feat(sync): Windows machines work as sync remotes

Remote temp dirs are now created and removed by the remote SubMiner itself (sync --make-temp / --remove-temp, validated against its own tmpdir) instead of mktemp/rm, and the flow detects the remote shell (POSIX, cmd, PowerShell) to pick quoting and SubMiner install-location candidates - %LOCALAPPDATA% app install, launcher shim, or PATH - with no POSIX PATH prefix on Windows. Remote temp paths are normalized to forward slashes for scp and the CLI. Verified end-to-end against a throwaway sshd with the app binary as the resolved remote command.
2026-07-27 16:49:51 -07:00 · 2026-07-11 23:53:40 -07:00
parent 7ed4d4f8e2
commit 94260bab16
20 changed files with 476 additions and 69 deletions
@@ -4,6 +4,7 @@

 ### Added
 - Stats Sync Without the Launcher: The stats sync engine now runs inside the app. The sync window no longer needs bun or the `subminer` command-line launcher installed, and a remote machine only needs SubMiner itself — the app answers `SubMiner --sync-cli sync ...` headless (works over SSH with no display), and remote lookup finds the app binary or the launcher automatically.
+- Stats Sync With Windows Remotes: Sync now detects the remote shell (POSIX, cmd, or PowerShell) and manages remote temp files through SubMiner itself (`sync --make-temp`/`--remove-temp`) instead of `mktemp`/`rm`, so a Windows machine with the built-in OpenSSH Server works as a sync remote; SubMiner is found in its default Windows install location automatically.

 ## v0.18.0 (2026-07-10)

@@ -4,6 +4,7 @@

 **Added**
 - Stats Sync Without the Launcher: The stats sync engine now runs inside the app. The sync window no longer needs bun or the `subminer` command-line launcher installed, and a remote machine only needs SubMiner itself — the app answers `SubMiner --sync-cli sync ...` headless (works over SSH with no display), and remote lookup finds the app binary or the launcher automatically.
+- Stats Sync With Windows Remotes: Sync now detects the remote shell (POSIX, cmd, or PowerShell) and manages remote temp files through SubMiner itself (`sync --make-temp`/`--remove-temp`) instead of `mktemp`/`rm`, so a Windows machine with the built-in OpenSSH Server works as a sync remote; SubMiner is found in its default Windows install location automatically.

 ## v0.18.0 (2026-07-10)

@@ -101,6 +101,8 @@ Close SubMiner (and stop the background stats daemon, `subminer stats -s`) on bo

 On the remote, sync looks for the `subminer` launcher first (PATH and `~/.local/bin`), then the app binary in `--sync-cli` mode (`SubMiner` on PATH, then the standard macOS `/Applications` and `~/Applications` installs), checking standard SubMiner and Bun locations (`~/.local/bin`, `~/.bun/bin`, Homebrew, `/usr/local/bin`, `/usr/bin`, and `/bin`) even when the non-interactive SSH shell omits them from `PATH`. An AppImage in a custom location can be addressed with `--remote-cmd /path/to/SubMiner.AppImage` (or symlink it as `SubMiner` somewhere on the remote PATH).

+Windows remotes are supported: enable Windows' built-in **OpenSSH Server** and sync detects the remote shell (cmd or PowerShell) automatically, finding SubMiner in its default install location (`%LOCALAPPDATA%\Programs\SubMiner`), the launcher shim (`%LOCALAPPDATA%\SubMiner\bin`), or on PATH. Temp files on the remote are created and removed by SubMiner itself (`sync --make-temp` / `--remove-temp`), so no POSIX tools are required on the remote side.
+
 Two lower-level modes are used internally over SSH and also work standalone for manual transfers (e.g. via a USB drive):

 ```bash
@@ -46,6 +46,8 @@ function createContext(): LauncherCommandContext {
      syncForce: false,
      syncJson: false,
      syncCheck: false,
+      syncMakeTemp: false,
+      syncRemoveTempPath: '',
      syncUi: false,
      logLevel: 'info',
      logRotation: 7,
@@ -19,6 +19,8 @@ function makeContext(overrides: Partial<Args>): LauncherCommandContext {
      syncRemoteCmd: '',
      syncDbPath: '',
      syncForce: false,
+      syncMakeTemp: false,
+      syncRemoveTempPath: '',
      logLevel: 'warn',
      ...overrides,
    } as Args,
@@ -85,7 +87,7 @@ test('runSyncCommand dispatches snapshot, merge, host, and missing-target modes'
    resolveRemoteSubminerCommand: () => 'subminer',
    runSsh: (_host: string, command: string) => {
      calls.push(`ssh:${command}`);
-      return command.startsWith('mktemp ') ? ok('/tmp/subminer-sync.remote\n') : ok();
+      return command.includes(' sync --make-temp') ? ok('/tmp/subminer-sync-remote\n') : ok();
    },
    runScp: (from: string, to: string) => {
      calls.push(`scp:${from}->${to}`);
@@ -148,7 +150,7 @@ test('runHostSync keeps tracker quiescent through local and remote merge and cle
    }) as typeof fs.mkdtempSync,
    runSsh: (_host: string, command: string) => {
      calls.push(`ssh:${command}`);
-      if (command.startsWith('mktemp ')) return ok('/tmp/subminer-sync.remote\n');
+      if (command.includes(' sync --make-temp')) return ok('/tmp/subminer-sync-remote\n');
      if (command.includes(' sync --snapshot ')) return ok();
      if (command.includes(' sync --merge ')) {
        return { status: 9, stdout: 'remote output', stderr: 'remote merge exploded' };
@@ -169,7 +171,7 @@ test('runHostSync keeps tracker quiescent through local and remote merge and cle
