diff --git a/lib/widgets/chain_system_ai_editor.dart b/lib/widgets/chain_system_ai_editor.dart
index 90d70d5..b113ac6 100644
--- a/lib/widgets/chain_system_ai_editor.dart
+++ b/lib/widgets/chain_system_ai_editor.dart
@@ -11,6 +11,7 @@ import '../data/hub.dart';
 import '../l10n/app_localizations.dart';
 import '../theme/theme.dart';
 import '../theme/tokens.dart';
+import 'chain_error_box.dart';
 import 'chain_pill.dart';
 
 /// Provider preset metadata kept in sync with
@@ -459,12 +460,10 @@ class _FaiSystemAiEditorState extends State<ChainSystemAiEditor> {
               ],
               if (_error != null) ...[
                 const SizedBox(height: ChainSpace.md),
-                Text(
-                  _error!,
-                  style: theme.textTheme.bodySmall?.copyWith(
-                    color: theme.colorScheme.error,
-                  ),
-                ),
+                // Copyable — every error the operator sees must be
+                // selectable + one-tap copyable (ChainErrorBox), never
+                // a bare Text they can't paste back.
+                ChainErrorBox(text: _error!, isError: true, maxHeight: 200),
               ],
               if (_testResult != null) ...[
                 const SizedBox(height: ChainSpace.md),
@@ -650,10 +649,17 @@ class _TestResultPanel extends StatelessWidget {
             ],
           ),
           const SizedBox(height: 4),
-          SelectableText(
-            ok ? l.systemAiReplyPrefix(result.text) : result.text,
-            style: ChainTheme.mono(size: 11, color: theme.colorScheme.onSurface),
-          ),
+          // Success → the reply preview (selectable). Failure → the
+          // raw error in a ChainErrorBox with an explicit copy button,
+          // so the operator can paste the exact failure back.
+          if (ok)
+            SelectableText(
+              l.systemAiReplyPrefix(result.text),
+              style:
+                  ChainTheme.mono(size: 11, color: theme.colorScheme.onSurface),
+            )
+          else
+            ChainErrorBox(text: result.text, isError: true, maxHeight: 200),
           if (!ok && result.fixHint(l).isNotEmpty) ...[
             const SizedBox(height: ChainSpace.xs),
             Text(