diff --git a/src/components/common/LaunchPenaltyWarning.tsx b/src/components/common/LaunchPenaltyWarning.tsx
new file mode 100644
index 00000000..d4b5097b
--- /dev/null
+++ b/src/components/common/LaunchPenaltyWarning.tsx
@@ -0,0 +1,44 @@
+import { AlertTriangle } from 'lucide-react';
+import { bpsToPercent } from '@/utils/numberFormat.utils';
+
+export interface LaunchPenaltyWarningProps {
+ /** Whether the sell falls within the key's 7-day launch window. */
+ visible: boolean;
+ /** Penalty rate in basis points that will be deducted. */
+ penaltyBps: number;
+}
+
+/**
+ * Prominent warning shown on the sell confirmation modal when the key is
+ * still within its 7-day launch window (#825). Deliberately styled bolder
+ * than `StaleDataWarning` — it precedes a signed transaction that will
+ * actually cost the holder the stated percentage of their proceeds.
+ */
+const LaunchPenaltyWarning: React.FC = ({
+ visible,
+ penaltyBps,
+}) => {
+ if (!visible) return null;
+
+ return (
+
+
+
+ Early sell penalty applies —{' '}
+
+ {bpsToPercent(penaltyBps)}
+ {' '}
+ will be deducted from your proceeds.
+
+
+ );
+};
+
+export default LaunchPenaltyWarning;
diff --git a/src/components/common/SellFeeBreakdown.tsx b/src/components/common/SellFeeBreakdown.tsx
new file mode 100644
index 00000000..ad1d84cc
--- /dev/null
+++ b/src/components/common/SellFeeBreakdown.tsx
@@ -0,0 +1,73 @@
+/**
+ * Sell fee breakdown display component.
+ * Shows estimated gross proceeds and, when the key is still within its
+ * 7-day launch window, the launch penalty deducted and the resulting net
+ * proceeds (#825).
+ */
+
+import { formatDisplayKeyPrice } from '@/utils/keyPriceDisplay.utils';
+import { bpsToPercent } from '@/utils/numberFormat.utils';
+import type { LaunchPenaltyBreakdown } from '@/utils/launchPenalty.utils';
+
+export interface SellFeeBreakdownProps {
+ /** Estimated gross proceeds in stroops, before any launch penalty. */
+ grossProceedsStroops: number | null;
+ /** Launch penalty breakdown computed for this sell. */
+ launchPenalty: LaunchPenaltyBreakdown;
+}
+
+/**
+ * Displays the sell proceeds estimate. When `launchPenalty.applies` is
+ * true, also renders the penalty amount deducted and the net proceeds
+ * remaining after the penalty.
+ */
+const SellFeeBreakdown: React.FC = ({
+ grossProceedsStroops,
+ launchPenalty,
+}) => {
+ return (
+
+ {grossProceedsStroops != null ? (
+ <>
+
+ Estimated proceeds (approximate)
+
+ {formatDisplayKeyPrice(grossProceedsStroops)}
+
+
+
+ {launchPenalty.applies && (
+ <>
+
+
+ Launch penalty ({bpsToPercent(launchPenalty.penaltyBps)})
+
+
+ -{formatDisplayKeyPrice(launchPenalty.penaltyStroops)}
+
+
+
+
+ Net proceeds
+
+
+ {formatDisplayKeyPrice(launchPenalty.netProceedsStroops)}
+
+
+ >
+ )}
+ >
+ ) : (
+ <>Estimated proceeds unavailable>
+ )}
+
+ );
+};
+
+export default SellFeeBreakdown;
diff --git a/src/components/common/TradeDialog.tsx b/src/components/common/TradeDialog.tsx
index 4dc5bdbf..8c235b0a 100644
--- a/src/components/common/TradeDialog.tsx
+++ b/src/components/common/TradeDialog.tsx
@@ -18,9 +18,12 @@ import {
import PercentageBadge from '@/components/common/PercentageBadge';
import NetworkFeeHint from '@/components/common/NetworkFeeHint';
import BuyFeeBreakdown from '@/components/common/BuyFeeBreakdown';