  assert.equal(calls.filter((call) => call === 'quiescent').length, 3);
  assert.ok(calls.indexOf('quiescent') < calls.findIndex((call) => call.startsWith('snapshot:')));
  assert.ok(calls.includes('local-merge'));
-  assert.ok(calls.some((call) => call.startsWith('ssh:rm -rf ')));
+  assert.ok(calls.some((call) => call.includes(' sync --remove-temp ')));
  assert.equal(fs.existsSync(localTmpDir), false);
 });

@@ -183,7 +185,7 @@ test('runHostSync includes remote snapshot stderr in failures', async () => {
    assertSafeSshHost: () => {},
    resolveRemoteSubminerCommand: () => 'subminer',
    runSsh: (_host: string, command: string) => {
-      if (command.startsWith('mktemp ')) return ok('/tmp/subminer-sync.remote\n');
+      if (command.includes(' sync --make-temp')) return ok('/tmp/subminer-sync-remote\n');
      if (command.includes(' sync --snapshot ')) {
        return { status: 5, stdout: '', stderr: 'snapshot permission denied' };
      }
@@ -218,7 +220,7 @@ function makeDirectionDeps(calls: string[]): Partial<SyncCommandDeps> {
    resolveRemoteSubminerCommand: () => 'subminer',
    runSsh: (_host: string, command: string) => {
      calls.push(`ssh:${command}`);
-      if (command.startsWith('mktemp ')) return ok('/tmp/subminer-sync.remote\n');
+      if (command.includes(' sync --make-temp')) return ok('/tmp/subminer-sync-remote\n');
      return ok();
    },
    runScp: (from: string, to: string) => {
@@ -278,7 +280,7 @@ test('runSyncCommand --json emits NDJSON progress events for a two-way host sync
      return true;
    }) as unknown as typeof process.stdout.write,
    runSsh: (_host: string, command: string) => {
-      if (command.startsWith('mktemp ')) return ok('/tmp/subminer-sync.remote\n');
+      if (command.includes(' sync --make-temp')) return ok('/tmp/subminer-sync-remote\n');
      if (command.includes(' sync --merge ')) return ok('remote summary text\n');
      return ok();
    },
@@ -314,7 +316,7 @@ test('runSyncCommand --json emits an error result when the sync fails', async ()
    },
    writeStdout: (() => true) as unknown as typeof process.stdout.write,
    runSsh: (_host: string, command: string) => {
-      if (command.startsWith('mktemp ')) return ok('/tmp/subminer-sync.remote\n');
+      if (command.includes(' sync --make-temp')) return ok('/tmp/subminer-sync-remote\n');
      if (command.includes(' sync --merge ')) {
        return { status: 9, stdout: '', stderr: 'remote merge exploded' };
      }
@@ -358,7 +360,7 @@ test('runSyncCommand records host sync results for saved-host bookkeeping', asyn
  const failingDeps: Partial<SyncCommandDeps> = {
    ...deps,
    runSsh: (_host: string, command: string) => {
-      if (command.startsWith('mktemp ')) return ok('/tmp/subminer-sync.remote\n');
+      if (command.includes(' sync --make-temp')) return ok('/tmp/subminer-sync-remote\n');
      if (command.includes(' sync --merge ')) {
        return { status: 9, stdout: '', stderr: 'boom' };
      }
@@ -453,3 +455,95 @@ test('runSyncCommand --check --json reports failures without throwing early', as
  assert.equal(check.ok, false);
  assert.match(check.error, /Could not find a runnable/);
 });
+
+test('runHostSync speaks Windows shells: app command, double quotes, temp protocol', async () => {
+  const sshCommands: string[] = [];
+  const scpCalls: string[] = [];
+  const winTemp = 'C:\\Users\\First Last\\AppData\\Local\\Temp\\subminer-sync-remote';
+  const deps: Partial<SyncCommandDeps> = {
+    ...noRecord,
+    createDbSnapshot: (_dbPath: string, outPath: string) => {
+      fs.writeFileSync(outPath, 'snapshot');
+    },
+    mergeSnapshotIntoDb: () => createEmptyMergeSummary(),
+    formatMergeSummary: () => 'summary',
+    ensureTrackerQuiescent: async () => {},
+    assertSafeSshHost: () => {},
+    detectRemoteShellFlavor: () => 'windows-cmd',
+    resolveRemoteSubminerCommand: () => '"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe" --sync-cli',
+    runSsh: (_host: string, command: string) => {
+      sshCommands.push(command);
+      if (command.includes(' sync --make-temp')) return ok(`${winTemp}\r\n`);
+      return ok();
+    },
+    runScp: (from: string, to: string) => {
+      scpCalls.push(`${from}->${to}`);
+      if (!to.includes(':')) fs.writeFileSync(to, 'pulled');
+    },
+  };
+
+  await runSyncCommand(
+    makeContext({ syncDbPath: '/tmp/local.sqlite', syncHost: 'win-box' }),
+    deps,
+  );
+
+  const expectedDir = 'C:/Users/First Last/AppData/Local/Temp/subminer-sync-remote';
+  assert.ok(
+    sshCommands.includes(
+      `"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe" --sync-cli sync --snapshot "${expectedDir}/snapshot.sqlite"`,
+    ),
+  );
+  assert.ok(
+    sshCommands.includes(
+      `"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe" --sync-cli sync --merge "${expectedDir}/incoming.sqlite"`,
+    ),
+  );
+  assert.ok(
+    sshCommands.includes(
+      `"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe" --sync-cli sync --remove-temp "${expectedDir}"`,
+    ),
+  );
+  assert.ok(scpCalls.some((call) => call.startsWith(`win-box:${expectedDir}/snapshot.sqlite->`)));
+  assert.ok(scpCalls.some((call) => call.endsWith(`->win-box:${expectedDir}/incoming.sqlite`)));
+  // No POSIX shell-isms reach a Windows remote.
