galacticcouncil · Divljo31 · Feb 3, 2026
diff --git a/examples/xc-transactor/esbuild.dev.mjs b/examples/xc-transactor/esbuild.dev.mjs
@@ -0,0 +1,24 @@
+import esbuild from 'esbuild';
+import { wasmLoader } from 'esbuild-plugin-wasm';
+import { createProxyServer } from '../../esbuild.proxy.mjs';
+
+const plugins = [wasmLoader({ mode: 'deferred' })];
+
+const options = {
+  entryPoints: ['src/index.ts'],
+  bundle: true,
+  format: 'esm',
+  platform: 'browser',
+  target: 'esnext',
+  preserveSymlinks: true,
+  treeShaking: true,
+  sourcemap: true,
+  outdir: 'out/',
+  logLevel: 'info',
+};
+
+const ctx = await esbuild.context({ ...options, plugins });
+await ctx.rebuild();
+await ctx.watch();
+const localServer = await ctx.serve({ servedir: './', host: '127.0.0.1' });
+createProxyServer(localServer);
diff --git a/examples/xc-transactor/index.html b/examples/xc-transactor/index.html
@@ -0,0 +1,19 @@
+<!doctype html>
+
+<html>
+  <head>
+    <meta charset="UTF-8" />
+    <meta name="viewport" content="width=device-width, initial-scale=1" />
+    <title>XC Transactor POC</title>
+  </head>
+
+  <body>
+    <noscript>You need to enable JavaScript to run this app.</noscript>
+    <script>
+      new EventSource('/esbuild').addEventListener('change', () =>
+        location.reload()
+      );
+    </script>
+    <script type="module" src="./out/index.js"></script>
+  </body>
+</html>
diff --git a/examples/xc-transactor/package.json b/examples/xc-transactor/package.json
@@ -0,0 +1,16 @@
+{
+  "name": "xc-transactor",
+  "private": true,
+  "type": "module",
+  "main": "out/index.js",
+  "scripts": {
+    "dev": "node ./esbuild.dev.mjs"
+  },
+  "devDependencies": {
+    "esbuild": "^0.25.0",
+    "esbuild-plugin-wasm": "^1.0.0"
+  },
+  "dependencies": {
+    "@galacticcouncil/xc": "^0.4.0"
+  }
+}
diff --git a/examples/xc-transactor/src/abi.ts b/examples/xc-transactor/src/abi.ts
@@ -0,0 +1,91 @@
+export const XCM_TRANSACTOR_ABI = [
+  {
+    inputs: [
+      {
+        components: [
+          { internalType: 'uint8', name: 'parents', type: 'uint8' },
+          { internalType: 'bytes[]', name: 'interior', type: 'bytes[]' },
+        ],
+        internalType: 'struct Multilocation',
+        name: 'dest',
+        type: 'tuple',
+      },
+      {
+        components: [
+          { internalType: 'uint8', name: 'parents', type: 'uint8' },
+          { internalType: 'bytes[]', name: 'interior', type: 'bytes[]' },
+        ],
+        internalType: 'struct Multilocation',
+        name: 'feeLocation',
+        type: 'tuple',
+      },
+      {
+        components: [
+          { internalType: 'uint64', name: 'refTime', type: 'uint64' },
+          { internalType: 'uint64', name: 'proofSize', type: 'uint64' },
+        ],
+        internalType: 'struct Weight',
+        name: 'transactRequiredWeightAtMost',
+        type: 'tuple',
+      },
+      { internalType: 'bytes', name: 'call', type: 'bytes' },
+      { internalType: 'uint256', name: 'feeAmount', type: 'uint256' },
+      {
+        components: [
+          { internalType: 'uint64', name: 'refTime', type: 'uint64' },
+          { internalType: 'uint64', name: 'proofSize', type: 'uint64' },
+        ],
+        internalType: 'struct Weight',
+        name: 'overallWeight',
+        type: 'tuple',
+      },
+      { internalType: 'bool', name: 'refund', type: 'bool' },
+    ],
+    name: 'transactThroughSignedMultilocation',
+    outputs: [],
+    stateMutability: 'nonpayable',
+    type: 'function',