+import SellFeeBreakdown from '@/components/common/SellFeeBreakdown';
+import LaunchPenaltyWarning from '@/components/common/LaunchPenaltyWarning';
import { TRADE_FEE_ESTIMATE, FEE_BOUNDS } from '@/constants/fees';
import { formatTransactionFeeDisplay } from '@/utils/transactionFee.utils';
import { clampBuyQuantity } from '@/utils/buyQuantity';
+import { calculateLaunchPenalty } from '@/utils/launchPenalty.utils';
import {
fetchPricePreview,
type FeeBreakdown,
@@ -41,6 +44,12 @@ export interface TradeDialogProps {
protocolFeeBps?: number;
/** Creator fee in basis points for fee preview (defaults to FEE_BOUNDS.DEFAULT_FEE_BPS) */
creatorFeeBps?: number;
+ /** Ledger sequence the key was created at, from the key detail API. */
+ createdAtLedger?: number | null;
+ /** Current network ledger sequence, used to evaluate the 7-day launch window. */
+ currentLedger?: number | null;
+ /** Early-sell penalty in basis points, from the key detail API. */
+ launchPenaltyBps?: number | null;
onOpenChange: (open: boolean) => void;
onConfirm: (
amount: number,
@@ -58,6 +67,9 @@ const TradeDialog: React.FC = ({
currentSupply,
protocolFeeBps = FEE_BOUNDS.DEFAULT_FEE_BPS,
creatorFeeBps = FEE_BOUNDS.DEFAULT_FEE_BPS,
+ createdAtLedger,
+ currentLedger,
+ launchPenaltyBps,
onOpenChange,
onConfirm,
isSubmitting = false,
@@ -141,6 +153,17 @@ const TradeDialog: React.FC = ({
return estimateSellProceeds(keyPriceStroops, currentSupply, parsedAmount);
}, [side, keyPriceStroops, currentSupply, parsedAmount]);
+ const launchPenalty = useMemo(
+ () =>
+ calculateLaunchPenalty(
+ estimatedProceedsStroops,
+ createdAtLedger,
+ currentLedger,
+ launchPenaltyBps
+ ),
+ [estimatedProceedsStroops, createdAtLedger, currentLedger, launchPenaltyBps]
+ );
+
const estimatedTotalStroops = useMemo(() => {
if (
side !== 'buy' ||
@@ -290,6 +313,13 @@ const TradeDialog: React.FC = ({
)}
+ {side === 'sell' && (
+
+ )}
+
)}
{side === 'sell' && (
-
- {estimatedProceedsStroops != null ? (
- <>
- Estimated proceeds (approximate):{' '}
-
- {formatDisplayKeyPrice(estimatedProceedsStroops)}
-
- >
- ) : (
- <>Estimated proceeds unavailable>
- )}
-
+
)}
diff --git a/src/components/common/__tests__/LaunchPenaltyWarning.test.tsx b/src/components/common/__tests__/LaunchPenaltyWarning.test.tsx
new file mode 100644
index 00000000..b12c4111
--- /dev/null
+++ b/src/components/common/__tests__/LaunchPenaltyWarning.test.tsx
@@ -0,0 +1,40 @@
+import { render, screen } from '@testing-library/react';
+import { describe, expect, it } from 'vitest';
+import LaunchPenaltyWarning from '@/components/common/LaunchPenaltyWarning';
+
+describe('LaunchPenaltyWarning', () => {
+ it('renders nothing when not visible', () => {
+ const { container } = render(
+
+ );
+
+ expect(container.firstChild).toBeNull();
+ });
+
+ it('renders the warning with the penalty percentage when visible', () => {
+ render();
+
+ const warning = screen.getByTestId('launch-penalty-warning');
+ expect(warning).toBeInTheDocument();
+ expect(warning).toHaveTextContent('Early sell penalty applies');
+ expect(warning).toHaveTextContent('will be deducted from your proceeds');
+ expect(screen.getByTestId('launch-penalty-rate')).toHaveTextContent('5%');
+ });
+
+ it('formats fractional penalty percentages', () => {
