diff --git a/src/__tests__/nlQueryParser.test.ts b/src/__tests__/nlQueryParser.test.ts
new file mode 100644
index 0000000..b630990
--- /dev/null
+++ b/src/__tests__/nlQueryParser.test.ts
@@ -0,0 +1,165 @@
+import { parseNaturalLanguageQuery, applyParsedFilters } from '@/lib/nlQueryParser';
+import { describe, it, expect } from 'vitest';
+
+describe('nlQueryParser', () => {
+  describe('parseNaturalLanguageQuery', () => {
+    it('should parse "unpaid invoices over 200 XLM from last month"', () => {
+      const result = parseNaturalLanguageQuery('unpaid invoices over 200 XLM from last month');
+      expect(result.filters.status).toBe('pending');
+      expect(result.filters.amountGte).toBe(200);
+      expect(result.filters.dueDateFrom).toBeDefined();
+      expect(result.filters.dueDateTo).toBeDefined();
+      expect(result.tokens.length).toBeGreaterThan(0);
+    });
+
+    it('should parse amount ranges', () => {
+      const result = parseNaturalLanguageQuery('invoices between 100 and 500 XLM');
+      expect(result.filters.amountGte).toBe(100);
+      expect(result.filters.amountLte).toBe(500);
+      expect(result.tokens.some((t) => t.type === 'amount_range')).toBe(true);
+    });
+
+    it('should parse minimum amount', () => {
+      const result = parseNaturalLanguageQuery('over 500 XLM');
+      expect(result.filters.amountGte).toBe(500);
+    });
+
+    it('should parse maximum amount', () => {
+      const result = parseNaturalLanguageQuery('under 1000 XLM');
+      expect(result.filters.amountLte).toBe(1000);
+    });
+
+    it('should parse status keywords', () => {
+      expect(parseNaturalLanguageQuery('unpaid').filters.status).toBe('pending');
+      expect(parseNaturalLanguageQuery('paid').filters.status).toBe('paid');
+      expect(parseNaturalLanguageQuery('overdue').filters.status).toBe('overdue');
+      expect(parseNaturalLanguageQuery('draft').filters.status).toBe('draft');
+    });
+
+    it('should parse relative dates', () => {
+      const result = parseNaturalLanguageQuery('this week');
+      expect(result.filters.dueDateFrom).toBeDefined();
+      expect(result.filters.dueDateTo).toBeDefined();
+    });
+
+    it('should parse "past N days"', () => {
+      const result = parseNaturalLanguageQuery('past 7 days');
+      expect(result.filters.dueDateFrom).toBeDefined();
+      expect(result.filters.dueDateTo).toBeDefined();
+    });
+
+    it('should parse asset names', () => {
+      expect(parseNaturalLanguageQuery('XLM').filters.asset).toBe('XLM');
+      expect(parseNaturalLanguageQuery('USDC').filters.asset).toBe('USDC');
+    });
+
+    it('should handle mixed case', () => {
+      const result = parseNaturalLanguageQuery('UNPAID Invoices OVER 200 xlm');
+      expect(result.filters.status).toBe('pending');
+      expect(result.filters.amountGte).toBe(200);
+    });
+
+    it('should handle typos gracefully (with keyword fallback)', () => {
+      const result = parseNaturalLanguageQuery('invoces for customer A');
+      expect(result.filters.titleKeyword).toBeDefined();
+    });
+
+    it('should handle complex query with multiple constraints', () => {
+      const result = parseNaturalLanguageQuery(
+        'unpaid invoices between 100 and 500 XLM in USDC status from last week'
+      );
+      expect(result.filters.status).toBe('pending');
+      expect(result.filters.amountGte).toBe(100);
+      expect(result.filters.amountLte).toBe(500);
+      expect(result.filters.dueDateFrom).toBeDefined();
+    });
+
+    it('should generate filter tokens', () => {
+      const result = parseNaturalLanguageQuery('paid invoices over 300 XLM this month');
+      expect(result.tokens.length).toBeGreaterThan(0);
+      expect(result.tokens.some((t) => t.type === 'status')).toBe(true);
+      expect(result.tokens.some((t) => t.type === 'amount_min')).toBe(true);
+    });
+
+    it('should handle empty query', () => {
+      const result = parseNaturalLanguageQuery('');
+      expect(result.filters).toEqual({});
+      expect(result.tokens.length).toBe(0);
+    });
+
+    it('should handle query with only whitespace', () => {
+      const result = parseNaturalLanguageQuery('   ');
+      expect(result.tokens.length).toBe(0);
+    });
+  });
+
+  describe('applyParsedFilters', () => {
+    const mockInvoices = [
+      {
+        id: '1',
+        title: 'Invoice 1',
+        amount: 150,
+        status: 'pending',
+        recipients: [{ address: 'customer1@example.com' }],
+      },
+      {
+        id: '2',
+        title: 'Invoice 2',
+        amount: 300,
+        status: 'paid',
+        recipients: [{ address: 'customer2@example.com' }],
+      },
+      {
+        id: '3',
+        title: 'Invoice 3',
+        amount: 600,
+        status: 'overdue',
+        recipients: [{ address: 'customer3@example.com' }],
+      },
+    ];
+
+    it('should filter by amount minimum', () => {
+      const result = applyParsedFilters(mockInvoices, { amountGte: 300 });
+      expect(result.length).toBe(2);
+      expect(result.map((i) => i.id)).toEqual(['2', '3']);
+    });
+
+    it('should filter by amount maximum', () => {
+      const result = applyParsedFilters(mockInvoices, { amountLte: 300 });
+      expect(result.length).toBe(2);
+      expect(result.map((i) => i.id)).toEqual(['1', '2']);
+    });
+
+    it('should filter by amount range', () => {
+      const result = applyParsedFilters(mockInvoices, {
+        amountGte: 200,
+        amountLte: 500,
+      });
+      expect(result.length).toBe(1);
+      expect(result[0].id).toBe('2');
+    });
+
+    it('should filter by status', () => {
+      const result = applyParsedFilters(mockInvoices, { status: 'paid' });
+      expect(result.length).toBe(1);
+      expect(result[0].id).toBe('2');
+    });
+
+    it('should filter by keyword', () => {
+      const result = applyParsedFilters(mockInvoices, {
+        titleKeyword: 'customer1',
+      });
+      expect(result.length).toBe(1);
+      expect(result[0].id).toBe('1');
+    });
+
+    it('should combine multiple filters', () => {
+      const result = applyParsedFilters(mockInvoices, {
+        status: 'paid',
+        amountGte: 250,
+      });
+      expect(result.length).toBe(1);
+      expect(result[0].id).toBe('2');
+    });
+  });
+});
diff --git a/src/app/api/invoices/share-links/route.ts b/src/app/api/invoices/share-links/route.ts
new file mode 100644
index 0000000..1c7ddd8
--- /dev/null
+++ b/src/app/api/invoices/share-links/route.ts
@@ -0,0 +1,124 @@
+import { NextRequest, NextResponse } from 'next/server';
+import {
+  createShareLink,
+  getShareLinksForInvoice,
+  revokeShareLink,
+  type ShareLinkPermission,
+} from '@/lib/shareLink';
+
+interface CreateShareLinkRequest {
+  invoiceId: string;
+  permissions?: ShareLinkPermission;
+  durationMs?: number;
+  maxUses?: boolean;
+}
+
+interface RevokeShareLinkRequest {
+  tokenHash: string;
+}
+
+/**
+ * POST - Generate a new share link
+ * Body: { invoiceId, permissions, durationMs, maxUses }
+ */
+export async function POST(request: NextRequest) {
+  try {
+    const body = (await request.json().catch(() => null)) as CreateShareLinkRequest | null;
+
+    if (!body?.invoiceId) {
+      return NextResponse.json({ error: 'invoiceId is required' }, { status: 400 });
+    }
+
