diff --git a/neode-ui/mock-backend.js b/neode-ui/mock-backend.js
index a1d8a20f..b0882bf6 100755
--- a/neode-ui/mock-backend.js
+++ b/neode-ui/mock-backend.js
@@ -2196,6 +2196,15 @@ app.post('/rpc/v1', (req, res) => {
       case 'content.download-peer-paid':
       case 'content.download-peer-invoice':
       case 'content.download-peer-onchain': {
+        // Deduct the price from the chosen rail so demo balances react.
+        const paid = params?.price_sats || 0
+        if (paid > 0 && method === 'content.download-peer-paid') {
+          if (params?.method === 'ark') walletState.ark_sats = Math.max(0, walletState.ark_sats - paid)
+          else if (params?.method === 'fedimint') {
+            const fed = (mockState.federations || [])[0]
+            if (fed) fed.balance_sats = Math.max(0, (fed.balance_sats || 0) - paid)
+          } else walletState.ecash_sats = Math.max(0, walletState.ecash_sats - paid)
+        }
         const filename = params?.filename || 'demo-content'
         const body = Buffer.from(
           `Archipelago demo — "${filename}"\n\nThis is sample paid content delivered over the ` +
@@ -3330,10 +3339,15 @@ app.post('/rpc/v1', (req, res) => {
       // Wallet / Ecash (Fedimint)
       // =====================================================================
       case 'wallet.ecash-balance': {
+        const fedSats = (mockState.federations || []).reduce((s, f) => s + (f.balance_sats || 0), 0)
         return res.json({
           result: {
             balance_sats: walletState.ecash_sats,
             balance_msat: walletState.ecash_sats * 1000,
+            cashu_sats: walletState.ecash_sats,
+            fedimint_sats: fedSats,
+            ark_sats: walletState.ark_sats,
+            total_sats: walletState.ecash_sats + fedSats + walletState.ark_sats,
             token_count: walletState.ecash_tokens,
             federations: [
               { federation_id: 'fed1-demo', name: 'Archy Signet Mint', balance_msat: walletState.ecash_sats * 1000, gateway_active: true },
diff --git a/neode-ui/src/components/ReceiveBitcoinModal.vue b/neode-ui/src/components/ReceiveBitcoinModal.vue
index 68e6b4ed..a120a1c7 100644
--- a/neode-ui/src/components/ReceiveBitcoinModal.vue
+++ b/neode-ui/src/components/ReceiveBitcoinModal.vue
@@ -3,12 +3,12 @@
         <!-- Method tabs -->
         <div class="flex gap-1 mb-4 p-1 bg-white/5 rounded-lg">
           <button
-            v-for="m in (['onchain', 'lightning', 'ecash'] as const)"
+            v-for="m in (['onchain', 'lightning', 'ecash', 'ark'] as const)"
             :key="m"
             @click="receiveMethod = m"
             class="flex-1 px-2 py-1.5 rounded text-xs font-medium capitalize transition-colors"
             :class="receiveMethod === m ? 'bg-white/15 text-white' : 'text-white/50 hover:text-white/80'"
-          >{{ m === 'onchain' ? t('receiveBitcoin.onChain') : m === 'lightning' ? t('receiveBitcoin.lightning') : t('receiveBitcoin.ecash') }}</button>
+          >{{ m === 'onchain' ? t('receiveBitcoin.onChain') : m === 'lightning' ? t('receiveBitcoin.lightning') : m === 'ecash' ? t('receiveBitcoin.ecash') : 'Ark' }}</button>
         </div>
 
         <!-- Lightning -->
@@ -43,6 +43,19 @@
           </div>
         </div>
 
+        <!-- Ark -->
+        <div v-if="receiveMethod === 'ark'">
+          <div v-if="arkAddress" class="mb-3 p-3 bg-white/5 rounded-lg text-center">
+            <canvas ref="arkQrCanvas" class="mx-auto mb-3 rounded-lg" style="image-rendering: pixelated;"></canvas>
+            <p class="text-white/50 text-xs mb-2">Your Ark address</p>
+            <p class="text-sm font-mono text-white/90 break-all">{{ arkAddress }}</p>
+            <button @click="copyText(arkAddress)" class="mt-2 text-xs text-orange-400 hover:text-orange-300">{{ t('common.copy') }}</button>
+          </div>
+          <div v-else class="mb-3 text-center">
+            <p class="text-white/50 text-sm mb-2">Generate a fresh Ark address to receive off-chain sats instantly.</p>
+          </div>
+        </div>
+
         <!-- Ecash -->
         <div v-if="receiveMethod === 'ecash'">
           <div class="mb-3">
@@ -57,7 +70,7 @@
         <div class="flex gap-3">
           <button @click="close" class="flex-1 glass-button px-4 py-2 rounded-lg text-sm">{{ t('common.close') }}</button>
           <button @click="receive" :disabled="processing" class="flex-1 glass-button glass-button-success px-4 py-2 rounded-lg text-sm font-medium disabled:opacity-50">
-            {{ processing ? t('receiveBitcoin.processing') : receiveMethod === 'onchain' ? t('receiveBitcoin.generateAddress') : receiveMethod === 'lightning' ? t('receiveBitcoin.createInvoice') : t('receiveBitcoin.receive') }}
+            {{ processing ? t('receiveBitcoin.processing') : receiveMethod === 'onchain' ? t('receiveBitcoin.generateAddress') : receiveMethod === 'lightning' ? t('receiveBitcoin.createInvoice') : receiveMethod === 'ark' ? 'Get Ark address' : t('receiveBitcoin.receive') }}
           </button>
         </div>
   </BaseModal>
@@ -75,15 +88,17 @@ const { t } = useI18n()
 defineProps<{ show: boolean }>()
 const emit = defineEmits<{ close: []; received: [] }>()
 
