BitBoxSwiss · strmci · May 18, 2026
@@ -149,6 +149,9 @@ func (lightning *Lightning) PostPreparePayment(r *http.Request) interface{} {
 
 	fee, err := lightning.PreparePayment(jsonBody.Bolt11, jsonBody.AmountSat)
 	if err != nil {
+		if fee != nil && jsonBody.AmountSat != nil && errp.Cause(err) == errLightningInsufficientFunds {
+			return responseDto{Success: false, ErrorCode: string(errLightningInsufficientFunds), Data: fee}
+		}
 		return errorResponse(err)
 	}
 

@@ -3,8 +3,10 @@
 package lightning
 
 import (
+	"errors"
 	"math/big"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/BitBoxSwiss/bitbox-wallet-app/backend/accounts"
@@ -13,7 +15,11 @@ import (
 	"github.com/breez/breez-sdk-spark-go/breez_sdk_spark"
 )
 
-const errPaymentApprovalRequired errp.ErrorCode = "paymentApprovalRequired"
+const (
+	errPaymentApprovalRequired     errp.ErrorCode = "paymentApprovalRequired"
+	errLightningInsufficientFunds  errp.ErrorCode = "lightningInsufficientFunds"
+	errLightningInvoiceAlreadyUsed errp.ErrorCode = "lightningInvoiceAlreadyUsed"
+)
 
 type lightningInvoice struct {
 	Bolt11      string  `json:"bolt11"`
@@ -241,20 +247,53 @@ func checkApprovedPaymentFee(fee uint64, approvedFee uint64) error {
 	return nil
 }
 
+func checkPaymentBalance(fee *paymentFee, balance *accounts.Balance) error {
+	if new(big.Int).SetUint64(fee.TotalDebitSat).Cmp(balance.Available().BigInt()) > 0 {
+		return errLightningInsufficientFunds
+	}
+	return nil
+}
+
+func lightningPaymentError(err error) error {
+	if err == nil {
+		return nil
+	}
+	if errors.Is(err, breez_sdk_spark.ErrSdkErrorInsufficientFunds) {
+		return errp.WithMessage(errLightningInsufficientFunds, err.Error())
+	}
+	errString := strings.ToLower(err.Error())
+	if strings.Contains(errString, "preimage request already exists") ||
+		(strings.Contains(errString, "duplicate_operation") && strings.Contains(errString, "paymenthash")) {
+		return errp.WithMessage(errLightningInvoiceAlreadyUsed, err.Error())
+	}
+	// Spark currently wraps insufficient funds as SdkErrorSparkError with this text.
+	if strings.Contains(errString, "insufficient funds") {
+		return errp.WithMessage(errLightningInsufficientFunds, err.Error())
+	}
+	return err
+}
+
 // PreparePayment computes the fee quote for the provided payment request.
 func (lightning *Lightning) PreparePayment(paymentInvoice string, amountSat *uint64) (*paymentFee, error) {
 	if err := lightning.CheckActive(); err != nil {
 		return nil, err
 	}
 	prepareResponse, err := lightning.sdkService.PrepareSendPayment(prepareSendPaymentRequest(paymentInvoice, amountSat))
 	if err != nil {
-		return nil, err
+		return nil, lightningPaymentError(err)
 	}
 
 	fee, err := preparedPaymentFee(prepareResponse)
 	if err != nil {
 		return nil, err
 	}
+	balance, err := lightning.Balance()
+	if err != nil {
+		return nil, err
+	}
+	if err := checkPaymentBalance(fee, balance); err != nil {
+		return fee, err
+	}
 	lightning.log.Printf("Lightning Fee: %v sats", fee.FeeSat)
 	return fee, nil
 }
@@ -271,13 +310,21 @@ func (lightning *Lightning) SendPayment(paymentInvoice string, amount *uint64, a
 
 	prepareResponse, err := lightning.sdkService.PrepareSendPayment(prepareSendPaymentRequest(paymentInvoice, amount))
 	if err != nil {
-		return err
+		return lightningPaymentError(err)
 	}
 
 	fee, err := preparedPaymentFee(prepareResponse)
 	if err != nil {
 		return err
 	}
+	balance, err := lightning.Balance()
+	if err != nil {
+		return err
+	}
+	// Re-check the balance because funds or the prepared fee can change between quote approval and send.
+	if err := checkPaymentBalance(fee, balance); err != nil {
+		return err
+	}
 	if err := checkApprovedPaymentFee(fee.FeeSat, approvedFee); err != nil {
 		return err
 	}
@@ -293,7 +340,7 @@ func (lightning *Lightning) SendPayment(paymentInvoice string, amount *uint64, a
 	_, err = lightning.sdkService.SendPayment(payRequest)
 
 	if err != nil {
-		return err
+		return lightningPaymentError(err)
 	}
 	return nil
 }

