fix(app)!: name herdr as down instead of blaming the connection

app/lib/l10n/app_en.arb

@@ -64,6 +64,7 @@
   "errorSshAuth": "Couldn't sign in to the host. Check the username, private key, and passphrase.",
   "errorHostConnection": "Couldn't reach the host. Check that it's online and the address and port are correct.",
   "errorHostConnectionLost": "Lost the connection to the host. If you connect over a VPN, check that it's still active.",
+  "errorHerdrServerUnreachable": "Connected to the host, but herdr isn't running on it. Start herdr on the host, then try again.",
   "herdrVersionTooOld": "herdr {found} on this host is older than the minimum supported version {minimum}. Update herdr on the host to start agents.",
   "@herdrVersionTooOld": {
     "placeholders": {

app/lib/l10n/app_ja.arb

@@ -54,6 +54,7 @@
   "errorSshAuth": "ホストにサインインできませんでした。ユーザー名・秘密鍵・パスフレーズを確認してください。",
   "errorHostConnection": "ホストに接続できませんでした。オンラインであること、アドレスとポートが正しいことを確認してください。",
   "errorHostConnectionLost": "ホストとの接続が切れました。VPN経由で接続している場合は、有効になっているか確認してください。",
+  "errorHerdrServerUnreachable": "ホストへの接続はできましたが、herdr が起動していません。ホストで herdr を起動してから、もう一度お試しください。",
   "herdrVersionTooOld": "このホストの herdr {found} は、drover が対応する最小バージョン {minimum} を下回っています。エージェントを起動するには、ホスト側の herdr を更新してください。",
   "errorGeneric": "問題が発生しました。",
   "errorDetailsLabel": "詳細",

app/lib/l10n/app_localizations.dart

@@ -416,6 +416,12 @@ abstract class AppLocalizations {
   /// **'Lost the connection to the host. If you connect over a VPN, check that it\'s still active.'**
   String get errorHostConnectionLost;
 
+  /// No description provided for @errorHerdrServerUnreachable.
+  ///
+  /// In en, this message translates to:
+  /// **'Connected to the host, but herdr isn\'t running on it. Start herdr on the host, then try again.'**
+  String get errorHerdrServerUnreachable;
+
   /// No description provided for @herdrVersionTooOld.
   ///
   /// In en, this message translates to:

app/lib/l10n/app_localizations_en.dart

@@ -191,6 +191,10 @@ class AppLocalizationsEn extends AppLocalizations {
   String get errorHostConnectionLost =>
       'Lost the connection to the host. If you connect over a VPN, check that it\'s still active.';
 
+  @override
+  String get errorHerdrServerUnreachable =>
+      'Connected to the host, but herdr isn\'t running on it. Start herdr on the host, then try again.';
+
   @override
   String herdrVersionTooOld(String found, String minimum) {
     return 'herdr $found on this host is older than the minimum supported version $minimum. Update herdr on the host to start agents.';

app/lib/l10n/app_localizations_ja.dart

@@ -180,6 +180,10 @@ class AppLocalizationsJa extends AppLocalizations {
   String get errorHostConnectionLost =>
       'ホストとの接続が切れました。VPN経由で接続している場合は、有効になっているか確認してください。';
 
+  @override
+  String get errorHerdrServerUnreachable =>
+      'ホストへの接続はできましたが、herdr が起動していません。ホストで herdr を起動してから、もう一度お試しください。';
+
   @override
   String herdrVersionTooOld(String found, String minimum) {
     return 'このホストの herdr $found は、drover が対応する最小バージョン $minimum を下回っています。エージェントを起動するには、ホスト側の herdr を更新してください。';

app/lib/previews/preview.dart

@@ -312,7 +312,7 @@ final _errorSamples = <(String, Object)>[
   ),
   (
     'herdr version unsupported',
-    const HerdrVersionUnsupportedException(found: '0.7.0', minimum: '0.7.5'),
+    const HerdrVersionUnsupportedException(found: '0.7.0', minimum: '0.8.0'),
   ),
 ];
 

app/lib/src/demo/demo_backend.dart

@@ -34,7 +34,7 @@ const demoDocsPaneId = 'demo:p3';
 const _reviewTabId = 'demo:t2';
 const _docsTabId = 'demo:t3';
 
