RFC: Custom Asset Claimer

[mrshiposha]

Summary

The proposed change provides a way to set a claimer to potentially dropped assets.
Currently, determining a claimer of dropped assets is implementation-specific, and there is no way to set a custom claimer.
The ability to set a custom claimer origin makes it easier to rescue the dropped assets, especially in the case of a reserve-based transfer.

[franciscoaguirre]

Awesome work specifying this new instruction! Left some comments but overall the addition seems solid. Thank you for contributing 😁

[Polkadot-Forum]

This pull request has been mentioned on Polkadot Forum. There might be relevant details there:

https://forum.polkadot.network/t/xcm-rfc-dropped-assets-claimers/3176/1

[gavofyork]

I suspect that being able to split up assets arbitrarily and allow for numerous claimants is probably going to be difficult to guarantee economic security. I think something like SetAssetTrapClaimer(MultiLocation) could work ok. Would this be sufficient to deliver the main benefits?

[mrshiposha]

I agree with Gavin's comment above. Indeed, having just one claimer for all the dropped assets should be enough to rescue them conveniently. Also, this instruction will be much easier to implement.

If there is a need for complex claiming logic, a smart contract could be set as a claimer.

The RFC is modified accordingly.

[mrshiposha]

@franciscoaguirre, the RFC is modified. Could you take a look, please?

[franciscoaguirre]

I like the simplification 🚀

[franciscoaguirre]

Starting the FCP (Final Comment Period), it will last 10 calendar days. After that, this RFC will be either accepted, rejected or explicitly postponed for a future time.

[Polkadot-Forum]

This pull request has been mentioned on Polkadot Forum. There might be relevant details there:

https://forum.polkadot.network/t/final-comment-period-for-two-xcm-rfcs/3516/1

[franciscoaguirre]

The FCP for this RFC is over. The RFC has been accepted!

The next steps would be to:

• Change the proposal name to 0037, since that's the PR number
• Change the proposal number to 37
• Change the proposal version to 4, since it will be included in XCMv4
  After that we can merge it. Once it's merged you should open a new PR that modifies README.md with the new instruction.

How does that sound @mrshiposha ?

[mrshiposha]

@franciscoaguirre sounds great!

[mrshiposha]

@franciscoaguirre I updated the RFC info:

• The RFC file is now named 0037-custom-asset-claimer.md
• The Number is now 37
• The Status is now Accepted
• The Version is now: 4

[franciscoaguirre]

@mrshiposha
Perfect. Could you create a new PR to master modifying the README?

[mrshiposha]

@franciscoaguirre Sure! Here it is: #41