+  assert.ok(!sshCommands.some((command) => command.startsWith('mktemp') || command.startsWith('rm ')));
+  assert.ok(!sshCommands.some((command) => command.includes('PATH="$HOME')));
+});
+
+test('runSyncCommand --make-temp prints a temp dir and --remove-temp only removes sync temp dirs', async () => {
+  const printed: string[] = [];
+  const removed: string[] = [];
+  const madeDir = fs.mkdtempSync(path.join(os.tmpdir(), 'subminer-sync-'));
+  try {
+    await runSyncCommand(makeContext({ syncMakeTemp: true }), {
+      ...noRecord,
+      mkdtempSync: (() => madeDir) as unknown as typeof fs.mkdtempSync,
+      consoleLog: (line: string) => {
+        printed.push(line);
+      },
+    });
+    assert.deepEqual(printed, [madeDir]);
+
+    await runSyncCommand(makeContext({ syncRemoveTempPath: madeDir }), {
+      ...noRecord,
+      rmSync: ((target: string) => {
+        removed.push(target);
+      }) as typeof fs.rmSync,
+    });
+    assert.deepEqual(removed, [madeDir]);
+
+    await assert.rejects(
+      () =>
+        runSyncCommand(makeContext({ syncRemoveTempPath: '/etc' }), {
+          ...noRecord,
+          rmSync: ((target: string) => {
+            removed.push(target);
+          }) as typeof fs.rmSync,
+        }),
+      /Refusing to remove a directory outside the sync temp area/,
+    );
+    assert.equal(removed.length, 1);
+  } finally {
+    fs.rmSync(madeDir, { recursive: true, force: true });
+  }
+});
@@ -10,6 +10,7 @@ import {
 } from '../sync/sync-db.js';
 import {
  assertSafeSshHost,
+  detectRemoteShellFlavor,
  resolveRemoteSubminerCommand,
  runScp,
  runSsh,
@@ -40,6 +41,7 @@ const defaultSyncCommandDeps: SyncCommandDeps = {
  formatMergeSummary,
  findLiveStatsDaemonPid,
  assertSafeSshHost,
+  detectRemoteShellFlavor,
  resolveRemoteSubminerCommand,
  runScp,
  runSsh,
@@ -145,6 +145,8 @@ test('applyInvocationsToArgs maps config and jellyfin invocation state', () => {
    syncForce: false,
    syncJson: false,
    syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
    syncLogLevel: null,
    syncUiTriggered: false,
    syncUiLogLevel: null,
@@ -204,6 +206,8 @@ test('applyInvocationsToArgs maps settings invocation to settings window', () =>
    syncForce: false,
    syncJson: false,
    syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
    syncLogLevel: null,
    syncUiTriggered: false,
    syncUiLogLevel: null,
@@ -256,6 +260,8 @@ test('applyInvocationsToArgs fails when config invocation has no action', () =>
      syncForce: false,
      syncJson: false,
      syncCheck: false,
+      syncMakeTemp: false,
+      syncRemoveTempPath: '',
      syncLogLevel: null,
      syncUiTriggered: false,
      syncUiLogLevel: null,
@@ -306,6 +312,8 @@ test('applyInvocationsToArgs maps texthooker browser-open request', () => {
    syncForce: false,
    syncJson: false,
    syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
    syncLogLevel: null,
    syncUiTriggered: false,
    syncUiLogLevel: null,
@@ -209,6 +209,8 @@ export function createDefaultArgs(
    syncForce: false,
    syncJson: false,
    syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
    syncUi: false,
    logLevel: loggingConfig.level ?? 'warn',
    logRotation: loggingConfig.rotation ?? 7,
@@ -286,6 +288,8 @@ export function applyInvocationsToArgs(parsed: Args, invocations: CliInvocations
    parsed.syncForce = invocations.syncForce;
    parsed.syncJson = invocations.syncJson;
    parsed.syncCheck = invocations.syncCheck;
+    parsed.syncMakeTemp = invocations.syncMakeTemp;
+    parsed.syncRemoveTempPath = invocations.syncRemoveTempPath ?? '';
    if (invocations.syncLogLevel) parsed.logLevel = parseLogLevel(invocations.syncLogLevel);
  }
  if (invocations.syncUiTriggered) {
@@ -48,6 +48,8 @@ export interface CliInvocations {
  syncForce: boolean;
  syncJson: boolean;
  syncCheck: boolean;
+  syncMakeTemp: boolean;
+  syncRemoveTempPath: string | null;
  syncLogLevel: string | null;
  syncUiTriggered: boolean;
  syncUiLogLevel: string | null;
@@ -188,6 +190,8 @@ export function parseCliPrograms(
  let syncForce = false;
  let syncJson = false;
  let syncCheck = false;
+  let syncMakeTemp = false;
+  let syncRemoveTempPath: string | null = null;
  let syncLogLevel: string | null = null;
  let syncUiTriggered = false;
  let syncUiLogLevel: string | null = null;
@@ -333,6 +337,8 @@ export function parseCliPrograms(
    .option('-f, --force', 'Skip the running-app safety check')
    .option('--check', 'Test the SSH connection and remote subminer availability')
    .option('--json', 'Emit machine-readable NDJSON progress output')
+    .option('--make-temp', 'Create a sync temp directory and print its path (used over SSH)')
+    .option('--remove-temp <dir>', 'Remove a sync temp directory created by --make-temp')
    .option('--ui', 'Open the SubMiner sync window')
    .option('--log-level <level>', 'Log level')
    .action((rawHost: string | undefined, options: Record<string, unknown>) => {
@@ -342,6 +348,8 @@ export function parseCliPrograms(
      const push = options.push === true;
      const pull = options.pull === true;
      const check = options.check === true;
+      const makeTemp = options.makeTemp === true;
+      const removeTemp = typeof options.removeTemp === 'string' ? options.removeTemp.trim() : '';
      if (options.ui === true) {
        if (host || snapshot || merge || push || pull || check || options.force === true) {
          throw new Error('Sync --ui cannot be combined with other sync options.');
@@ -364,12 +372,21 @@ export function parseCliPrograms(
          'Sync --check cannot be combined with --push, --pull, --snapshot, or --merge.',
        );
      }
-      const modes = [Boolean(host), Boolean(snapshot), Boolean(merge)].filter(Boolean).length;
+      if ((makeTemp || removeTemp) && (push || pull || check)) {
+        throw new Error('Sync --make-temp/--remove-temp cannot be combined with other sync options.');
+      }
+      const modes = [
+        Boolean(host),
+        Boolean(snapshot),
+        Boolean(merge),
+        makeTemp,
+        Boolean(removeTemp),
+      ].filter(Boolean).length;
      if (modes === 0) {
        throw new Error('Sync requires a host, --snapshot <file>, or --merge <file>.');
      }
      if (modes > 1) {
-        throw new Error('Sync host, --snapshot, and --merge cannot be combined.');
+        throw new Error('Sync host, --snapshot, --merge, --make-temp, and --remove-temp cannot be combined.');
      }
      syncTriggered = true;
      syncHost = host || null;