+  },
+  {
+    inputs: [
+      {
+        components: [
+          { internalType: 'uint8', name: 'parents', type: 'uint8' },
+          { internalType: 'bytes[]', name: 'interior', type: 'bytes[]' },
+        ],
+        internalType: 'struct Multilocation',
+        name: 'dest',
+        type: 'tuple',
+      },
+      { internalType: 'address', name: 'feeLocationAddress', type: 'address' },
+      {
+        components: [
+          { internalType: 'uint64', name: 'refTime', type: 'uint64' },
+          { internalType: 'uint64', name: 'proofSize', type: 'uint64' },
+        ],
+        internalType: 'struct Weight',
+        name: 'transactRequiredWeightAtMost',
+        type: 'tuple',
+      },
+      { internalType: 'bytes', name: 'call', type: 'bytes' },
+      { internalType: 'uint256', name: 'feeAmount', type: 'uint256' },
+      {
+        components: [
+          { internalType: 'uint64', name: 'refTime', type: 'uint64' },
+          { internalType: 'uint64', name: 'proofSize', type: 'uint64' },
+        ],
+        internalType: 'struct Weight',
+        name: 'overallWeight',
+        type: 'tuple',
+      },
+      { internalType: 'bool', name: 'refund', type: 'bool' },
+    ],
+    name: 'transactThroughSigned',
+    outputs: [],
+    stateMutability: 'nonpayable',
+    type: 'function',
+  },
+] as const;
+
+export const XCM_TRANSACTOR_V3 =
+  '0x0000000000000000000000000000000000000817' as `0x${string}`;
diff --git a/examples/xc-transactor/src/index.ts b/examples/xc-transactor/src/index.ts
@@ -0,0 +1,115 @@
+import {
+  acc,
+  addr,
+  Abi,
+  AnyEvmChain,
+  CallType,
+  Precompile,
+} from '@galacticcouncil/xc-core';
+import { EvmCall } from '@galacticcouncil/xc-sdk';
+import { encodeFunctionData } from 'viem';
+
+import { XCM_TRANSACTOR_ABI, XCM_TRANSACTOR_V3 } from './abi';
+import { sign } from './signers';
+import { ctx } from './setup';
+import { encodeParachainJunction } from './utils';
+
+const { config } = ctx;
+
+// Define transfer constraints
+const srcChain = config.getChain('moonbeam') as AnyEvmChain;
+
+const HYDRATION_PARACHAIN_ID = 2034;
+const MOONBEAM_PARACHAIN_ID = 2004;
+
+// Define source & dest accounts
+const srcAddr = '0x03F067F5174DF6E4E49285D32d9Ce1615711BCe9';
+// 7L53bUTBopuwFt3mKUfmkzgGLayYa1Yvn1hAg9v5UMrQzTfh
+
+// HDX XC-20 address on Moonbeam
+const HDX_XC20 = '0xffffffff345dc44ddae98df024eb494321e73fcc' as `0x${string}`;
+
+// Compute derived origin account on Hydration
+const derivedAccount = acc.getMultilocationDerivatedAccount(
+  MOONBEAM_PARACHAIN_ID,
+  srcAddr,
+  1, // parents = 1 (sibling parachain)
+  false
+);
+const derivedPubKey = addr.Ss58Addr.getPubKey(derivedAccount) as `0x${string}`;
+
+console.log('Moonbeam sender:', srcAddr);
+console.log('Derived origin account on Hydration:', derivedAccount);
+
+// Subcall 1: Fund derived account via PolkadotXcm.transferAssetsToPara32
+// Sends HDX from Moonbeam to the derived account on Hydration.
+// HDX is used as fee asset on Hydration for the subsequent transact call.
+const fundCallData = encodeFunctionData({
+  abi: Abi.PolkadotXcm,
+  functionName: 'transferAssetsToPara32',
+  args: [
+    HYDRATION_PARACHAIN_ID,
+    derivedPubKey,
+    [{ asset: HDX_XC20, amount: 10_000_000_000_000n }], // 10 HDX (12 decimals)
+    0, // feeAssetItem
+  ],
+});
+
+// Subcall 2: Remote transact via XcmTransactor precompile
+// Executes balances.transferKeepAlive on Hydration from the derived account.
+// Fees are paid in HDX (funded by subcall 1).
