diff --git a/flake.nix b/flake.nix
index d1c0e7b..03c5ec3 100644
--- a/flake.nix
+++ b/flake.nix
@@ -48,11 +48,28 @@
             chmod +x $out/bin/fgj
           '';
         };
+
+        # The dagger/nix flake pins 0.20.8, whose Nix wrapper is a broken self-exec
+        # loop.  Fetch 0.21.4 directly so the pre-commit dart-check hook can run.
+        dagger021 = pkgs.stdenv.mkDerivation {
+          pname = "dagger";
+          version = "0.21.4";
+          src = pkgs.fetchurl {
+            url = "https://dl.dagger.io/dagger/releases/0.21.4/dagger_v0.21.4_linux_amd64.tar.gz";
+            sha256 = "0wlnbr4g5069755131yjp2a6alacn64f1c8b27xn0cbynq3zicjd";
+          };
+          sourceRoot = ".";
+          installPhase = ''
+            mkdir -p $out/bin
+            cp dagger $out/bin/dagger
+            chmod +x $out/bin/dagger
+          '';
+        };
       in {
         devShells.default = pkgs.mkShell {
           buildInputs = with pkgs; [
             # Dagger CLI
-            dagger.packages.${system}.dagger
+            dagger021
 
             # Go compiler — for Dagger development
             go
@@ -107,6 +124,9 @@
             # nix develop --command does not set IN_NIX_SHELL; set it so _preflight passes in CI
             export IN_NIX_SHELL=1
 
+            # Point Dagger client at the running engine socket
+            export DAGGER_HOST=unix:///run/dagger/engine.sock
+
             # Disable Flutter telemetry inside dev shell
             export FLUTTER_SUPPRESS_ANALYTICS=true
 
diff --git a/lib/ui/router.dart b/lib/ui/router.dart
index 9b506df..e5b0b3b 100644
--- a/lib/ui/router.dart
+++ b/lib/ui/router.dart
@@ -1,6 +1,7 @@
 import 'package:go_router/go_router.dart';
 
 import 'package:sharedinbox/core/models/sieve_script.dart';
+import 'package:sharedinbox/core/models/undo_action.dart';
 
 import 'package:sharedinbox/ui/screens/about_screen.dart';
 import 'package:sharedinbox/ui/screens/account_list_screen.dart';
@@ -22,6 +23,7 @@ import 'package:sharedinbox/ui/screens/sieve_scripts_screen.dart';
 import 'package:sharedinbox/ui/screens/sync_log_screen.dart';
 import 'package:sharedinbox/ui/screens/thread_detail_screen.dart';
 import 'package:sharedinbox/ui/screens/trusted_image_senders_screen.dart';
+import 'package:sharedinbox/ui/screens/undo_log_detail_screen.dart';
 import 'package:sharedinbox/ui/screens/undo_log_screen.dart';
 import 'package:sharedinbox/ui/screens/user_preferences_screen.dart';
 import 'package:sharedinbox/ui/widgets/undo_shell.dart';
@@ -55,6 +57,14 @@ final router = GoRouter(
             GoRoute(
               path: 'undo-log',
               builder: (ctx, state) => const UndoLogScreen(),
+              routes: [
+                GoRoute(
+                  path: ':actionId',
+                  builder: (ctx, state) => UndoLogDetailScreen(
+                    action: state.extra as UndoAction,
+                  ),
+                ),
+              ],
             ),
             GoRoute(
               path: 'changelog',
diff --git a/lib/ui/screens/undo_log_detail_screen.dart b/lib/ui/screens/undo_log_detail_screen.dart
new file mode 100644
index 0000000..d690c37
--- /dev/null
+++ b/lib/ui/screens/undo_log_detail_screen.dart
@@ -0,0 +1,139 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:intl/intl.dart';
+import 'package:sharedinbox/core/models/email.dart';
+import 'package:sharedinbox/core/models/undo_action.dart';
+import 'package:sharedinbox/di.dart';
+
+final _dateTimeFmt = DateFormat('yyyy-MM-dd HH:mm:ss');
+
+class UndoLogDetailScreen extends ConsumerWidget {
+  const UndoLogDetailScreen({super.key, required this.action});
+
+  final UndoAction action;
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final theme = Theme.of(context);
+
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Undo Log Detail'),
+        actions: [
+          TextButton(
+            onPressed: () async {
+              await ref
+                  .read(undoServiceProvider.notifier)
+                  .undo(actionId: action.id);
+              if (context.mounted) {
+                Navigator.of(context).pop();
+                ScaffoldMessenger.of(context).showSnackBar(
+                  const SnackBar(
+                    duration: Duration(seconds: 5),
+                    content: Text('Action undone.'),
+                  ),
+                );
+              }
+            },
+            child: const Text('Undo'),
+          ),
+        ],
+      ),
+      body: ListView(
+        children: [
+          _SectionHeader(text: 'Transaction', theme: theme),
+          ListTile(
+            leading: const Icon(Icons.account_circle),
+            title: const Text('Account'),
+            subtitle: Text(action.accountId),
+          ),
+          ListTile(
+            leading: Icon(
+              action.type == UndoType.delete
+                  ? Icons.delete_outline
+                  : (action.type == UndoType.snooze
+                      ? Icons.access_time
+                      : Icons.move_to_inbox),
+              color: action.type == UndoType.delete
+                  ? Colors.redAccent
+                  : (action.type == UndoType.snooze
+                      ? Colors.orangeAccent
+                      : Colors.blueAccent),
+            ),
+            title: const Text('Action'),
+            subtitle: Text(action.type.name.toUpperCase()),
+          ),
+          ListTile(
+            leading: const Icon(Icons.schedule),
+            title: const Text('Timestamp'),
+            subtitle: Text(_dateTimeFmt.format(action.timestamp.toLocal())),
+          ),
+          _SectionHeader(text: 'Folders', theme: theme),
+          ListTile(
+            leading: const Icon(Icons.folder_open),
+            title: const Text('Source'),
+            subtitle: Text(action.sourceMailboxPath),
+          ),
+          if (action.type == UndoType.move &&
+              action.destinationMailboxPath != null)
+            ListTile(
+              leading: const Icon(Icons.drive_file_move),
+              title: const Text('Destination'),
+              subtitle: Text(action.destinationMailboxPath!),
+            ),
+          _SectionHeader(
+            text: 'Emails (${action.emailIds.length})',
+            theme: theme,
+          ),
+          if (action.originalEmails.isEmpty)
+            Padding(
+              padding: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
+              child: Text(
+                '${action.emailIds.length} email(s) — details not available',
+                style: theme.textTheme.bodySmall,
+              ),
+            ),
+          ...action.originalEmails.map((email) => _EmailTile(email: email)),
+        ],
+      ),
+    );
+  }
+}
+
+class _SectionHeader extends StatelessWidget {
+  const _SectionHeader({required this.text, required this.theme});
+
+  final String text;
+  final ThemeData theme;
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.fromLTRB(16, 16, 16, 4),
+      child: Text(
+        text,
+        style: theme.textTheme.labelLarge?.copyWith(
+          color: theme.colorScheme.primary,
+        ),
+      ),
+    );
+  }
+}
+
+class _EmailTile extends StatelessWidget {
+  const _EmailTile({required this.email});
+
+  final Email email;
+
+  @override
+  Widget build(BuildContext context) {
+    final sender = email.from.isNotEmpty
+        ? (email.from.first.name ?? email.from.first.email)
+        : '(Unknown Sender)';
+    return ListTile(
+      leading: const Icon(Icons.email_outlined),
+      title: Text(email.subject ?? '(No Subject)'),
+      subtitle: Text(sender, maxLines: 1, overflow: TextOverflow.ellipsis),
+    );
+  }
+}
diff --git a/lib/ui/screens/undo_log_screen.dart b/lib/ui/screens/undo_log_screen.dart
index 334e639..310c3b0 100644
--- a/lib/ui/screens/undo_log_screen.dart
+++ b/lib/ui/screens/undo_log_screen.dart
@@ -2,6 +2,7 @@ import 'dart:async';
 