+ render();
+
+ expect(screen.getByTestId('launch-penalty-rate')).toHaveTextContent(
+ '3.33%'
+ );
+ });
+
+ it('has an alert role so assistive tech announces it', () => {
+ render();
+
+ expect(screen.getByTestId('launch-penalty-warning')).toHaveAttribute(
+ 'role',
+ 'alert'
+ );
+ });
+});
diff --git a/src/components/common/__tests__/SellFeeBreakdown.test.tsx b/src/components/common/__tests__/SellFeeBreakdown.test.tsx
new file mode 100644
index 00000000..2e431c89
--- /dev/null
+++ b/src/components/common/__tests__/SellFeeBreakdown.test.tsx
@@ -0,0 +1,88 @@
+import { render, screen } from '@testing-library/react';
+import { describe, expect, it } from 'vitest';
+import SellFeeBreakdown from '@/components/common/SellFeeBreakdown';
+import type { LaunchPenaltyBreakdown } from '@/utils/launchPenalty.utils';
+
+const noPenalty: LaunchPenaltyBreakdown = {
+ applies: false,
+ penaltyBps: 0,
+ penaltyStroops: 0,
+ netProceedsStroops: 1_000_000,
+};
+
+describe('SellFeeBreakdown', () => {
+ it('shows only the gross proceeds estimate when no penalty applies', () => {
+ render(
+
+ );
+
+ expect(screen.getByText(/Estimated proceeds/i)).toBeInTheDocument();
+ expect(screen.getByText(/0\.10? XLM/)).toBeInTheDocument();
+ expect(
+ screen.queryByTestId('sell-fee-breakdown-penalty')
+ ).not.toBeInTheDocument();
+ expect(
+ screen.queryByTestId('sell-fee-breakdown-net')
+ ).not.toBeInTheDocument();
+ });
+
+ it('shows "Estimated proceeds unavailable" when gross proceeds are null', () => {
+ render(
+
+ );
+
+ expect(
+ screen.getByText('Estimated proceeds unavailable')
+ ).toBeInTheDocument();
+ });
+
+ it('shows the penalty line item and net proceeds when the penalty applies', () => {
+ const penalty: LaunchPenaltyBreakdown = {
+ applies: true,
+ penaltyBps: 500,
+ penaltyStroops: 50_000,
+ netProceedsStroops: 950_000,
+ };
+
+ render(
+
+ );
+
+ const penaltyRow = screen.getByTestId('sell-fee-breakdown-penalty');
+ expect(penaltyRow).toHaveTextContent('Launch penalty (5%)');
+ expect(penaltyRow).toHaveTextContent('0.005 XLM');
+
+ const netRow = screen.getByTestId('sell-fee-breakdown-net');
+ expect(netRow).toHaveTextContent('Net proceeds');
+ expect(netRow).toHaveTextContent('0.095 XLM');
+ });
+
+ it('formats the net proceeds correctly for a large penalty', () => {
+ const penalty: LaunchPenaltyBreakdown = {
+ applies: true,
+ penaltyBps: 2000, // 20%
+ penaltyStroops: 200_000,
+ netProceedsStroops: 800_000,
+ };
+
+ render(
+
+ );
+
+ expect(screen.getByTestId('sell-fee-breakdown-penalty')).toHaveTextContent(
+ 'Launch penalty (20%)'
+ );
+ expect(screen.getByTestId('sell-fee-breakdown-net')).toHaveTextContent(
+ '0.08 XLM'
+ );
+ });
+});
diff --git a/src/components/common/__tests__/TradeDialog.launchPenalty.test.tsx b/src/components/common/__tests__/TradeDialog.launchPenalty.test.tsx
new file mode 100644
index 00000000..7bd08ccc
--- /dev/null
+++ b/src/components/common/__tests__/TradeDialog.launchPenalty.test.tsx
@@ -0,0 +1,151 @@
+/**
+ * Unit tests for the launch penalty warning on the sell confirmation
+ * modal (#825). Holders selling within 7 days of a key's creation incur
+ * an early-sell penalty; the modal must surface a warning plus an updated
+ * fee breakdown before the user signs, and let them proceed anyway.