-const receiveMethod = ref<'lightning' | 'onchain' | 'ecash'>('onchain')
+const receiveMethod = ref<'lightning' | 'onchain' | 'ecash' | 'ark'>('onchain')
 const invoiceAmount = ref<number>(0)
 const invoiceMemo = ref('')
 const invoiceResult = ref('')
 const onchainAddress = ref('')
+const arkAddress = ref('')
 const ecashToken = ref('')
 const ecashResult = ref('')
 const onchainQrCanvas = ref<HTMLCanvasElement | null>(null)
 const lightningQrCanvas = ref<HTMLCanvasElement | null>(null)
+const arkQrCanvas = ref<HTMLCanvasElement | null>(null)
 const processing = ref(false)
 const error = ref('')
 
@@ -102,6 +117,7 @@ async function renderQr(data: string, canvas: HTMLCanvasElement | null, prefix =
 function close() {
   invoiceResult.value = ''
   onchainAddress.value = ''
+  arkAddress.value = ''
   ecashToken.value = ''
   ecashResult.value = ''
   error.value = ''
@@ -131,6 +147,11 @@ async function receive() {
       }
       onchainAddress.value = res.address
       nextTick(() => renderQr(res.address, onchainQrCanvas.value, 'bitcoin:'))
+    } else if (receiveMethod.value === 'ark') {
+      const res = await rpcClient.call<{ address: string }>({ method: 'wallet.ark-address' })
+      if (!res.address) throw new Error('barkd did not return an Ark address')
+      arkAddress.value = res.address
+      nextTick(() => renderQr(res.address, arkQrCanvas.value))
     } else {
       if (!ecashToken.value.trim()) { error.value = t('receiveBitcoin.pasteAnEcashToken'); return }
       // The backend auto-detects the token type: a Cashu token (cashuA/B…) is
diff --git a/neode-ui/src/components/SendBitcoinModal.vue b/neode-ui/src/components/SendBitcoinModal.vue
index 10ead66d..ceb3ada7 100644
--- a/neode-ui/src/components/SendBitcoinModal.vue
+++ b/neode-ui/src/components/SendBitcoinModal.vue
@@ -3,12 +3,12 @@
         <!-- Method tabs -->
         <div class="flex gap-1 mb-4 p-1 bg-white/5 rounded-lg">
           <button
-            v-for="m in (['auto', 'lightning', 'onchain', 'ecash'] as const)"
+            v-for="m in (['auto', 'lightning', 'onchain', 'ecash', 'ark'] as const)"
             :key="m"
             @click="sendMethod = m"
             class="flex-1 px-2 py-1.5 rounded text-xs font-medium capitalize transition-colors"
             :class="sendMethod === m ? 'bg-white/15 text-white' : 'text-white/50 hover:text-white/80'"
-          >{{ m === 'onchain' ? t('sendBitcoin.onChain') : m === 'lightning' ? t('sendBitcoin.lightning') : m === 'ecash' ? t('sendBitcoin.ecash') : t('sendBitcoin.auto') }}</button>
+          >{{ m === 'onchain' ? t('sendBitcoin.onChain') : m === 'lightning' ? t('sendBitcoin.lightning') : m === 'ecash' ? t('sendBitcoin.ecash') : m === 'ark' ? 'Ark' : t('sendBitcoin.auto') }}</button>
         </div>
 
         <div v-if="sendMethod === 'auto'" class="mb-3 p-2 bg-white/5 rounded-lg">
@@ -22,9 +22,9 @@
 