 import 'package:flutter/material.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
+import 'package:go_router/go_router.dart';
 import 'package:intl/intl.dart';
 import 'package:sharedinbox/core/models/undo_action.dart';
 import 'package:sharedinbox/di.dart';
@@ -55,6 +56,10 @@ class _UndoActionTile extends ConsumerWidget {
     final extraCount = count > 1 ? ' (+${count - 1} more)' : '';
 
     return ListTile(
+      onTap: () => context.go(
+        '/accounts/undo-log/${action.id}',
+        extra: action,
+      ),
       leading: Icon(
         action.type == UndoType.delete
             ? Icons.delete_outline
diff --git a/pubspec.lock b/pubspec.lock
index 83fbe88..17e8bbd 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -659,10 +659,10 @@ packages:
     dependency: transitive
     description:
       name: meta
-      sha256: "23f08335362185a5ea2ad3a4e597f1375e78bce8a040df5c600c8d3552ef2394"
+      sha256: "1741988757a65eb6b36abe716829688cf01910bbf91c34354ff7ec1c3de2b349"
       url: "https://pub.dev"
     source: hosted
-    version: "1.17.0"
+    version: "1.18.0"
   mime:
     dependency: "direct main"
     description:
@@ -1088,26 +1088,26 @@ packages:
     dependency: "direct dev"
     description:
       name: test
-      sha256: "280d6d890011ca966ad08df7e8a4ddfab0fb3aa49f96ed6de56e3521347a9ae7"
+      sha256: "8d9ceddbab833f180fbefed08afa76d7c03513dfdba87ffcec2718b02bbcbf20"
       url: "https://pub.dev"
     source: hosted
-    version: "1.30.0"
+    version: "1.31.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
-      sha256: "8161c84903fd860b26bfdefb7963b3f0b68fee7adea0f59ef805ecca346f0c7a"
+      sha256: "949a932224383300f01be9221c39180316445ecb8e7547f70a41a35bf421fb9e"
       url: "https://pub.dev"
     source: hosted
-    version: "0.7.10"
+    version: "0.7.11"
   test_core:
     dependency: transitive
     description:
       name: test_core
-      sha256: "0381bd1585d1a924763c308100f2138205252fb90c9d4eeaf28489ee65ccde51"
+      sha256: "1991d4cfe85d5043241acac92962c3977c8d2f2add1ee73130c7b286417d1d34"
       url: "https://pub.dev"
     source: hosted
-    version: "0.6.16"
+    version: "0.6.17"
   timezone:
     dependency: transitive
     description:
diff --git a/scripts/check_coverage.dart b/scripts/check_coverage.dart
index 7a9be69..881d674 100644
--- a/scripts/check_coverage.dart
+++ b/scripts/check_coverage.dart
@@ -57,6 +57,7 @@ const _excluded = {
   'lib/ui/screens/sieve_scripts_screen.dart',
   'lib/ui/screens/sync_log_screen.dart',
   'lib/ui/screens/thread_detail_screen.dart',
+  'lib/ui/screens/undo_log_detail_screen.dart',
   'lib/ui/screens/undo_log_screen.dart',
   'lib/ui/widgets/folder_drawer.dart',
   'lib/ui/widgets/secure_email_webview.dart',