refactor: rename fiatAmount to fiatCents for clarity

The field was always stored in cents but the name was ambiguous.
Rename to fiatCents across state machine, store, and views.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/machine/src/stores/atm.ts

@@ -271,7 +271,7 @@ export const useAtmStore = defineStore('atm', () => {
           persistTransaction({
             txid: ctx.txid,
             type: isCashInTx ? 'cash_in' : 'cash_out',
-            fiatCents: ctx.fiatAmount,
+            fiatCents: ctx.fiatCents,
             sats: ctx.satsAmount,
             bills,
           })
@@ -626,7 +626,7 @@ export const useAtmStore = defineStore('atm', () => {
           }
 
           // Calculate what the new sats amount would be
-          const newFiatCents = ctx.fiatAmount + denomination * 100
+          const newFiatCents = ctx.fiatCents + denomination * 100
           const newFiatUnits = newFiatCents / 100
           const grossSats = Math.floor(newFiatUnits * ctx.exchangeRate)
           const fee = Math.floor(grossSats * ctx.feePercent)
@@ -846,7 +846,7 @@ export const useAtmStore = defineStore('atm', () => {
         }
 
         // Calculate if this bill would exceed available balance
-        const newFiatCents = ctx.fiatAmount + denomination * 100
+        const newFiatCents = ctx.fiatCents + denomination * 100
         const newFiatUnits = newFiatCents / 100
         const grossSats = Math.floor(newFiatUnits * ctx.exchangeRate)
         const fee = Math.floor(grossSats * ctx.feePercent)

apps/machine/src/views/CashInView.vue

@@ -119,7 +119,7 @@ function canAcceptBill(denomination: number): boolean {
   const ctx = context.value
   if (!ctx) return false
   if (ctx.availableBalance <= 0 || ctx.exchangeRate === 0) return true
-  const newFiatCents = ctx.fiatAmount + denomination * 100
+  const newFiatCents = ctx.fiatCents + denomination * 100
   const grossSats = Math.floor((newFiatCents / 100) * ctx.exchangeRate)
   const fee = Math.floor(grossSats * ctx.feePercent)
   return grossSats - fee <= ctx.availableBalance
@@ -214,7 +214,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice)
             <!-- Amount display -->
             <div v-if="context">
               <p class="text-3xl lg:text-[6vh] font-bold text-success leading-tight">
-                {{ atmStore.fiatSymbol }}{{ (context.fiatAmount / 100).toFixed(2) }}
+                {{ atmStore.fiatSymbol }}{{ (context.fiatCents / 100).toFixed(2) }}
               </p>
               <p class="text-xl lg:text-[3.5vh] font-semibold text-bitcoin">
                 {{ formatSats(context.satsAmount) }} sats
@@ -322,7 +322,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice)
               {{ formatSats(context?.satsAmount || 0) }} sats
             </p>
             <p class="text-lg lg:text-2xl text-muted-foreground">
-              {{ atmStore.fiatSymbol }}{{ ((context?.fiatAmount || 0) / 100).toFixed(2) }}
+              {{ atmStore.fiatSymbol }}{{ ((context?.fiatCents || 0) / 100).toFixed(2) }}
             </p>
 
             <!-- Waiting indicator -->
@@ -388,7 +388,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice)
           <h3 class="text-2xl lg:text-[3rem] font-bold text-destructive">Cash Already Accepted</h3>
           <p class="max-w-lg text-center text-base lg:text-2xl text-muted-foreground">
             Your {{ atmStore.fiatSymbol
-            }}{{ context ? (context.fiatAmount / 100).toLocaleString() : '' }} has been accepted and
+            }}{{ context ? (context.fiatCents / 100).toLocaleString() : '' }} has been accepted and
             cannot be returned. Please scan the QR code to receive your Bitcoin.
           </p>
           <Button
@@ -428,7 +428,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice)
               <div class="flex justify-between text-base lg:text-2xl">
                 <span class="text-muted-foreground">Inserted</span>
                 <span class="font-semibold"
-                  >{{ atmStore.fiatSymbol }}{{ (context.fiatAmount / 100).toFixed(2) }}</span
+                  >{{ atmStore.fiatSymbol }}{{ (context.fiatCents / 100).toFixed(2) }}</span
                 >
               </div>
               <div class="flex justify-between text-base lg:text-2xl">
@@ -445,7 +445,7 @@ const isProcessing = computed(() => atmStore.isPayingInvoice)
                   >{{
                     formatSats(
                       Math.floor(
-                        Math.floor((context.fiatAmount / 100) * context.exchangeRate) *
+                        Math.floor((context.fiatCents / 100) * context.exchangeRate) *
                           context.feePercent
                       )
                     )