+    const permissions: ShareLinkPermission = body.permissions || 'read';
+    const durationMs = body.durationMs || 3600000; // 1 hour default
+    const maxUses = body.maxUses ? 1 : undefined; // Single-use if specified
+
+    // Validate duration
+    if (durationMs < 300000 || durationMs > 2592000000) {
+      // 5 minutes to 30 days
+      return NextResponse.json(
+        { error: 'durationMs must be between 5 minutes and 30 days' },
+        { status: 400 }
+      );
+    }
+
+    const shareLink = createShareLink(body.invoiceId, permissions, durationMs, maxUses);
+
+    return NextResponse.json({
+      tokenHash: shareLink.tokenHash,
+      token: shareLink.token, // Return this only on creation
+      invoiceId: shareLink.invoiceId,
+      permissions: shareLink.permissions,
+      expiresAt: shareLink.expiresAt,
+      maxUses: shareLink.maxUses,
+      createdAt: shareLink.createdAt,
+    });
+  } catch (error) {
+    console.error('Error creating share link:', error);
+    return NextResponse.json(
+      { error: 'Failed to create share link' },
+      { status: 500 }
+    );
+  }
+}
+
+/**
+ * GET - List share links for an invoice
+ * Query: invoiceId
+ */
+export async function GET(request: NextRequest) {
+  try {
+    const invoiceId = request.nextUrl.searchParams.get('invoiceId');
+
+    if (!invoiceId) {
+      return NextResponse.json({ error: 'invoiceId is required' }, { status: 400 });
+    }
+
+    const links = getShareLinksForInvoice(invoiceId);
+
+    return NextResponse.json({
+      links: links.map((link) => ({
+        tokenHash: link.tokenHash,
+        permissions: link.permissions,
+        expiresAt: link.expiresAt,
+        maxUses: link.maxUses,
+        usesConsumed: link.usesConsumed,
+        createdAt: link.createdAt,
+      })),
+    });
+  } catch (error) {
+    console.error('Error fetching share links:', error);
+    return NextResponse.json(
+      { error: 'Failed to fetch share links' },
+      { status: 500 }
+    );
+  }
+}
+
+/**
+ * DELETE - Revoke a share link
+ * Body: { tokenHash }
+ */
+export async function DELETE(request: NextRequest) {
+  try {
+    const body = (await request.json().catch(() => null)) as RevokeShareLinkRequest | null;
+
+    if (!body?.tokenHash) {
+      return NextResponse.json({ error: 'tokenHash is required' }, { status: 400 });
+    }
+
+    const revoked = revokeShareLink(body.tokenHash);
+
+    if (!revoked) {
+      return NextResponse.json({ error: 'Share link not found' }, { status: 404 });
+    }
+
+    return NextResponse.json({ success: true });
+  } catch (error) {
+    console.error('Error revoking share link:', error);
+    return NextResponse.json(
+      { error: 'Failed to revoke share link' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/app/share/[token]/route.ts b/src/app/share/[token]/route.ts
new file mode 100644
index 0000000..a095d83
--- /dev/null
+++ b/src/app/share/[token]/route.ts
@@ -0,0 +1,115 @@
+import { NextRequest, NextResponse } from 'next/server';
+import {
+  validateShareLink,
+  incrementShareLinkUse,
+  hashToken,
+} from '@/lib/shareLink';
+
+/**
+ * GET - Validate and access a shared invoice
+ * Returns: Invoice data or redirect based on permission
+ */
+export async function GET(
+  request: NextRequest,
+  { params }: { params: { token: string } }
+) {
+  try {
+    const token = params.token;
+
+    if (!token) {
+      return NextResponse.json(
+        { error: 'Invalid share link' },
+        { status: 404 }
+      );
+    }
+
+    const validation = validateShareLink(token);
+
+    if (!validation.valid) {
+      return NextResponse.json(
+        {
+          error: 'Share link not available',
+          reason: validation.reason,
+        },
+        { status: 404 }
+      );
+    }
+
+    const { link, permission } = validation;
+
+    // Increment usage counter
+    incrementShareLinkUse(hashToken(token));
+
+    // Create a session cookie or token for this session
+    // The response includes the invoice data and permission scope
+    const response = NextResponse.json({
+      invoiceId: link.invoiceId,
+      permission,
+      expiresAt: link.expiresAt,
+      accessGrantedAt: new Date(),
+    });
+
+    // Set a secure, HTTP-only cookie for this session
+    // This cookie grants temporary access to the invoice
+    response.cookies.set({
+      name: 'share_session',
+      value: JSON.stringify({
+        invoiceId: link.invoiceId,
+        permission,
+        expiresAt: link.expiresAt.toISOString(),
+        accessGrantedAt: new Date().toISOString(),
+      }),
+      httpOnly: true,
+      secure: process.env.NODE_ENV === 'production',
+      sameSite: 'lax',
+      maxAge: 3600, // 1 hour
+    });
+
+    return response;
+  } catch (error) {
+    console.error('Error accessing shared invoice:', error);
+    return NextResponse.json(
+      { error: 'Failed to access share link' },
+      { status: 500 }
+    );
+  }
+}
+
+/**
+ * HEAD - Check if share link is valid without incrementing uses
+ */
+export async function HEAD(
+  request: NextRequest,
+  { params }: { params: { token: string } }
+) {
+  try {
+    const token = params.token;
+
+    if (!token) {
+      return NextResponse.json(
+        { error: 'Invalid share link' },
+        { status: 404 }
+      );
+    }
+
+    const validation = validateShareLink(token);
+
+    if (!validation.valid) {
+      return NextResponse.json(
+        {
+          error: 'Share link not available',
+          reason: validation.reason,
+        },
+        { status: 404 }
+      );
+    }
+
+    return NextResponse.json({ valid: true });
+  } catch (error) {
+    console.error('Error validating shared invoice:', error);
+    return NextResponse.json(
+      { error: 'Failed to validate share link' },
+      { status: 500 }
+    );
+  }
+}
diff --git a/src/components/invoice/CostEstimatorPanel.tsx b/src/components/invoice/CostEstimatorPanel.tsx
new file mode 100644
index 0000000..1e04528
--- /dev/null
+++ b/src/components/invoice/CostEstimatorPanel.tsx
@@ -0,0 +1,207 @@
+'use client';
+
+import { type CostBreakdown } from '@/hooks/useInvoiceCostEstimate';
+
+interface CostEstimatorPanelProps {
+  breakdown: CostBreakdown;
+  isBalanceSufficient: boolean | null;
+  creatorBalance: number | null;
+  invoiceAmountXlm: number;
+  loading?: boolean;
+  error?: string | null;
+  disabled?: boolean;
+}
+
+export default function CostEstimatorPanel({
+  breakdown,
+  isBalanceSufficient,
+  creatorBalance,
+  invoiceAmountXlm,
+  loading = false,
+  error = null,
+  disabled = false,
+}: CostEstimatorPanelProps) {
+  const totalRequired = invoiceAmountXlm + breakdown.totalXlm;
+
+  return (
+    <div
+      className={`p-4 rounded-lg border ${
+        isBalanceSufficient === false
+          ? 'bg-red-500/5 border-red-500/30'
+          : 'bg-blue-500/5 border-blue-500/30'
+      }`}
+    >
+      <h3 className="text-sm font-semibold text-gray-200 mb-4">Cost Estimate</h3>
+
+      {error && (
+        <div className="mb-4 p-3 bg-red-500/10 border border-red-500/30 rounded text-red-400 text-sm">
+          {error}
+        </div>
+      )}
+
+      {loading && (
+        <div className="mb-4 p-3 bg-blue-500/10 border border-blue-500/30 rounded text-blue-400 text-sm">
+          Loading cost estimate...
