A Lightning invoice that Spending can't cover, with too little in Savings to move over, is offered the door that works: a Lightning receive into Spending. "can you help me" (a user, 2026-11-03, screenshot): 546 sats in Savings, 0 in Spending, a 175-sat invoice — the ask said "Move Savings into Spending first", and that button led to a board panel saying "Needs at least 1,000 sats in Savings" (the coinos server's board minimum), a dead end dressed as a way through. The ask now knows whether Savings can fund a move at all — the server's minimum, from the live manager or the last copy of its info seen, plus the board transaction's chain fee — and when it can't, says what Savings holds and what a move needs and offers "Receive over Lightning instead", which opens Spending's Receive page; a Lightning receive lands in Spending directly, no confirmation, and the invoice can be paid from there. The same question replaces the hardcoded "more than 1,000 sats in Savings" guess behind the pasted-invoice path (its error now carries the same sentence), the Ark send review's move door and the zap card's "Move sats into Spending" button (arkSavingsCanBoard hook), and the board offer's prefill honours the minimum before the manager is connected (it read 0 then, and prefilled 179). tools/ark-ln-savings-small-test.js: 546 sats → the receive door, no move button; 1,000 sats (the minimum, but not the fee on top) → the same; 5,000 → the move, straight to the board panel prefilled at the minimum

Co-Authored-By: Claude Fable 5.1 <[email protected]>
Claude-Session: https://claude.ai/code/session_01VMan6TFgisGKUDhdStLUvs

3 files changed, 48 insertions, 14 deletions

diff --git a/src/features/ark.js b/src/features/ark.js
index d1fa356..5d3b293 100644
--- a/src/features/ark.js
+++ b/src/features/ark.js
@@ -491,6 +491,23 @@ export function arkFeature(ctx) {
       localStorage.setItem(ARK_INFO_KEY + url, JSON.stringify(tip ? { info, tip, at: Date.now() } : { info, tip: (prev && prev.tip) || 0, at: (prev && prev.at) || Date.now() }));
     } catch {}
   }
+  // Whether Savings can fund a move into Spending at all: the server's board
+  // minimum (1,000 sats on coinos) plus the board transaction's chain fee.
+  // A Savings balance under that — 546 sats, say — must not be offered a
+  // move the board panel then refuses with "Needs at least 1,000 sats"; the
+  // way into Spending for it is a Lightning receive, which lands there
+  // directly. The minimum comes from the live manager or the last copy of
+  // the server's info seen, so the answer is right before connect too.
+  function savingsBoardMin() {
+    const info = (ark && ark.info) || ((cachedArkInfo((getArkConfig() || {}).ark) || {}).info) || null;
+    return info ? (info.minBoardAmountSat || 0) : 1000;
+  }
+  function savingsCanBoard() {
+    if (!arkAvailable()) return false;
+    const min = savingsBoardMin();
+    if (min >= 2_100_000_000_000_000 || wallet.spendable < min) return false; // paused, or short
+    try { return previewBoardFunding(wallet, ark, min).fundingSat >= min; } catch { return false; } // the fee on top
+  }
   // the tip, live or estimated from the last one seen (a block per ten minutes)
   function arkTipNow(mgr) {
     if (mgr && mgr._tipH) return mgr._tipH;
@@ -930,7 +947,7 @@ export function arkFeature(ctx) {
         h('button', { class: 'btn-ghost', onClick: () => { ui.arkSend = null; ui.sendError = ''; render(); } }, t('back')),
         ui.busy
           ? h('button', { class: 'btn-primary grow', disabled: true }, h('span', { class: 'spinner' }))
-          : a.amountSat > (arkBalance()?.spendableSat || 0) && wallet.spendable > 0 && !wallet.watchOnly
+          : a.amountSat > (arkBalance()?.spendableSat || 0) && savingsCanBoard()
             ? h('button', { class: 'btn-primary grow', onClick: () => {
                 const need = a.amountSat;
                 ui.arkSend = null; ui.sendError = '';
@@ -1953,11 +1970,16 @@ export function arkFeature(ctx) {
   }
 