+ */
+import { describe, expect, it, vi } from 'vitest';
+import { render, screen, fireEvent } from '@testing-library/react';
+import TradeDialog from '@/components/common/TradeDialog';
+import { LAUNCH_WINDOW_LEDGERS } from '@/utils/launchPenalty.utils';
+
+describe('TradeDialog – launch penalty warning (#825)', () => {
+ function renderSellDialog(
+ overrides: Partial> = {}
+ ) {
+ return render(
+
+ );
+ }
+
+ it('shows the warning when selling within the 7-day launch window', () => {
+ renderSellDialog({
+ createdAtLedger: 1000,
+ currentLedger: 1000 + 100,
+ launchPenaltyBps: 500, // 5%
+ });
+
+ const warning = screen.getByTestId('launch-penalty-warning');
+ expect(warning).toBeInTheDocument();
+ expect(warning).toHaveTextContent('Early sell penalty applies');
+ expect(screen.getByTestId('launch-penalty-rate')).toHaveTextContent('5%');
+ });
+
+ it('hides the warning once the key is past the launch window', () => {
+ renderSellDialog({
+ createdAtLedger: 1000,
+ currentLedger: 1000 + LAUNCH_WINDOW_LEDGERS + 1,
+ launchPenaltyBps: 500,
+ });
+
+ expect(
+ screen.queryByTestId('launch-penalty-warning')
+ ).not.toBeInTheDocument();
+ });
+
+ it('hides the warning when no launch penalty is configured', () => {
+ renderSellDialog({
+ createdAtLedger: 1000,
+ currentLedger: 1000 + 10,
+ launchPenaltyBps: 0,
+ });
+
+ expect(
+ screen.queryByTestId('launch-penalty-warning')
+ ).not.toBeInTheDocument();
+ });
+
+ it('hides the warning when ledger data is unavailable', () => {
+ renderSellDialog();
+
+ expect(
+ screen.queryByTestId('launch-penalty-warning')
+ ).not.toBeInTheDocument();
+ });
+
+ it('never shows the warning on the buy side', () => {
+ renderSellDialog({
+ side: 'buy',
+ createdAtLedger: 1000,
+ currentLedger: 1050,
+ launchPenaltyBps: 500,
+ });
+
+ expect(
+ screen.queryByTestId('launch-penalty-warning')
+ ).not.toBeInTheDocument();
+ });
+
+ it('displays the penalty amount and net proceeds in the fee breakdown', () => {
+ renderSellDialog({
+ createdAtLedger: 1000,
+ currentLedger: 1050,
+ launchPenaltyBps: 500, // 5%
+ });
+
+ const input = screen.getByTestId('trade-dialog-amount');
+ // keyPriceStroops=500_000 * quantity=4 = 2_000_000 stroops gross (0.2 XLM)
+ fireEvent.change(input, { target: { value: '4' } });
+
+ expect(screen.getByTestId('sell-fee-breakdown-penalty')).toHaveTextContent(
+ 'Launch penalty (5%)'
+ );
+ // 5% of 0.2 XLM = 0.01 XLM
+ expect(screen.getByTestId('sell-fee-breakdown-penalty')).toHaveTextContent(
+ '0.01 XLM'
+ );
+ expect(screen.getByTestId('sell-fee-breakdown-net')).toHaveTextContent(
+ 'Net proceeds'
+ );
+ // 0.2 XLM - 0.01 XLM = 0.19 XLM
+ expect(screen.getByTestId('sell-fee-breakdown-net')).toHaveTextContent(
+ '0.19 XLM'
+ );
+ });
+
+ it('does not show a penalty line item when past the launch window', () => {
+ renderSellDialog({
+ createdAtLedger: 1000,
+ currentLedger: 1000 + LAUNCH_WINDOW_LEDGERS + 1,
+ launchPenaltyBps: 500,
+ });
+
+ const input = screen.getByTestId('trade-dialog-amount');
