Setting Trust Lines | XRPL Development in JavaScript - Level 3

Setting a trust line allows an account to receive a specific currency.

For basic knowledge of trust lines, please refer to this page.

This guide will explain the process using A.USD issued by Issuer A and B.EUR issued by Issuer B.

To proceed with learning about cross-currency payments, we need to perform some basic setups for the accounts created in the previous chapter. Please create and run the following script.

Methods to be Used

In this chapter, we will use the following methods created in the previous chapter.

// Function to set a trust line
export async function setTrustLine(client, wallet, currency, issuer, limit) {
  try {
    const trustSet = {
      TransactionType: 'TrustSet',
      Account: wallet.classicAddress,
      LimitAmount: {
        currency: currency,
        issuer: issuer,
        value: limit,
      },
    };
    const response = await client.submitAndWait(trustSet, { wallet });
    console.log(`Trust line set for ${wallet.classicAddress}:`, response);
    return response;
  } catch (error) {
    console.error(
      `Error setting trust line for ${wallet.classicAddress}: ${error}`
    );
    throw error;
  }
}

Creating the Script

Create a new file named setTrustline.js in your project directory.

Paste the following code into setTrustline.js.

import { Client, AccountSetAsfFlags } from 'xrpl';
import { wallets } from './wallets.js';
import { setTrustLine } from './utils/trustSet.js';
import { setAccountFlags } from './utils/setAccountFlags.js';

const client = new Client('wss://s.altnet.rippletest.net:51233'); // Using the testnet

const main = async () => {
  try {
    await client.connect();

    const { issuerA, issuerB, alice, bob, charlie, daniel } = wallets;
    const limitAmount = '10000';

    // Allow rippling
    await setAccountFlags(client, issuerA, AccountSetAsfFlags.asfDefaultRipple);
    await setAccountFlags(client, issuerB, AccountSetAsfFlags.asfDefaultRipple);

    // Set trust lines for Alice to receive issuerA's USD and issuerB's EUR
    await setTrustLine(client, alice, 'USD', issuerA.classicAddress, limitAmount);
    await setTrustLine(client, alice, 'EUR', issuerB.classicAddress, limitAmount);

    // Set trust line for Bob to receive issuerB's EUR
    await setTrustLine(client, bob, 'EUR', issuerB.classicAddress, limitAmount);

    // Set trust line for Charlie to receive issuerA's USD
    await setTrustLine(client, charlie, 'USD', issuerA.classicAddress, limitAmount);

    // Set trust line for Daniel to receive issuerB's EUR
    await setTrustLine(client, daniel, 'EUR', issuerB.classicAddress, limitAmount);
  } catch (error) {
    console.error(`Error in trust line setup: ${error}`);
  } finally {
    await client.disconnect();
  }
};

main();

Running the Script

Run the following command in the command line to execute the script.
Terminal window
```
node setTrustLine.js
```

If you see console logs like the following, the execution should have been successful.

