How to Create a Payment Channel | XRPL Development in JavaScript - Level 4

In this chapter, we will introduce how to create a payment channel.

Simply put, a payment channel allows payments to be made from a deposited amount of XRP at a later time. By creating a channel and making a deposit in advance, off-chain payments become possible.

Additionally, XRPL’s payment channel functionality is provided natively, without the need for smart contracts or external dependencies. This ensures safe transactions (*) and makes the feature developer-friendly.

*Except for core bugs in XRPL.

Creating the Script

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

Paste the following code into createAccounts.js.

import { xrpToDrops, unixTimeToRippleTime } from 'xrpl';
import { client, aliceWallet, bobWallet } from './config.js';

const createPaymentChannel = async () => {
    try {
        const tx = {
            TransactionType: 'PaymentChannelCreate', // Transaction type: PaymentChannelCreate
            Account: bobWallet.address, // Sender's (Bob's) account address
            Amount: xrpToDrops('10'), // Amount of XRP to deposit in the channel (10 XRP here)
            Destination: aliceWallet.address, // Recipient's (Alice's) account address
            SettleDelay: 86400, // Grace period before the source address can close the channel if there is unclaimed XRP. Waiting time in seconds (1 day here)
            PublicKey: bobWallet.publicKey, // Sender's (Bob's) public key
            CancelAfter: CancelAfter: unixTimeToRippleTime(Math.floor(Date.now() / 1000) + 86400 * 30), // Seconds until the channel can be canceled (1 month here)
        };

        console.log('Submitting a PaymentChannelCreate transaction...');

        const paymentChannelResponse = await client.submitAndWait(tx, {
            wallet: bobWallet,
        });

        console.log(
            'PaymentChannelCreate transaction response:',
            paymentChannelResponse
        );

        // Get the channel_id
        const response = await client.request({
            command: 'account_channels',
            account: bobWallet.address,
        });

        const channelId = response.result.channels[0].channel_id;
        console.log(`Created Payment Channel with ID: ${channelId}`);

        return channelId;
    } catch (error) {
        console.error('Error creating Payment Channel:', error);
    }
};

const main = async () => {
    try {
        await client.connect();
        const channelId = await createPaymentChannel();
    } catch (error) {
        console.error('Error connecting to XRPL:', error);
    } finally {
        await client.disconnect();
    }
};

main();

Running the Script

Run the script by executing the following command in your command line:
Terminal window
```
node createPaymentChannel.js
```

If successful, the console will display the following:

Submitting a PaymentChannelCreate transaction...
PaymentChannelCreate transaction response: {
    id: 10,
    result: {
        Account: 'rDW8W3rzDFUyU4pw5Ei8QL1J9nQ947h68f',
        Amount: '10000000',
        CancelAfter: 1719738684,
        Destination: 'rM6Nt2E1WKJLKMN1tbkcifveAshzVuyJmj',
        Fee: '12',
        Flags: 0,
        LastLedgerSequence: 1742776,
        PublicKey: 'ED9F9B58A0A209A1D0F90832FE83F3ED49C0091259E3F67A2FCAA3D3EAAF718FFE',
        Sequence: 1742740,
        SettleDelay: 86400,
        SigningPubKey: 'ED9F9B58A0A209A1D0F90832FE83F3ED49C0091259E3F67A2FCAA3D3EAAF718FFE',
        TransactionType: 'PaymentChannelCreate',
        TxnSignature: '8B87011388FFED13070AFB88D936D7903D26A481036043ABD27BEC13CA5531610A667BCFE18B2F7090EB04E611EAFDC3DA0082C72937FCB9DB2EEDE6AA5F4602',
        ctid: 'C01A97A600070001',
        date: 772449090,
        hash: '860DD9F668836971343AE84BE111D451A3F0C4BBE4BD92E36D3BCAC5E2571BB4',
        inLedger: 1742758,
        ledger_index: 1742758,
        meta: {
            AffectedNodes: [Array],
            TransactionIndex: 7,
            TransactionResult: 'tesSUCCESS'
        },
        validated: true
    },
    type: 'response'
}
Created Payment Channel with ID: 25C67138FB51F65A7015632C07E00AD0AE1C8A21F0282FD0401BAEDFDFD3423E

The ID displayed at the end of the log (25C67138FB51F65A7015632C07E00AD0AE1C8A21F0282FD0401BAEDFDFD3423E) is the Channel ID, so make a note of it.

In actual development, you will need to carry forward this ID to perform off-chain transactions and other operations.

Next, we will perform off-chain transactions using the created Channel ID. The specific steps will be explained in the next section.