   // The ask itself: switch and continue, move Savings over first, or not.
+  // When Savings can't fund a move either (under the board minimum, as a
+  // 546-sat Savings against coinos's 1,000 is), the door offered is the one
+  // that works: a Lightning receive, which lands in Spending directly.
   function arkLnFromSavingsView() {
     const p = ui.arkLnFromSavings;
     const have = arkBalance()?.spendableSat || 0;
     const need = p.amountSat || 0;
     const enough = !need || have >= need;
+    const canMove = savingsCanBoard();
+    const close = () => { ui.arkLnFromSavings = null; ui.sendError = ''; ui.send = blankSend(); };
     const proceed = () => {
       ui.arkLnFromSavings = null;
       ctx.setAccount('spending', 'right');
@@ -1965,20 +1987,27 @@ export function arkFeature(ctx) {
       if (startArkLnPay(p.invoice, p.meta)) return;
       ui.arkLnFromSavingsOk = false;
       // Spending can't carry it: the same offer the Spending side makes
-      if (need && wallet.spendable > 1000 && ctx.hook('arkOfferBoard', need)) return;
+      if (need && canMove && ctx.hook('arkOfferBoard', need)) return;
       ui.sendError = t('arkLnExceedsSpending', { need: fmtAmount(need) + ' ' + unitLabel(), have: fmtAmount(have) + ' ' + unitLabel() });
       render();
     };
+    const moveFirst = () => { ui.arkLnFromSavings = null; ctx.hook('arkOfferBoard', need || 0); };
+    const receiveInstead = () => { close(); ctx.setAccount('spending', 'right'); render(); };
+    const sats = (n) => fmtAmount(n) + ' ' + unitLabel();
     return h('div', { class: 'card col', style: 'gap:12px' },
       h('h3', { style: 'margin:0' }, t('arkLnFromSavingsTitle')),
-      h('p', { class: 'small muted', style: 'margin:0' }, t('arkLnFromSavingsBody', { have: fmtAmount(have) + ' ' + unitLabel() })),
-      need ? h('div', { class: 'row between' }, h('span', { class: 'small muted' }, t('lnPayAmount')), h('span', { class: 'small' }, fmtAmount(need) + ' ' + unitLabel())) : null,
-      !enough ? h('div', { class: 'notice info small' }, t('arkLnFromSavingsShort')) : null,
-      h('button', { class: 'btn-primary btn-block', onClick: proceed }, enough ? t('arkLnUseSpending') : t('arkLnMoveFirst')),
-      enough && wallet.spendable > 1000
-        ? h('button', { class: 'btn-block', onClick: () => { ui.arkLnFromSavings = null; ctx.hook('arkOfferBoard', need || 0); } }, t('arkLnMoveFirst'))
+      h('p', { class: 'small muted', style: 'margin:0' }, t('arkLnFromSavingsBody', { have: sats(have) })),
+      need ? h('div', { class: 'row between' }, h('span', { class: 'small muted' }, t('lnPayAmount')), h('span', { class: 'small' }, sats(need))) : null,
+      enough ? null
+        : canMove ? h('div', { class: 'notice info small' }, t('arkLnFromSavingsShort'))
+        : h('div', { class: 'notice info small' }, t('arkLnSavingsTooSmall', { have: sats(wallet.spendable || 0), min: sats(savingsBoardMin()) })),
+      enough ? h('button', { class: 'btn-primary btn-block', onClick: proceed }, t('arkLnUseSpending'))
+        : canMove ? h('button', { class: 'btn-primary btn-block', onClick: moveFirst }, t('arkLnMoveFirst'))
+        : h('button', { class: 'btn-primary btn-block', onClick: receiveInstead }, t('arkLnReceiveInstead')),
+      enough && canMove
+        ? h('button', { class: 'btn-block', onClick: moveFirst }, t('arkLnMoveFirst'))
         : null,
-      h('button', { class: 'btn-ghost btn-block', onClick: () => { ui.arkLnFromSavings = null; ui.sendError = ''; ui.send = blankSend(); render(); } }, t('cancel')));
+      h('button', { class: 'btn-ghost btn-block', onClick: () => { close(); render(); } }, t('cancel')));
   }
 