+        </div>
+      )}
+
+      <div className="space-y-3">
+        {/* Invoice Amount */}
+        <div className="flex justify-between items-center text-sm">
+          <span className="text-gray-400">Invoice Amount</span>
+          <span className="text-gray-200 font-medium">{invoiceAmountXlm.toFixed(2)} XLM</span>
+        </div>
+
+        {/* Network Fee */}
+        {breakdown.networkFeeXlm > 0 && (
+          <div className="flex justify-between items-center text-sm">
+            <div className="flex items-center gap-2">
+              <span className="text-gray-400">Network Fee</span>
+              <div className="group relative">
+                <button
+                  type="button"
+                  className="text-gray-500 hover:text-gray-400"
+                  aria-label="Network fee info"
+                >
+                  <svg
+                    className="w-4 h-4"
+                    fill="currentColor"
+                    viewBox="0 0 20 20"
+                  >
+                    <path
+                      fillRule="evenodd"
+                      d="M18 10a8 8 0 11-16 0 8 8 0 0116 0zm-7-4a1 1 0 11-2 0 1 1 0 012 0zm-1 12a7 7 0 110-2h.01a7.003 7.003 0 0 1 0 2z"
+                    />
+                  </svg>
+                </button>
+                <div className="absolute bottom-full left-1/2 transform -translate-x-1/2 mb-2 px-3 py-2 bg-gray-800 text-gray-200 text-xs rounded whitespace-nowrap pointer-events-none opacity-0 group-hover:opacity-100 transition-opacity">
+                  Stellar network transaction fee
+                </div>
+              </div>
+            </div>
+            <span className="text-gray-200 font-medium">
+              {breakdown.networkFeeXlm.toFixed(6)} XLM
+            </span>
+          </div>
+        )}
+
+        {/* Platform Fee */}
+        {breakdown.platformFeeXlm > 0 && (
+          <div className="flex justify-between items-center text-sm">
+            <div className="flex items-center gap-2">
+              <span className="text-gray-400">Platform Fee</span>
+              <div className="group relative">
+                <button
+                  type="button"
+                  className="text-gray-500 hover:text-gray-400"
+                  aria-label="Platform fee info"
+                >
+                  <svg
+                    className="w-4 h-4"
+                    fill="currentColor"
+                    viewBox="0 0 20 20"
+                  >
+                    <path
+                      fillRule="evenodd"
+                      d="M18 10a8 8 0 11-16 0 8 8 0 0116 0zm-7-4a1 1 0 11-2 0 1 1 0 012 0zm-1 12a7 7 0 110-2h.01a7.003 7.003 0 0 1 0 2z"
+                    />
+                  </svg>
+                </button>
+                <div className="absolute bottom-full left-1/2 transform -translate-x-1/2 mb-2 px-3 py-2 bg-gray-800 text-gray-200 text-xs rounded whitespace-nowrap pointer-events-none opacity-0 group-hover:opacity-100 transition-opacity">
+                  StellarSplit service fee (1% minimum 0.1 XLM)
+                </div>
+              </div>
+            </div>
+            <span className="text-gray-200 font-medium">
+              {breakdown.platformFeeXlm.toFixed(4)} XLM
+            </span>
+          </div>
+        )}
+
+        {/* Reserve Top-up */}
+        {breakdown.reserveTopUpXlm > 0 && (
+          <div className="flex justify-between items-center text-sm">
+            <div className="flex items-center gap-2">
+              <span className="text-gray-400">Trustline Reserve</span>
+              <div className="group relative">
+                <button
+                  type="button"
+                  className="text-gray-500 hover:text-gray-400"
+                  aria-label="Trustline reserve info"
+                >
+                  <svg
+                    className="w-4 h-4"
+                    fill="currentColor"
+                    viewBox="0 0 20 20"
+                  >
+                    <path
+                      fillRule="evenodd"
+                      d="M18 10a8 8 0 11-16 0 8 8 0 0116 0zm-7-4a1 1 0 11-2 0 1 1 0 012 0zm-1 12a7 7 0 110-2h.01a7.003 7.003 0 0 1 0 2z"
+                    />
+                  </svg>
+                </button>
+                <div className="absolute bottom-full left-1/2 transform -translate-x-1/2 mb-2 px-3 py-2 bg-gray-800 text-gray-200 text-xs rounded whitespace-nowrap pointer-events-none opacity-0 group-hover:opacity-100 transition-opacity">
+                  Reserve for new trustlines (0.5 XLM each)
+                </div>
+              </div>
+            </div>
+            <span className="text-yellow-400 font-medium">
+              {breakdown.reserveTopUpXlm.toFixed(4)} XLM
+            </span>
+          </div>
+        )}
+
+        {/* Add-on Costs */}
+        {breakdown.addOnCostsXlm > 0 && (
+          <div className="flex justify-between items-center text-sm">
+            <span className="text-gray-400">Add-on Features</span>
+            <span className="text-gray-200 font-medium">
+              {breakdown.addOnCostsXlm.toFixed(4)} XLM
+            </span>
+          </div>
+        )}
+
+        {/* Divider */}
+        <div className="border-t border-gray-700 my-2" />
+
+        {/* Total */}
+        <div className="flex justify-between items-center text-base">
+          <span className="font-semibold text-gray-100">Total Required</span>
+          <span className={`font-bold ${isBalanceSufficient === false ? 'text-red-400' : 'text-indigo-400'}`}>
+            {totalRequired.toFixed(4)} XLM
+          </span>
+        </div>
+
+        {/* Balance Status */}
+        {creatorBalance !== null && (
+          <div className="mt-3 pt-3 border-t border-gray-700">
+            <div className="flex justify-between items-center text-sm mb-2">
+              <span className="text-gray-400">Your Balance</span>
+              <span
+                className={
+                  isBalanceSufficient === false
+                    ? 'text-red-400 font-medium'
+                    : 'text-green-400 font-medium'
+                }
+              >
+                {creatorBalance.toFixed(4)} XLM
+              </span>
+            </div>
+
+            {isBalanceSufficient === false && (
+              <div className="p-2 bg-red-500/10 border border-red-500/30 rounded text-red-400 text-xs">
+                Insufficient balance. Need {(totalRequired - creatorBalance).toFixed(4)} XLM more.
+              </div>
+            )}
+          </div>
+        )}
+      </div>
+
+      {disabled && (
+        <div className="mt-4 p-2 bg-yellow-500/10 border border-yellow-500/30 rounded text-yellow-400 text-xs">
+          Submit button will be disabled until all costs can be covered.
+        </div>
+      )}
+    </div>
+  );
+}
diff --git a/src/components/invoice/PaymentRetryWizard.tsx b/src/components/invoice/PaymentRetryWizard.tsx
new file mode 100644
index 0000000..1423ac9
--- /dev/null
+++ b/src/components/invoice/PaymentRetryWizard.tsx
@@ -0,0 +1,255 @@
+"use client";
+
+import { useCallback, useState } from "react";
+import FocusTrap from "@/components/FocusTrap";
+import { parseStellarError, type ParsedStellarError } from "@/lib/stellarErrorParser";
+
+interface PaymentRetryWizardProps {
+  open: boolean;
+  error: any;
+  invoiceId: string;
+  retryAttempt: number;
+  onRetry: (feeMultiplier?: number) => Promise<void>;
+  onRefreshSequence: () => Promise<void>;
+  onClose: () => void;
+}
+
+const MAX_RETRY_ATTEMPTS = 3;
+
+export default function PaymentRetryWizard({
+  open,
+  error,
+  invoiceId,
+  retryAttempt,
+  onRetry,
+  onRefreshSequence,
+  onClose,
+}: PaymentRetryWizardProps) {
+  const [step, setStep] = useState<"explanation" | "action" | "complete">("explanation");
+  const [loading, setLoading] = useState(false);
+  const [feeMultiplier, setFeeMultiplier] = useState(1.5);
+  const [actionError, setActionError] = useState<string | null>(null);
+
+  const parsedError: ParsedStellarError = parseStellarError(
+    error?.message || error?.code || String(error),
+    error
+  );
+
+  const isMaxRetriesReached = retryAttempt >= MAX_RETRY_ATTEMPTS;
+
+  const handleBumpFeeRetry = useCallback(async () => {
+    setLoading(true);
+    setActionError(null);
+    try {
+      await onRetry(feeMultiplier);
+      setStep("complete");
+    } catch (err) {
+      setActionError(err instanceof Error ? err.message : String(err));
+      setLoading(false);
+    }
+  }, [feeMultiplier, onRetry]);
+
+  const handleRefreshSequence = useCallback(async () => {
+    setLoading(true);
+    setActionError(null);
+    try {
+      await onRefreshSequence();
+      setStep("complete");
+    } catch (err) {
+      setActionError(err instanceof Error ? err.message : String(err));
+      setLoading(false);
+    }
+  }, [onRefreshSequence]);
+
+  const handleRetry = useCallback(async () => {
+    setLoading(true);
+    setActionError(null);
+    try {
+      await onRetry();
+      setStep("complete");
+    } catch (err) {
+      setActionError(err instanceof Error ? err.message : String(err));
+      setLoading(false);
+    }
+  }, [onRetry]);
+
+  if (!open) return null;
+
+  return (
+    <FocusTrap onClose={onClose}>
+      <div
+        className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 px-4"
+        role="dialog"
+        aria-modal="true"
+        aria-labelledby="retry-wizard-title"
+      >
+        <div className="bg-gray-900 rounded-lg shadow-2xl max-w-md w-full border border-gray-700">
+          <div className="p-6">
+            {step === "explanation" && (
+              <>
+                <h2
+                  id="retry-wizard-title"
+                  className="text-xl font-bold text-white mb-2"
+                >
+                  {parsedError.title}
+                </h2>
+                <p className="text-gray-400 mb-4">{parsedError.explanation}</p>
+
+                {isMaxRetriesReached && (
+                  <div className="mb-4 p-3 bg-red-500/10 border border-red-500/30 rounded text-red-400 text-sm">
+                    You have reached the maximum number of retry attempts ({MAX_RETRY_ATTEMPTS}).
