for IBTC and INT on July 4th 2022, targeting a XCM transaction cost of 0.02$.

If you are interested, the hex-encoded call data for this proposal in [Moonbeam](https://polkadot.js.org/apps/?rpc=wss%3A%2F%2Fwss.api.moonbeam.network#/extrinsics/decode) is:

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

As a prerequisite, the parachain’s sovereign account must contain at least 20 DOT to be locked as collateral (10 for each channel direction), plus some DOT to pay for XCM execution fees.

Send a batch of dispatch calls and atomically execute them.
The whole transaction will rollback and fail if any of the calls failed.

May be called from any origin.

- `calls`: The calls to be dispatched from the same origin. The number of call must not
  exceed the constant: `batched_calls_limit` (available in constant metadata).

If origin is root then call are dispatch without checking origin filter. (This includes
bypassing `frame_system::Config::BaseCallFilter`).

# <weight>
- Complexity: O(C) where C is the number of calls to be batched.
# </weight>

- The proposal is to open a channel between Moonbeam and Interlay.
- They want to transfer IBTC and INT tokens between the two chains.
- They also want to register IBTC as xcIBTC and INT as xcINT.
- They provided details about the assets, including their names, symbols, decimals, and addresses.
- They explained the technical details of how the channels will be opened and the extrinsics that need to be executed.

#46 Open/Accept HRMP channel to/from Interlay and Register IBTC-INT