         <div v-if="effectiveMethod !== 'ecash'" class="mb-3">
           <label class="text-white/60 text-sm block mb-1">
-            {{ effectiveMethod === 'lightning' ? t('sendBitcoin.lightningInvoice') : t('sendBitcoin.bitcoinAddress') }}
+            {{ effectiveMethod === 'lightning' ? t('sendBitcoin.lightningInvoice') : effectiveMethod === 'ark' ? 'Ark address, invoice or lightning address' : t('sendBitcoin.bitcoinAddress') }}
           </label>
-          <textarea v-model="dest" rows="2" :placeholder="effectiveMethod === 'lightning' ? 'lnbc...' : 'bc1...'" class="w-full input-glass font-mono"></textarea>
+          <textarea v-model="dest" rows="2" :placeholder="effectiveMethod === 'lightning' ? 'lnbc...' : effectiveMethod === 'ark' ? 'tark1… / lnbc… / user@lnaddress' : 'bc1...'" class="w-full input-glass font-mono"></textarea>
         </div>
 
         <div v-if="ecashToken && effectiveMethod === 'ecash'" class="mb-3 p-2 bg-white/5 rounded-lg">
@@ -39,6 +39,9 @@
         <div v-if="resultHash" class="mb-3 alert-success">
           <p class="text-xs">{{ t('sendBitcoin.paidHash', { hash: resultHash }) }}</p>
         </div>
+        <div v-if="resultArk" class="mb-3 alert-success">
+          <p class="text-xs">{{ resultArk }}</p>
+        </div>
 
         <div v-if="error" class="mb-3 alert-error">{{ error }}</div>
 
@@ -62,13 +65,14 @@ const { t } = useI18n()
 const props = defineProps<{ show: boolean }>()
 const emit = defineEmits<{ close: []; sent: [] }>()
 
-const sendMethod = ref<'auto' | 'lightning' | 'onchain' | 'ecash'>('auto')
+const sendMethod = ref<'auto' | 'lightning' | 'onchain' | 'ecash' | 'ark'>('auto')
 const amount = ref<number>(0)
 const dest = ref('')
 const processing = ref(false)
 const error = ref('')
 const resultTxid = ref('')
 const resultHash = ref('')
+const resultArk = ref('')
 const ecashToken = ref('')
 
 const effectiveMethod = computed(() => {
@@ -84,6 +88,7 @@ function close() {
   error.value = ''
   resultTxid.value = ''
   resultHash.value = ''
+  resultArk.value = ''
   ecashToken.value = ''
   emit('close')
 }
@@ -99,10 +104,20 @@ async function send() {
   ecashToken.value = ''
   resultTxid.value = ''
   resultHash.value = ''
+  resultArk.value = ''
 
