Tutorials > Interoperability > XCM Transfers

tutorials/interoperability/.pages

@@ -2,3 +2,4 @@ title: Interoperability
 nav:
   - index.md
   - xcm-channels
+  - xcm-transfers

tutorials/interoperability/xcm-transfers/.pages

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+title: XCM Transfers
+nav:
+  - index.md
+  - 'From Relay Chain to Parachain': from-relaychain-to-parachain.md

tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain.md

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+---
+title: From Relay Chain to Parachain
+description: Learn how to perform a reserve-backed asset transfer between a relay chain and a parachain using XCM for cross-chain interoperability.
+---
+
+# From Relay Chain to Parachain
+
+## Introduction
+
+[Cross-Consensus Messaging (XCM)](/develop/interoperability/intro-to-xcm/){target=\_blank} facilitates asset transfers both within the same consensus system and between different ones, such as between a relay chain and its parachains. For cross-system transfers, two main methods are available:
+
+- [**Asset teleportation**](https://paritytech.github.io/xcm-docs/journey/transfers/teleports.html){target=\_blank} - a simple and efficient method involving only the source and destination chains, ideal for systems with a high level of trust
+- [**Reserve-Backed transfers**](https://paritytech.github.io/xcm-docs/journey/transfers/reserve.html){target=\_blank} - involves a trusted reserve holding real assets and mints derivative tokens to track ownership. This method is suited for systems with lower trust levels
+
+In this tutorial, you will learn how to perform a reserve-backed transfer of DOT between a relay chain (Polkadot) and a parachain (Astar).
+
+## Prerequisites
+
+To send messages between different consensus systems, you must first open HRMP channels. For detailed guidance, refer to the [XCM Channels](/develop/interoperability/xcm-channels/#xcm-channels){target=\_blank} article before for further information about.
+
+This tutorial uses Chopsticks to fork a relay chain and a parachain connected via HRMP channels. For more details on this setup, see the [XCM Testing](/tutorials/polkadot-sdk/testing/fork-live-chains/#xcm-testing){target=\_blank} section on the Chopsticks page.
+
+## Setup
+
+To simulate XCM operations between different consensus systems, start by forking the network with the following command:
+
+```bash
+chopsticks xcm -r polkadot -p astar
+```
+After executing this command, the relay chain and parachain will expose the following WebSocket endpoints:
+
+=== "Polkadot (relay chain)"
+
+    ```bash
+    ws://localhost:8001
+    ```
+
+=== "Astar (parachain)"
+
+    ```bash
+    ws://localhost:8000
+    ```
+
+Open two browser tabs and can connect these endpoints using the [Polkadot.js Apps](https://polkadot.js.org/apps/){target=\_blank} interface:
+
+a. Add the custom endpoint for each chain
+
+b. Click **Switch** to connect to the respective network
+
+![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-01.webp)
+
+
+## Procedure to Execute a Reserve-Backed Transfer
+
+This method facilitates asset transfers from a local chain to a destination chain by trusting a third party called a reserve to store the real assets. Fees on the destination chain are deducted from the asset specified in the assets vector at the `fee_asset_item` index, covering up to the specified `weight_limit.` The operation fails if the required weight exceeds this limit, potentially putting the transferred assets at risk.
+
+!!! warning
+    The [`reserve_transfer_assets`](https://paritytech.github.io/polkadot-sdk/master/pallet_xcm/pallet/dispatchables/fn.reserve_transfer_assets.html){target=\_blank} extrinsic is deprecated in favor of the [`limited_reserve_transfer_assets`](https://paritytech.github.io/polkadot-sdk/master/pallet_xcm/pallet/dispatchables/fn.limited_reserve_transfer_assets.html){target=\_blank} extrinsic. 
+
+The following steps outline how to execute a reserve-backed transfer from the Polkadot relay chain to the Astar parachain.
+
+### From the Relay Chain Perspective
+
+1. Navigate to the Extrinsics page
+    1. Click on the **Developer** tab from the top navigation bar
+    2. Select **Extrinsics** from the dropdown
+
+    ![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-02.webp)
+
+2. Select **xcmPallet**
+
+    ![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-03.webp)
+
+3. Select the **limitedReservedAssetTransfer** extrinsic from the dropdown list
+
+    ![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-04.webp)
+
+4. Fill out the required fields
+    1. **dest** - specifies the destination context for the assets. Commonly set to `[Parent, Parachain(..)]` for parachain-to-parachain transfers or `[Parachain(..)]` for relay chain-to-parachain transfers. In this case, since the transfer is from a relay chain to a parachain, the destination context is the following:
+
+        ```bash
+        { parents: 1, interior: { X1: [{ Parachain: 2006 }] } }
+        ```
+
+    2. **beneficiary** - defines the recipient of the assets within the destination context, typically represented as an `AccountId32` value. This example uses the following account present in the destination chain:
+
+        ```bash
+        X2mE9hCGX771c3zzV6tPa8U2cDz4U4zkqUdmBrQn83M3cm7
+        ```
+
+    3. **assets** - lists the assets to be withdrawn, including those designated for fee payment on the destination chain
+    4. **feeAssetItem** - indicates the index of the asset within the assets list to be used for paying fees
+    5. **weightLimit** - specifies the weight limit, if applicable, for the fee payment on the remote chain
+    6. Click on the **Submit Transaction** button to send the transaction
+
+        ![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-05.webp)
+
+After submitting the transaction, verify that the `xcmPallet.FeesPaid` and `xcmPallet.Sent` events have been emitted:
+
+![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-06.webp)
+
+### From the Parachain Perspective
+
+After submitting the transaction from the relay chain, confirm its success by checking the parachain's events. Look for the `assets.Issued` event, which verifies that the assets have been issued to the destination as expected:
+
+![](/images/tutorials/interoperability/xcm-transfers/from-relaychain-to-parachain/from-relaychain-to-parachain-07.webp)
+
+## Additional Resources
+
+You can perform these operations using the Asset Transfer API for an alternative approach. Refer to the [Asset Transfer API](/develop/toolkit/interoperability/asset-transfer-api/){target=\_blank} guide in the documentation for more details.

tutorials/interoperability/xcm-transfers/index.md

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+---
+title: XCM Transfers
+description: Explore tutorials on performing transfers between different consensus systems using XCM technology to enable cross-chain interoperability.
+hide: 
+- feedback
+template: index-page.html
+---
+
+# XCM Transfers
+
+Discover comprehensive tutorials that guide you through performing asset transfers between distinct consensus systems. These tutorials leverage [XCM (Cross-Consensus Messaging)](/develop/interoperability/intro-to-xcm/){target=\_blank} technology, that enables cross-chain communication and asset exchanges across different blockchain networks. Whether you're working within the same ecosystem or bridging multiple systems, XCM ensures secure, efficient, and interoperable solutions.
+
+By mastering XCM-based transfers, you'll unlock new possibilities for building cross-chain applications and expanding blockchain utility. Learn the methods, tools, and best practices for testibg XCM-powered transfers, ensuring your systems achieve robust interoperability.
+
+## In This Section
+
+:::INSERT_IN_THIS_SECTION:::