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Transfer native token

Let's use transfer_multiasset to:

  • transfer native token of parachainId 2000 to a Wrapped version in 2007
  • for amount 10000000000000000000

1. Define call as payable​

As the call will be on behalf of the contract, the native amount should be held by the contract. Please make the function payable to ensure the native token will be transferred to contract.

    function transfer_native() external payable {

2. Asset Multilocation​

The Native token Multilocation is defined by: Multilocation: { parents: 0, interior: Here } The interior field is an empty bytes array (equivalent of Here).

bytes[] memory interior1 = new bytes[](0);
XCM.Multilocation memory asset = XCM.Multilocation({
    parents: 0,
    interior: interior1
});

3. Beneficiary Multilocation​

Let's suppose the beneficiary is the EVM address 0xd43593c715fdd31c61141abd04a99fd6822c8558 of the contract in parachain 2007. The Multilocation is { parents: 1, interior: X2 [Parachain: 2007, AccountId20: { id: *caller address* , network: any }] }. The interior field is of type H160 (20 bytes EVM address) so prefixed with 0x03 and suffix with 0x00 (network: any). The interior bytes are 0x03 + EVM address + 0x00

bytes[] memory interior = new bytes[](2);
interior[0] = bytes.concat(hex"00", bytes4(uint32(2007)));
interior[1] = bytes.concat(hex"03", msg.sender, hex"00");
XCM.Multilocation memory destination = XCM.Multilocation({
    parents: 1,
    interior: interior
});

4. Weight​

The weight we want to buy in the destination chain, to set the weightlimit to Unlimited, you should use the value 0 for ref_time.

XCM.WeightV2 memory weight = XCM.WeightV2({
    ref_time: 30_000_000_000,
    proof_size: 300_000
});

5. calling XCM precompiles​

Import the XCM precompiles in your contract and call it like this:

address public constant XCM_ADDRESS =
0x0000000000000000000000000000000000005004;

require(
    XCM(XCM_ADDRESS).transfer_multiasset(
        asset,
        amount,
        destination,
        weight
    ),
    "Failed to send xcm"
);

Please check full example in the XCM EVM SDK