Claiming Funds from a Payment Channel | XRPL Development in JavaScript - Level 4

In this chapter, we will introduce how to claim funds from the balance of a created payment channel.

Prerequisites

Bob has already performed the following actions for Alice:

• Created a channel and deposited 10 XRP.
• Completed a total of 1 XRP worth of off-ledger transactions.

Creating the Script

1. Create a new file named claimPaymentChannel.js in your project directory.

2. Paste the following code into claimPaymentChannel.js.

   This code is a sample for claiming transactions for a specified channel ID, payment amount, and signature.

   claimPaymentChannel.js

    import { xrpToDrops, signPaymentChannelClaim } from 'xrpl';
    import { client, aliceWallet, bobWallet } from './config.js';
   
    const claimPaymentChannel = async (channelId, amount, paychanSignature) => {
        try {
            // Create the PaymentChannelClaim transaction
            const tx = {
                TransactionType: 'PaymentChannelClaim',
                Account: aliceWallet.address, // Recipient (Alice's) address
                Channel: channelId, // Channel ID
                Balance: xrpToDrops(amount), // Amount to claim (in drops)
                Amount: xrpToDrops(amount), // Amount to pay (in drops)
                Signature: paychanSignature, // Off-ledger transaction signature string
                PublicKey: bobWallet.publicKey, // Sender's public key
            };
   
            console.log('Submitting a PaymentChannelClaim transaction...');
            const response = await client.submitAndWait(tx, { wallet: aliceWallet }); // Alice signs the transaction
            console.log('PaymentChannelClaim transaction response:', response);
        } catch (error) {
            console.error('Error claiming Payment Channel:', error);
        }
    };
   
    const main = async () => {
        try {
            await client.connect();
   
            const channelId = 'CHANNEL_ID_HERE'; // Enter the previously created channel ID
            const amount = '1'; // Enter the amount in XRP
   
            // Specify the previously created off-ledger payment signature
            const paychanSignature = 'SIGNATURE_HERE';
   
            // 実行
            await claimPaymentChannel(channelId, amount, paychanSignature);
        } catch (error) {
            console.error('Error connecting to XRPL:', error);
        } finally {
            await client.disconnect();
        }
    };
   
    main();

Running the Script

1. Run the script by executing the following command in your command line:

   node claimPaymentChannel.js

2. If successful, the console will display the following:

   Submitting a PaymentChannelClaim transaction...
   PaymentChannelClaim transaction response: {
       id: 12,
       result: {
           Account: 'rM6Nt2E1WKJLKMN1tbkcifveAshzVuyJmj', // Alice"s address
           Amount: '1000000',
           Balance: '1000000',
           Channel: '25C67138FB51F65A7015632C07E00AD0AE1C8A21F0282FD0401BAEDFDFD3423E',
           Fee: '12',
           Flags: 0,
           LastLedgerSequence: 1743094,
           PublicKey: 'ED9F9B58A0A209A1D0F90832FE83F3ED49C0091259E3F67A2FCAA3D3EAAF718FFE',
           Sequence: 1742737,
           Signature: '7465B7BCC66F1053D4CB8EF3785BE951A235868420F546160EF446429DA58632EEBBA90810F6714500E7B0A73E9DBABFE47307DC6BEC9D911D24DB473988BE04',
           SigningPubKey: 'EDE80DD6F71A48928EC70B22912D6E9B4005D1D9666939C658F931186CC9DA80B7',
           TransactionType: 'PaymentChannelClaim',
           TxnSignature: 'A9CC66C22C9000CE5B939E828FDB621419A8EE7180604B3844D52D32D27BD4F00CCB93D8AF85C0E7F08EA7DD27D5E475F8CA00FEA1EF2B6BB826EB6DA95A4902',
           ctid: 'C01A98E400000001',
           date: 772450171,
           hash: '885C753CDE40000A7452F31FB120293EFDCE39F3A442B1C5E6E924440FD32381',
           inLedger: 1743076,
           ledger_index: 1743076,
           meta: {
               AffectedNodes: [Array],
               TransactionIndex: 0,
               TransactionResult: 'tesSUCCESS' // Success
           },
           validated: true
       },
       type: 'response'
   }

   Alice has successfully claimed the specified channel ID.

3. Attempting to claim the same amount again will naturally fail.

   Submitting a PaymentChannelClaim transaction...
   PaymentChannelClaim transaction response: {
       id: 12,
       result: {
           Account: 'rM6Nt2E1WKJLKMN1tbkcifveAshzVuyJmj',
           Amount: '1000000',
           Balance: '1000000',
           Channel: '25C67138FB51F65A7015632C07E00AD0AE1C8A21F0282FD0401BAEDFDFD3423E',
           Fee: '12',
           Flags: 0,
           LastLedgerSequence: 1744099,
           PublicKey: 'ED9F9B58A0A209A1D0F90832FE83F3ED49C0091259E3F67A2FCAA3D3EAAF718FFE',
           Sequence: 1742738,
           Signature: '7465B7BCC66F1053D4CB8EF3785BE951A235868420F546160EF446429DA58632EEBBA90810F6714500E7B0A73E9DBABFE47307DC6BEC9D911D24DB473988BE04',
           SigningPubKey: 'EDE80DD6F71A48928EC70B22912D6E9B4005D1D9666939C658F931186CC9DA80B7',
           TransactionType: 'PaymentChannelClaim',
           TxnSignature: 'A95B769AC9AD834D4798C1409B3B6708D1D4DFF79DF2F59AA185B358810930A925B948D7BD3E83EF20308FDE75275AFC5B75C164A4D70F8CB49BCDC9148A8D01',
           ctid: 'C01A9CD100330001',
           date: 772453560,
           hash: 'D3F6D62CAE3A3B8C2DAD0DEE314A55145AA1EBF2544C8B09CDD1F698EDE6621E',
           inLedger: 1744081,
           ledger_index: 1744081,
           meta: {
               AffectedNodes: [Array],
               TransactionIndex: 51,
               TransactionResult: 'tecUNFUNDED_PAYMENT' // Failure
           },
           validated: true
       },
       type: 'response'
   }

   What is tecUNFUNDED_PAYMENT?

   The tec code 104 is tecUNFUNDED_PAYMENT. This typically means that the transaction failed because the sending account attempted to send an amount exceeding its XRP balance without considering the reserve.
   Here, it means “There is no balance to claim on the payment channel.”

   Run node checkChannelBalance.js again to check the Balance, and it should look like this:

   Channel ID: E965B919E140BCF98280B29F6861C23BBB753B9D5515EDD57A285391BA20CCA2
   Balance: 1000000 drops // Balance already claimed by the recipient (currently: 1 XRP)
   Amount: 10000000 drops // Amount deposited (10 XRP)

Summary

If the balances are approximately as follows, the process has been successful.

• Alice: 100.999988 XRP
• Bob: 89.999988 XRP

Check Alice and Bob’s addresses using the explorer for the testnet.

• Alice claimed 1 XRP from the payment channel created by Bob, but since she bore the transaction fee, she actually received 0.999988 XRP.
• Bob initially deposited 10 XRP with the PaymentChannelCreate transaction, paying the deposit and fees upfront, so his balance should be 89.999988 XRP.

Additionally, it is beneficial to examine the transaction data for more detailed insights.