+                    Please contact support if the issue persists.
+                  </div>
+                )}
+
+                <div className="flex gap-3">
+                  <button
+                    onClick={onClose}
+                    className="flex-1 px-4 py-2 rounded-lg bg-gray-800 text-gray-200 hover:bg-gray-700 transition-colors"
+                  >
+                    Cancel
+                  </button>
+                  <button
+                    onClick={() => setStep("action")}
+                    disabled={isMaxRetriesReached}
+                    className="flex-1 px-4 py-2 rounded-lg bg-indigo-600 text-white hover:bg-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+                  >
+                    Try Fix
+                  </button>
+                </div>
+              </>
+            )}
+
+            {step === "action" && (
+              <>
+                <h2 className="text-xl font-bold text-white mb-3">
+                  {parsedError.actionType === "bump-fee" && "Increase Transaction Fee"}
+                  {parsedError.actionType === "refresh-seq" && "Refresh Sequence Number"}
+                  {parsedError.actionType === "fund-destination" && "Fund Destination Account"}
+                  {parsedError.actionType === "manual" && "Resolve Issue"}
+                </h2>
+
+                <p className="text-gray-400 mb-4">{parsedError.suggestedAction}</p>
+
+                {actionError && (
+                  <div className="mb-4 p-3 bg-red-500/10 border border-red-500/30 rounded text-red-400 text-sm">
+                    {actionError}
+                  </div>
+                )}
+
+                {parsedError.actionType === "bump-fee" && (
+                  <div className="mb-4">
+                    <label className="block text-sm text-gray-300 mb-2">
+                      Fee Multiplier: {feeMultiplier.toFixed(1)}x
+                    </label>
+                    <input
+                      type="range"
+                      min="1"
+                      max="5"
+                      step="0.1"
+                      value={feeMultiplier}
+                      onChange={(e) => setFeeMultiplier(parseFloat(e.target.value))}
+                      className="w-full"
+                      disabled={loading}
+                    />
+                    <p className="text-xs text-gray-500 mt-1">
+                      Higher multiplier = faster confirmation but higher cost
+                    </p>
+                  </div>
+                )}
+
+                {parsedError.actionType === "fund-destination" && (
+                  <div className="mb-4 p-3 bg-blue-500/10 border border-blue-500/30 rounded text-blue-400 text-sm">
+                    <p>
+                      On testnet: Use{" "}
+                      <a
+                        href="https://developers.stellar.org/docs/networks/testnet-reset/"
+                        target="_blank"
+                        rel="noopener noreferrer"
+                        className="underline"
+                      >
+                        Friendbot
+                      </a>{" "}
+                      to fund the destination.
+                    </p>
+                  </div>
+                )}
+
+                <div className="flex gap-3">
+                  <button
+                    onClick={() => setStep("explanation")}
+                    disabled={loading}
+                    className="flex-1 px-4 py-2 rounded-lg bg-gray-800 text-gray-200 hover:bg-gray-700 disabled:opacity-50 transition-colors"
+                  >
+                    Back
+                  </button>
+                  {parsedError.actionType === "bump-fee" && (
+                    <button
+                      onClick={handleBumpFeeRetry}
+                      disabled={loading}
+                      className="flex-1 px-4 py-2 rounded-lg bg-indigo-600 text-white hover:bg-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+                    >
+                      {loading ? "Retrying..." : "Retry with Higher Fee"}
+                    </button>
+                  )}
+                  {parsedError.actionType === "refresh-seq" && (
+                    <button
+                      onClick={handleRefreshSequence}
+                      disabled={loading}
+                      className="flex-1 px-4 py-2 rounded-lg bg-indigo-600 text-white hover:bg-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+                    >
+                      {loading ? "Refreshing..." : "Refresh & Retry"}
+                    </button>
+                  )}
+                  {(parsedError.actionType === "fund-destination" ||
+                    parsedError.actionType === "manual") && (
+                    <button
+                      onClick={handleRetry}
+                      disabled={loading}
+                      className="flex-1 px-4 py-2 rounded-lg bg-indigo-600 text-white hover:bg-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors"
+                    >
+                      {loading ? "Retrying..." : "Retry"}
+                    </button>
+                  )}
+                </div>
+              </>
+            )}
+
+            {step === "complete" && (
+              <>
+                <div className="text-center mb-4">
+                  <div className="inline-flex items-center justify-center w-12 h-12 rounded-full bg-green-500/10 border border-green-500/30 mb-3">
+                    <svg
+                      className="w-6 h-6 text-green-400"
+                      fill="none"
+                      stroke="currentColor"
+                      viewBox="0 0 24 24"
+                    >
+                      <path
+                        strokeLinecap="round"
+                        strokeLinejoin="round"
+                        strokeWidth={2}
+                        d="M5 13l4 4L19 7"
+                      />
+                    </svg>
+                  </div>
+                  <h2 className="text-xl font-bold text-white">Retry Submitted</h2>
+                  <p className="text-gray-400 text-sm mt-2">
+                    Your transaction has been resubmitted. It should process shortly.
+                  </p>
+                </div>
+
+                <button
+                  onClick={onClose}
+                  className="w-full px-4 py-2 rounded-lg bg-indigo-600 text-white hover:bg-indigo-700 transition-colors"
+                >
+                  Close
+                </button>
+              </>
+            )}
+          </div>
+        </div>
+      </div>
+    </FocusTrap>
+  );
+}
diff --git a/src/components/invoice/ShareLinkModal.tsx b/src/components/invoice/ShareLinkModal.tsx
new file mode 100644
index 0000000..b93a8c8
--- /dev/null
+++ b/src/components/invoice/ShareLinkModal.tsx
@@ -0,0 +1,313 @@
+'use client';
+
+import { useCallback, useEffect, useState } from 'react';
+import FocusTrap from '@/components/FocusTrap';
+import { formatShareLinkDuration } from '@/lib/shareLink';
+import type { ShareLinkPermission } from '@/lib/shareLink';
+
+interface ActiveShareLink {
+  tokenHash: string;
+  permissions: ShareLinkPermission;
+  expiresAt: string;
+  maxUses?: number;
+  usesConsumed: number;
+  createdAt: string;
+}
+
+interface ShareLinkModalProps {
+  open: boolean;
+  invoiceId: string;
+  onClose: () => void;
+}
+
+const DURATION_OPTIONS = [
+  { label: '1 hour', ms: 3600000 },
+  { label: '24 hours', ms: 86400000 },
+  { label: '7 days', ms: 604800000 },
+  { label: '30 days', ms: 2592000000 },
+] as const;
+
+export default function ShareLinkModal({
+  open,
+  invoiceId,
+  onClose,
+}: ShareLinkModalProps) {
+  const [selectedDuration, setSelectedDuration] = useState(3600000);
+  const [selectedPermission, setSelectedPermission] = useState<ShareLinkPermission>('read');
+  const [singleUse, setSingleUse] = useState(false);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+  const [generatedLink, setGeneratedLink] = useState<string | null>(null);
+  const [activeLinks, setActiveLinks] = useState<ActiveShareLink[]>([]);
