So far, five parachains have requested an HRMP channel with Statemint. This motion accepts them all and opens return channels.

## Opening Notes

### Handy Info

- Treasury Address: `13UVJyLnbVp9RBZYFwFGyDvVd1y27Tt8tkntv6Q7JVPhFsTB`
- Treasury `AccountId`: `0x6d6f646c70792f74727372790000000000000000000000000000000000000000`
- Statemint Address: `13YMK2edbuhwMBxeUWm9c643A2wyYHwSVh1bCM7tShtg7Dtk`
- Statemint `AccountId`: `0x70617261e8030000000000000000000000000000000000000000000000000000`

### Parachains that want channels

- 2011
- 2000
- 2004
- 2006
- 2012

### Channel Config

- `maxCapacity: 1,000`
- `maxTotalSize: 102,400`

### HRMP Config

- `hrmpSenderDeposit: 100,000,000,000`
- `hrmpRecipientDeposit: 100,000,000,000`

## Call Construction

These are constructed **backwards.** That is, the call to use as the proposal is at the **end.**

### Relay Chain Call to Execute

First, we need the call that Statemint will execute on the Relay Chain. This accepts all channel requests and returns channel requests to the initiators.

![](https://i.imgur.com/azd1Ygm.png)
![](https://i.imgur.com/zWItDfE.png)

Encoded Call Data:

```
0x1a02283c01db0700003c01d00700003c01d40700003c01d60700003c01dc0700003c00db070000e8030000009001003c00d0070000e8030000009001003c00d4070000e8030000009001003c00d6070000e8030000009001003c00dc070000e803000000900100
```

### Message from Statemint

The above message needs to come _from Statemint._ So we put it into an XCM (the "Transact" instruction) along with purchasing some execution capacity and returning any leftover fees to the Treasury.

![](https://i.imgur.com/i3SHuZV.png)
![](https://i.imgur.com/eXXtCrw.png)

Encoded Call Data:

```
0x1f0001010002140004000000000700c817a80413000000000700c817a80400060002286bee9d011a02283c01db0700003c01d00700003c01d40700003c01d60700003c01dc0700003c00db070000e8030000009001003c00d0070000e8030000009001003c00d4070000e8030000009001003c00d6070000e8030000009001003c00dc070000e803000000900100140d01010000000004000101006d6f646c70792f74727372790000000000000000000000000000000000000000
```

### Proposal on the Relay Chain

But, governance is on the Relay Chain, not Statemint. So take some DOT from the Treasury (100 DOT for 10 channels at 10 DOT each plus 2 DOT for fees) and send a message to Statemint telling it to send a message back. This is the proposal to vote on.

![](https://i.imgur.com/WvVLRuK.png)

Encoded Call Data:

```
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
```

Call Hash:

```
0x6306b068f6a71eb1db5abd9609a0ffbbe7c441c9144ecf8a49e7c2bc19f7f6e9
```

## Appendix: Relevant Storage Items

**`configuration.activeConfig: PolkadotRuntimeParachainsConfigurationHostConfiguration`**

```json=
{
  maxCodeSize: 10,485,760
  maxHeadDataSize: 20,480
  maxUpwardQueueCount: 10
  maxUpwardQueueSize: 51,200
  maxUpwardMessageSize: 51,200
  maxUpwardMessageNumPerCandidate: 10
  hrmpMaxMessageNumPerCandidate: 10
  validationUpgradeCooldown: 14,400
  validationUpgradeDelay: 600
  maxPovSize: 5,242,880
  maxDownwardMessageSize: 51,200
  umpServiceTotalWeight: 100,000,000,000
  hrmpMaxParachainOutboundChannels: 10
  hrmpMaxParathreadOutboundChannels: 0
  hrmpSenderDeposit: 100,000,000,000
  hrmpRecipientDeposit: 100,000,000,000
  hrmpChannelMaxCapacity: 1,000
  hrmpChannelMaxTotalSize: 102,400
  hrmpMaxParachainInboundChannels: 10
  hrmpMaxParathreadInboundChannels: 0
  hrmpChannelMaxMessageSize: 102,400
  codeRetentionPeriod: 14,400
  parathreadCores: 0
  parathreadRetries: 0
  groupRotationFrequency: 10
  chainAvailabilityPeriod: 10
  threadAvailabilityPeriod: 10
  schedulingLookahead: 1
  maxValidatorsPerCore: 5
  maxValidators: 200
  disputePeriod: 6
  disputePostConclusionAcceptancePeriod: 600
  disputeMaxSpamSlots: 2
  disputeConclusionByTimeOutPeriod: 600
  noShowSlots: 2
  nDelayTranches: 89
  zerothDelayTrancheWidth: 0
  neededApprovals: 30
  relayVrfModuloSamples: 40
  umpMaxIndividualWeight: 20,000,000,000
  pvfCheckingEnabled: false
  pvfVotingTtl: 2
  minimumValidationUpgradeDelay: 20
}
```

**`hrmp.hrmpOpenChannelRequests: Option<PolkadotRuntimeParachainsHrmpHrmpOpenChannelRequest>`**

```json
[
  [
    [
      {
        sender: 2,011
        recipient: 1,000
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,000
        recipient: 2,035
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,000
        recipient: 2,034
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,000
        recipient: 2,032
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,012
        recipient: 2,000
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,000
        recipient: 1,000
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,004
        recipient: 1,000
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,006
        recipient: 1,000
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
  [
    [
      {
        sender: 2,012
        recipient: 1,000
      }
    ]
    {
      confirmed: false
      age: 0
      senderDeposit: 100,000,000,000
      maxMessageSize: 102,400
      maxCapacity: 1,000
      maxTotalSize: 102,400
    }
  ]
]
```


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>

- Five parachains want to have a channel with Statemint.
- The channel configuration allows for a maximum capacity of 1,000 and a maximum total size of 102,400.
- The HRMP configuration requires a deposit of 100,000,000,000 for both the sender and recipient.
- There is a proposal to accept all the channel requests and open return channels.
- The proposal needs to be voted on by the governance on the Relay Chain.

#62 First Statemint HRMP Channels