-const _demoHerdrVersion = '0.7.5';
+const _demoHerdrVersion = '0.8.0';
 
 /// The demo session's identity, reported as the agent's `agent_session` value.
 /// Must be a real UUID: every native-transcript loader gates on

app/lib/src/herdr/herdr_version.dart

@@ -5,7 +5,14 @@ typedef HerdrVersion = (int, int, int);
 /// prompt` with no fallback or version detection, and `startAgent`/`agent
 /// wait` rely on the `--pane`/`--until` shapes — all 0.7.5-only behaviors
 /// documented in docs/herdr-notes.md. Below this, starting an agent errors.
-const kMinHerdrVersion = (0, 7, 5);
+/// Raised from 0.7.5 to 0.8.0 on 2026-08-13 as a deliberate diagnosability
+/// floor, not because a command shape changed: 0.8.0 is the first version that
+/// reports a stopped herdr server as a `server_not_running` error envelope,
+/// which `app_error.dart` classifies into a message naming herdr rather than
+/// the network. On 0.7.x that same failure surfaces as a bare `Error: Os
+/// { ... }` string users misread as an SSH failure (issue #160), and drover
+/// deliberately does not parse it.
+const kMinHerdrVersion = (0, 8, 0);
 
 /// Extracts the first `major.minor.patch` run of digits from raw `herdr
 /// --version` stdout (e.g. `"herdr 0.7.5\n"`), or null if none is found.

app/lib/src/infra/app_error.dart

@@ -14,6 +14,9 @@ enum AppErrorKind {
   /// The transport layer could not reach or stay connected to the host.
   hostConnection,
 
+  /// SSH reached the host, but herdr's background server isn't running there.
+  herdrServerUnreachable,
+
   /// The host's herdr is older than drover's minimum supported version.
   herdrVersionUnsupported,
 
@@ -26,16 +29,22 @@ enum AppErrorKind {
 /// SSH failures reach the UI two ways: bare (from direct SFTP calls like
 /// listDirectory/resolvePath) or wrapped as a [HerdrException] whose [cause]
 /// is the original SSH exception (from herdr commands, which funnel through
-/// `_exec`). Both are handled. A [HerdrException] with a non-null [cause]
-/// means the transport threw (a real connectivity problem); one with no cause
-/// means herdr ran and reported a failure (or returned junk) — treated as
-/// [AppErrorKind.unknown] so we never tell the user to "check the connection"
-/// for a command that actually reached the host.
+/// `_exec`). Both are handled. A [HerdrException]'s `code` is checked first —
+/// `server_not_running` means SSH reached the host but herdr's background
+/// server is down, regardless of whether a [cause] happens to be set. Only
+/// then does [cause] matter: non-null means the transport threw (a real
+/// connectivity problem); null means herdr ran and reported some other
+/// failure (or returned junk) — treated as [AppErrorKind.unknown] so we never
+/// tell the user to "check the connection" for a command that actually
+/// reached the host.
 AppErrorKind classifyError(Object error) {
   if (error is HerdrVersionUnsupportedException) {
     return AppErrorKind.herdrVersionUnsupported;
   }
   if (error is HerdrException) {
+    if (error.code == 'server_not_running') {
+      return AppErrorKind.herdrServerUnreachable;
+    }
     final cause = error.cause;
     if (cause is SshHostKeyMismatchException) {
       return AppErrorKind.hostKeyMismatch;

app/lib/src/widgets/error_message_view.dart

@@ -32,6 +32,8 @@ String errorHeadline(
       return hostEverConnected
           ? l10n.errorHostConnectionLost
           : l10n.errorHostConnection;
+    case AppErrorKind.herdrServerUnreachable:
+      return l10n.errorHerdrServerUnreachable;
     case AppErrorKind.herdrVersionUnsupported:
       final e = error as HerdrVersionUnsupportedException;
       return l10n.herdrVersionTooOld(e.found, e.minimum);

app/test/demo/demo_backend_test.dart

@@ -143,6 +143,6 @@ void main() {
 
   test('reports a supported herdr version', () async {
     final client = DemoBackend().buildClient();
-    expect(await client.version(), contains('0.7.5'));
+    expect(await client.version(), contains('0.8.0'));
   });
 }

app/test/herdr/herdr_client_test.dart

@@ -104,6 +104,34 @@ void main() {
       );
     });
 