@@ -3,6 +3,7 @@
 package lightning
 
 import (
+	"errors"
 	"math/big"
 	"testing"
 
@@ -283,3 +284,89 @@ func coinAmountWithConversions(amount string) coin.FormattedAmountWithConversion
 func stringPointer(value string) *string {
 	return &value
 }
+
+func TestCheckPaymentBalance(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name          string
+		totalDebitSat uint64
+		availableSat  int64
+		expectedErr   error
+	}{
+		{
+			name:          "total debit below available balance",
+			totalDebitSat: 99,
+			availableSat:  100,
+		},
+		{
+			name:          "total debit equals available balance",
+			totalDebitSat: 100,
+			availableSat:  100,
+		},
+		{
+			name:          "total debit exceeds available balance",
+			totalDebitSat: 101,
+			availableSat:  100,
+			expectedErr:   errLightningInsufficientFunds,
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			t.Parallel()
+
+			balance := accounts.NewBalance(coin.NewAmountFromInt64(testCase.availableSat), coin.NewAmountFromInt64(0))
+			err := checkPaymentBalance(&paymentFee{TotalDebitSat: testCase.totalDebitSat}, balance)
+			require.Equal(t, testCase.expectedErr, errp.Cause(err))
+		})
+	}
+}
+
+func TestLightningPaymentError(t *testing.T) {
+	t.Parallel()
+
+	unrelatedErr := errors.New("network unavailable")
+	testCases := []struct {
+		name                  string
+		err                   error
+		expectedErr           error
+		expectedErrorContains []string
+	}{
+		{
+			name:                  "typed SDK insufficient funds",
+			err:                   breez_sdk_spark.NewSdkErrorInsufficientFunds(),
+			expectedErr:           errLightningInsufficientFunds,
+			expectedErrorContains: []string{"SdkError: InsufficientFunds", "lightningInsufficientFunds"},
+		},
+		{
+			name:                  "Spark insufficient funds",
+			err:                   breez_sdk_spark.NewSdkErrorSparkError("Tree service error: insufficient funds"),
+			expectedErr:           errLightningInsufficientFunds,
+			expectedErrorContains: []string{"Tree service error: insufficient funds", "lightningInsufficientFunds"},
+		},
+		{
+			name:                  "Spark already used invoice",
+			err:                   breez_sdk_spark.NewSdkErrorSparkError("Service error: status: AlreadyExists, message: preimage request already exists for paymentHash abc, details: DUPLICATE_OPERATION"),
+			expectedErr:           errLightningInvoiceAlreadyUsed,
+			expectedErrorContains: []string{"preimage request already exists", "lightningInvoiceAlreadyUsed"},
+		},
+		{
+			name:        "unrelated error",
+			err:         unrelatedErr,
+			expectedErr: unrelatedErr,
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			t.Parallel()
+
+			err := lightningPaymentError(testCase.err)
+			require.Equal(t, testCase.expectedErr, errp.Cause(err))
+			for _, expectedText := range testCase.expectedErrorContains {
+				require.Contains(t, err.Error(), expectedText)
+			}
+		})
+	}
+}
@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: Apache-2.0
 
-import { apiGet, apiPost } from '../utils/request';
-import { AccountCode, TAmountWithConversions, TBalance, TTransactionStatus } from './account';
-import { TSubscriptionCallback, TUnsubscribe, subscribeEndpoint } from './subscribe';
+import type { AccountCode, TAmountWithConversions, TBalance, TTransactionStatus } from '@/api/account';
+import type { TSubscriptionCallback, TUnsubscribe } from '@/api/subscribe';
+import { subscribeEndpoint } from '@/api/subscribe';
+import { apiGet, apiPost } from '@/utils/request';
 
 export type TLightningResponse<T> =
   | {
@@ -11,6 +12,7 @@ export type TLightningResponse<T> =
   }
   | {
     success: false;
+    data?: T;
     errorMessage?: string;
     errorCode?: string;
   };
@@ -79,12 +81,14 @@ export type TParsePaymentInputRequest = {
   s: string;
 };
 
-export class TSdkError extends Error {
+export class TSdkError<T = unknown> extends Error {
   code?: string;
+  data?: T;
 
-  constructor(message: string, code?: string) {
+  constructor(message: string, code?: string, data?: T) {
     super(message);
     this.code = code;
+    this.data = data;
 
