feat: probe payment paths before LDK Node payments to improve routing

android/app/src/main/java/app/zeusln/zeus/LdkNodeModule.kt

@@ -1297,6 +1297,48 @@ class LdkNodeModule(reactContext: ReactApplicationContext) : ReactContextBaseJav
         }
     }
 
+    // Probe Methods
+
+    @ReactMethod
+    fun sendBolt11Probes(invoice: String, maxTotalRoutingFeeMsat: Double, maxPathCount: Double, promise: Promise) {
+        val routeParams = buildRouteParameters(maxTotalRoutingFeeMsat, maxPathCount)
+        moduleScope.launch {
+            try {
+                val node = this@LdkNodeModule.node ?: throw Exception("Node not initialized")
+                val bolt11 = node.bolt11Payment()
+                val invoiceObj = Bolt11Invoice.fromStr(invoice)
+                bolt11.sendProbes(invoiceObj, routeParams)
+                withContext(Dispatchers.Main) {
+                    promise.resolve(null)
+                }
+            } catch (e: Exception) {
+                withContext(Dispatchers.Main) {
+                    promise.reject("error", errorMessage(e))
+                }
+            }
+        }
+    }
+
+    @ReactMethod
+    fun sendBolt11ProbesUsingAmount(invoice: String, amountMsat: Double, maxTotalRoutingFeeMsat: Double, maxPathCount: Double, promise: Promise) {
+        val routeParams = buildRouteParameters(maxTotalRoutingFeeMsat, maxPathCount)
+        moduleScope.launch {
+            try {
+                val node = this@LdkNodeModule.node ?: throw Exception("Node not initialized")
+                val bolt11 = node.bolt11Payment()
+                val invoiceObj = Bolt11Invoice.fromStr(invoice)
+                bolt11.sendProbesUsingAmount(invoiceObj, amountMsat.toLong().toULong(), routeParams)
+                withContext(Dispatchers.Main) {
+                    promise.resolve(null)
+                }
+            } catch (e: Exception) {
+                withContext(Dispatchers.Main) {
+                    promise.reject("error", errorMessage(e))
+                }
+            }
+        }
+    }
+
     // Spontaneous Payment Methods
 
     @ReactMethod

ios/LdkNodeMobile/LdkNodeModule.m

@@ -65,6 +65,10 @@ RCT_EXTERN_METHOD(receiveVariableAmountBolt11:(NSString *)invoiceDescription exp
 RCT_EXTERN_METHOD(sendBolt11:(NSString *)invoice maxTotalRoutingFeeMsat:(double)maxTotalRoutingFeeMsat maxPathCount:(double)maxPathCount resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject)
 RCT_EXTERN_METHOD(sendBolt11UsingAmount:(NSString *)invoice amountMsat:(double)amountMsat maxTotalRoutingFeeMsat:(double)maxTotalRoutingFeeMsat maxPathCount:(double)maxPathCount resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject)
 
+// Probe Methods
+RCT_EXTERN_METHOD(sendBolt11Probes:(NSString *)invoice maxTotalRoutingFeeMsat:(double)maxTotalRoutingFeeMsat maxPathCount:(double)maxPathCount resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject)
+RCT_EXTERN_METHOD(sendBolt11ProbesUsingAmount:(NSString *)invoice amountMsat:(double)amountMsat maxTotalRoutingFeeMsat:(double)maxTotalRoutingFeeMsat maxPathCount:(double)maxPathCount resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject)
+
 // Spontaneous Payment Methods
 RCT_EXTERN_METHOD(sendSpontaneousPayment:(NSString *)nodeId amountMsat:(double)amountMsat maxTotalRoutingFeeMsat:(double)maxTotalRoutingFeeMsat maxPathCount:(double)maxPathCount resolver:(RCTPromiseResolveBlock)resolve rejecter:(RCTPromiseRejectBlock)reject)
 

ios/LdkNodeMobile/LdkNodeModule.swift

@@ -1157,6 +1157,50 @@ class LdkNodeModule: RCTEventEmitter {
         }
     }
 
+    // MARK: - Probe Methods
+
+    @objc(sendBolt11Probes:maxTotalRoutingFeeMsat:maxPathCount:resolver:rejecter:)
+    func sendBolt11Probes(_ invoice: String, maxTotalRoutingFeeMsat: Double, maxPathCount: Double, resolver resolve: @escaping RCTPromiseResolveBlock, rejecter reject: @escaping RCTPromiseRejectBlock) {
+        guard let node = self.getNode() else {
+            reject("error", "Node not initialized", nil)
+            return
+        }
+
+        let routeParams = buildRouteParameters(maxTotalRoutingFeeMsat: maxTotalRoutingFeeMsat, maxPathCount: maxPathCount)
+
+        DispatchQueue.global(qos: .userInitiated).async {
+            do {
+                let bolt11 = node.bolt11Payment()
+                let bolt11Invoice = try Bolt11Invoice.fromStr(invoiceStr: invoice)
+                try bolt11.sendProbes(invoice: bolt11Invoice, routeParameters: routeParams)
+                resolve(nil)
+            } catch {
+                reject("error", self.errorMessage(error), error)
+            }
+        }
+    }
+
+    @objc(sendBolt11ProbesUsingAmount:amountMsat:maxTotalRoutingFeeMsat:maxPathCount:resolver:rejecter:)
+    func sendBolt11ProbesUsingAmount(_ invoice: String, amountMsat: Double, maxTotalRoutingFeeMsat: Double, maxPathCount: Double, resolver resolve: @escaping RCTPromiseResolveBlock, rejecter reject: @escaping RCTPromiseRejectBlock) {
+        guard let node = self.getNode() else {
+            reject("error", "Node not initialized", nil)
+            return
+        }
+
+        let routeParams = buildRouteParameters(maxTotalRoutingFeeMsat: maxTotalRoutingFeeMsat, maxPathCount: maxPathCount)
+
+        DispatchQueue.global(qos: .userInitiated).async {
+            do {
+                let bolt11 = node.bolt11Payment()
+                let bolt11Invoice = try Bolt11Invoice.fromStr(invoiceStr: invoice)
+                try bolt11.sendProbesUsingAmount(invoice: bolt11Invoice, amountMsat: UInt64(amountMsat), routeParameters: routeParams)
+                resolve(nil)
+            } catch {
+                reject("error", self.errorMessage(error), error)
+            }
+        }
+    }
+
     // MARK: - Spontaneous Payment Methods
 