@@ -382,6 +399,8 @@ export function parseCliPrograms(
      syncForce = options.force === true;
      syncJson = options.json === true;
      syncCheck = check;
+      syncMakeTemp = makeTemp;
+      syncRemoveTempPath = removeTemp || null;
      syncLogLevel = typeof options.logLevel === 'string' ? options.logLevel : null;
    });

@@ -506,6 +525,8 @@ export function parseCliPrograms(
      syncForce,
      syncJson,
      syncCheck,
+      syncMakeTemp,
+      syncRemoveTempPath,
      syncLogLevel,
      syncUiTriggered,
      syncUiLogLevel,
@@ -40,6 +40,8 @@ function createArgs(): Args {
    syncForce: false,
    syncJson: false,
    syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
    syncUi: false,
    logLevel: 'info',
    logRotation: 7,
@@ -581,6 +581,8 @@ function makeArgs(overrides: Partial<Args> = {}): Args {
    syncForce: false,
    syncJson: false,
    syncCheck: false,
+    syncMakeTemp: false,
+    syncRemoveTempPath: '',
    syncUi: false,
    logLevel: 'error',
    logRotation: 7,
@@ -1,6 +1,18 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { assertSafeSshHost, resolveRemoteSubminerCommand, runScp, shellQuote } from './ssh.js';
+import {
+  assertSafeSshHost,
+  detectRemoteShellFlavor,
+  quoteForRemoteShell,
+  resolveRemoteSubminerCommand,
+  runScp,
+  shellQuote,
+  type RemoteRunResult,
+} from './ssh.js';
+
+function remoteResult(status: number, stdout = ''): RemoteRunResult {
+  return { status, stdout, stderr: '' };
+}

 test('assertSafeSshHost rejects option-like hosts', () => {
  assert.throws(() => assertSafeSshHost('-oProxyCommand=touch pwned'), /looks like an option/);
@@ -32,9 +44,9 @@ test('runScp rejects option-like remote host components', () => {

 test('resolveRemoteSubminerCommand verifies the launcher under the remote runtime PATH', () => {
  const calls: Array<{ host: string; remoteCommand: string }> = [];
-  const command = resolveRemoteSubminerCommand('macbook', null, (host, remoteCommand) => {
+  const command = resolveRemoteSubminerCommand('macbook', null, 'posix', (host, remoteCommand) => {
    calls.push({ host, remoteCommand });
-    return { status: 0, stdout: '', stderr: '' };
+    return remoteResult(0);
  });

  assert.equal(
@@ -52,9 +64,9 @@ test('resolveRemoteSubminerCommand verifies the launcher under the remote runtim

 test('resolveRemoteSubminerCommand falls back to the app binary in --sync-cli mode', () => {
  const probed: string[] = [];
-  const command = resolveRemoteSubminerCommand('media-box', null, (_host, remoteCommand) => {
+  const command = resolveRemoteSubminerCommand('media-box', null, 'posix', (_host, remoteCommand) => {
    probed.push(remoteCommand);
-    return { status: remoteCommand.includes('SubMiner --sync-cli') ? 0 : 1, stdout: '', stderr: '' };
+    return remoteResult(remoteCommand.includes('SubMiner --sync-cli') ? 0 : 1);
  });

  assert.match(command, / SubMiner --sync-cli$/);
@@ -65,25 +77,86 @@ test('resolveRemoteSubminerCommand falls back to the app binary in --sync-cli mo
 });

 test('resolveRemoteSubminerCommand probes a user override as app first, then launcher', () => {
-  const probed: string[] = [];
-  const asApp = resolveRemoteSubminerCommand('media-box', '/opt/SubMiner.AppImage', (_host, cmd) => {
-    probed.push(cmd);
-    return { status: cmd.includes('--sync-cli') ? 0 : 1, stdout: '', stderr: '' };
-  });
+  const asApp = resolveRemoteSubminerCommand('media-box', '/opt/SubMiner.AppImage', 'posix', (_host, cmd) =>
+    remoteResult(cmd.includes('--sync-cli') ? 0 : 1),
+  );
  assert.match(asApp, /'\/opt\/SubMiner\.AppImage' --sync-cli$/);

-  const asLauncher = resolveRemoteSubminerCommand('media-box', '/opt/subminer', (_host, cmd) => {
-    return { status: cmd.includes('--sync-cli') ? 1 : 0, stdout: '', stderr: '' };
-  });
+  const asLauncher = resolveRemoteSubminerCommand('media-box', '/opt/subminer', 'posix', (_host, cmd) =>
+    remoteResult(cmd.includes('--sync-cli') ? 1 : 0),
+  );
  assert.match(asLauncher, /'\/opt\/subminer'$/);

  assert.throws(
-    () =>
-      resolveRemoteSubminerCommand('media-box', '/missing', () => ({
-        status: 127,
-        stdout: '',
-        stderr: '',
-      })),
+    () => resolveRemoteSubminerCommand('media-box', '/missing', 'posix', () => remoteResult(127)),
    /Remote command not found on media-box: \/missing/,
  );
 });
+
+test('resolveRemoteSubminerCommand probes Windows install locations without a PATH prefix', () => {
+  const probed: string[] = [];
+  const command = resolveRemoteSubminerCommand('win-box', null, 'windows-cmd', (_host, cmd) => {
+    probed.push(cmd);
+    return remoteResult(cmd.includes('Programs\\SubMiner\\SubMiner.exe') ? 0 : 1);
+  });
+
+  assert.equal(command, '"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe" --sync-cli');
+  assert.equal(probed[0], 'subminer --help');
+  assert.equal(probed[1], '"%LOCALAPPDATA%\\SubMiner\\bin\\subminer.cmd" --help');
+
+  const powershell = resolveRemoteSubminerCommand('win-box', null, 'windows-powershell', (_host, cmd) =>
+    remoteResult(cmd.includes('Programs\\SubMiner\\SubMiner.exe') ? 0 : 1),
+  );
+  assert.equal(powershell, '& "$env:LOCALAPPDATA\\Programs\\SubMiner\\SubMiner.exe" --sync-cli');
+});
+
+test('resolveRemoteSubminerCommand quotes Windows overrides with double quotes', () => {
+  const command = resolveRemoteSubminerCommand(
+    'win-box',
+    'C:/Apps/SubMiner/SubMiner.exe',
+    'windows-cmd',
+    (_host, cmd) => remoteResult(cmd.includes('--sync-cli') ? 0 : 1),
+  );
+  assert.equal(command, '"C:/Apps/SubMiner/SubMiner.exe" --sync-cli');
+});
+
+test('detectRemoteShellFlavor identifies posix, cmd, and powershell remotes', () => {
+  assert.equal(
+    detectRemoteShellFlavor('linux-box', (_host, cmd) =>
+      cmd === 'uname -s' ? remoteResult(0, 'Linux\n') : remoteResult(1),
+    ),
+    'posix',
+  );
+  assert.equal(
+    detectRemoteShellFlavor('win-box', (_host, cmd) => {
+      if (cmd === 'uname -s') return remoteResult(1);
+      if (cmd === 'echo %OS%') return remoteResult(0, 'Windows_NT\r\n');
+      return remoteResult(1);
+    }),
+    'windows-cmd',
+  );
+  assert.equal(
+    detectRemoteShellFlavor('ps-box', (_host, cmd) => {
+      if (cmd === 'uname -s') return remoteResult(1);
+      if (cmd === 'echo %OS%') return remoteResult(0, '%OS%\r\n');
+      if (cmd === 'echo $env:OS') return remoteResult(0, 'Windows_NT\r\n');
+      return remoteResult(1);
+    }),
+    'windows-powershell',
+  );
+  // Unidentifiable remotes keep the pre-detection POSIX behavior.
