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15 votes

How to open HRMP channels between parachains?

Feel free to update/modify this if you see something that can be improved upon Opening HRMP channels between parachains If you are new to XCM, read the following: https://polkadot.network/blog/xcm-...
Bruno's user avatar
  • 8,315
9 votes
Accepted

How are the costs of XCM messages designed?

Since XCM is configurable, this can depend from chain to chain. However, most(if not all) Dotsama chains adopt the same approach. We rely on parity's implementation of XcmExecutor (here) and various ...
Dinonard's user avatar
  • 587
7 votes
Accepted

How to enable cross-chain asset transfers to a parachain?

The ORML Xtokens pallet is just the first step, as you try to configure it in your chain, you'll quickly see that it requires an XcmExecutor configuration item, which the xcm-executor module offers a ...
Keith Yeung's user avatar
  • 2,121
6 votes
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Barrier error during initiating HRMP channel with Rockmine on Rococo

First, this is because you're using a non-root account to send the XCM of HRMP request. You should use sudo or governance to do this. If you use a non-root account to call polkadotXcm.send, it will ...
Guantong's user avatar
  • 1,848
4 votes
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XCM TooExpensive when reserve transferring

Trappist does not support using the Asset you are using to pay for execution fees. Currently it supports USDT, Realy token, native token. You can change the trader to support more tokens. https://...
Guantong's user avatar
  • 1,848
4 votes
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XCM error. OverweightEnqueued event instead of opening HRMP channel

Well, this is because requireWeightAtMost you specified is greater than umpMaxIndividualWeight, you should use the values from my answer in your other question(5,000,000,000), hrmp.hrmpInitOpenChannel ...
Guantong's user avatar
  • 1,848
4 votes

How can I query the deposit in DOT to create an HRMP channel?

You actually need to go to "Developer" > "Chain State" to check for the HRMP deposit. The function to call is activeConfig() under the configuration pallet. You'll see the ...
Keith Yeung's user avatar
  • 2,121
2 votes
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Attempting to establish hrmp channels on rococo-local reports `Execution errored at 0: Unimplemented`

From the logs and your comment, it looks like you are sending hrmpInitOpenChannel and hrmpAcceptOpenChannel to the other parachain? You actually want to send these to the Relay Chain. If that doesn't ...
joepetrowski's user avatar
  • 2,955
2 votes

Is there a link or guide on how to get a Sovereign Account Address?

The quick way for Kusama and Polkadot is to check subscan for the proper parachain: https://kusama.subscan.io/parachain/2023 In the case of most parachains on Rococo, the Owner is also the Sovereign ...
gluneau's user avatar
  • 66
2 votes
Accepted

How to open HRMP with Rococo chain?

As Xavier mentioned, relaychain and parachain interact via VMP, so there is no need to open HRMP between parachain and relaychain(Rococo/Kusama/Polkadot), and there is no HRMP between parachain and ...
Guantong's user avatar
  • 1,848
1 vote

How to open HRMP with Rococo chain?

H means horizontal. V means vertical. So, you should use VMP to interact with relaychain. releychain / \ (vmp) (vmp) / \ para a---(hrmp)---para b ...
AurevoirXavier's user avatar
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1 vote
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Do I need to create a proposal on OpenGov in order to open an HRMP channel?

This wiki page should answer your question: https://wiki.polkadot.network/docs/build-hrmp-channels#opening-hrmp-channels-with-system-parachains
Iker's user avatar
  • 1,356
1 vote

Opening HRMP Channel from AssetHub to Parachain using only paraId

From my understanding they will need to use force_open_hrmp_channel any way, because they want to open a channel to a system chain. Looking over the code, I don't see any requirement for the parachain ...
bkchr's user avatar
  • 11.6k
1 vote

Setting up an HRMP Channel between a Parachain and Rococo Asset Hub (Rockmine)

Check this tutorial about how to open HRMP with AssetHub, where it explains in detail how to opening the channel from AssetHub to your parachain and how to open the channel from your parachain to ...
Alex Bean's user avatar
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1 vote
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How to make a HRMP channel between two parachains in mock.rs?

If you only want to mock this communications to test your instructions take a look at the XCM docs examples. It has an example of how to mock a Relay Chain runtime and a parachain Runtime, and it uses ...
Alex Bean's user avatar
  • 5,757
1 vote
Accepted

Why is `HrmpChannelAccepted` described as only being safe to originate from a relay chain and not a parachain?

HRMP is a stop-gap protocol for XCMP, it stores all messages in the Relay Chain storage. Before the channel is opened, the two parachains are not interoperable, and can only establish a connection ...
Guantong's user avatar
  • 1,848
1 vote

FailedToTransactAsset when trying to establish HRMP when using XCM

Here is the description of the error you are getting: /// An asset transaction (like withdraw or deposit) failed (typically due to type conversions). #[codec(index = 9)] FailedToTransactAsset(#[codec(...
Bruno's user avatar
  • 8,315
1 vote

Why does opening an HRMP channel use the Transact instruction instead of the HrmpNewChannelOpenRequest instruction?

HrmpNewChannelOpenRequest instruction is not implemented yet in xcm-executor, https://github.com/paritytech/polkadot/blob/release-v0.9.31/xcm/xcm-executor/src/lib.rs#L507
Guantong's user avatar
  • 1,848
1 vote

Barrier error during initiating HRMP channel with Rockmine on Rococo

Great tutorial for opening channel with Common good parachain. link
rust.dev's user avatar
  • 519
1 vote
Accepted

XCM BuyExecution Fail: TooExpensive when transferring Native Token from your parachain to clone parachain

Thanks for all the comments. Based on the suggestions, I have identified the issue and posted here which may help other Substrate builders in the future. As mentioned by @Gav, there is a problem with ...
jpcoder's user avatar
  • 98

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