+    test('throws a server_not_running HerdrException when herdr reports its '
+        'background server is down', () async {
+      final runner = FakeCommandRunner(
+        (_) => const CommandResult(
+          exitCode: 1,
+          stdout: '',
+          // Verified against herdr 0.8.0: the envelope lands on stderr with
+          // an empty stdout (see docs/herdr-notes.md).
+          stderr:
+              '{"id":"cli:agent:list","error":{"code":"server_not_running",'
+              '"message":"no herdr server is running at /tmp/nope.sock; run '
+              '`herdr` to start or attach it"}}',
+        ),
+      );
+      final client = HerdrClient(runner);
+
+      await expectLater(
+        client.listAgents(),
+        throwsA(
+          isA<HerdrException>().having(
+            (e) => e.code,
+            'code',
+            'server_not_running',
+          ),
+        ),
+      );
+    });
+
     test('throws the coded error when a non-zero exit carries a JSON error '
         'envelope on stderr', () async {
       final runner = FakeCommandRunner(

app/test/herdr/herdr_version_test.dart

@@ -36,8 +36,8 @@ void main() {
     });
 
     test('accepts a version above the minimum', () {
-      expect(isHerdrVersionSupported((0, 7, 6)), isTrue);
-      expect(isHerdrVersionSupported((0, 8, 0)), isTrue);
+      expect(isHerdrVersionSupported((0, 8, 1)), isTrue);
+      expect(isHerdrVersionSupported((0, 9, 0)), isTrue);
       expect(isHerdrVersionSupported((1, 0, 0)), isTrue);
     });
   });

app/test/infra/app_error_test.dart

@@ -54,6 +54,24 @@ void main() {
       expect(classifyError(error), AppErrorKind.unknown);
     });
 
+    test(
+      'server_not_running without a cause classifies as herdrServerUnreachable',
+      () {
+        final error = HerdrException('server_not_running', 'no server');
+        expect(classifyError(error), AppErrorKind.herdrServerUnreachable);
+      },
+    );
+
+    test('server_not_running with a cause still classifies as '
+        'herdrServerUnreachable', () {
+      final error = HerdrException(
+        'server_not_running',
+        'no server',
+        cause: Exception('socket'),
+      );
+      expect(classifyError(error), AppErrorKind.herdrServerUnreachable);
+    });
+
     test('a plain exception classifies as unknown', () {
       expect(classifyError(Exception('weird')), AppErrorKind.unknown);
     });

app/test/widgets/error_message_view_test.dart

@@ -97,5 +97,24 @@ void main() {
         );
       },
     );
+
+    testWidgets(
+      'server_not_running shows a distinct herdr-not-running message',
+      (tester) async {
+        await tester.pumpWidget(
+          _host(const HerdrException('server_not_running', 'no server')),
+        );
+        await tester.pumpAndSettle();
+        expect(
+          find.textContaining("herdr isn't running on it"),
+          findsOneWidget,
+        );
+        expect(
+          find.textContaining('address and port are correct'),
+          findsNothing,
+        );
+        expect(find.textContaining('Lost the connection'), findsNothing);
+      },
+    );
   });
 }

docs/app-store-submission.md

@@ -113,7 +113,7 @@ before setting anything up.
 WHAT YOU NEED
 Drover is a client for a machine you already own. To use it for real you need a
 computer running Herdr (herdr.dev) with your coding agents in it, SSH access to
-that machine with key-based authentication, and Herdr 0.7.5 or newer.
+that machine with key-based authentication, and Herdr 0.8.0 or newer.
 