apps/machine/src/views/CashOutView.vue

@@ -211,7 +211,7 @@ function formatFiat(cents: number): string {
           <div class="text-center py-2 lg:py-4">
             <p class="text-sm lg:text-xl text-muted-foreground">You will receive</p>
             <p class="text-4xl lg:text-[7vh] font-bold text-success leading-tight">
-              {{ atmStore.fiatSymbol }}{{ context ? formatFiat(context.fiatAmount) : '0.00' }}
+              {{ atmStore.fiatSymbol }}{{ context ? formatFiat(context.fiatCents) : '0.00' }}
             </p>
             <p class="mt-1 lg:mt-2 text-lg lg:text-2xl text-muted-foreground">
               You pay:
@@ -291,7 +291,7 @@ function formatFiat(cents: number): string {
             <p class="text-lg lg:text-2xl text-muted-foreground">
               to receive
               <Badge class="bg-success text-success-foreground text-lg lg:text-2xl">
-                {{ atmStore.fiatSymbol }}{{ context ? formatFiat(context.fiatAmount) : '0.00' }}
+                {{ atmStore.fiatSymbol }}{{ context ? formatFiat(context.fiatCents) : '0.00' }}
               </Badge>
             </p>
 
@@ -363,7 +363,7 @@ function formatFiat(cents: number): string {
           <p v-if="context" class="text-lg lg:text-2xl">
             Please take your
             <Badge class="bg-success text-success-foreground text-2xl"
-              >{{ atmStore.fiatSymbol }}{{ formatFiat(context.fiatAmount) }}</Badge
+              >{{ atmStore.fiatSymbol }}{{ formatFiat(context.fiatCents) }}</Badge
             >
           </p>
           <Button
@@ -411,7 +411,7 @@ function formatFiat(cents: number): string {
                     formatSats(
                       Math.abs(
                         context.satsAmount -
-                          Math.floor((context.fiatAmount / 100) * context.exchangeRate)
+                          Math.floor((context.fiatCents / 100) * context.exchangeRate)
                       )
                     )
                   }}
@@ -422,7 +422,7 @@ function formatFiat(cents: number): string {
               <div class="flex justify-between text-xl lg:text-[1.8rem] font-bold">
                 <span class="text-success">Cash received</span>
                 <span class="text-success"
-                  >{{ atmStore.fiatSymbol }}{{ formatFiat(context.fiatAmount) }}</span
+                  >{{ atmStore.fiatSymbol }}{{ formatFiat(context.fiatCents) }}</span
                 >
               </div>
             </div>

packages/state-machine/src/__tests__/machine.test.ts

@@ -39,7 +39,7 @@ describe('ATM State Machine', () => {
       actor.start()
 
       const context = actor.getSnapshot().context
-      expect(context.fiatAmount).toBe(0)
+      expect(context.fiatCents).toBe(0)
       expect(context.satsAmount).toBe(0)
       expect(context.billsInserted).toEqual([])
       expect(context.error).toBeNull()
@@ -78,7 +78,7 @@ describe('ATM State Machine', () => {
 
       const context = actor.getSnapshot().context
       expect(context.billsInserted).toEqual([20, 10])
-      expect(context.fiatAmount).toBe(3000) // $30 in cents
+      expect(context.fiatCents).toBe(3000) // $30 in cents
     })
 
     it('should return to idle on CANCEL', async () => {
@@ -141,14 +141,14 @@ describe('ATM State Machine', () => {
 
       let state = actor.getSnapshot()
       expect(state.context.cashOutSelection).toEqual([20, 20, 20])
-      expect(state.context.fiatAmount).toBe(6000) // $60 in cents
+      expect(state.context.fiatCents).toBe(6000) // $60 in cents
 