Account flags set for rfkJ7Uz6NrNV1FdbmKB5wepoim51KFpYQp: {
  id: 12,
  result: {
    Account: 'rfkJ7Uz6NrNV1FdbmKB5wepoim51KFpYQp',
    Fee: '12',
    Flags: 0,
    LastLedgerSequence: 1048947,
    Sequence: 1046418,
    SetFlag: 8,
    SigningPubKey: 'EDEBAB4C81CF854860D393191A001822A9B58242302710A2D3EFE5BE8620A1F8A9',
    TransactionType: 'AccountSet',
    TxnSignature: '0F1D6C311E50499CBF1B08D3423D83797AAE3139A444ED2461E41F0D6D2F7F61415C65C2302C6230F2EE85C55B3505FEE120C9169D2EC90754848EED663EB50A',
    ctid: 'C010016100000001',
    date: 770216691,
    hash: 'FEEABF75F7220CF3CED9FB9D71CADE7C3C78F433812FCA7D3321958A07F3608F',
    inLedger: 1048929,
    ledger_index: 1048929,
    meta: {
      AffectedNodes: [Array],
      TransactionIndex: 0,
      TransactionResult: 'tesSUCCESS'
    },
    validated: true
  },
  type: 'response'
}
Account flags set for rstM9rxhKo4N4WEaQgQmQSPQRgZqkhHkaU: {
  id: 24,
  result: {
    Account: 'rstM9rxhKo4N4WEaQgQmQSPQRgZqkhHkaU',
    Fee: '12',
    Flags: 0,
    LastLedgerSequence: 1048949,
    Sequence: 1046420,
    SetFlag: 8,
    SigningPubKey: 'EDBE91E21E32E1848B805B22597D87667FBC6B045B9ABADC67807DB88CD1767A97',
    TransactionType: 'AccountSet',
    TxnSignature: '85CD26FCCAFBB90218F7DBA03CA2807D129452BAE5001A9D13B610FFBFFA4EF9F84E98F5B91F282C022D07D14A78BE740C315A70F2003CB28DB4DAF200B78D09',
    ctid: 'C010016300000001',
    date: 770216701,
    hash: '6B1CFBC84B221C0790D38961C05BB944374C5E35C4E9D0042E9A853AA6BA5618',
    inLedger: 1048931,
    ledger_index: 1048931,
    meta: {
      AffectedNodes: [Array],
      TransactionIndex: 0,
      TransactionResult: 'tesSUCCESS'
    },
    validated: true
  },
  type: 'response'
}
Trust line set for r3KQdHtUHUouGkLBFLZRxRYiugbW8cNwyJ: {
  id: 36,
  result: {
    Account: 'r3KQdHtUHUouGkLBFLZRxRYiugbW8cNwyJ',
    Fee: '12',
    Flags: 0,
    LastLedgerSequence: 1048951,
    LimitAmount: {
      currency: 'USD',
      issuer: 'rfkJ7Uz6NrNV1FdbmKB5wepoim51KFpYQp',
      value: '10000'
    },
    Sequence: 1046422,
    SigningPubKey: 'ED84F179E4978F5FA3C5DDAA2305A074B954755975135D4CA3E56E2B09124A98AB',
    TransactionType: 'TrustSet',
    TxnSignature: 'A717516A634F6A1FC25D09EB740E3CD686EA35B3A141618C40C1454BB2E05216B1785E57E791EF1CCA95DE8655D5673FDED04A3002656DB5A1320622826A9102',
    ctid: 'C010016500010001',
    date: 770216710,
    hash: 'E30668CA07772CD1A299E3FFD8FC38DE4E62C3E1ECF0518BAE86B7AF9035FDA4',
    inLedger: 1048933,
    ledger_index: 1048933,
    meta: {
      AffectedNodes: [Array],
      TransactionIndex: 1,
      TransactionResult: 'tesSUCCESS'
    },
    validated: true
  },
  type: 'response'
}
Trust line set for r3KQdHtUHUouGkLBFLZRxRYiugbW8cNwyJ: {
  id: 51,
  result: {
    Account: 'r3KQdHtUHUouGkLBFLZRxRYiugbW8cNwyJ',
    Fee: '12',
    Flags: 0,
    LastLedgerSequence: 1048953,
    LimitAmount: {
      currency: 'EUR',
      issuer: 'rstM9rxhKo4N4WEaQgQmQSPQRgZqkhHkaU',
      value: '10000'
    },
    Sequence: 1046423,
    SigningPubKey: 'ED84F179E4978F5FA3C5DDAA2305A074B954755975135D4CA3E56E2B09124A98AB',
    TransactionType: 'TrustSet',
    TxnSignature: '34501D584CF69D79421A1328AA1D91BD65069AA143784874A95979F43AC635CEFD9425F65B2FC8CCE95690C90743A3E6B86D877DBB68FFB369D4411FAD586D07',
    ctid: 'C0100167001E0001',
    date: 770216712,
    hash: '94C3B5CFB87CA96B48A77EFD3480DB88161DEF0A23FF0FC25EE9E2BAD9812084',
    inLedger: 1048935,
    ledger_index: 1048935,
    meta: {
      AffectedNodes: [Array],
      TransactionIndex: 30,
      TransactionResult: 'tesSUCCESS'
    },
    validated: true
  },
  type: 'response'
}
Trust line set for rn9GFEPHW5tX2CaKVc7mA4L2GyXh88JiTy: {
  id: 63,
  result: {
    Account: 'rn9GFEPHW5tX2CaKVc7mA4L2GyXh88JiTy',
    Fee: '12',
    Flags: 0,
    LastLedgerSequence: 1048955,
    LimitAmount: {
      currency: 'EUR',
      issuer: 'rstM9rxhKo4N4WEaQgQmQSPQRgZqkhHkaU',
      value: '10000'
    },
    Sequence: 1046424,
    SigningPubKey: 'EDA33B78BB0BCE6D1E18015AE195AE3D67456F3B7A2C34ECD95D5AD8B0477EE96A',
    TransactionType: 'TrustSet',
    TxnSignature: '7A6EB874E4676EA1C2C6A9B37C8093214F4A30F17C9ED90ADE3F92200937131072AF9BF67AAB094540D5708155849AABB90B0F9DC0DE0FDEE9D1D7AC059FD100',
    ctid: 'C010016900010001',
    date: 770216721,
    hash: '9FB732C996091FE868D9C47A0B1EE29691AA4C5CA0E6FC92D1D782C00A743DA5',
    inLedger: 1048937,
    ledger_index: 1048937,
    meta: {
      AffectedNodes: [Array],
      TransactionIndex: 1,
      TransactionResult: 'tesSUCCESS'
    },
    validated: true
  },
  type: 'response'
}
...