diff --git a/app/src/agentworld/pages/IdentitiesSection.test.tsx b/app/src/agentworld/pages/IdentitiesSection.test.tsx
index b1535af6a..3e58a1c73 100644
--- a/app/src/agentworld/pages/IdentitiesSection.test.tsx
+++ b/app/src/agentworld/pages/IdentitiesSection.test.tsx
@@ -1046,6 +1046,77 @@ describe('Trading tab — buy identity (x402)', () => {
     });
   });
 
+  test('Buy buttons re-enable after a purchase and Dismiss clears the banner (#4196)', async () => {
+    vi.mocked(apiClient.marketplace.buyIdentity)
+      .mockResolvedValueOnce({
+        challenge: { amount: '20000000', asset: 'USDC', network: 'solana-devnet' },
+        walletBalance: { raw: '50000000', formatted: '50', decimals: 6, assetSymbol: 'USDC' },
+        walletAddress: 'WalletXyz12345678',
+      })
+      .mockResolvedValueOnce({ result: { saleId: 's1' }, payment: { onChainTx: 'TxId1' } });
+    render(<IdentitiesSection />);
+    await gotoTab('Trading');
+    await userEvent.click(await screen.findByRole('button', { name: 'Buy' }));
+    await userEvent.click(await screen.findByTestId('x402-confirm'));
+
+    // Purchase completed.
+    await screen.findByTestId('buy-identity-success');
+
+    // Regression: the Buy button must NOT stay permanently disabled after a
+    // completed purchase (the old `disabled={buying !== null}` never reset
+    // because `closeBuy` was only reachable from the now-unmounted dialog).
+    expect(screen.getByRole('button', { name: 'Buy' })).toBeEnabled();
+
+    // Dismiss clears the terminal banner and keeps Buy usable.
+    await userEvent.click(screen.getByTestId('buy-identity-dismiss'));
+    expect(screen.queryByTestId('buy-identity-success')).not.toBeInTheDocument();
+    expect(screen.getByRole('button', { name: 'Buy' })).toBeEnabled();
+  });
+
+  test('a failed purchase shows the error banner and Dismiss resets it (#4196)', async () => {
+    vi.mocked(apiClient.marketplace.buyIdentity)
+      .mockResolvedValueOnce({
+        challenge: { amount: '20000000', asset: 'USDC', network: 'solana-devnet' },
+        walletBalance: { raw: '50000000', formatted: '50', decimals: 6, assetSymbol: 'USDC' },
+        walletAddress: 'WalletXyz12345678',
+      })
+      .mockRejectedValueOnce(new Error('settlement boom'));
+    render(<IdentitiesSection />);
+    await gotoTab('Trading');
+    await userEvent.click(await screen.findByRole('button', { name: 'Buy' }));
+    await userEvent.click(await screen.findByTestId('x402-confirm'));
+
+    const errorBanner = await screen.findByTestId('buy-identity-error');
+    expect(errorBanner).toHaveTextContent('Purchase failed.');
+
+    // Buy must re-enable after a failed attempt, and Dismiss clears the banner.
+    expect(screen.getByRole('button', { name: 'Buy' })).toBeEnabled();
+    await userEvent.click(screen.getByTestId('buy-identity-dismiss'));
+    expect(screen.queryByTestId('buy-identity-error')).not.toBeInTheDocument();
+    expect(screen.getByRole('button', { name: 'Buy' })).toBeEnabled();
+  });
+
+  test('a post-payment failure surfaces the broadcast tx in the buy error banner (#4196)', async () => {
+    // The settlement broadcast went out but the purchase did not finalize: the
+    // error carries an `onChainTx=`, so the banner must report "Payment sent…"
+    // (the truthy branch of the buy error message) and re-enable Buy.