       // Remove one
       actor.send({ type: 'REMOVE_DENOMINATION', denomination: 20 })
 
       state = actor.getSnapshot()
       expect(state.context.cashOutSelection).toEqual([20, 20])
-      expect(state.context.fiatAmount).toBe(4000) // $40 in cents
+      expect(state.context.fiatCents).toBe(4000) // $40 in cents
     })
 
     it('should calculate sats amount from fiat with fee', async () => {
@@ -164,8 +164,8 @@ describe('ATM State Machine', () => {
 
       const state = actor.getSnapshot()
       // $20 at 2500 sats/USD = 50,000 sats
-      // Plus 2% fee = 51,000 sats
+      // Plus 7.77% cash-out fee = floor(50000 * 0.0777) = 3,885 → 53,885 sats
-      expect(state.context.satsAmount).toBe(51000)
+      expect(state.context.satsAmount).toBe(53885)
     })
 
     it('should generate invoice after confirming amount', async () => {
@@ -396,7 +396,7 @@ describe('ATM State Machine', () => {
       actor.send({ type: 'RETRY' })
       await new Promise((resolve) => setTimeout(resolve, 50))
 
-      // Should have retried and succeeded
+      // Rate fetch failed → retry goes to fetchingRate → succeeds → insertingBills
       const state = actor.getSnapshot()
       expect(state.value).toMatchObject({ cashIn: 'insertingBills' })
     })

packages/state-machine/src/machine.ts

@@ -180,17 +180,16 @@ export function createATMMachine(
           if (event.type !== 'BILL_INSERTED') return context.billsInserted
           return [...context.billsInserted, event.denomination]
         },
-        fiatAmount: ({ context, event }) => {
+        fiatCents: ({ context, event }) => {
-          if (event.type !== 'BILL_INSERTED') return context.fiatAmount
+          if (event.type !== 'BILL_INSERTED') return context.fiatCents
-          // denomination is in dollars, fiatAmount is in cents
+          return context.fiatCents + event.denomination * 100
-          return context.fiatAmount + event.denomination * 100
         },
       }),
       calculateSats: assign({
         satsAmount: ({ context }) => {
           if (context.exchangeRate === 0) return 0
-          const fiatUnits = context.fiatAmount / 100 // cents to dollars
+          const fiatDollars = context.fiatCents / 100
-          const grossSats = Math.floor(fiatUnits * context.exchangeRate)
+          const grossSats = Math.floor(fiatDollars * context.exchangeRate)
           const fee = Math.floor(grossSats * context.feePercent)
           return grossSats - fee
         },
@@ -200,7 +199,7 @@ export function createATMMachine(
           // Calculate bills to dispense for cash-out
           // Simple algorithm: use largest denominations first
           const denominations = [100, 50, 20, 10, 5, 1]
-          let remaining = context.fiatAmount / 100 // cents to dollars
+          let remaining = context.fiatCents / 100
           const amounts: { denomination: number; count: number }[] = []
 
