Layerswap Docs

Fuel call_data is a JSON string containing a serialized script transaction and the coin quantities required to fund it:

{
  "script": {},
  "quantities": [
    { "amount": "1000000", "assetId": "0x..." }
  ]
}

Supported networks: Fuel Mainnet, Fuel Testnet Reconstruct the request with the Fuel TypeScript SDK, estimate and fund it through the source wallet, simulate it, and then submit it.

Transaction construction

Parse call_data

Deserialize the JSON string and extract the script and quantities fields.

Reconstruct the ScriptTransactionRequest

Use ScriptTransactionRequest.from() to create a proper transaction request object from the serialized data.

Estimate and fund

Call estimateAndFund() on the transaction with the wallet and required quantities. This estimates gas costs and adds the necessary coin inputs.

Simulate (optional)

Simulate the transaction against the Fuel provider to verify it will succeed before sending.

Send the transaction

Submit the transaction through the Fuel wallet and get the transaction id.

Full example

The Server-side tab signs with a raw private key. The Browser tab uses the Fuel Wallet extension via the Fuel connector. The @fuels/react tab wraps it as a hook for React apps.

import { Provider, Wallet, ScriptTransactionRequest, coinQuantityfy } from 'fuels';

async function executeFuelDeposit(action, privateKey) {
  const provider = new Provider(action.network.node_url);
  const wallet = Wallet.fromPrivateKey(privateKey, provider);

  const prepared = JSON.parse(action.call_data);
  const request = ScriptTransactionRequest.from(prepared.script);
  const quantities = prepared.quantities.map((quantity) =>
    coinQuantityfy(quantity),
  );

  await request.estimateAndFund(wallet, { quantities });
  await provider.simulate(request); // optional but recommended

  const response = await wallet.sendTransaction(request);
  return response.id;
}

import { Provider, ScriptTransactionRequest, coinQuantityfy } from 'fuels';

async function executeFuelDeposit(action, fuel, senderAddress) {
  const provider = new Provider(action.network.node_url);
  const wallet = await fuel.getWallet(senderAddress, provider);
  if (!wallet) {
    throw new Error('Fuel wallet not found');
  }

  const prepared = JSON.parse(action.call_data);
  const request = ScriptTransactionRequest.from(prepared.script);
  const quantities = prepared.quantities.map((quantity) =>
    coinQuantityfy(quantity),
  );

  await request.estimateAndFund(wallet, { quantities });
  await provider.simulate(request);

  const response = await wallet.sendTransaction(request);
  return response.id;
}

import { useFuel } from '@fuels/react';
import { Provider, ScriptTransactionRequest, coinQuantityfy } from 'fuels';

function useFuelDeposit() {
  const { fuel } = useFuel();

  async function executeDeposit(action, senderAddress) {
    if (!fuel) {
      throw new Error('Fuel not initialized');
    }

    const provider = new Provider(action.network.node_url);
    const wallet = await fuel.getWallet(senderAddress, provider);
    if (!wallet) {
      throw new Error('Fuel wallet not found');
    }

    const prepared = JSON.parse(action.call_data);
    const request = ScriptTransactionRequest.from(prepared.script);
    const quantities = prepared.quantities.map((quantity) =>
      coinQuantityfy(quantity),
    );

    await request.estimateAndFund(wallet, { quantities });
    await provider.simulate(request);

    const response = await wallet.sendTransaction(request);
    return response.id;
  }

  return { executeDeposit };
}

The wallet must be connected to action.network.node_url and hold the required assets and fee token. Do not edit the returned script, outputs, asset ids, or quantities before funding it. Store the transaction id and track the swap.

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Funding

Operations

Recipes

Endpoints

Fuel

Transaction construction

Full example

​Transaction construction

​Full example

Transaction construction

Full example