+    vi.mocked(apiClient.marketplace.buyIdentity)
+      .mockResolvedValueOnce({
+        challenge: { amount: '20000000', asset: 'USDC', network: 'solana-devnet' },
+        walletBalance: { raw: '50000000', formatted: '50', decimals: 6, assetSymbol: 'USDC' },
+        walletAddress: 'WalletXyz12345678',
+      })
+      .mockRejectedValueOnce(new Error('paid but not confirmed (onChainTx=BuyTx99)'));
+    render(<IdentitiesSection />);
+    await gotoTab('Trading');
+    await userEvent.click(await screen.findByRole('button', { name: 'Buy' }));
+    await userEvent.click(await screen.findByTestId('x402-confirm'));
+
+    const errorBanner = await screen.findByTestId('buy-identity-error');
+    expect(errorBanner).toHaveTextContent('Payment sent but purchase did not complete.');
+    expect(screen.getByRole('button', { name: 'Buy' })).toBeEnabled();
+  });
+
   test('auction listings do not show a Buy button', async () => {
     vi.mocked(apiClient.marketplace.listIdentities).mockResolvedValue({
       identities: [{ ...fixedListing, listingType: 'auction' as const }],
diff --git a/app/src/agentworld/pages/IdentitiesSection.tsx b/app/src/agentworld/pages/IdentitiesSection.tsx
index fa5cdda8f..398e14cfb 100644
--- a/app/src/agentworld/pages/IdentitiesSection.tsx
+++ b/app/src/agentworld/pages/IdentitiesSection.tsx
@@ -707,6 +707,13 @@ function TradingTab() {
   const [buying, setBuying] = useState<IdentityListing | null>(null);
   const buy = useX402Buy((id, opts) => apiClient.marketplace.buyIdentity(id, opts));
   const bs = buy.state;
+  // A buy is "in flight" only while the probe/confirm/pay round-trip is active.
+  // Once it reaches a terminal banner (success/error) the Buy buttons must
+  // re-enable so the user can buy again. Otherwise `buying` stays set forever —
+  // `closeBuy` is only reachable from the dialog, which unmounts on success/error
+  // — and `disabled={buying !== null}` leaves every Buy button permanently
+  // greyed out after the first attempt (#4196).
+  const buyInFlight = buying !== null && bs.phase !== 'success' && bs.phase !== 'error';
   function startBuy(listing: IdentityListing) {
     setBuying(listing);
     buy.begin(listing.listingId);
@@ -810,7 +817,7 @@ function TradingTab() {
                       variant="primary"
                       size="xs"
                       className="flex-1"
-                      disabled={buying !== null}
+                      disabled={buyInFlight}
                       onClick={() => startBuy(listing)}>
                       Buy
                     </Button>
@@ -876,7 +883,16 @@ function TradingTab() {
           <div
             className="mt-3 rounded-md border border-green-500/30 bg-green-500/10 p-3"
             data-testid="buy-identity-success">
-            <p className="text-xs font-medium text-green-500">Purchased {buying.name}</p>
+            <div className="flex items-start justify-between gap-2">
+              <p className="text-xs font-medium text-green-500">Purchased {buying.name}</p>
+              <Button
+                variant="secondary"
+                size="xs"
+                onClick={closeBuy}
+                data-testid="buy-identity-dismiss">
+                Dismiss
+              </Button>
+            </div>
             {bs.onChainTx && (
               <a
                 href={buyExplorerTxUrl(bs.onChainTx, bs.network)}
@@ -892,9 +908,18 @@ function TradingTab() {
           <div
             className="mt-3 rounded-md border border-red-500/30 bg-red-500/10 p-3"
             data-testid="buy-identity-error">
-            <p className="text-xs font-medium text-red-500">
-              {bs.onChainTx ? 'Payment sent but purchase did not complete.' : 'Purchase failed.'}
-            </p>
+            <div className="flex items-start justify-between gap-2">
+              <p className="text-xs font-medium text-red-500">
+                {bs.onChainTx ? 'Payment sent but purchase did not complete.' : 'Purchase failed.'}
+              </p>
+              <Button
+                variant="secondary"
+                size="xs"
+                onClick={closeBuy}
+                data-testid="buy-identity-dismiss">
+                Dismiss
+              </Button>
+            </div>
             <p className="mt-1 text-xs text-content-muted">{bs.message}</p>
           </div>
         )}