expected fees

proto/autogenerated/client.md

@@ -1472,12 +1472,14 @@ The nostr server will send back a message response, and inside the body there wi
 ### PayAppUserInvoiceRequest
   - __amount__: _number_
   - __debit_npub__: _string_ *this field is optional
+  - __expected_fees__: _[CumulativeFees](#CumulativeFees)_ *this field is optional
   - __invoice__: _string_
   - __user_identifier__: _string_
 
 ### PayInvoiceRequest
   - __amount__: _number_
   - __debit_npub__: _string_ *this field is optional
+  - __expected_fees__: _[CumulativeFees](#CumulativeFees)_ *this field is optional
   - __invoice__: _string_
 
 ### PayInvoiceResponse

proto/autogenerated/go/types.go

@@ -555,15 +555,17 @@ type PayAddressResponse struct {
 	Txid         string `json:"txId"`
 }
 type PayAppUserInvoiceRequest struct {
-	Amount          int64  `json:"amount"`
-	Debit_npub      string `json:"debit_npub"`
-	Invoice         string `json:"invoice"`
-	User_identifier string `json:"user_identifier"`
+	Amount          int64           `json:"amount"`
+	Debit_npub      string          `json:"debit_npub"`
+	Expected_fees   *CumulativeFees `json:"expected_fees"`
+	Invoice         string          `json:"invoice"`
+	User_identifier string          `json:"user_identifier"`
 }
 type PayInvoiceRequest struct {
-	Amount     int64  `json:"amount"`
-	Debit_npub string `json:"debit_npub"`
-	Invoice    string `json:"invoice"`
+	Amount        int64           `json:"amount"`
+	Debit_npub    string          `json:"debit_npub"`
+	Expected_fees *CumulativeFees `json:"expected_fees"`
+	Invoice       string          `json:"invoice"`
 }
 type PayInvoiceResponse struct {
 	Amount_paid    int64  `json:"amount_paid"`

proto/autogenerated/ts/types.ts

@@ -3262,15 +3262,17 @@ export const PayAddressResponseValidate = (o?: PayAddressResponse, opts: PayAddr
 export type PayAppUserInvoiceRequest = {
     amount: number
     debit_npub?: string
+    expected_fees?: CumulativeFees
     invoice: string
     user_identifier: string
 }
-export type PayAppUserInvoiceRequestOptionalField = 'debit_npub'
-export const PayAppUserInvoiceRequestOptionalFields: PayAppUserInvoiceRequestOptionalField[] = ['debit_npub']
+export type PayAppUserInvoiceRequestOptionalField = 'debit_npub' | 'expected_fees'
+export const PayAppUserInvoiceRequestOptionalFields: PayAppUserInvoiceRequestOptionalField[] = ['debit_npub', 'expected_fees']
 export type PayAppUserInvoiceRequestOptions = OptionsBaseMessage & {
     checkOptionalsAreSet?: PayAppUserInvoiceRequestOptionalField[]
     amount_CustomCheck?: (v: number) => boolean
     debit_npub_CustomCheck?: (v?: string) => boolean
+    expected_fees_Options?: CumulativeFeesOptions
     invoice_CustomCheck?: (v: string) => boolean
     user_identifier_CustomCheck?: (v: string) => boolean
 }
@@ -3284,6 +3286,12 @@ export const PayAppUserInvoiceRequestValidate = (o?: PayAppUserInvoiceRequest, o
     if ((o.debit_npub || opts.allOptionalsAreSet || opts.checkOptionalsAreSet?.includes('debit_npub')) && typeof o.debit_npub !== 'string') return new Error(`${path}.debit_npub: is not a string`)
     if (opts.debit_npub_CustomCheck && !opts.debit_npub_CustomCheck(o.debit_npub)) return new Error(`${path}.debit_npub: custom check failed`)
 
+    if (typeof o.expected_fees === 'object' || opts.allOptionalsAreSet || opts.checkOptionalsAreSet?.includes('expected_fees')) {
+        const expected_feesErr = CumulativeFeesValidate(o.expected_fees, opts.expected_fees_Options, `${path}.expected_fees`)
+        if (expected_feesErr !== null) return expected_feesErr
+    }
+    
+
     if (typeof o.invoice !== 'string') return new Error(`${path}.invoice: is not a string`)
     if (opts.invoice_CustomCheck && !opts.invoice_CustomCheck(o.invoice)) return new Error(`${path}.invoice: custom check failed`)
 