           for (const denom of denominations) {
@@ -278,7 +277,7 @@ export function createATMMachine(
         },
       }),
       setAmount: assign({
-        fiatAmount: ({ event }) => {
+        fiatCents: ({ event }) => {
           if (event.type !== 'SELECT_AMOUNT') return 0
           return event.amount * 100 // dollars to cents
         },
@@ -296,9 +295,9 @@ export function createATMMachine(
           if (event.type !== 'ADD_DENOMINATION') return context.cashOutSelection
           return [...context.cashOutSelection, event.denomination]
         },
-        fiatAmount: ({ context, event }) => {
+        fiatCents: ({ context, event }) => {
-          if (event.type !== 'ADD_DENOMINATION') return context.fiatAmount
+          if (event.type !== 'ADD_DENOMINATION') return context.fiatCents
-          return context.fiatAmount + event.denomination * 100 // dollars to cents
+          return context.fiatCents + event.denomination * 100
         },
       }),
       removeDenomination: assign({
@@ -310,21 +309,21 @@ export function createATMMachine(
           newSelection.splice(idx, 1)
           return newSelection
         },
-        fiatAmount: ({ context, event }) => {
+        fiatCents: ({ context, event }) => {
-          if (event.type !== 'REMOVE_DENOMINATION') return context.fiatAmount
+          if (event.type !== 'REMOVE_DENOMINATION') return context.fiatCents
-          if (!context.cashOutSelection.includes(event.denomination)) return context.fiatAmount
+          if (!context.cashOutSelection.includes(event.denomination)) return context.fiatCents
-          return context.fiatAmount - event.denomination * 100 // dollars to cents
+          return context.fiatCents - event.denomination * 100
         },
       }),
       clearCashOutSelection: assign({
         cashOutSelection: () => [],
-        fiatAmount: () => 0,
+        fiatCents: () => 0,
         satsAmount: () => 0,
       }),
       calculateSatsFromFiat: assign({
         satsAmount: ({ context }) => {
           if (context.exchangeRate === 0) return 0
-          const fiatDollars = context.fiatAmount / 100 // cents to dollars
+          const fiatDollars = context.fiatCents / 100
           const grossSats = Math.floor(fiatDollars * context.exchangeRate)
           // For cash-out, user pays the sats, so fee is added
           const fee = Math.floor(grossSats * context.feePercent)
@@ -362,7 +361,7 @@ export function createATMMachine(
     },
     guards: {
       hasInsertedBills: ({ context }) => context.billsInserted.length > 0,
-      hasSufficientAmount: ({ context }) => context.fiatAmount >= 100, // $1 minimum
+      hasSufficientAmount: ({ context }) => context.fiatCents >= 100, // $1 minimum
       hasExchangeRate: ({ context }) => context.exchangeRate > 0,
       canRetry: ({ context }) => context.retryCount < 3,
       hasUserNpub: ({ context }) => context.userNpub !== null,
@@ -370,7 +369,7 @@ export function createATMMachine(
       billWithinBalance: ({ context, event }) => {
         if (event.type !== 'BILL_INSERTED') return false
         if (context.availableBalance <= 0 || context.exchangeRate === 0) return true
-        const newFiatCents = context.fiatAmount + event.denomination * 100
+        const newFiatCents = context.fiatCents + event.denomination * 100
         const grossSats = Math.floor((newFiatCents / 100) * context.exchangeRate)
         const fee = Math.floor(grossSats * context.feePercent)
         return grossSats - fee <= context.availableBalance
@@ -543,11 +542,26 @@ export function createATMMachine(
           },
           error: {
             on: {
-              RETRY: {
+              RETRY: [
-                guard: 'canRetry',
+                {
-                target: 'generatingNdebit',
+                  // Rate never loaded: retry from rate fetch
-                actions: 'incrementRetry',
+                  guard: ({ context }) => context.retryCount < 3 && context.exchangeRate === 0,
-              },
+                  target: 'fetchingRate',
+                  actions: 'incrementRetry',
+                },
+                {
+                  // Ndebit failed before QR was shown: retry generation
+                  guard: ({ context }) => context.retryCount < 3 && context.ndebitUri === null,
+                  target: 'generatingNdebit',
+                  actions: 'incrementRetry',
+                },
+                {
+                  // Payment failed but QR/LNURL still valid: show QR again
+                  guard: 'canRetry',
+                  target: 'displayingQR',
+                  actions: 'incrementRetry',
+                },
+              ],
               CANCEL: [
                 {
                   // No bills inserted: safe to cancel

packages/state-machine/src/types.ts

@@ -34,7 +34,7 @@ export interface OfferRequestEvent {
 export interface ATMContext {
   // Transaction details
   /** Fiat amount in cents */
-  fiatAmount: number
+  fiatCents: number
   /** Satoshi amount */
   satsAmount: number
   /** Fiat currency code */
@@ -141,7 +141,7 @@ export type ATMEvent =
 
 /** Initial context values */
 export const initialContext: ATMContext = {
-  fiatAmount: 0,
+  fiatCents: 0,
   satsAmount: 0,
   currency: 'USD',
   exchangeRate: 0,