 PRIVACY
 Speech recognition runs entirely on your device — Drover will not fall back to
@@ -157,7 +157,7 @@ Drover は端末から自分のマシンへ SSH で直接つなぎます。途
 必要なもの
 Drover は、すでにあなたが持っているマシンのためのクライアントです。実際に使う
 には、コーディングエージェントを動かしている Herdr (herdr.dev) 入りのコンピュータ、
-鍵認証による SSH アクセス、そして Herdr 0.7.5 以降が必要です。
+鍵認証による SSH アクセス、そして Herdr 0.8.0 以降が必要です。
 
 プライバシー
 音声認識は完全に端末内で処理され、サーバーにフォールバックすることはありません。

docs/herdr-notes.md

@@ -25,7 +25,9 @@ which agent is running in the pane.
   <text>`, which types the text and submits it in a single atomic call.
   drover's `HerdrClient.prompt` uses `agent prompt` directly (no fallback, no
   version detection — herdr 0.7.5+ only).
-- (2026-07-24) drover now enforces this 0.7.5 floor itself: `HerdScreen` reads
+- (2026-07-24) drover now enforces a version floor itself — 0.7.5 at the time,
+  raised to 0.8.0 on 2026-08-13 (see the `server_not_running` note below).
+  `HerdScreen` reads
   `herdr --version` per host (`HerdrClient.version`, `herdr_version.dart`'s
   `kMinHerdrVersion`) and shows a persistent warning plus blocks launching new
   agents on any host reporting an older version, since the `agent prompt`/
@@ -146,6 +148,18 @@ which agent is running in the pane.
   now checks both stdout and stderr for a JSON error envelope regardless of
   exit code, so callers see the real `code` no matter which shape a given
   herdr command uses.
+- **A stopped/unreachable herdr background server surfaces as a coded error
+  envelope.** (2026-08-13, herdr 0.8.0) Pointing a command at a missing or
+  listener-less socket (`HERDR_SOCKET_PATH=/tmp/nope.sock herdr agent list`)
+  returns exit 1 with an **empty stdout** and the envelope on **stderr**:
+  `{"error":{"code":"server_not_running","message":"no herdr server is running
+  at /tmp/nope.sock; run herdr to start or attach it"}}`. No client change was
+  needed — `HerdrClient._exec` already probes both channels on a non-zero exit
+  — but note the channel: a stdout-only probe would miss this entirely. Older
+  herdr instead printed a bare `Error: Os { code: 61, kind: ConnectionRefused,
+  ... }` string on stderr with exit 0 for the same situation, which drover
+  surfaces as an opaque message users misread as an SSH failure (issue #160);
+  that is why the minimum supported herdr version moved to 0.8.0.
 
 ## Measurements (Stage 0, 2026-07-18, localhost loopback, Claude Code agent)
 

docs/push-notifications.md

@@ -16,7 +16,7 @@ installs or updates executable code on the Herdr host.
 
 The plugin lives in its own repo,
 [`keinstn/drover-notify`](https://github.com/keinstn/drover-notify). The host
-needs Herdr 0.7.5 or newer and Node.js 18 or newer. Install it on the host:
+needs Herdr 0.8.0 or newer and Node.js 18 or newer. Install it on the host:
 
 ```sh
 herdr plugin install keinstn/drover-notify

site/support/index.md

@@ -27,9 +27,11 @@ You need:
      `C:\ProgramData\ssh\administrators_authorized_keys`, not
      `~\.ssh\authorized_keys` — otherwise the connection fails with "All
      authentication methods failed".
-3. **Herdr 0.7.5 or newer** on that machine. Drover enforces this — starting an
-   agent on an older Herdr fails, because `agent prompt` and the `--pane` /
-   `--until` command shapes it relies on only exist from 0.7.5.
+3. **Herdr 0.8.0 or newer** on that machine. Drover enforces this — starting an
+   agent on an older Herdr fails. `agent prompt` and the `--pane` / `--until`
+   command shapes Drover relies on only exist from 0.7.5, and from 0.8.0 Herdr
+   reports a stopped background server clearly enough for Drover to say so,
+   instead of showing an error that reads like a network failure.
 
 If you just want to see what Drover does before setting any of this up, use the
 demo on the setup screen. It runs entirely on your device with sample data.