+  const [copied, setCopied] = useState(false);
+
+  // Fetch active links
+  const fetchActiveLinks = useCallback(async () => {
+    try {
+      const response = await fetch(`/api/invoices/share-links?invoiceId=${invoiceId}`);
+      if (response.ok) {
+        const data = await response.json();
+        setActiveLinks(data.links || []);
+      }
+    } catch (err) {
+      console.error('Failed to fetch share links:', err);
+    }
+  }, [invoiceId]);
+
+  useEffect(() => {
+    if (open) {
+      fetchActiveLinks();
+    }
+  }, [open, fetchActiveLinks]);
+
+  const handleGenerateLink = async () => {
+    setLoading(true);
+    setError(null);
+    setGeneratedLink(null);
+
+    try {
+      const response = await fetch('/api/invoices/share-links', {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          invoiceId,
+          permissions: selectedPermission,
+          durationMs: selectedDuration,
+          maxUses: singleUse,
+        }),
+      });
+
+      if (!response.ok) {
+        const error = await response.json();
+        throw new Error(error.error || 'Failed to generate share link');
+      }
+
+      const data = await response.json();
+      const baseUrl = typeof window !== 'undefined' ? window.location.origin : '';
+      const fullLink = `${baseUrl}/share/${data.token}`;
+      setGeneratedLink(fullLink);
+
+      // Refresh active links
+      await fetchActiveLinks();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Failed to generate link');
+    } finally {
+      setLoading(false);
+    }
+  };
+
+  const handleCopyLink = () => {
+    if (generatedLink) {
+      navigator.clipboard.writeText(generatedLink).then(() => {
+        setCopied(true);
+        setTimeout(() => setCopied(false), 2000);
+      });
+    }
+  };
+
+  const handleRevokeLink = async (tokenHash: string) => {
+    try {
+      const response = await fetch('/api/invoices/share-links', {
+        method: 'DELETE',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ tokenHash }),
+      });
+
+      if (!response.ok) {
+        throw new Error('Failed to revoke link');
+      }
+
+      // Refresh active links
+      await fetchActiveLinks();
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'Failed to revoke link');
+    }
+  };
+
+  if (!open) return null;
+
+  return (
+    <FocusTrap onClose={onClose}>
+      <div
+        className="fixed inset-0 z-50 flex items-center justify-center bg-black/60 px-4"
+        role="dialog"
+        aria-modal="true"
+        aria-labelledby="share-link-title"
+      >
+        <div className="bg-gray-900 rounded-lg shadow-2xl max-w-lg w-full border border-gray-700 max-h-[90vh] overflow-y-auto">
+          <div className="p-6 space-y-6">
+            {/* Header */}
+            <div className="flex items-center justify-between">
+              <h2 id="share-link-title" className="text-xl font-bold text-white">
+                Share Invoice
+              </h2>
+              <button
+                onClick={onClose}
+                className="text-gray-400 hover:text-gray-300 transition-colors"
+              >
+                <svg className="w-6 h-6" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
+                </svg>
+              </button>
+            </div>
+
+            {/* Generate Link Section */}
+            <div className="space-y-4">
+              <h3 className="text-sm font-semibold text-gray-200">Generate New Link</h3>
+
+              {error && (
+                <div className="p-3 bg-red-500/10 border border-red-500/30 rounded text-red-400 text-sm">
+                  {error}
+                </div>
+              )}
+
+              {/* Duration */}
+              <div>
+                <label className="block text-xs font-medium text-gray-400 mb-2">
+                  Link Duration
+                </label>
+                <select
+                  value={selectedDuration}
+                  onChange={(e) => setSelectedDuration(Number(e.target.value))}
+                  disabled={loading}
+                  className="w-full px-3 py-2 rounded-lg bg-gray-800 border border-gray-700 text-gray-200 text-sm disabled:opacity-50"
+                >
+                  {DURATION_OPTIONS.map((opt) => (
+                    <option key={opt.ms} value={opt.ms}>
+                      {opt.label}
+                    </option>
+                  ))}
+                </select>
+              </div>
+
+              {/* Permission */}
+              <div>
+                <label className="block text-xs font-medium text-gray-400 mb-2">
+                  Permission Level
+                </label>
+                <div className="space-y-2">
+                  {(['read', 'comment', 'read-only'] as const).map((perm) => (
+                    <label key={perm} className="flex items-center gap-2 cursor-pointer">
+                      <input
+                        type="radio"
+                        name="permission"
+                        value={perm}
+                        checked={selectedPermission === perm}
+                        onChange={(e) => setSelectedPermission(e.target.value as ShareLinkPermission)}
+                        disabled={loading}
+                        className="w-4 h-4"
+                      />
+                      <span className="text-sm text-gray-300 capitalize">{perm}</span>
+                      <span className="text-xs text-gray-500">
+                        {perm === 'read' && '(view only)'}
+                        {perm === 'comment' && '(view + comment)'}
+                        {perm === 'read-only' && '(view only)'}
+                      </span>
+                    </label>
+                  ))}
+                </div>
+              </div>
+
+              {/* Single Use */}
+              <label className="flex items-center gap-2 cursor-pointer">
+                <input
+                  type="checkbox"
+                  checked={singleUse}
+                  onChange={(e) => setSingleUse(e.target.checked)}
+                  disabled={loading}
+                  className="w-4 h-4"
+                />
+                <span className="text-sm text-gray-300">Single use only (expires after first access)</span>
+              </label>
+
+              {/* Generated Link */}
+              {generatedLink && (
+                <div className="p-3 bg-green-500/10 border border-green-500/30 rounded space-y-2">
+                  <p className="text-xs font-medium text-green-400">Link Generated!</p>
+                  <div className="flex gap-2">
+                    <input
+                      type="text"
+                      value={generatedLink}
+                      readOnly
+                      className="flex-1 px-2 py-1 bg-gray-800 border border-gray-700 rounded text-xs text-gray-300 font-mono"
+                    />
+                    <button
+                      onClick={handleCopyLink}
+                      className={`px-3 py-1 rounded text-xs font-medium transition-colors ${
+                        copied
+                          ? 'bg-green-600 text-white'
+                          : 'bg-indigo-600 text-white hover:bg-indigo-700'
+                      }`}
+                    >
+                      {copied ? 'Copied!' : 'Copy'}
+                    </button>
+                  </div>
+                </div>
+              )}
+
+              {/* Generate Button */}
+              <button
+                onClick={handleGenerateLink}
+                disabled={loading}
+                className="w-full px-4 py-2 rounded-lg bg-indigo-600 text-white hover:bg-indigo-700 disabled:opacity-50 disabled:cursor-not-allowed transition-colors font-medium text-sm"
+              >
+                {loading ? 'Generating...' : 'Generate Link'}
+              </button>
+            </div>
+
+            {/* Active Links */}
+            {activeLinks.length > 0 && (
+              <div className="space-y-3">
+                <h3 className="text-sm font-semibold text-gray-200">Active Links</h3>