+ fireEvent.change(input, { target: { value: '4' } });
+
+ expect(
+ screen.queryByTestId('sell-fee-breakdown-penalty')
+ ).not.toBeInTheDocument();
+ expect(
+ screen.queryByTestId('sell-fee-breakdown-net')
+ ).not.toBeInTheDocument();
+ });
+
+ it('still lets the user confirm the sale after the warning is shown', () => {
+ const onConfirm = vi.fn();
+ renderSellDialog({
+ createdAtLedger: 1000,
+ currentLedger: 1050,
+ launchPenaltyBps: 500,
+ onConfirm,
+ });
+
+ expect(screen.getByTestId('launch-penalty-warning')).toBeInTheDocument();
+
+ const input = screen.getByTestId('trade-dialog-amount');
+ fireEvent.change(input, { target: { value: '2' } });
+ fireEvent.click(screen.getByTestId('trade-dialog-confirm'));
+
+ expect(onConfirm).toHaveBeenCalledWith(2, null);
+ });
+});
diff --git a/src/pages/LandingPage.tsx b/src/pages/LandingPage.tsx
index 9712237d..e1996977 100644
--- a/src/pages/LandingPage.tsx
+++ b/src/pages/LandingPage.tsx
@@ -1865,6 +1865,9 @@ function LandingPage() {
keyPriceStroops={resolveCreatorKeyPriceStroops(featuredCreator)}
protocolFeeBps={250}
creatorFeeBps={250}
+ createdAtLedger={featuredCreator?.createdAtLedger}
+ currentLedger={featuredCreator?.currentLedger}
+ launchPenaltyBps={featuredCreator?.launchPenaltyBps}
isSubmitting={tradeSubmitting}
onOpenChange={setTradeDialogOpen}
onConfirm={handleConfirmTrade}
diff --git a/src/services/course.service.ts b/src/services/course.service.ts
index 3da0cdda..7a845bc2 100644
--- a/src/services/course.service.ts
+++ b/src/services/course.service.ts
@@ -51,6 +51,10 @@ export interface Course {
* Applied to sells within the first 7 days after key creation.
*/
launchPenaltyBps?: number;
+ /** Ledger sequence at which this key was created; anchors the 7-day launch window. */
+ createdAtLedger?: number;
+ /** Network ledger sequence as of this response, used to evaluate the launch window. */
+ currentLedger?: number;
}
export type CourseSortOption =
diff --git a/src/utils/__tests__/launchPenalty.utils.test.ts b/src/utils/__tests__/launchPenalty.utils.test.ts
new file mode 100644
index 00000000..94b04aac
--- /dev/null
+++ b/src/utils/__tests__/launchPenalty.utils.test.ts
@@ -0,0 +1,127 @@
+import { describe, it, expect } from 'vitest';
+import {
+ isWithinLaunchWindow,
+ calculateLaunchPenalty,
+ LAUNCH_WINDOW_LEDGERS,
+} from '../launchPenalty.utils';
+
+describe('isWithinLaunchWindow', () => {
+ it('returns true when the sell happens right at creation', () => {
+ expect(isWithinLaunchWindow(1000, 1000)).toBe(true);
+ });
+
+ it('returns true when the sell happens partway through the 7-day window', () => {
+ expect(isWithinLaunchWindow(1000, 1000 + LAUNCH_WINDOW_LEDGERS - 1)).toBe(
+ true
+ );
+ });
+
+ it('returns false once the sell happens at exactly 7 days out', () => {
+ expect(isWithinLaunchWindow(1000, 1000 + LAUNCH_WINDOW_LEDGERS)).toBe(
+ false
+ );
+ });
+
+ it('returns false well past the launch window', () => {
+ expect(
