diff --git a/src/ClaudeDo.Data/Wire.cs b/src/ClaudeDo.Data/Wire.cs
index 0cef71f3..3f8fe2f0 100644
--- a/src/ClaudeDo.Data/Wire.cs
+++ b/src/ClaudeDo.Data/Wire.cs
@@ -105,6 +105,11 @@ public record ListConfigDto(string? Model, string? SystemPrompt, string? AgentPa
 
 public record SeedResultDto(int Copied, int Skipped);
 
+/// <param name="Value">What worker.config.json holds (a command name or a full path).</param>
+/// <param name="ResolvedPath">Where it actually resolves to right now, or null if nothing resolves —
+/// the whole point of surfacing this setting is telling those two cases apart.</param>
+public record ClaudeBinDto(string Value, string? ResolvedPath);
+
 public record OnlineInboxStateDto(
     bool Enabled,
     string ApiBaseUrl,
diff --git a/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs b/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs
index bfbb19c8..8e67a927 100644
--- a/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs
+++ b/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs
@@ -194,6 +194,9 @@ public interface IWorkerClient : INotifyPropertyChanged
     Task<(bool Ok, string? Error)> SetWorktreeStateAsync(string taskId, WorktreeState newState);
     Task<ForceRemoveResultDto?> ForceRemoveWorktreeAsync(string taskId);
 
+    Task<ClaudeBinDto?> GetClaudeBinAsync();
+    Task<ClaudeBinDto?> SetClaudeBinAsync(string? value);
+
     Task<OnlineInboxStateDto?> GetOnlineInboxStateAsync();
     Task SetOnlineInboxConfigAsync(OnlineInboxConfigInputDto input);
     Task SetOnlineInboxAuthAsync(string refreshToken);
diff --git a/src/ClaudeDo.Ui/Services/WorkerClient.cs b/src/ClaudeDo.Ui/Services/WorkerClient.cs
index d83b5413..27077d3b 100644
--- a/src/ClaudeDo.Ui/Services/WorkerClient.cs
+++ b/src/ClaudeDo.Ui/Services/WorkerClient.cs
@@ -664,6 +664,12 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
         await InvokeTimedAsync("QueuePlanningSubtasksAsync", () => _hub.InvokeAsync("QueuePlanningSubtasksAsync", parentTaskId, ct));
     }
 
+    public Task<ClaudeBinDto?> GetClaudeBinAsync()
+        => TryInvokeAsync<ClaudeBinDto>("GetClaudeBin");
+
+    public Task<ClaudeBinDto?> SetClaudeBinAsync(string? value)
+        => TryInvokeAsync<ClaudeBinDto>("SetClaudeBin", value);
+
     public Task<OnlineInboxStateDto?> GetOnlineInboxStateAsync()
         => TryInvokeAsync<OnlineInboxStateDto>("GetOnlineInboxState");
 
diff --git a/src/ClaudeDo.Ui/ViewModels/Modals/Settings/FilesSettingsTabViewModel.cs b/src/ClaudeDo.Ui/ViewModels/Modals/Settings/FilesSettingsTabViewModel.cs
index 4013bd66..fcd050fe 100644
--- a/src/ClaudeDo.Ui/ViewModels/Modals/Settings/FilesSettingsTabViewModel.cs
+++ b/src/ClaudeDo.Ui/ViewModels/Modals/Settings/FilesSettingsTabViewModel.cs
@@ -12,6 +12,12 @@ public sealed partial class FilesSettingsTabViewModel : ViewModelBase
     private readonly IWorkerClient _worker;
 
     public OperationStatus RestoreOp { get; } = new();
+    public OperationStatus ClaudeBinOp { get; } = new();
+
+    // worker.config.json's claude_bin: a command name or a full path to the CLI. Saved on its own
+    // (not with the modal's Save button) because the worker owns the file, not app_settings.
+    [ObservableProperty] private string _claudeBin = "";
+    [ObservableProperty] private string _claudeBinResolvedHint = "";
 
     [ObservableProperty] private string _statusMessage = "";
     [ObservableProperty] private bool _hasCustomizedPrompts;
@@ -37,6 +43,34 @@ public sealed partial class FilesSettingsTabViewModel : ViewModelBase
         };
     }
 
