feat: add custom message support for subwallet transfers

- Add optional message field to TransferRequest model
- Update Transfer function to use custom message with 'transfer' as fallback
- Update HTTP and Wails handlers to extract and pass message parameter
- Add message input field to IsolatedAppTopupDialog and IsolatedAppDrawDownDialog
- Maintains backward compatibility with empty message defaulting to 'transfer'

Closes #2066

Author: naveenkumar29052006

api/models.go

@@ -14,7 +14,7 @@ import (
 type API interface {
 	CreateApp(createAppRequest *CreateAppRequest) (*CreateAppResponse, error)
 	UpdateApp(app *db.App, updateAppRequest *UpdateAppRequest) error
-	Transfer(ctx context.Context, fromAppId *uint, toAppId *uint, amountMsat uint64) error
+	Transfer(ctx context.Context, fromAppId *uint, toAppId *uint, amountMsat uint64, message string) error
 	DeleteApp(app *db.App) error
 	GetApp(app *db.App) *App
 	ListApps(limit uint64, offset uint64, filters ListAppsFilters, orderBy string) (*ListAppsResponse, error)
@@ -129,9 +129,10 @@ type UpdateAppRequest struct {
 }
 
 type TransferRequest struct {
-	AmountSat uint64 `json:"amountSat"`
-	FromAppId *uint  `json:"fromAppId"`
-	ToAppId   *uint  `json:"toAppId"`
+	AmountSat uint64  `json:"amountSat"`
+	FromAppId *uint   `json:"fromAppId"`
+	ToAppId   *uint   `json:"toAppId"`
+	Message   *string `json:"message"`
 }
 
 type CreateAppRequest struct {

api/transactions.go

@@ -127,7 +127,7 @@ func toApiTransaction(transaction *transactions.Transaction) *Transaction {
 	}
 }
 
-func (api *api) Transfer(ctx context.Context, fromAppId *uint, toAppId *uint, amountMsat uint64) error {
+func (api *api) Transfer(ctx context.Context, fromAppId *uint, toAppId *uint, amountMsat uint64, message string) error {
 	if api.svc.GetLNClient() == nil {
 		return errors.New("LNClient not started")
 	}
@@ -144,7 +144,13 @@ func (api *api) Transfer(ctx context.Context, fromAppId *uint, toAppId *uint, am
 		}
 	}
 
-	transaction, err := api.svc.GetTransactionsService().MakeInvoice(ctx, amountMsat, "transfer", "", 0, nil, api.svc.GetLNClient(), toAppId, nil, nil)
+	// Use custom message or default to "transfer"
+	description := message
+	if description == "" {
+		description = "transfer"
+	}
+
+	transaction, err := api.svc.GetTransactionsService().MakeInvoice(ctx, amountMsat, description, "", 0, nil, api.svc.GetLNClient(), toAppId, nil, nil)
 
 	if err != nil {
 		return err

frontend/src/components/IsolatedAppDrawDownDialog.tsx

@@ -26,6 +26,7 @@ export function IsolatedAppDrawDownDialog({
 }: React.PropsWithChildren<IsolatedAppTopupProps>) {
   const { mutate: reloadApp } = useApp(appId);
   const [amountSat, setAmountSat] = React.useState("");
+  const [message, setMessage] = React.useState("");
   const [loading, setLoading] = React.useState(false);
   const [open, setOpen] = React.useState(false);
   async function onSubmit(e: React.FormEvent) {
@@ -40,6 +41,7 @@ export function IsolatedAppDrawDownDialog({
         body: JSON.stringify({
           fromAppId: appId,
           amountSat: +amountSat,
+          ...(message && { message }), // Only include if not empty
         }),
       });
       await reloadApp();
@@ -54,6 +56,7 @@ export function IsolatedAppDrawDownDialog({
   function reset() {
     setOpen(false);
     setAmountSat("");
+    setMessage("");
   }
 
   return (
@@ -80,6 +83,18 @@ export function IsolatedAppDrawDownDialog({
               }}
             />
           </div>
+          <div className="grid gap-2 mt-3">
+            <Label htmlFor="message">Message (optional)</Label>
+            <Input
+              id="message"
+              type="text"
+              placeholder="e.g., Returning unused funds"
+              value={message}
+              onChange={(e) => {
+                setMessage(e.target.value);
+              }}
+            />
+          </div>
           <DialogFooter className="mt-5">
             <LoadingButton loading={loading}>Decrease</LoadingButton>
           </DialogFooter>

frontend/src/components/IsolatedAppTopupDialog.tsx

@@ -26,6 +26,7 @@ export function IsolatedAppTopupDialog({
 }: React.PropsWithChildren<IsolatedAppTopupProps>) {
   const { mutate: reloadApp } = useApp(appId);
   const [amountSat, setAmountSat] = React.useState("");
+  const [message, setMessage] = React.useState("");
   const [loading, setLoading] = React.useState(false);
   const [open, setOpen] = React.useState(false);
   async function onSubmit(e: React.FormEvent) {
@@ -40,6 +41,7 @@ export function IsolatedAppTopupDialog({
         body: JSON.stringify({
           toAppId: appId,
           amountSat: +amountSat,
+          ...(message && { message }), // Only include if not empty
         }),
       });
       await reloadApp();
@@ -54,6 +56,7 @@ export function IsolatedAppTopupDialog({
   function reset() {
     setOpen(false);
     setAmountSat("");
+    setMessage("");
   }
 
   return (
@@ -82,6 +85,18 @@ export function IsolatedAppTopupDialog({
               }}
             />
           </div>
+          <div className="grid gap-2 mt-3">
+            <Label htmlFor="message">Message (optional)</Label>
+            <Input
+              id="message"
+              type="text"
+              placeholder="e.g., Weekly allowance"
+              value={message}
+              onChange={(e) => {
+                setMessage(e.target.value);
+              }}
+            />
+          </div>
           <DialogFooter className="mt-5">
             <LoadingButton loading={loading}>Increase</LoadingButton>
           </DialogFooter>

http/http_service.go

@@ -1120,7 +1120,12 @@ func (httpSvc *HttpService) transfersHandler(c echo.Context) error {
 		})
 	}
 
-	err := httpSvc.api.Transfer(c.Request().Context(), requestData.FromAppId, requestData.ToAppId, requestData.AmountSat*1000)
+	message := ""
+	if requestData.Message != nil {
+		message = *requestData.Message
+	}
+
+	err := httpSvc.api.Transfer(c.Request().Context(), requestData.FromAppId, requestData.ToAppId, requestData.AmountSat*1000, message)
 
 	if err != nil {
 		logger.Logger.WithError(err).Error("Failed to transfer funds")

wails/wails_handlers.go

@@ -358,7 +358,13 @@ func (app *WailsApp) WailsRequestRouter(route string, method string, body string
 			}).WithError(err).Error("Failed to decode request to wails router")
 			return WailsRequestRouterResponse{Body: nil, Error: err.Error()}
 		}
-		err = app.api.Transfer(ctx, transferRequest.FromAppId, transferRequest.ToAppId, transferRequest.AmountSat*1000)
+
+		message := ""
+		if transferRequest.Message != nil {
+			message = *transferRequest.Message
+		}
+
+		err = app.api.Transfer(ctx, transferRequest.FromAppId, transferRequest.ToAppId, transferRequest.AmountSat*1000, message)
 		if err != nil {
 			return WailsRequestRouterResponse{Body: nil, Error: err.Error()}
 		}