   const method = effectiveMethod.value
   try {
-    if (method === 'ecash') {
+    if (method === 'ark') {
+      if (!dest.value.trim()) { error.value = 'Enter an Ark address, invoice or lightning address'; return }
+      await rpcClient.call<{ sent: boolean }>({
+        method: 'wallet.ark-send',
+        params: { destination: dest.value.trim(), amount_sats: amount.value },
+        // Ark sends can wait on round participation.
+        timeout: 130000,
+      })
+      resultArk.value = `Sent ${amount.value.toLocaleString()} sats via Ark`
+    } else if (method === 'ecash') {
       const res = await rpcClient.call<{ token: string }>({
         method: 'wallet.ecash-send',
         params: { amount_sats: amount.value },
diff --git a/neode-ui/src/components/TransactionsModal.vue b/neode-ui/src/components/TransactionsModal.vue
index ad28b79c..6a0d0818 100644
--- a/neode-ui/src/components/TransactionsModal.vue
+++ b/neode-ui/src/components/TransactionsModal.vue
@@ -1,5 +1,7 @@
 <template>
-  <BaseModal :show="show" :title="t('transactions.title')" max-width="max-w-2xl" content-class="max-h-[90vh] flex flex-col" @close="close">
+  <!-- Mobile: cap at ~60% of the LIVE visible viewport (not dvh — see
+       syncViewportHeightVar in main.ts) so the tx list doesn't fill the screen. -->
+  <BaseModal :show="show" :title="t('transactions.title')" max-width="max-w-2xl" content-class="max-h-[calc(var(--visual-viewport-height,100dvh)*0.6)] md:max-h-[90vh] flex flex-col" @close="close">
         <!-- Rail filter: instant ecash micro-payments pile up fast and bury
              on-chain/Lightning rows; chips keep the standard txs reachable. -->
         <div v-if="transactions.length > 0" class="flex gap-1.5 mb-3 shrink-0 flex-wrap">
diff --git a/neode-ui/src/views/PeerFiles.vue b/neode-ui/src/views/PeerFiles.vue
index 4f0ff5f9..fef576c6 100644
--- a/neode-ui/src/views/PeerFiles.vue
+++ b/neode-ui/src/views/PeerFiles.vue
@@ -441,16 +441,16 @@
                    switch to the other if it has enough balance. -->
               <div class="space-y-2">
                 <button
-                  v-for="b in (['cashu', 'fedimint'] as const)"
+                  v-for="b in (['cashu', 'fedimint', 'ark'] as const)"
                   :key="b"
                   @click="ecashPlan.chosen = b"
                   :disabled="ecashBalanceOf(b) < getItemPrice(payItem.access)"
                   class="w-full px-4 py-3 rounded-xl flex items-center gap-3 text-left border transition-colors disabled:opacity-40 disabled:cursor-not-allowed"
                   :class="ecashPlan.chosen === b ? 'border-green-400/70 bg-green-400/10' : 'border-white/10 bg-white/5 hover:bg-white/10'"
                 >
-                  <span class="text-xl shrink-0">{{ b === 'cashu' ? '🥜' : '🤝' }}</span>
+                  <span class="text-xl shrink-0">{{ b === 'cashu' ? '🥜' : b === 'fedimint' ? '🤝' : '⚓' }}</span>
                   <span class="flex-1 min-w-0">
-                    <span class="block text-base text-white">{{ b === 'cashu' ? 'Cashu' : 'Fedimint' }}</span>
+                    <span class="block text-base text-white">{{ b === 'cashu' ? 'Cashu' : b === 'fedimint' ? 'Fedimint' : 'Ark' }}</span>
                     <span class="block text-xs text-white/50">Balance: {{ ecashBalanceOf(b).toLocaleString() }} sats<span v-if="ecashBalanceOf(b) < getItemPrice(payItem.access)"> · not enough</span></span>
                   </span>
                   <svg v-if="ecashPlan.chosen === b" class="w-5 h-5 text-green-400 shrink-0" fill="none" stroke="currentColor" viewBox="0 0 24 24">
@@ -707,10 +707,11 @@ const payMode = ref<'choose' | 'ecash-confirm' | 'qr'>('choose')
 // Ecash confirmation step: after the user picks "pay from this node's ecash",
 // we look at both balances, decide which backend covers the price, and show a
 // confirm screen so they see (and can switch) which ecash is spent (#3).
-type EcashBackend = 'cashu' | 'fedimint'
+type EcashBackend = 'cashu' | 'fedimint' | 'ark'
 const ecashPlan = ref<{
   cashu: number
   fedimint: number
+  ark: number
   total: number
   chosen: EcashBackend | null
 } | null>(null)
@@ -1135,7 +1136,7 @@ async function pollOnchain(address: string) {
 /** Spendable balance for a given ecash backend in the current plan. */
 function ecashBalanceOf(b: EcashBackend): number {
   if (!ecashPlan.value) return 0
-  return b === 'cashu' ? ecashPlan.value.cashu : ecashPlan.value.fedimint
+  return b === 'cashu' ? ecashPlan.value.cashu : b === 'fedimint' ? ecashPlan.value.fedimint : ecashPlan.value.ark
 }
 
 /**
@@ -1152,23 +1153,25 @@ async function prepareEcashPay() {
   try {
     let cashu = 0
     let fedimint = 0
+    let ark = 0
     try {
-      const res = await rpcClient.call<{ cashu_sats?: number; fedimint_sats?: number; total_sats?: number; balance_sats?: number }>({
+      const res = await rpcClient.call<{ cashu_sats?: number; fedimint_sats?: number; ark_sats?: number; total_sats?: number; balance_sats?: number }>({
         method: 'wallet.ecash-balance',
       })
       cashu = res?.cashu_sats ?? res?.balance_sats ?? 0
       fedimint = res?.fedimint_sats ?? 0
+      ark = res?.ark_sats ?? 0
     } catch {
       // Couldn't read balances — let the user try anyway (auto backend).
     }
-    const total = cashu + fedimint
-    // Prefer Cashu when it covers the price, else Fedimint, else leave null
-    // (insufficient — shown in the confirm screen, Confirm disabled).
+    const total = cashu + fedimint + ark
+    // Prefer Cashu when it covers the price, else Fedimint, else Ark, else
+    // leave null (insufficient — shown in the confirm screen, Confirm disabled).
     const chosen: EcashBackend | null =
-      cashu >= price ? 'cashu' : fedimint >= price ? 'fedimint' : null
-    ecashPlan.value = { cashu, fedimint, total, chosen }
+      cashu >= price ? 'cashu' : fedimint >= price ? 'fedimint' : ark >= price ? 'ark' : null
+    ecashPlan.value = { cashu, fedimint, ark, total, chosen }
     if (!chosen) {
-      purchaseError.value = `Not enough ecash: Cashu ${cashu} + Fedimint ${fedimint} sats, need ${price}. Fund a wallet, or pay another way.`
+      purchaseError.value = `Not enough funds: Cashu ${cashu} + Fedimint ${fedimint} + Ark ${ark} sats, need ${price}. Fund a wallet, or pay another way.`
     }
     payMode.value = 'ecash-confirm'
   } finally {