     Object.setPrototypeOf(this, TSdkError.prototype);
   }
@@ -103,7 +107,7 @@ const queryString = (params: Record<string, string | number | undefined | null>)
 const getApiResponse = async <T>(url: string, defaultError: string = 'Error'): Promise<T> => {
   const response: TLightningResponse<T> = await apiGet(url);
   if (!response.success) {
-    throw new TSdkError(response.errorMessage || defaultError, response.errorCode);
+    throw new TSdkError(response.errorMessage || defaultError, response.errorCode, response.data);
   }
   if (response.data === undefined) {
     throw new TSdkError(defaultError);
@@ -114,7 +118,7 @@ const getApiResponse = async <T>(url: string, defaultError: string = 'Error'): P
 const postApiResponse = async <T, C extends object | undefined>(url: string, data: C, defaultError: string = 'Error'): Promise<T> => {
   const response: TLightningResponse<T> = await apiPost(url, data);
   if (!response.success) {
-    throw new TSdkError(response.errorMessage || defaultError, response.errorCode);
+    throw new TSdkError(response.errorMessage || defaultError, response.errorCode, response.data);
   }
   if (response.data === undefined) {
     return undefined as T;

@@ -916,6 +916,8 @@
     "aoppUnsupportedKeystore": "The connected device cannot sign messages for this asset.",
     "aoppVersion": "Unknown version.",
     "keystoreTimeout": "Wallet request expired. Please try again.",
+    "lightningInsufficientFunds": "Insufficient funds in your Lightning wallet.",
+    "lightningInvoiceAlreadyUsed": "This Lightning invoice was already used. Please request a new invoice.",
     "paymentApprovalRequired": "Payment fee increased. Please review and approve again.",
     "wrongKeystore": "Wrong wallet connected. Please make sure to insert the correct device matching this account.",
     "wrongKeystore2": " If you are using the optional passphrase, make sure you have entered the correct passphrase for the account."

@@ -14,7 +14,6 @@ export const ConfirmStep = () => {
   const {
     paymentDetails,
     paymentQuote,
-    returnToEditInvoice,
     sendPayment,
   } = useLightningSendContext();
 
@@ -23,10 +22,6 @@ export const ConfirmStep = () => {
   }
 
   const handleBack = () => {
-    if (!paymentDetails.invoice.amountSat) {
-      returnToEditInvoice();
-      return;
-    }
     navigate(-1);
   };
 

@@ -5,23 +5,39 @@ import { useTranslation } from 'react-i18next';
 import { TPaymentInputTypeVariant } from '@/api/lightning';
 import { Button, Input } from '@/components/forms';
 import { Column, Grid } from '@/components/layout';
+import { Status } from '@/components/status/status';
 import { View, ViewButtons, ViewContent } from '@/components/view/view';
 import { useLightningSendContext } from '../lightning-send-context';
+import { PaymentFeeDetails } from './invoice-details';
 
 export const EditInvoiceStep = () => {
   const { t } = useTranslation();
   const {
     customAmount,
+    customPrepareState,
     paymentDetails,
-    preparePayment,
     resetPayment,
+    sendPayment,
     setCustomAmount,
   } = useLightningSendContext();
 
   if (paymentDetails?.type !== TPaymentInputTypeVariant.BOLT11) {
     return null;
   }
 
+  const currentQuote = customPrepareState.status === 'success' && customPrepareState.amountSat === customAmount
+    ? customPrepareState.quote
+    : undefined;
+  const errorQuote = customPrepareState.status === 'error' && customPrepareState.amountSat === customAmount
+    ? customPrepareState.quote
+    : undefined;
+  const isPreparing = customPrepareState.status === 'loading' && customPrepareState.amountSat === customAmount;
+  const prepareError = customPrepareState.status === 'error' && customPrepareState.amountSat === customAmount
+    ? customPrepareState.error
+    : undefined;
+  const displayedQuote = currentQuote || errorQuote;
+  const showQuote = isPreparing || displayedQuote;
+
   return (
     <View fitContent minHeight="100%">
       <ViewContent>
@@ -33,7 +49,10 @@ export const EditInvoiceStep = () => {
               label={t('lightning.receive.amountSats.label')}
               placeholder={t('lightning.receive.amountSats.placeholder')}
               id="amountSatsInput"
-              onInput={(event: ChangeEvent<HTMLInputElement>) => setCustomAmount(event.target.valueAsNumber)}
+              onInput={(event: ChangeEvent<HTMLInputElement>) => {
+                const amount = event.target.valueAsNumber;
+                setCustomAmount(Number.isNaN(amount) ? undefined : amount);
+              }}
               value={customAmount ? `${customAmount}` : ''}
               autoFocus
             />
@@ -46,15 +65,19 @@ export const EditInvoiceStep = () => {
               disabled
               value={paymentDetails.invoice.description || ''}
             />
+            <Status dismissibleKey="" type="error" hidden={!prepareError}>
+              {prepareError}
+            </Status>
+            {showQuote && <PaymentFeeDetails quote={displayedQuote} />}
           </Column>
         </Grid>
       </ViewContent>
       <ViewButtons>
         <Button
           primary
-          onClick={preparePayment}
-          disabled={!customAmount}>
-          {t('button.continue')}
+          onClick={sendPayment}
+          disabled={!currentQuote}>
+          {t('generic.send')}
         </Button>
         <Button secondary onClick={resetPayment}>
           {t('button.back')}