+  assert.equal(
+    detectRemoteShellFlavor('odd-box', () => remoteResult(1)),
+    'posix',
+  );
+});
+
+test('quoteForRemoteShell quotes per flavor and rejects unsafe Windows values', () => {
+  assert.equal(quoteForRemoteShell('posix', "/tmp/it's"), `'/tmp/it'\\''s'`);
+  assert.equal(
+    quoteForRemoteShell('windows-cmd', 'C:/Users/First Last/AppData/Local/Temp/subminer-sync-ab'),
+    '"C:/Users/First Last/AppData/Local/Temp/subminer-sync-ab"',
+  );
+  assert.throws(() => quoteForRemoteShell('windows-cmd', 'a"b'), /Refusing to quote/);
+  assert.throws(() => quoteForRemoteShell('windows-powershell', 'a\nb'), /Refusing to quote/);
+});
@@ -2,9 +2,12 @@
 // app's --sync-cli mode resolve remotes and shell out identically.
 export {
  assertSafeSshHost,
+  detectRemoteShellFlavor,
+  quoteForRemoteShell,
  resolveRemoteSubminerCommand,
  runScp,
  runSsh,
  shellQuote,
  type RemoteRunResult,
+  type RemoteShellFlavor,
 } from '../../src/core/services/stats-sync/ssh.js';
@@ -123,6 +123,8 @@ export interface Args {
  syncForce: boolean;
  syncJson: boolean;
  syncCheck: boolean;
+  syncMakeTemp: boolean;
+  syncRemoveTempPath: string;
  syncUi: boolean;
  logLevel: LogLevel;
  logRotation: LogRotation;
@@ -36,6 +36,21 @@ test('parseSyncCliTokens handles help, version, and run modes', () => {
  }
 });

+test('parseSyncCliTokens handles the temp-dir protocol modes', () => {
+  const makeTemp = parseSyncCliTokens(['sync', '--make-temp']);
+  assert.equal(makeTemp.kind, 'run');
+  if (makeTemp.kind === 'run') assert.equal(makeTemp.args.syncMakeTemp, true);
+
+  const removeTemp = parseSyncCliTokens(['sync', '--remove-temp', '/tmp/subminer-sync-x']);
+  assert.equal(removeTemp.kind, 'run');
+  if (removeTemp.kind === 'run') {
+    assert.equal(removeTemp.args.syncRemoveTempPath, '/tmp/subminer-sync-x');
+  }
+
+  assert.equal(parseSyncCliTokens(['sync', '--make-temp', 'host']).kind, 'error');
+  assert.equal(parseSyncCliTokens(['sync', '--make-temp', '--remove-temp', '/tmp/x']).kind, 'error');
+});
+
 test('parseSyncCliTokens mirrors launcher sync validation', () => {
  assert.equal(parseSyncCliTokens([]).kind, 'error');
  assert.equal(parseSyncCliTokens(['sync']).kind, 'error');
@@ -40,6 +40,8 @@ export function parseSyncCliTokens(tokens: readonly string[]): ParsedSyncCli {
  let check = false;
  let force = false;
  let json = false;
+  let makeTemp = false;
+  let removeTemp = '';
  let remoteCmd = '';
  let dbPath = '';
  let logLevel = 'warn';
@@ -47,6 +49,7 @@ export function parseSyncCliTokens(tokens: readonly string[]): ParsedSyncCli {
  const valueFlags = new Map<string, (value: string) => void>([
    ['--snapshot', (value) => (snapshot = value.trim())],
    ['--merge', (value) => (merge = value.trim())],
+    ['--remove-temp', (value) => (removeTemp = value.trim())],
    ['--remote-cmd', (value) => (remoteCmd = value.trim())],
    ['--db', (value) => (dbPath = value.trim())],
    ['--log-level', (value) => (logLevel = value.trim() || 'warn')],
@@ -73,6 +76,7 @@ export function parseSyncCliTokens(tokens: readonly string[]): ParsedSyncCli {
    else if (token === '--check') check = true;
    else if (token === '--force' || token === '-f') force = true;
    else if (token === '--json') json = true;
+    else if (token === '--make-temp') makeTemp = true;
    else if (token.startsWith('-')) {
      return { kind: 'error', message: `Unknown sync option: ${token}` };
    } else if (host) {
@@ -93,12 +97,21 @@ export function parseSyncCliTokens(tokens: readonly string[]): ParsedSyncCli {
      message: 'Sync --check cannot be combined with --push, --pull, --snapshot, or --merge.',
    };
  }
-  const modes = [Boolean(host), Boolean(snapshot), Boolean(merge)].filter(Boolean).length;
+  const modes = [
+    Boolean(host),
+    Boolean(snapshot),
+    Boolean(merge),
+    makeTemp,
+    Boolean(removeTemp),
+  ].filter(Boolean).length;
  if (modes === 0) {
    return { kind: 'error', message: 'Sync requires a host, --snapshot <file>, or --merge <file>.' };
  }
  if (modes > 1) {
-    return { kind: 'error', message: 'Sync host, --snapshot, and --merge cannot be combined.' };
+    return {
+      kind: 'error',
+      message: 'Sync host, --snapshot, --merge, --make-temp, and --remove-temp cannot be combined.',
+    };
  }

  return {
@@ -114,6 +127,8 @@ export function parseSyncCliTokens(tokens: readonly string[]): ParsedSyncCli {
      syncForce: force,
      syncJson: json,
      syncCheck: check,
+      syncMakeTemp: makeTemp,
+      syncRemoveTempPath: removeTemp,
      logLevel,
    },
  };
@@ -138,6 +153,8 @@ export function syncCliUsage(): string {
    '  --remote-cmd <cmd>   SubMiner app or launcher command to run on the remote host',
    '  -f, --force          Skip the running-app safety check',
    '  --json               Emit machine-readable NDJSON progress output',
+    '  --make-temp          Create a sync temp directory and print its path (used over SSH)',
+    '  --remove-temp <dir>  Remove a sync temp directory created by --make-temp',
    '  --log-level <level>  Log level',
    '  --help               Show this help',
    '  --version            Show the SubMiner version',
@@ -71,6 +71,48 @@ export function shellQuote(value: string): string {
  return `'${value.replaceAll("'", `'\\''`)}'`;
 }

+/**
+ * The shell that Windows OpenSSH hands remote commands to (cmd.exe by
+ * default, PowerShell when DefaultShell is changed) — it decides quoting,
+ * environment-variable expansion, and which SubMiner install paths to probe.