+                <div className="space-y-2 max-h-48 overflow-y-auto">
+                  {activeLinks.map((link) => {
+                    const expiresAt = new Date(link.expiresAt);
+                    const isExpiringSoon = expiresAt.getTime() - Date.now() < 3600000; // < 1 hour
+                    return (
+                      <div
+                        key={link.tokenHash}
+                        className="p-3 bg-gray-800/50 border border-gray-700 rounded space-y-2"
+                      >
+                        <div className="flex items-start justify-between gap-2">
+                          <div className="flex-1 min-w-0">
+                            <p className="text-xs font-medium text-gray-300">
+                              Permission: <span className="capitalize">{link.permissions}</span>
+                            </p>
+                            <p className={`text-xs ${isExpiringSoon ? 'text-yellow-400' : 'text-gray-400'}`}>
+                              Expires: {expiresAt.toLocaleString()}
+                            </p>
+                            {link.maxUses && (
+                              <p className="text-xs text-gray-400">
+                                Uses: {link.usesConsumed}/{link.maxUses}
+                              </p>
+                            )}
+                          </div>
+                          <button
+                            onClick={() => handleRevokeLink(link.tokenHash)}
+                            className="px-2 py-1 text-xs bg-red-600/20 text-red-400 hover:bg-red-600/30 rounded transition-colors"
+                          >
+                            Revoke
+                          </button>
+                        </div>
+                      </div>
+                    );
+                  })}
+                </div>
+              </div>
+            )}
+
+            {/* Footer */}
+            <div className="pt-4 border-t border-gray-700 flex justify-end">
+              <button
+                onClick={onClose}
+                className="px-4 py-2 rounded-lg bg-gray-800 text-gray-200 hover:bg-gray-700 transition-colors font-medium text-sm"
+              >
+                Close
+              </button>
+            </div>
+          </div>
+        </div>
+      </div>
+    </FocusTrap>
+  );
+}
diff --git a/src/hooks/useInvoiceCostEstimate.ts b/src/hooks/useInvoiceCostEstimate.ts
new file mode 100644
index 0000000..c907884
--- /dev/null
+++ b/src/hooks/useInvoiceCostEstimate.ts
@@ -0,0 +1,111 @@
+'use client';
+
+import { useCallback, useMemo, useState, useEffect } from 'react';
+import {
+  calculatePlatformFee,
+  calculateReserveTopUp,
+  getAddOnCosts,
+  type FeatureAddOn,
+} from '@/lib/feeConfig';
+
+export interface CostBreakdown {
+  networkFeeXlm: number;
+  reserveTopUpXlm: number;
+  platformFeeXlm: number;
+  addOnCostsXlm: number;
+  totalXlm: number;
+}
+
+interface UseInvoiceCostEstimateParams {
+  invoiceAmountXlm: number;
+  recipientAddresses: string[];
+  creatorAddress: string;
+  enabledAddOns?: FeatureAddOn[];
+  feeTierMultiplier?: number;
+}
+
+const BASE_NETWORK_FEE_XLM = 0.00001; // 100 stroops
+
+export function useInvoiceCostEstimate({
+  invoiceAmountXlm,
+  recipientAddresses,
+  creatorAddress,
+  enabledAddOns = [],
+  feeTierMultiplier = 1,
+}: UseInvoiceCostEstimateParams) {
+  const [existingTrustlines, setExistingTrustlines] = useState<Set<string>>(new Set());
+  const [creatorBalance, setCreatorBalance] = useState<number | null>(null);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  useEffect(() => {
+    const fetchAccountData = async () => {
+      if (!creatorAddress || !recipientAddresses.length) return;
+
+      setLoading(true);
+      setError(null);
+
+      try {
+        const { Horizon } = await import('@stellar/stellar-sdk');
+        const horizonUrl = process.env.NEXT_PUBLIC_HORIZON_URL || 'https://horizon-testnet.stellar.org';
+        const server = new Horizon.Server(horizonUrl);
+
+        // Fetch creator account for balance and existing trustlines
+        const creatorAccount = await server.loadAccount(creatorAddress);
+        const balances = creatorAccount.balances;
+        const nativeBalance = balances.find((b: any) => b.asset_type === 'native');
+        setCreatorBalance(parseFloat(nativeBalance?.balance || '0'));
+
+        const trustlines = new Set<string>();
+        balances.forEach((b: any) => {
+          if (b.asset_type !== 'native') {
+            trustlines.add(`${b.asset_code}:${b.asset_issuer}`);
+          }
+        });
+        setExistingTrustlines(trustlines);
+      } catch (err) {
+        console.error('Failed to fetch account data:', err);
+        setError(err instanceof Error ? err.message : 'Failed to load account data');
+      } finally {
+        setLoading(false);
+      }
+    };
+
+    fetchAccountData();
+  }, [creatorAddress, recipientAddresses]);
+
+  const breakdown = useMemo((): CostBreakdown => {
+    const networkFeeXlm = BASE_NETWORK_FEE_XLM * feeTierMultiplier;
+    const platformFeeXlm = calculatePlatformFee(invoiceAmountXlm);
+
+    // Estimate new trustlines needed (simplified: assume each recipient might need one)
+    // In reality, this would depend on assets being transferred
+    const estimatedNewTrustlines = Math.max(0, recipientAddresses.length - 1);
+    const reserveTopUpXlm = calculateReserveTopUp(estimatedNewTrustlines);
+
+    const addOnCostsXlm = getAddOnCosts(enabledAddOns);
+
+    const totalXlm = networkFeeXlm + platformFeeXlm + reserveTopUpXlm + addOnCostsXlm;
+
+    return {
+      networkFeeXlm,
+      reserveTopUpXlm,
+      platformFeeXlm,
+      addOnCostsXlm,
+      totalXlm,
+    };
+  }, [invoiceAmountXlm, recipientAddresses.length, feeTierMultiplier, enabledAddOns]);
+
+  const isBalanceSufficient = useMemo(() => {
+    if (creatorBalance === null) return null;
+    return creatorBalance >= invoiceAmountXlm + breakdown.totalXlm;
+  }, [creatorBalance, invoiceAmountXlm, breakdown.totalXlm]);
+
+  return {
+    breakdown,
+    isBalanceSufficient,
+    creatorBalance,
+    loading,
+    error,
+  };
+}
diff --git a/src/lib/feeConfig.ts b/src/lib/feeConfig.ts
new file mode 100644
index 0000000..bb14220
--- /dev/null
+++ b/src/lib/feeConfig.ts
@@ -0,0 +1,52 @@
+/**
+ * Platform fee configuration for invoice creation and management.
+ * These values can be updated to adjust pricing over time.
+ */
+
+export const PLATFORM_FEE_CONFIG = {
+  invoiceCreation: {
+    percentage: 0.01, // 1% of invoice amount
+    minimumXlm: 0.1, // Minimum 0.1 XLM
+  },
+  trustlineReserve: {
+    costXlm: 0.5, // Each trustline costs 0.5 XLM in reserve
+  },
+  networkBaseFee: 100, // stroops (0.00001 XLM), Stellar base fee
+} as const;
+
+export const FEATURE_ADD_ON_COSTS = {
+  installmentPlan: {
+    costXlm: 0.5,
+    description: "Installment payment plan",
+  },
+  customBranding: {
+    costXlm: 1.0,
+    description: "Custom branding and styling",
+  },
+} as const;
+
+export type FeatureAddOn = keyof typeof FEATURE_ADD_ON_COSTS;
+
+/**
+ * Calculate minimum platform fee based on amount
+ */
+export function calculatePlatformFee(invoiceAmountXlm: number): number {
+  const percentage = invoiceAmountXlm * PLATFORM_FEE_CONFIG.invoiceCreation.percentage;
+  return Math.max(percentage, PLATFORM_FEE_CONFIG.invoiceCreation.minimumXlm);
+}
+
+/**
+ * Calculate reserve top-up based on number of new trustlines
+ */
+export function calculateReserveTopUp(newTrustlineCount: number): number {
+  return newTrustlineCount * PLATFORM_FEE_CONFIG.trustlineReserve.costXlm;
+}
+
+/**
+ * Get cost for enabled add-ons
+ */
+export function getAddOnCosts(enabledAddOns: FeatureAddOn[]): number {
+  return enabledAddOns.reduce((total, addon) => {
+    return total + FEATURE_ADD_ON_COSTS[addon].costXlm;
+  }, 0);
+}
diff --git a/src/lib/nlQueryParser.ts b/src/lib/nlQueryParser.ts
new file mode 100644
index 0000000..e553ce7
--- /dev/null
+++ b/src/lib/nlQueryParser.ts
@@ -0,0 +1,316 @@
+/**
+ * Natural language query parser for invoice search.
+ * Parses freeform queries into structured filter parameters.