   // shared by the ark and lightning zap flows (see zaps.js for the twin)
@@ -3666,7 +3695,7 @@ export function arkFeature(ctx) {
   const boardsPaused = () => ((ark && ark.info && ark.info.minBoardAmountSat) || 0) >= 2_100_000_000_000_000;
   function boardForm() {
     if (boardsPaused()) return h('div', { class: 'notice small' }, t('arkBoardPaused'));
-    const minBoard = (ark && ark.info && ark.info.minBoardAmountSat) || 0;
+    const minBoard = savingsBoardMin();
     const canBoard = wallet.spendable >= minBoard;
     return h('div', { class: 'col', style: 'width:100%;gap:8px' },
       h('div', { class: 'input-group' },
@@ -4035,6 +4064,7 @@ export function arkFeature(ctx) {
       return mgr.fetchBolt12(offerStr, amountSat);
     },
     lnSpendableSat() { const b = arkBalance(); return b ? b.spendableSat : 0; },
+    arkSavingsCanBoard() { return savingsCanBoard(); },
     spendingRenewingSat() { return renewingSat(); },
     // Max for any Lightning amount form: spendable minus estimated fees.
     lnMaxSendSat() { return lnMaxSat(); },
@@ -4058,7 +4088,7 @@ export function arkFeature(ctx) {
       const short = Math.max(0, Math.ceil(needSat * 1.01) + 2 - have);
       let gross = short;
       try { for (let i = 0; i < 4; i++) gross = short + boardFee(gross, ark.info.boardFees); } catch {}
-      const minBoard = (ark && ark.info && ark.info.minBoardAmountSat) || 0;
+      const minBoard = savingsBoardMin(); // remembered info too: the offer can come before connect
       ctx.goHome();
       ui.arkMoveOpen = true;
       ui.arkMoveDir = 'toSpending';
@@ -4209,11 +4239,13 @@ export function arkFeature(ctx) {
           // paste. Own it: offer to board the shortfall from Savings when
           // there is one, else say plainly what's short.
           const need = (maybeLnInvoice(inv) || {}).amountSat || 0;
-          if (need && wallet.spendable > 1000 && ctx.hook('arkOfferBoard', need)) return true;
+          if (need && savingsCanBoard() && ctx.hook('arkOfferBoard', need)) return true;
           ui.sendError = t('arkLnExceedsSpending', {
             need: fmtAmount(need) + ' ' + unitLabel(),
             have: fmtAmount(arkBalance()?.spendableSat || 0) + ' ' + unitLabel(),
-          });
+          }) + (wallet.spendable > 0 && !savingsCanBoard() // Savings has sats, just too few to move
+            ? ' ' + t('arkLnSavingsTooSmall', { have: fmtAmount(wallet.spendable) + ' ' + unitLabel(), min: fmtAmount(savingsBoardMin()) + ' ' + unitLabel() })
+            : '');
           render();
           return true;
         }
diff --git a/src/features/zaps.js b/src/features/zaps.js
index 76296cf..fbdc2e9 100644
--- a/src/features/zaps.js
+++ b/src/features/zaps.js
@@ -487,7 +487,7 @@ export function zapsFeature(ctx) {
     // what this payment needs (extra is one edit away).
     const typedSats = parseAmount(z.amount, getUnit()) || 0;
     const theirMaxSat = Math.floor(p.maxSendable / 1000);
-    const boardable = !!hook('arkReady') && ours != null;
+    const boardable = !!hook('arkReady') && ours != null && !!hook('arkSavingsCanBoard');
     const renewing = hook('spendingRenewingSat') || 0;
     const waitingOnRenewal = renewing > 0 && broke && ours + renewing >= Math.max(min, p.fixedSat || typedSats);
     const needsBoard = !waitingOnRenewal && boardable && (broke || (typedSats > 0 && typedSats > ours && typedSats <= theirMaxSat));
diff --git a/src/i18n.js b/src/i18n.js
index db54708..36beef0 100644
--- a/src/i18n.js
+++ b/src/i18n.js
@@ -1359,6 +1359,8 @@ const STR = {
     arkLnFromSavingsShort: 'Spending can’t cover this one. Move funds over from Savings first. That takes an on-chain confirmation, so ask for a fresh invoice afterwards.',
     arkLnUseSpending: 'Switch to Spending and continue',
     arkLnMoveFirst: 'Move Savings into Spending first',
+    arkLnSavingsTooSmall: 'Savings holds {have}, and a move into Spending needs at least {min} plus the on-chain fee. Receive over Lightning to fund Spending directly, or add to Savings first.',
+    arkLnReceiveInstead: 'Receive over Lightning instead',
     arkLnFee: 'Fee',
     arkLnPaying: 'Paying invoice…',
     arkLnRetrying: 'Route failed. Retrying with a bigger fee budget ({n}/{of})…',