+ */
+export type RemoteShellFlavor = 'posix' | 'windows-cmd' | 'windows-powershell';
+
+/**
+ * Identify the remote shell with probes that are harmless everywhere:
+ * `uname -s` only succeeds on a POSIX shell, `echo %OS%` only expands under
+ * cmd.exe, and `echo $env:OS` only expands under PowerShell. Defaults to
+ * posix so unreachable/odd hosts fail with the familiar POSIX errors.
+ */
+export function detectRemoteShellFlavor(
+  host: string,
+  runRemote: typeof runSsh = runSsh,
+): RemoteShellFlavor {
+  const posixProbe = runRemote(host, 'uname -s');
+  if (posixProbe.status === 0 && posixProbe.stdout.trim().length > 0) return 'posix';
+  const cmdProbe = runRemote(host, 'echo %OS%');
+  if (cmdProbe.status === 0 && cmdProbe.stdout.includes('Windows_NT')) return 'windows-cmd';
+  const powershellProbe = runRemote(host, 'echo $env:OS');
+  if (powershellProbe.status === 0 && powershellProbe.stdout.includes('Windows_NT')) {
+    return 'windows-powershell';
+  }
+  return 'posix';
+}
+
+/**
+ * Quote one argument for the detected remote shell. Windows shells have no
+ * safe single-quote escaping (cmd treats ' literally; PowerShell and cmd
+ * disagree on embedded double quotes), so quote-containing values are
+ * rejected instead of escaped — sync only ever quotes paths it composed.
+ */
+export function quoteForRemoteShell(flavor: RemoteShellFlavor, value: string): string {
+  if (flavor === 'posix') return shellQuote(value);
+  if (value.includes('"') || /[\r\n]/.test(value)) {
+    throw new Error(`Refusing to quote a value with quotes or newlines for a Windows shell: ${value}`);
+  }
+  return `"${value}"`;
+}
+
 const REMOTE_RUNTIME_PATH =
  'PATH="$HOME/.local/bin:$HOME/.bun/bin:/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:$PATH"';

@@ -83,7 +125,27 @@ interface RemoteCandidate {
  invocation: string;
 }

-function defaultRemoteCandidates(): RemoteCandidate[] {
+function defaultRemoteCandidates(flavor: RemoteShellFlavor): RemoteCandidate[] {
+  if (flavor === 'windows-cmd' || flavor === 'windows-powershell') {
+    // cmd.exe expands %VAR% inside double quotes; PowerShell needs $env: and
+    // the & call operator to run a quoted path.
+    const launcherShim =
+      flavor === 'windows-cmd'
+        ? `"%LOCALAPPDATA%\\SubMiner\\bin\\subminer.cmd"`
+        : `& "$env:LOCALAPPDATA\\SubMiner\\bin\\subminer.cmd"`;
+    const appInstall =
+      flavor === 'windows-cmd'
+        ? `"%LOCALAPPDATA%\\Programs\\SubMiner\\SubMiner.exe"`
+        : `& "$env:LOCALAPPDATA\\Programs\\SubMiner\\SubMiner.exe"`;
+    return [
+      // Command-line launcher shim on PATH or in its default install dir.
+      { invocation: 'subminer' },
+      { invocation: launcherShim },
+      // The app binary itself in sync-CLI mode (default NSIS install dir).
+      { invocation: `${appInstall} ${APP_SYNC_CLI_FLAG}` },
+      { invocation: `SubMiner ${APP_SYNC_CLI_FLAG}` },
+    ];
+  }
  return [
    // Command-line launcher (bun script) on PATH or in its default install dir.
    { invocation: 'subminer' },
@@ -95,29 +157,38 @@ function defaultRemoteCandidates(): RemoteCandidate[] {
  ];
 }

+function preferredCandidates(flavor: RemoteShellFlavor, preferred: string): RemoteCandidate[] {
+  const quoted = quoteForRemoteShell(flavor, preferred);
+  const invocation = flavor === 'windows-powershell' ? `& ${quoted}` : quoted;
+  // App binaries also answer plain --help by opening the GUI-oriented help
+  // path, so probe the sync-CLI shape first.
+  return [{ invocation: `${invocation} ${APP_SYNC_CLI_FLAG}` }, { invocation }];
+}
+
 /**
- * Non-interactive SSH shells often miss user-installed launchers and Bun.
- * Probe candidates under the same deterministic PATH used by sync itself.
- * Trusted defaults stay unquoted so the remote shell expands `~`; a
- * user-supplied override is shell-quoted to prevent command injection and
- * probed both as an app binary (--sync-cli) and as a launcher.
+ * Non-interactive POSIX SSH shells often miss user-installed launchers and
+ * Bun, so those candidates are probed under the same deterministic PATH sync
+ * itself uses; Windows shells get their default install locations instead.
+ * Trusted defaults stay unquoted so the remote shell expands `~`/%VAR%; a
+ * user-supplied override is quoted to prevent command injection and probed
+ * both as an app binary (--sync-cli) and as a launcher.
 */
 export function resolveRemoteSubminerCommand(
  host: string,
  preferred: string | null,
+  flavor: RemoteShellFlavor = 'posix',
  runRemote: typeof runSsh = runSsh,
 ): string {
-  const candidates: RemoteCandidate[] = preferred
-    ? [
-        // App binaries also answer plain --help by opening the GUI-oriented
-        // help path, so probe the sync-CLI shape first.