+ isWithinLaunchWindow(1000, 1000 + LAUNCH_WINDOW_LEDGERS * 10)
+ ).toBe(false);
+ });
+
+ it('returns false when currentLedger precedes createdAtLedger', () => {
+ expect(isWithinLaunchWindow(1000, 999)).toBe(false);
+ });
+
+ it.each([
+ [null, 1000],
+ [1000, null],
+ [undefined, 1000],
+ [1000, undefined],
+ [NaN, 1000],
+ [1000, NaN],
+ ])(
+ 'returns false when createdAtLedger=%s or currentLedger=%s is missing/invalid',
+ (createdAtLedger, currentLedger) => {
+ expect(isWithinLaunchWindow(createdAtLedger, currentLedger)).toBe(
+ false
+ );
+ }
+ );
+});
+
+describe('calculateLaunchPenalty', () => {
+ it('applies the penalty within the launch window', () => {
+ const result = calculateLaunchPenalty(1_000_000, 1000, 1500, 500); // 5%
+
+ expect(result).toEqual({
+ applies: true,
+ penaltyBps: 500,
+ penaltyStroops: 50_000,
+ netProceedsStroops: 950_000,
+ });
+ });
+
+ it('does not apply the penalty past the launch window', () => {
+ const result = calculateLaunchPenalty(
+ 1_000_000,
+ 1000,
+ 1000 + LAUNCH_WINDOW_LEDGERS,
+ 500
+ );
+
+ expect(result).toEqual({
+ applies: false,
+ penaltyBps: 0,
+ penaltyStroops: 0,
+ netProceedsStroops: 1_000_000,
+ });
+ });
+
+ it('does not apply when the creator has no launch penalty configured', () => {
+ const result = calculateLaunchPenalty(1_000_000, 1000, 1200, 0);
+
+ expect(result.applies).toBe(false);
+ expect(result.netProceedsStroops).toBe(1_000_000);
+ });
+
+ it('does not apply when launchPenaltyBps is missing', () => {
+ const result = calculateLaunchPenalty(1_000_000, 1000, 1200, undefined);
+
+ expect(result.applies).toBe(false);
+ expect(result.netProceedsStroops).toBe(1_000_000);
+ });
+
+ it('does not apply when ledger data is missing', () => {
+ const result = calculateLaunchPenalty(1_000_000, null, null, 500);
+
+ expect(result.applies).toBe(false);
+ expect(result.netProceedsStroops).toBe(1_000_000);
+ });
+
+ it('falls back to 0 net proceeds when gross proceeds are unavailable', () => {
+ const result = calculateLaunchPenalty(null, 1000, 1200, 500);
+
+ expect(result).toEqual({
+ applies: false,
+ penaltyBps: 0,
+ penaltyStroops: 0,
+ netProceedsStroops: 0,
+ });
+ });
+
+ it('rounds the penalty amount to the nearest stroop', () => {
+ const result = calculateLaunchPenalty(1_000_000, 1000, 1200, 333); // 3.33%
+
+ expect(result.penaltyStroops).toBe(Math.round((1_000_000 * 333) / 10_000));
+ expect(result.netProceedsStroops).toBe(
+ 1_000_000 - result.penaltyStroops
+ );
+ });
+
+ it('applies the maximum configured penalty (20%)', () => {
+ const result = calculateLaunchPenalty(1_000_000, 1000, 1000, 2000);
+
+ expect(result.penaltyStroops).toBe(200_000);
+ expect(result.netProceedsStroops).toBe(800_000);
+ });
+});
diff --git a/src/utils/launchPenalty.utils.ts b/src/utils/launchPenalty.utils.ts
new file mode 100644
index 00000000..696df8d7
--- /dev/null
+++ b/src/utils/launchPenalty.utils.ts
@@ -0,0 +1,105 @@
+/**
+ * Launch penalty utilities for the sell confirmation flow (#825).
