# Description Add `transfer_assets_using()` for transferring assets from local chain to destination chain using explicit XCM transfer types such as: - `TransferType::LocalReserve`: transfer assets to sovereign account of destination chain and forward a notification XCM to `dest` to mint and deposit reserve-based assets to `beneficiary`. - `TransferType::DestinationReserve`: burn local assets and forward a notification to `dest` chain to withdraw the reserve assets from this chain's sovereign account and deposit them to `beneficiary`. - `TransferType::RemoteReserve(reserve)`: burn local assets, forward XCM to `reserve` chain to move reserves from this chain's SA to `dest` chain's SA, and forward another XCM to `dest` to mint and deposit reserve-based assets to `beneficiary`. Typically the remote `reserve` is Asset Hub. - `TransferType::Teleport`: burn local assets and forward XCM to `dest` chain to mint/teleport assets and deposit them to `beneficiary`. By default, an asset's reserve is its origin chain. But sometimes we may want to explicitly use another chain as reserve (as long as allowed by runtime `IsReserve` filter). This is very helpful for transferring assets with multiple configured reserves (such as Asset Hub ForeignAssets), when the transfer strictly depends on the used reserve. E.g. For transferring Foreign Assets over a bridge, Asset Hub must be used as the reserve location. # Example usage scenarios ## Transfer bridged ethereum ERC20-tokenX between ecosystem parachains. ERC20-tokenX is registered on AssetHub as a ForeignAsset by the Polkadot<>Ethereum bridge (Snowbridge). Its asset_id is something like `(parents:2, (GlobalConsensus(Ethereum), Address(tokenX_contract)))`. Its _original_ reserve is Ethereum (only we can't use Ethereum as a reserve in local transfers); but, since tokenX is also registered on AssetHub as a ForeignAsset, we can use AssetHub as a reserve. With this PR we can transfer tokenX from ParaA to ParaB while using AssetHub as a reserve. ## Transfer AssetHub ForeignAssets between parachains AssetA created on ParaA but also registered as foreign asset on Asset Hub. Can use AssetHub as a reserve. And all of the above can be done while still controlling transfer type for `fees` so mixing assets in same transfer is supported. # Tests Added integration tests for showcasing: - transferring local (not bridged) assets from parachain over bridge using local Asset Hub reserve, - transferring foreign assets from parachain to Asset Hub, - transferring foreign assets from Asset Hub to parachain, - transferring foreign assets from parachain to parachain using local Asset Hub reserve. --------- Co-authored-by: Branislav Kontur <bkontur@gmail.com> Co-authored-by: command-bot <>
NOTE: We have recently made significant changes to our repository structure. In order to streamline our development process and foster better contributions, we have merged three separate repositories Cumulus, Substrate and Polkadot into this repository. Read more about the changes here.
Polkadot SDK
The Polkadot SDK repository provides all the resources needed to start building on the Polkadot network, a multi-chain blockchain platform that enables different blockchains to interoperate and share information in a secure and scalable way. The Polkadot SDK comprises three main pieces of software:
Polkadot
Implementation of a node for the https://polkadot.network in Rust, using the Substrate framework. This directory
currently contains runtimes for the Westend and Rococo test networks. Polkadot, Kusama and their system chain runtimes
are located in the runtimes repository maintained by
the Polkadot Technical Fellowship.
Substrate
Substrate is the primary blockchain SDK used by developers to create the parachains that make up the Polkadot network. Additionally, it allows for the development of self-sovereign blockchains that operate completely independently of Polkadot.
Cumulus
Cumulus is a set of tools for writing Substrate-based Polkadot parachains.
Releases
Note
Our release process is still Work-In-Progress and may not yet reflect the aspired outline here.
The Polkadot-SDK has two release channels: stable and nightly. Production software is advised to only use stable.
nightly is meant for tinkerers to try out the latest features. The detailed release process is described in
RELEASE.md.
Stable
stable releases have a support duration of three months. In this period, the release will not have any breaking
changes. It will receive bug fixes, security fixes, performance fixes and new non-breaking features on a two week
cadence.
Nightly
nightly releases are released every night from the master branch, potentially with breaking changes. They have
pre-release version numbers in the format major.0.0-nightlyYYMMDD.
Upstream Dependencies
Below are the primary upstream dependencies utilized in this project:
Security
The security policy and procedures can be found in docs/contributor/SECURITY.md.
Contributing & Code of Conduct
Ensure you follow our contribution guidelines. In every interaction and contribution, this project adheres to the Contributor Covenant Code of Conduct.
Additional Resources
- For monitoring upcoming changes and current proposals related to the technical implementation of the Polkadot network,
visit the
Requests for Comment (RFC)repository. While it's maintained by the Polkadot Fellowship, the RFC process welcomes contributions from everyone.