-        { invocation: `${shellQuote(preferred)} ${APP_SYNC_CLI_FLAG}` },
-        { invocation: shellQuote(preferred) },
-      ]
-    : defaultRemoteCandidates();
+  const candidates = preferred
+    ? preferredCandidates(flavor, preferred)
+    : defaultRemoteCandidates(flavor);
  for (const candidate of candidates) {
-    const command = `${REMOTE_RUNTIME_PATH} ${candidate.invocation}`;
-    const probe = runRemote(host, `${command} --help >/dev/null 2>&1`);
+    const command =
+      flavor === 'posix' ? `${REMOTE_RUNTIME_PATH} ${candidate.invocation}` : candidate.invocation;
+    const probe = runRemote(
+      host,
+      flavor === 'posix' ? `${command} --help >/dev/null 2>&1` : `${command} --help`,
+    );
    if (probe.status === 0) {
      return command;
    }
@@ -125,6 +196,6 @@ export function resolveRemoteSubminerCommand(
  throw new Error(
    preferred
      ? `Remote command not found on ${host}: ${preferred}`
-      : `SubMiner not found on ${host} (tried the subminer launcher on PATH and ~/.local/bin, and the SubMiner app binary). Pass --remote-cmd <path> pointing at the SubMiner app or launcher.`,
+      : `SubMiner not found on ${host} (tried the subminer launcher and the SubMiner app binary in their default install locations). Pass --remote-cmd <path> pointing at the SubMiner app or launcher.`,
  );
 }
@@ -1,7 +1,7 @@
 import os from 'node:os';
 import path from 'node:path';
-import { shellQuote } from './ssh';
-import type { RemoteRunResult } from './ssh';
+import { quoteForRemoteShell } from './ssh';
+import type { RemoteRunResult, RemoteShellFlavor } from './ssh';
 import type { SyncMergeSummary, SyncProgressEvent } from '../../../shared/sync/sync-events';
 import type { SyncResultStatus } from '../../../shared/sync/sync-hosts-store';

@@ -16,6 +16,8 @@ export interface SyncFlowArgs {
  syncForce: boolean;
  syncJson: boolean;
  syncCheck: boolean;
+  syncMakeTemp: boolean;
+  syncRemoveTempPath: string;
  logLevel: string;
 }

@@ -35,7 +37,15 @@ export interface SyncFlowDeps {
  formatMergeSummary: (summary: SyncMergeSummary) => string;
  findLiveStatsDaemonPid: (dbPath: string) => number | null;
  assertSafeSshHost: (host: string) => void;
-  resolveRemoteSubminerCommand: (host: string, preferred: string | null) => string;
+  detectRemoteShellFlavor: (
+    host: string,
+    runRemote: (host: string, remoteCommand: string) => RemoteRunResult,
+  ) => RemoteShellFlavor;
+  resolveRemoteSubminerCommand: (
+    host: string,
+    preferred: string | null,
+    flavor: RemoteShellFlavor,
+  ) => string;
  runScp: (from: string, to: string) => void;
  runSsh: (host: string, remoteCommand: string) => RemoteRunResult;
  fail: (message: string) => never;
@@ -53,6 +63,40 @@ export interface SyncFlowDeps {
  resolvePath: (value: string) => string;
 }

+/**
+ * Prefix shared by every sync temp dir, local or remote. Remote temp dirs are
+ * created and removed by the remote SubMiner itself (sync --make-temp /
+ * --remove-temp) so the flow never depends on mktemp/rm existing in the
+ * remote shell — that is what makes Windows remotes work.
+ */
+export const SYNC_TEMP_PREFIX = 'subminer-sync-';
+
+export function makeSyncTempDir(mkdtempSync: SyncFlowDeps['mkdtempSync']): string {
+  return mkdtempSync(path.join(os.tmpdir(), SYNC_TEMP_PREFIX));
+}
+
+/** Only dirs directly under os.tmpdir() with the sync prefix may be removed. */
+export function assertRemovableSyncTempDir(target: string): string {
+  const resolved = path.resolve(target.trim());
+  const normalizeCase = (value: string) =>
+    process.platform === 'win32' ? value.toLowerCase() : value;
+  const insideTmp =
+    normalizeCase(path.dirname(resolved)) === normalizeCase(path.resolve(os.tmpdir()));
+  if (!insideTmp || !path.basename(resolved).startsWith(SYNC_TEMP_PREFIX)) {
+    throw new Error(`Refusing to remove a directory outside the sync temp area: ${target}`);
+  }
+  return resolved;
+}
+
+export function runMakeTempMode(deps: SyncFlowDeps): void {
+  deps.consoleLog(makeSyncTempDir(deps.mkdtempSync));
+}
+
+export function runRemoveTempMode(context: SyncFlowContext, deps: SyncFlowDeps): void {
+  const target = assertRemovableSyncTempDir(context.args.syncRemoveTempPath);
+  deps.rmSync(target, { recursive: true, force: true });
+}
+
 export function resolveSyncDbPath(context: SyncFlowContext, deps: SyncFlowDeps): string {
  const override = context.args.syncDbPath.trim();
  return override ? deps.resolvePath(override) : deps.resolveDefaultDbPath();
@@ -160,7 +204,9 @@ export async function runCheckMode(context: SyncFlowContext, deps: SyncFlowDeps)
  } else {
    deps.consoleLog('SSH connection: ok');
    try {
-      remoteCommand = deps.resolveRemoteSubminerCommand(host, args.syncRemoteCmd || null);
+      const flavor = deps.detectRemoteShellFlavor(host, deps.runSsh);
+      if (flavor !== 'posix') deps.consoleLog(`Remote platform: Windows (${flavor})`);
+      remoteCommand = deps.resolveRemoteSubminerCommand(host, args.syncRemoteCmd || null, flavor);
      const version = deps.runSsh(host, `${remoteCommand} --version`);
      remoteVersion = version.status === 0 ? version.stdout.trim() || null : null;
      deps.consoleLog(
@@ -187,9 +233,32 @@ export async function runCheckMode(context: SyncFlowContext, deps: SyncFlowDeps)
  deps.consoleLog('Check passed.');
 }

-function cleanupRemote(host: string, remoteTmpDir: string, deps: SyncFlowDeps): void {
-  if (!remoteTmpDir.startsWith('/tmp/')) return;
-  deps.runSsh(host, `rm -rf ${shellQuote(remoteTmpDir)}`);
+// The remote validates --remove-temp against its own tmpdir; this guard only
+// keeps garbage output from an earlier failure out of the remote command.
+function cleanupRemote(
+  host: string,
+  remoteCmd: string,
+  remoteTmpDir: string,
+  quote: (value: string) => string,
+  deps: SyncFlowDeps,
+): void {
+  if (!path.posix.basename(remoteTmpDir).startsWith(SYNC_TEMP_PREFIX)) return;
+  deps.runSsh(host, `${remoteCmd} sync --remove-temp ${quote(remoteTmpDir)}`);
+}
+
+/**
+ * `sync --make-temp` prints the created dir as its last stdout line (a
+ * launcher wrapper may log above it). Backslashes are normalized to forward
+ * slashes: scp, the remote SubMiner, and Windows itself all accept them, and
+ * it keeps the later `${dir}/file` compositions valid on every platform.