     @objc(sendSpontaneousPayment:amountMsat:maxTotalRoutingFeeMsat:maxPathCount:resolver:rejecter:)

ldknode/LdkNode.d.ts

@@ -565,6 +565,19 @@ export interface ILdkNodeModule {
         maxPathCount: number
     ): Promise<string>;
 
+    // Probe Methods
+    sendBolt11Probes(
+        invoice: string,
+        maxTotalRoutingFeeMsat: number,
+        maxPathCount: number
+    ): Promise<void>;
+    sendBolt11ProbesUsingAmount(
+        invoice: string,
+        amountMsat: number,
+        maxTotalRoutingFeeMsat: number,
+        maxPathCount: number
+    ): Promise<void>;
+
     // Spontaneous Payment Methods
     sendSpontaneousPayment(
         nodeId: string,

ldknode/LdkNodeInjection.ts

@@ -464,6 +464,45 @@ const sendBolt11UsingAmount = async ({
     return result.paymentId;
 };
 
+// ============================================================================
+// Probe Functions
+// ============================================================================
+
+const sendBolt11Probes = async ({
+    invoice,
+    maxTotalRoutingFeeMsat,
+    maxPathCount
+}: {
+    invoice: string;
+    maxTotalRoutingFeeMsat?: number;
+    maxPathCount?: number;
+}): Promise<void> => {
+    await LdkNodeModule.sendBolt11Probes(
+        invoice,
+        maxTotalRoutingFeeMsat ?? -1,
+        maxPathCount ?? -1
+    );
+};
+
+const sendBolt11ProbesUsingAmount = async ({
+    invoice,
+    amountMsat,
+    maxTotalRoutingFeeMsat,
+    maxPathCount
+}: {
+    invoice: string;
+    amountMsat: number;
+    maxTotalRoutingFeeMsat?: number;
+    maxPathCount?: number;
+}): Promise<void> => {
+    await LdkNodeModule.sendBolt11ProbesUsingAmount(
+        invoice,
+        amountMsat,
+        maxTotalRoutingFeeMsat ?? -1,
+        maxPathCount ?? -1
+    );
+};
+
 // ============================================================================
 // Spontaneous Payment Functions
 // ============================================================================
@@ -1062,6 +1101,17 @@ export interface ILdkNodeInjections {
             maxTotalRoutingFeeMsat?: number;
             maxPathCount?: number;
         }) => Promise<string>;
+        sendBolt11Probes: (params: {
+            invoice: string;
+            maxTotalRoutingFeeMsat?: number;
+            maxPathCount?: number;
+        }) => Promise<void>;
+        sendBolt11ProbesUsingAmount: (params: {
+            invoice: string;
+            amountMsat: number;
+            maxTotalRoutingFeeMsat?: number;
+            maxPathCount?: number;
+        }) => Promise<void>;
     };
     spontaneous: {
         sendSpontaneousPayment: (params: {
@@ -1237,7 +1287,9 @@ const LdkNodeInjection: ILdkNodeInjections = {
         receiveBolt11,
         receiveVariableAmountBolt11,
         sendBolt11,
-        sendBolt11UsingAmount
+        sendBolt11UsingAmount,
+        sendBolt11Probes,
+        sendBolt11ProbesUsingAmount
     },
     spontaneous: {
         sendSpontaneousPayment

stores/InvoicesStore.ts

@@ -14,6 +14,7 @@ import LSPStore from './LSPStore';
 import BackendUtils from '../utils/BackendUtils';
 import { localeString } from '../utils/LocaleUtils';
 import { errorToUserFriendly } from '../utils/ErrorUtils';
+import LdkNodeInjection from '../ldknode/LdkNodeInjection';
 import ChannelsStore from './ChannelsStore';
 import NodeInfoStore from './NodeInfoStore';
 import WithdrawalRequest from '../models/WithdrawalRequest';
@@ -70,6 +71,14 @@ export default class InvoicesStore {
                         this.pay_req.getRequestAmount
                     );
                 }
+                // Send probes for LDK Node to warm up the scorer
+                // while the user reviews the payment request
+                if (
+                    this.pay_req &&
+                    this.settingsStore.implementation === 'ldk-node'
+                ) {
+                    this.sendLdkProbes();
+                }
             }
         );
     }
@@ -760,4 +769,24 @@ export default class InvoicesStore {
             })
             .catch(() => this.getRoutesError());
     };
+
+    /**
+     * Send probes along the payment path for LDK Node.
+     * This warms up the probabilistic scorer so the actual
+     * payment has better routing information. Fire-and-forget.
+     * Only probes fixed-amount invoices — variable-amount
+     * invoices can't be probed without knowing the amount.
+     */
+    private sendLdkProbes = async () => {
+        try {
+            const amount = this.pay_req?.getRequestAmount;
+            if (!amount || Number(amount) <= 0) return;
+
+            await LdkNodeInjection.bolt11.sendBolt11Probes({
+                invoice: this.paymentRequest
+            });
+        } catch {
+            // Probe failures are expected and non-fatal
+        }
+    };
 }