+
+// Pre-encoded Hydration call: Balances.transfer_keep_alive(dest, 100000)
+// Encoded via Polkadot.js Apps, can be replaced with any Hydration extrinsic
+const encodedHydrationCall =
+  '0x070382fb02afe02fe5d6c793145a75e6860c4e206682c3ab395a9d2a941eb7c0d30d0b00a0724e1809';
+
+const transactCallData = encodeFunctionData({
+  abi: XCM_TRANSACTOR_ABI,
+  functionName: 'transactThroughSigned',
+  args: [
+    // dest: Hydration (parachain 2034)
+    { parents: 1, interior: [encodeParachainJunction(HYDRATION_PARACHAIN_ID)] },
+    // feeLocationAddress: HDX XC-20 on Moonbeam
+    HDX_XC20,
+    // transactRequiredWeightAtMost
+    { refTime: 1_000_000_000n, proofSize: 50_000n },
+    // call (SCALE-encoded Hydration extrinsic)
+    encodedHydrationCall as `0x${string}`,
+    // feeAmount: 5 HDX (pays XCM execution fees on Hydration, 12 decimals)
+    5_000_000_000_000n,
+    // overallWeight: overall weight for full XCM program
+    { refTime: 2_000_000_000n, proofSize: 100_000n },
+    // refund surplus
+    true,
+  ],
+});
+
+// Batch both subcalls via Moonbeam Batch precompile (0x0808)
+const batchCallData = encodeFunctionData({
+  abi: Abi.Batch,
+  functionName: 'batchAll',
+  args: [
+    [Precompile.PolkadotXcm, XCM_TRANSACTOR_V3],
+    [0n, 0n],
+    [fundCallData, transactCallData],
+    [],
+  ],
+});
+
+// Dump call info
+console.log('Encoded Hydration call:', encodedHydrationCall);
+console.log('Batched calldata:', batchCallData);
+
+const call: EvmCall = {
+  from: srcAddr,
+  data: batchCallData,
+  type: CallType.Evm,
+  to: Precompile.Batch as `0x${string}`,
+  dryRun: async () => undefined,
+};
+
+console.log(call);
+
+// Sign & send
+await sign(call, srcChain);
diff --git a/examples/xc-transactor/src/setup.ts b/examples/xc-transactor/src/setup.ts
@@ -0,0 +1,3 @@
+import { createXcContext } from '@galacticcouncil/xc';
+
+export const ctx = await createXcContext();
diff --git a/examples/xc-transactor/src/signers/evm.ts b/examples/xc-transactor/src/signers/evm.ts
@@ -0,0 +1,51 @@
+import { h160 } from '@galacticcouncil/common';
+import { AnyChain, AnyEvmChain } from '@galacticcouncil/xc-core';
+import { Call, EvmCall } from '@galacticcouncil/xc-sdk';
+
+const { H160 } = h160;
+
+export async function signAndSend(
+  call: Call,
+  chain: AnyChain,
+  onTransactionSend: (hash: string | null) => void,
+  onTransactionReceipt: (receipt: any) => void,
+  onError: (error: unknown) => void
+) {
+  const evmChain = chain as AnyEvmChain;
+  const client = evmChain.evmClient;
+  const account = H160.fromAny(call.from);
+
+  const provider = client.getProvider();
+  const signer = client.getSigner(account);
+
+  await signer.switchChain({ id: client.chain.id });
+  await signer.request({ method: 'eth_requestAccounts' });
+
+  const { data, to, value } = call as EvmCall;
+  const estGas = await provider.estimateGas({
+    account: account as `0x${string}`,
+    data: data as `0x${string}`,
+    to: to as `0x${string}`,
+    value: value,
+  });
+  console.log('Est gas: ' + estGas);
+
+  const txHash = await signer.sendTransaction({
+    account: account as `0x${string}`,
+    chain: client.chain,
+    data: data as `0x${string}`,
+    to: to as `0x${string}`,
+    value: value,
+  });
+
+  onTransactionSend(txHash);
+  provider
+    .waitForTransactionReceipt({
+      hash: txHash,
+    })
+    .then((receipt) => onTransactionReceipt(receipt))
+    .catch((error: any) => {
+      console.log(error);
+      onError(error);
+    });
+}
diff --git a/examples/xc-transactor/src/signers/index.ts b/examples/xc-transactor/src/signers/index.ts
@@ -0,0 +1,20 @@
+import { AnyChain } from '@galacticcouncil/xc-core';
+import { Call } from '@galacticcouncil/xc-sdk';
+
+import * as evm from './evm';
+
+export async function sign(call: Call, chain: AnyChain) {
+  evm.signAndSend(
+    call,
+    chain,
+    (hash) => {
+      console.log('TxHash: ' + hash);
+    },
+    (receipt) => {
+      console.log(receipt);
+    },
+    (error) => {
+      console.error(error);
+    }
+  );
+}
diff --git a/examples/xc-transactor/src/utils.ts b/examples/xc-transactor/src/utils.ts
@@ -0,0 +1,17 @@
+// Encode Parachain junction for Moonbeam Multilocation struct
+// Selector 0x00 + 4-byte parachain ID (big-endian)
+export function encodeParachainJunction(id: number): `0x${string}` {
+  return `0x00${id.toString(16).padStart(8, '0')}`;
+}
+
+// Encode PalletInstance junction for Moonbeam Multilocation struct
+// Selector 0x04 + 1-byte pallet index
+export function encodePalletInstanceJunction(index: number): `0x${string}` {
+  return `0x04${index.toString(16).padStart(2, '0')}`;
+}
+
+// Encode GeneralIndex junction for Moonbeam Multilocation struct
+// Selector 0x05 + 16-byte index (big-endian u128)
+export function encodeGeneralIndexJunction(index: number): `0x${string}` {
+  return `0x05${index.toString(16).padStart(32, '0')}`;
+}
diff --git a/examples/xc-transactor/tsconfig.json b/examples/xc-transactor/tsconfig.json
@@ -0,0 +1,8 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "baseUrl": "src",
+    "noImplicitAny": false
+  },
+  "include": ["src/**/*.ts"]
+}
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		import { createXcContext } from '@galacticcouncil/xc';

		export const ctx = await createXcContext();