+ */
+function parseRemoteTempDir(stdout: string): string {
+  const lines = stdout
+    .split('\n')
+    .map((line) => line.trim())
+    .filter((line) => line.length > 0);
+  const candidate = (lines[lines.length - 1] ?? '').replaceAll('\\', '/');
+  return path.posix.basename(candidate).startsWith(SYNC_TEMP_PREFIX) ? candidate : '';
 }

 function formatRemoteRunError(message: string, run: RemoteRunResult): string {
@@ -211,20 +280,24 @@ export async function runHostSync(

  await deps.ensureTrackerQuiescent(context, dbPath);

-  const remoteCmd = deps.resolveRemoteSubminerCommand(host, args.syncRemoteCmd || null);
-  deps.log('debug', args.logLevel, `Remote subminer command: ${remoteCmd}`);
+  const flavor = deps.detectRemoteShellFlavor(host, deps.runSsh);
+  const remoteCmd = deps.resolveRemoteSubminerCommand(host, args.syncRemoteCmd || null, flavor);
+  const quote = (value: string) => quoteForRemoteShell(flavor, value);
+  deps.log('debug', args.logLevel, `Remote subminer command (${flavor}): ${remoteCmd}`);

-  const localTmpDir = deps.mkdtempSync(path.join(os.tmpdir(), 'subminer-sync-'));
+  const localTmpDir = makeSyncTempDir(deps.mkdtempSync);
  let remoteTmpDir = '';
  let pulledSummary: SyncMergeSummary | null = null;
  try {
    // Signal failures by throwing (not fail(), which exits synchronously and
    // would skip the finally cleanup, leaking temp dirs holding snapshot data).
    // main().catch() reports the message the same way fail() would.
-    const mktemp = deps.runSsh(host, 'mktemp -d /tmp/subminer-sync.XXXXXX');
-    remoteTmpDir = mktemp.stdout.trim();
-    if (mktemp.status !== 0 || !remoteTmpDir.startsWith('/tmp/')) {
-      throw new Error(`Could not create a temporary directory on ${host}.`);
+    const mktemp = deps.runSsh(host, `${remoteCmd} sync --make-temp`);
+    remoteTmpDir = mktemp.status === 0 ? parseRemoteTempDir(mktemp.stdout) : '';
+    if (!remoteTmpDir) {
+      throw new Error(
+        formatRemoteRunError(`Could not create a temporary directory on ${host}.`, mktemp),
+      );
    }

    const forceFlag = args.syncForce ? ' --force' : '';
@@ -246,7 +319,7 @@ export async function runHostSync(
      deps.emitEvent({ type: 'stage', stage: 'snapshot-remote', message: `Snapshotting ${host}` });
      const snapshotRun = deps.runSsh(
        host,
-        `${remoteCmd} sync --snapshot ${shellQuote(remoteSnapshot)}${forceFlag}`,
+        `${remoteCmd} sync --snapshot ${quote(remoteSnapshot)}${forceFlag}`,
      );
      if (snapshotRun.status !== 0) {
        throw new Error(formatRemoteRunError(`Remote snapshot failed on ${host}.`, snapshotRun));
@@ -292,7 +365,7 @@ export async function runHostSync(
      await deps.ensureTrackerQuiescent(context, dbPath);
      const mergeRun = deps.runSsh(
        host,
-        `${remoteCmd} sync --merge ${shellQuote(incomingSnapshot)}${forceFlag}`,
+        `${remoteCmd} sync --merge ${quote(incomingSnapshot)}${forceFlag}`,
      );
      deps.writeStdout(mergeRun.stdout);
      if (mergeRun.stdout.trim()) {
@@ -328,7 +401,7 @@ export async function runHostSync(
    deps.rmSync(localTmpDir, { recursive: true, force: true });
    if (remoteTmpDir) {
      try {
-        cleanupRemote(host, remoteTmpDir, deps);
+        cleanupRemote(host, remoteCmd, remoteTmpDir, quote, deps);
      } catch {
        // best effort
      }
@@ -342,8 +415,18 @@ export async function runSyncFlow(context: SyncFlowContext, inputDeps: SyncFlowD
  if (!args.sync) return false;
  if (args.syncJson) deps = withJsonEvents(deps);

-  const dbPath = resolveSyncDbPath(context, deps);
  try {
+    if (args.syncMakeTemp) {
+      runMakeTempMode(deps);
+      if (args.syncJson) deps.emitEvent({ type: 'result', ok: true, error: null });
+      return true;
+    }
+    if (args.syncRemoveTempPath) {
+      runRemoveTempMode(context, deps);
+      if (args.syncJson) deps.emitEvent({ type: 'result', ok: true, error: null });
+      return true;
+    }
+    const dbPath = resolveSyncDbPath(context, deps);
    if (args.syncCheck) {
      await runCheckMode(context, deps);
    } else if (args.syncSnapshotPath) {
@@ -17,6 +17,7 @@ import {
 import { formatMergeSummary, mergeSnapshotIntoDb } from '../core/services/stats-sync/merge';
 import {
  assertSafeSshHost,
+  detectRemoteShellFlavor,
  resolveRemoteSubminerCommand,
  runScp,
  runSsh,
@@ -122,6 +123,7 @@ function buildSyncCliDeps(): SyncFlowDeps {
    formatMergeSummary,
    findLiveStatsDaemonPid,
    assertSafeSshHost,
+    detectRemoteShellFlavor,
    resolveRemoteSubminerCommand,
    runScp,
    runSsh,
@@ -69,9 +69,11 @@
                <code>ssh-copy-id user@hostname</code> (no password prompts).
              </li>
              <li>
-                The remote machine just needs SubMiner installed. It is found automatically as
-                <code>SubMiner</code> on the remote PATH, a macOS <code>/Applications</code>
-                install, or the optional <code>subminer</code> command-line launcher.
+                The remote machine just needs SubMiner installed. It is found automatically in
+                its default install location (Windows), as <code>SubMiner</code> on the remote
+                PATH, a macOS <code>/Applications</code> install, or the optional
+                <code>subminer</code> command-line launcher. Windows remotes need the built-in
+                OpenSSH Server enabled.
              </li>
              <li>
                Use <em>Test connection</em> to verify both. It checks SSH and finds SubMiner on