+ */
+
+export interface ParsedFilter {
+  amountGte?: number;
+  amountLte?: number;
+  asset?: string;
+  status?: 'pending' | 'paid' | 'overdue' | 'draft';
+  dueDateFrom?: Date;
+  dueDateTo?: Date;
+  recipientKeyword?: string;
+  titleKeyword?: string;
+}
+
+export interface FilterToken {
+  type:
+    | 'amount_range'
+    | 'amount_min'
+    | 'amount_max'
+    | 'status'
+    | 'date_range'
+    | 'date_min'
+    | 'date_max'
+    | 'asset'
+    | 'keyword';
+  label: string;
+  value: string;
+}
+
+/**
+ * Parse relative date strings into dates
+ */
+function parseRelativeDate(
+  dateStr: string
+): { from: Date; to: Date } | null {
+  const now = new Date();
+  const today = new Date(now.getFullYear(), now.getMonth(), now.getDate());
+  const yesterday = new Date(today);
+  yesterday.setDate(yesterday.getDate() - 1);
+  const tomorrow = new Date(today);
+  tomorrow.setDate(tomorrow.getDate() + 1);
+
+  const normalized = dateStr.toLowerCase().trim();
+
+  // Yesterday
+  if (normalized === 'yesterday') {
+    const end = new Date(yesterday);
+    end.setHours(23, 59, 59, 999);
+    return { from: yesterday, to: end };
+  }
+
+  // Today
+  if (normalized === 'today') {
+    const end = new Date(today);
+    end.setHours(23, 59, 59, 999);
+    return { from: today, to: end };
+  }
+
+  // Tomorrow
+  if (normalized === 'tomorrow') {
+    const end = new Date(tomorrow);
+    end.setHours(23, 59, 59, 999);
+    return { from: tomorrow, to: end };
+  }
+
+  // This week (Monday to Sunday)
+  if (normalized === 'this week') {
+    const from = new Date(today);
+    const dayOfWeek = from.getDay();
+    from.setDate(from.getDate() - (dayOfWeek === 0 ? 6 : dayOfWeek - 1));
+    const to = new Date(from);
+    to.setDate(to.getDate() + 6);
+    to.setHours(23, 59, 59, 999);
+    return { from, to };
+  }
+
+  // Last week
+  if (normalized === 'last week') {
+    const from = new Date(today);
+    const dayOfWeek = from.getDay();
+    from.setDate(from.getDate() - (dayOfWeek === 0 ? 6 : dayOfWeek - 1) - 7);
+    const to = new Date(from);
+    to.setDate(to.getDate() + 6);
+    to.setHours(23, 59, 59, 999);
+    return { from, to };
+  }
+
+  // This month
+  if (normalized === 'this month') {
+    const from = new Date(today.getFullYear(), today.getMonth(), 1);
+    const to = new Date(today.getFullYear(), today.getMonth() + 1, 0);
+    to.setHours(23, 59, 59, 999);
+    return { from, to };
+  }
+
+  // Last month
+  if (normalized === 'last month') {
+    const from = new Date(today.getFullYear(), today.getMonth() - 1, 1);
+    const to = new Date(today.getFullYear(), today.getMonth(), 0);
+    to.setHours(23, 59, 59, 999);
+    return { from, to };
+  }
+
+  // Past N days
+  const pastDaysMatch = normalized.match(/past\s+(\d+)\s+days?/);
+  if (pastDaysMatch) {
+    const days = parseInt(pastDaysMatch[1], 10);
+    const from = new Date(today);
+    from.setDate(from.getDate() - days);
+    const to = new Date(today);
+    to.setHours(23, 59, 59, 999);
+    return { from, to };
+  }
+
+  return null;
+}
+
+/**
+ * Parse amount from string like "100", "100 XLM", "100xlm"
+ */
+function parseAmount(str: string): number | null {
+  const match = str.match(/(\d+(?:\.\d+)?)/);
+  if (!match) return null;
+  return parseFloat(match[1]);
+}
+
+/**
+ * Parse status keywords
+ */
+function parseStatus(keyword: string): ParsedFilter['status'] | null {
+  const normalized = keyword.toLowerCase().trim();
+  const statusMap: Record<string, ParsedFilter['status']> = {
+    unpaid: 'pending',
+    pending: 'pending',
+    paid: 'paid',
+    overdue: 'overdue',
+    draft: 'draft',
+    cancelled: 'paid', // Map cancelled to paid for filtering
+  };
+  return statusMap[normalized] || null;
+}
+
+/**
+ * Parse asset name
+ */
+function parseAsset(keyword: string): string | null {
+  const normalized = keyword.toUpperCase().trim();
+  const validAssets = ['XLM', 'USDC', 'EURC', 'ETH', 'USDT'];
+  return validAssets.includes(normalized) ? normalized : null;
+}
+
+/**
+ * Main parser function
+ */
+export function parseNaturalLanguageQuery(
+  query: string
+): { filters: ParsedFilter; tokens: FilterToken[] } {
+  const tokens: FilterToken[] = [];
+  const filters: ParsedFilter = {};
+  let remainingQuery = query;
+
+  // Amount range: "between 200 and 400"
+  const betweenMatch = remainingQuery.match(
+    /between\s+(\d+(?:\.\d+)?)\s+(?:and|to)\s+(\d+(?:\.\d+)?)\s*(?:xlm)?/i
+  );
+  if (betweenMatch) {
+    const min = parseFloat(betweenMatch[1]);
+    const max = parseFloat(betweenMatch[2]);
+    filters.amountGte = Math.min(min, max);
+    filters.amountLte = Math.max(min, max);
+    tokens.push({
+      type: 'amount_range',
+      label: `Amount between ${min} and ${max} XLM`,
+      value: `${min}-${max}`,
+    });
+    remainingQuery = remainingQuery.replace(betweenMatch[0], '');
+  }
+
+  // Amount minimum: "over X", "more than X", "at least X"
+  const amountMinMatch = remainingQuery.match(
+    /(?:over|more\s+than|at\s+least)\s+(\d+(?:\.\d+)?)\s*(?:xlm)?/i
+  );
+  if (amountMinMatch) {
+    const amount = parseFloat(amountMinMatch[1]);
+    filters.amountGte = amount;
+    tokens.push({
+      type: 'amount_min',
+      label: `Amount ≥ ${amount} XLM`,
+      value: String(amount),
+    });
+    remainingQuery = remainingQuery.replace(amountMinMatch[0], '');
+  }
+
+  // Amount maximum: "under X", "less than X", "below X"
+  const amountMaxMatch = remainingQuery.match(
+    /(?:under|less\s+than|below)\s+(\d+(?:\.\d+)?)\s*(?:xlm)?/i
+  );
+  if (amountMaxMatch) {
+    const amount = parseFloat(amountMaxMatch[1]);
+    filters.amountLte = amount;
+    tokens.push({
+      type: 'amount_max',
+      label: `Amount ≤ ${amount} XLM`,
+      value: String(amount),
+    });
+    remainingQuery = remainingQuery.replace(amountMaxMatch[0], '');
+  }
+
+  // Status keywords
+  const statusKeywords = ['unpaid', 'pending', 'paid', 'overdue', 'draft', 'cancelled'];
+  for (const keyword of statusKeywords) {
+    const regex = new RegExp(`\\b${keyword}\\b`, 'i');
+    if (regex.test(remainingQuery)) {
+      const status = parseStatus(keyword);
+      if (status) {
+        filters.status = status;
+        tokens.push({
+          type: 'status',
+          label: `Status: ${status}`,
+          value: status,
+        });
+      }
+      remainingQuery = remainingQuery.replace(regex, '');
+      break;
+    }
+  }
+
+  // Relative date ranges
+  const datePatterns = [
+    'past \\d+ days?',
+    'last month',
+    'last week',
+    'this month',
+    'this week',
+    'today',
+    'yesterday',
+    'tomorrow',
+  ];
+  for (const pattern of datePatterns) {
+    const regex = new RegExp(pattern, 'i');
+    const match = remainingQuery.match(regex);
+    if (match) {
+      const dateRange = parseRelativeDate(match[0]);
+      if (dateRange) {
+        filters.dueDateFrom = dateRange.from;
+        filters.dueDateTo = dateRange.to;
+        tokens.push({
+          type: 'date_range',
+          label: `Date: ${match[0]}`,
+          value: match[0],
+        });
+      }
+      remainingQuery = remainingQuery.replace(regex, '');
+      break;
+    }
+  }
+
+  // Asset name: "XLM", "USDC", etc.
+  const assetMatch = remainingQuery.match(/\b(xlm|usdc|eurc|eth|usdt)\b/i);
+  if (assetMatch) {
+    const asset = parseAsset(assetMatch[1]);
+    if (asset) {
+      filters.asset = asset;
+      tokens.push({
+        type: 'asset',
+        label: `Asset: ${asset}`,
+        value: asset,
+      });
+    }
+    remainingQuery = remainingQuery.replace(assetMatch[0], '');
+  }
+
+  // Remaining text as keyword fallback
+  const keyword = remainingQuery.trim();
+  if (keyword.length > 0) {
+    filters.titleKeyword = keyword;
+    tokens.push({
+      type: 'keyword',
+      label: `Keyword: ${keyword}`,
+      value: keyword,
+    });
+  }
+
+  return { filters, tokens };
+}
+
+/**
+ * Apply parsed filters to invoice array
+ */
+export function applyParsedFilters<T extends { amount?: number; status?: string; title?: string; recipients?: Array<{ address: string }> }>(
+  items: T[],
+  filters: ParsedFilter
+): T[] {
+  return items.filter((item) => {
+    if (filters.amountGte !== undefined && (item.amount || 0) < filters.amountGte) {
+      return false;
+    }
+    if (filters.amountLte !== undefined && (item.amount || 0) > filters.amountLte) {
+      return false;
+    }
+    if (filters.status && item.status !== filters.status) {
+      return false;
+    }
+    if (filters.titleKeyword) {
+      const title = (item.title || '').toLowerCase();
+      const recipientAddrs = (item.recipients || []).map((r) => r.address.toLowerCase()).join(' ');
+      const searchText = title + ' ' + recipientAddrs;
+      if (!searchText.includes(filters.titleKeyword.toLowerCase())) {
+        return false;
+      }
+    }
+    return true;
+  });
+}
diff --git a/src/lib/shareLink.ts b/src/lib/shareLink.ts
new file mode 100644
index 0000000..dadd5ca
--- /dev/null
+++ b/src/lib/shareLink.ts
@@ -0,0 +1,154 @@
+import crypto from 'crypto';
+
+export type ShareLinkPermission = 'read' | 'comment' | 'read-only';
+
+export interface ShareLink {
+  tokenHash: string;
+  invoiceId: string;
+  permissions: ShareLinkPermission;
+  expiresAt: Date;
+  maxUses?: number;
+  usesConsumed: number;
+  createdAt: Date;
+  revokedAt?: Date;
+  token?: string; // Only returned when creating
+}
+
+/**
+ * In-memory store for share links.