@@ -3296,14 +3304,16 @@ export const PayAppUserInvoiceRequestValidate = (o?: PayAppUserInvoiceRequest, o
 export type PayInvoiceRequest = {
     amount: number
     debit_npub?: string
+    expected_fees?: CumulativeFees
     invoice: string
 }
-export type PayInvoiceRequestOptionalField = 'debit_npub'
-export const PayInvoiceRequestOptionalFields: PayInvoiceRequestOptionalField[] = ['debit_npub']
+export type PayInvoiceRequestOptionalField = 'debit_npub' | 'expected_fees'
+export const PayInvoiceRequestOptionalFields: PayInvoiceRequestOptionalField[] = ['debit_npub', 'expected_fees']
 export type PayInvoiceRequestOptions = OptionsBaseMessage & {
     checkOptionalsAreSet?: PayInvoiceRequestOptionalField[]
     amount_CustomCheck?: (v: number) => boolean
     debit_npub_CustomCheck?: (v?: string) => boolean
+    expected_fees_Options?: CumulativeFeesOptions
     invoice_CustomCheck?: (v: string) => boolean
 }
 export const PayInvoiceRequestValidate = (o?: PayInvoiceRequest, opts: PayInvoiceRequestOptions = {}, path: string = 'PayInvoiceRequest::root.'): Error | null => {
@@ -3316,6 +3326,12 @@ export const PayInvoiceRequestValidate = (o?: PayInvoiceRequest, opts: PayInvoic
     if ((o.debit_npub || opts.allOptionalsAreSet || opts.checkOptionalsAreSet?.includes('debit_npub')) && typeof o.debit_npub !== 'string') return new Error(`${path}.debit_npub: is not a string`)
     if (opts.debit_npub_CustomCheck && !opts.debit_npub_CustomCheck(o.debit_npub)) return new Error(`${path}.debit_npub: custom check failed`)
 
+    if (typeof o.expected_fees === 'object' || opts.allOptionalsAreSet || opts.checkOptionalsAreSet?.includes('expected_fees')) {
+        const expected_feesErr = CumulativeFeesValidate(o.expected_fees, opts.expected_fees_Options, `${path}.expected_fees`)
+        if (expected_feesErr !== null) return expected_feesErr
+    }
+    
+
     if (typeof o.invoice !== 'string') return new Error(`${path}.invoice: is not a string`)
     if (opts.invoice_CustomCheck && !opts.invoice_CustomCheck(o.invoice)) return new Error(`${path}.invoice: custom check failed`)
 

proto/service/structs.proto

@@ -390,6 +390,7 @@ message PayAppUserInvoiceRequest {
     string invoice = 2;
     int64 amount = 3;
     optional string debit_npub = 4; 
+    optional CumulativeFees expected_fees = 5;
 }
 
 message SendAppUserToAppUserPaymentRequest {
@@ -466,6 +467,7 @@ message PayInvoiceRequest{
     string invoice = 1;
     int64 amount = 2;
     optional string debit_npub = 3; 
+    optional CumulativeFees expected_fees = 4;
 }
 
 message PayInvoiceResponse{

src/services/main/appUserManager.ts

@@ -107,6 +107,7 @@ export default class {
             invoice: req.invoice,
             user_identifier: ctx.app_user_id,
             debit_npub: req.debit_npub,
+            expected_fees: req.expected_fees,
         })
     }
 

src/services/main/liquidityProvider.ts

@@ -170,8 +170,8 @@ export class LiquidityProvider {
         return Object.values(this.pendingPayments).reduce((a, b) => a + b, 0)
     }
 
-    GetServiceFee = (amount: number) => {
-        const fees = this.GetFees()
+    GetServiceFee = (amount: number, f?: Types.CumulativeFees) => {
+        const fees = f ? f : this.GetFees()
         const serviceFeeRate = fees.serviceFeeBps / 10000
         const serviceFee = Math.ceil(serviceFeeRate * amount)
         return Math.max(serviceFee, fees.networkFeeFixed)
@@ -221,7 +221,8 @@ export class LiquidityProvider {
             if (!this.IsReady()) {
                 throw new Error("liquidity provider is not ready yet, disabled or unreachable")
             }
-            const providerServiceFee = this.GetServiceFee(decodedAmount)
+            const fees = this.GetFees()
+            const providerServiceFee = this.GetServiceFee(decodedAmount, fees)
             this.pendingPayments[invoice] = decodedAmount + providerServiceFee
             const timeout = setTimeout(() => {
                 if (!this.pendingPaymentsAck[invoice]) {
@@ -231,8 +232,9 @@ export class LiquidityProvider {
                 this.lastSeenBeacon = 0
             }, 1000 * 10)
             this.pendingPaymentsAck[invoice] = true
-            const res = await this.client.PayInvoice({ invoice, amount: 0 })
+            const res = await this.client.PayInvoice({ invoice, amount: 0, expected_fees: fees })
             delete this.pendingPaymentsAck[invoice]
+            clearTimeout(timeout)
             if (res.status === 'ERROR') {
                 this.log("error paying invoice", res.reason)
                 throw new Error(res.reason)

src/services/main/paymentManager.ts

@@ -273,6 +273,14 @@ export default class {
         if (maybeBanned.locked) {
             throw new Error("user is banned, cannot send payment")
         }
+        if (req.expected_fees) {
+            const { networkFeeFixed, serviceFeeBps } = req.expected_fees
+            const serviceFixed = this.settings.getSettings().lndSettings.feeFixedLimit
+            const serviceBps = this.settings.getSettings().serviceFeeSettings.outgoingAppUserInvoiceFeeBps
+            if (serviceFixed !== networkFeeFixed || serviceBps !== serviceFeeBps) {
+                throw new Error("fees do not match the expected fees")
+            }
+        }
         const decoded = await this.lnd.DecodeInvoice(req.invoice)
         if (decoded.numSatoshis !== 0 && req.amount !== 0) {
             throw new Error("invoice has value, do not provide amount the the request")