+ *
+ * Holders who sell within 7 days of a key's creation incur an early-sell
+ * penalty (configured per-creator via `LaunchPenaltyPanel` / the
+ * `set_launch_penalty` contract call, see `launchPenaltyBps` on `Course`).
+ * These helpers determine whether that launch window is still open and
+ * compute the resulting penalty against a sell's gross proceeds.
+ */
+
+/** Stellar's approximate ledger close time, in milliseconds. */
+const STELLAR_LEDGER_TIME_MS = 5000;
+
+/** Length of the early-sell launch window, in milliseconds (7 days). */
+export const LAUNCH_WINDOW_MS = 7 * 24 * 60 * 60 * 1000;
+
+/** Length of the early-sell launch window, expressed in ledgers. */
+export const LAUNCH_WINDOW_LEDGERS = Math.round(
+ LAUNCH_WINDOW_MS / STELLAR_LEDGER_TIME_MS
+);
+
+/**
+ * Determines whether a sell at `currentLedger` falls within the 7-day
+ * launch window that started at `createdAtLedger`.
+ *
+ * Returns `false` (no penalty) whenever either ledger is missing/invalid,
+ * or when `currentLedger` is at or before `createdAtLedger` (clock skew /
+ * stale data) so a malformed pair never accidentally blocks a sell.
+ */
+export function isWithinLaunchWindow(
+ createdAtLedger: number | null | undefined,
+ currentLedger: number | null | undefined
+): boolean {
+ if (
+ createdAtLedger == null ||
+ currentLedger == null ||
+ !Number.isFinite(createdAtLedger) ||
+ !Number.isFinite(currentLedger)
+ ) {
+ return false;
+ }
+
+ const ledgersSinceCreation = currentLedger - createdAtLedger;
+ return (
+ ledgersSinceCreation >= 0 && ledgersSinceCreation < LAUNCH_WINDOW_LEDGERS
+ );
+}
+
+export interface LaunchPenaltyBreakdown {
+ /** Whether the launch penalty applies to this sell. */
+ applies: boolean;
+ /** Penalty rate in basis points actually applied (0 when it doesn't apply). */
+ penaltyBps: number;
+ /** Penalty amount deducted from gross proceeds, in stroops. */
+ penaltyStroops: number;
+ /** Proceeds remaining after the penalty is deducted, in stroops. */
+ netProceedsStroops: number;
+}
+
+/**
+ * Computes the launch-penalty breakdown for a sell.
+ *
+ * When the key is past its 7-day launch window, or has no penalty
+ * configured, `applies` is `false` and `netProceedsStroops` simply mirrors
+ * `grossProceedsStroops` (falling back to `0` when the gross amount isn't
+ * available).
+ */
+export function calculateLaunchPenalty(
+ grossProceedsStroops: number | null | undefined,
+ createdAtLedger: number | null | undefined,
+ currentLedger: number | null | undefined,
+ launchPenaltyBps: number | null | undefined
+): LaunchPenaltyBreakdown {
+ const gross =
+ grossProceedsStroops != null && Number.isFinite(grossProceedsStroops)
+ ? grossProceedsStroops
+ : 0;
+
+ const withinWindow = isWithinLaunchWindow(createdAtLedger, currentLedger);
+ const bps =
+ launchPenaltyBps != null && Number.isFinite(launchPenaltyBps)
+ ? launchPenaltyBps
+ : 0;
+
+ const applies = withinWindow && bps > 0 && gross > 0;
+
+ if (!applies) {
+ return {
+ applies: false,
+ penaltyBps: 0,
+ penaltyStroops: 0,
+ netProceedsStroops: gross,
+ };
+ }
+
+ const penaltyStroops = Math.round((gross * bps) / 10_000);
+ const netProceedsStroops = gross - penaltyStroops;
+
+ return {
+ applies: true,
+ penaltyBps: bps,
+ penaltyStroops,
+ netProceedsStroops,
+ };
+}