+ * In production, this should be replaced with a database.
+ */
+const shareLinkStore = new Map<string, ShareLink>();
+
+/**
+ * Generate a cryptographically secure random token
+ */
+export function generateShareToken(): string {
+  return crypto.randomBytes(32).toString('hex');
+}
+
+/**
+ * Hash a token using SHA-256 (for storage)
+ */
+export function hashToken(token: string): string {
+  return crypto.createHash('sha256').update(token).digest('hex');
+}
+
+/**
+ * Timing-safe token comparison
+ */
+export function timingSafeCompareToken(provided: string, stored: string): boolean {
+  return crypto.timingSafeEqual(Buffer.from(provided), Buffer.from(stored));
+}
+
+/**
+ * Create a new share link
+ */
+export function createShareLink(
+  invoiceId: string,
+  permissions: ShareLinkPermission = 'read',
+  durationMs: number = 3600000, // 1 hour default
+  maxUses?: number
+): ShareLink {
+  const token = generateShareToken();
+  const tokenHash = hashToken(token);
+  const now = new Date();
+  const expiresAt = new Date(now.getTime() + durationMs);
+
+  const shareLink: ShareLink = {
+    tokenHash,
+    invoiceId,
+    permissions,
+    expiresAt,
+    maxUses,
+    usesConsumed: 0,
+    createdAt: now,
+    token, // Return the unhashed token once
+  };
+
+  shareLinkStore.set(tokenHash, shareLink);
+  return shareLink;
+}
+
+/**
+ * Validate and retrieve a share link by token
+ */
+export function validateShareLink(
+  token: string
+): { valid: false; reason: string } | { valid: true; link: ShareLink; permission: ShareLinkPermission } {
+  const tokenHash = hashToken(token);
+  const link = shareLinkStore.get(tokenHash);
+
+  if (!link) {
+    return { valid: false, reason: 'Link not found or revoked' };
+  }
+
+  if (link.revokedAt) {
+    return { valid: false, reason: 'Link has been revoked' };
+  }
+
+  if (new Date() > link.expiresAt) {
+    return { valid: false, reason: 'Link has expired' };
+  }
+
+  if (link.maxUses && link.usesConsumed >= link.maxUses) {
+    return { valid: false, reason: 'Link has reached maximum uses' };
+  }
+
+  return { valid: true, link, permission: link.permissions };
+}
+
+/**
+ * Increment uses for a share link
+ */
+export function incrementShareLinkUse(tokenHash: string): void {
+  const link = shareLinkStore.get(tokenHash);
+  if (link) {
+    link.usesConsumed += 1;
+  }
+}
+
+/**
+ * Revoke a share link
+ */
+export function revokeShareLink(tokenHash: string): boolean {
+  const link = shareLinkStore.get(tokenHash);
+  if (link) {
+    link.revokedAt = new Date();
+    return true;
+  }
+  return false;
+}
+
+/**
+ * Get all active share links for an invoice
+ */
+export function getShareLinksForInvoice(invoiceId: string): ShareLink[] {
+  return Array.from(shareLinkStore.values()).filter((link) => {
+    return (
+      link.invoiceId === invoiceId &&
+      !link.revokedAt &&
+      new Date() <= link.expiresAt
+    );
+  });
+}
+
+/**
+ * Format duration for display
+ */
+export function formatShareLinkDuration(ms: number): string {
+  const hours = ms / 3600000;
+  const days = hours / 24;
+
+  if (hours < 1) {
+    const minutes = Math.round(ms / 60000);
+    return `${minutes} minute${minutes !== 1 ? 's' : ''}`;
+  }
+  if (hours < 24) {
+    const h = Math.round(hours);
+    return `${h} hour${h !== 1 ? 's' : ''}`;
+  }
+
+  const d = Math.round(days);
+  return `${d} day${d !== 1 ? 's' : ''}`;
+}
diff --git a/src/lib/stellarErrorParser.ts b/src/lib/stellarErrorParser.ts
new file mode 100644
index 0000000..3615c60
--- /dev/null
+++ b/src/lib/stellarErrorParser.ts
@@ -0,0 +1,100 @@
+export type ErrorActionType = 'bump-fee' | 'refresh-seq' | 'fund-destination' | 'manual';
+
+export interface ParsedStellarError {
+  code: string;
+  title: string;
+  explanation: string;
+  suggestedAction: string;
+  actionType: ErrorActionType;
+}
+
+const ERROR_MAPPING: Record<string, ParsedStellarError> = {
+  tx_insufficient_fee: {
+    code: 'tx_insufficient_fee',
+    title: 'Insufficient Transaction Fee',
+    explanation: 'The transaction fee is too low for current network conditions. Network fees fluctuate based on demand.',
+    suggestedAction: 'Increase the transaction fee using the fee bump slider. Check the median network fee and increase yours accordingly.',
+    actionType: 'bump-fee',
+  },
+  tx_bad_seq: {
+    code: 'tx_bad_seq',
+    title: 'Invalid Sequence Number',
+    explanation: 'The transaction sequence number is outdated or invalid. This can happen if another transaction from this account was recently submitted.',
+    suggestedAction: 'Refresh the sequence number from the blockchain and rebuild the transaction.',
+    actionType: 'refresh-seq',
+  },
+  op_no_destination: {
+    code: 'op_no_destination',
+    title: 'Destination Account Not Found',
+    explanation: 'The recipient account does not exist on the Stellar network. New accounts must be funded first.',
+    suggestedAction: 'Fund the destination account with at least 1 XLM (or use Friendbot on testnet), then retry this payment.',
+    actionType: 'fund-destination',
+  },
+  op_underfunded: {
+    code: 'op_underfunded',
+    title: 'Insufficient Balance',
+    explanation: 'The source account does not have enough balance to cover the payment and transaction fees.',
+    suggestedAction: 'Add more funds to your account and try again.',
+    actionType: 'manual',
+  },
+  tx_failed: {
+    code: 'tx_failed',
+    title: 'Transaction Failed',
+    explanation: 'An operation in the transaction failed. This could be due to various reasons including trustline issues.',
+    suggestedAction: 'Check the detailed error message and verify all account requirements are met.',
+    actionType: 'manual',
+  },
+  op_no_trust: {
+    code: 'op_no_trust',
+    title: 'Missing Trustline',
+    explanation: 'The account does not have a trustline for the asset being transferred.',
+    suggestedAction: 'Establish a trustline for this asset first, then retry.',
+    actionType: 'manual',
+  },
+};
+
+export function parseStellarError(errorCode: string, rawError?: any): ParsedStellarError {
+  const normalizedCode = errorCode.toLowerCase().trim();
+
+  // Check direct mapping
+  if (ERROR_MAPPING[normalizedCode]) {
+    return ERROR_MAPPING[normalizedCode];
+  }
+
+  // Try to extract result_code from Horizon error response
+  const resultCode = rawError?.response?.data?.result_code || rawError?.result_code;
+  if (resultCode && ERROR_MAPPING[resultCode]) {
+    return ERROR_MAPPING[resultCode];
+  }
+
+  // Check for partial matches (e.g., "tx_insufficient_fee" in larger error string)
+  for (const [key, value] of Object.entries(ERROR_MAPPING)) {
+    if (normalizedCode.includes(key) || (typeof rawError === 'string' && rawError.includes(key))) {
+      return value;
+    }
+  }
+
+  // Fallback for unknown errors
+  return {
+    code: 'unknown_error',
+    title: 'Transaction Error',
+    explanation: `The transaction failed with error: ${errorCode}`,
+    suggestedAction: 'Review the error details and contact support if the issue persists.',
+    actionType: 'manual',
+  };
+}
+
+export function isBumpFeeError(error: any): boolean {
+  const parsed = parseStellarError(error?.message || error?.code || String(error), error);
+  return parsed.actionType === 'bump-fee';
+}
+
+export function isSequenceError(error: any): boolean {
+  const parsed = parseStellarError(error?.message || error?.code || String(error), error);
+  return parsed.actionType === 'refresh-seq';
+}
+
+export function isFundingError(error: any): boolean {
+  const parsed = parseStellarError(error?.message || error?.code || String(error), error);
+  return parsed.actionType === 'fund-destination';
+}