+    public async Task LoadClaudeBinAsync()
+    {
+        var dto = await _worker.GetClaudeBinAsync();
+        if (dto is null) return;
+        ClaudeBin = dto.Value;
+        ApplyResolvedHint(dto);
+    }
+
+    [RelayCommand]
+    private async Task SaveClaudeBin()
+    {
+        StatusMessage = "";
+        using var op = ClaudeBinOp.Begin(Loc.T("ops.claudeBin.saving"));
+        var dto = await _worker.SetClaudeBinAsync(ClaudeBin);
+        if (dto is null)
+        {
+            StatusMessage = Loc.T("vm.filesTab.workerOffline");
+            return;
+        }
+        ClaudeBin = dto.Value;
+        ApplyResolvedHint(dto);
+    }
+
+    private void ApplyResolvedHint(ClaudeBinDto dto) =>
+        ClaudeBinResolvedHint = dto.ResolvedPath is null
+            ? Loc.T("settings.files.claudeBinUnresolved")
+            : Loc.T("settings.files.claudeBinResolved", dto.ResolvedPath);
+
     private bool CanRestoreDefaultAgents() => !RestoreOp.IsRunning;
 
     [RelayCommand(CanExecute = nameof(CanRestoreDefaultAgents))]
diff --git a/src/ClaudeDo.Worker/Config/WorkerConfig.cs b/src/ClaudeDo.Worker/Config/WorkerConfig.cs
index 3045bdd8..5a8a2026 100644
--- a/src/ClaudeDo.Worker/Config/WorkerConfig.cs
+++ b/src/ClaudeDo.Worker/Config/WorkerConfig.cs
@@ -96,6 +96,14 @@ public sealed class WorkerConfig
     /// Reads the existing JSON, replaces the <c>online_inbox</c> node, and writes back indented.
     /// </summary>
     public void SaveOnlineInbox(string? path = null)
+        => SaveKey("online_inbox", JsonSerializer.SerializeToNode(OnlineInbox, InboxSerializerOpts), path);
+
+    /// <summary>Persists ONLY <c>claude_bin</c>, same read-modify-write as
+    /// <see cref="SaveOnlineInbox"/> — every other field in the file stays untouched.</summary>
+    public void SaveClaudeBin(string? path = null)
+        => SaveKey("claude_bin", JsonValue.Create(ClaudeBin), path);
+
+    private static void SaveKey(string key, JsonNode? value, string? path)
     {
         path ??= DefaultConfigPath;
 
@@ -103,7 +111,7 @@ public sealed class WorkerConfig
             ? JsonNode.Parse(File.ReadAllText(path)) as JsonObject ?? new JsonObject()
             : new JsonObject();
 
-        root["online_inbox"] = JsonSerializer.SerializeToNode(OnlineInbox, InboxSerializerOpts);
+        root[key] = value;
 
         Directory.CreateDirectory(Path.GetDirectoryName(path)!);
         File.WriteAllText(path, root.ToJsonString(WriteOpts));
diff --git a/src/ClaudeDo.Worker/Hub/WorkerHub.cs b/src/ClaudeDo.Worker/Hub/WorkerHub.cs
index 1dd28135..69818515 100644
--- a/src/ClaudeDo.Worker/Hub/WorkerHub.cs
+++ b/src/ClaudeDo.Worker/Hub/WorkerHub.cs
@@ -1,6 +1,7 @@
 using System.Globalization;
 using System.Reflection;
 using ClaudeDo.Data;
+using ClaudeDo.Data.Environment;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Agents;
@@ -1000,6 +1001,22 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         return ids.Count;
     }
 
+    public ClaudeBinDto GetClaudeBin() => DescribeClaudeBin();
+
+    /// Blank resets to the plain "claude" command. WorkerConfig is a DI singleton and
+    /// ClaudeProcess resolves it per spawn, so the change applies to the next run without a
+    /// restart — but it is persisted too, since Load() re-reads the file on startup.
+    public ClaudeBinDto SetClaudeBin(string? value)
+    {
+        _cfg.ClaudeBin = string.IsNullOrWhiteSpace(value) ? "claude" : value.Trim();
+        _cfg.SaveClaudeBin();
+        _ = _broadcaster.WorkerLog($"claude_bin set to '{_cfg.ClaudeBin}'", WorkerLogLevel.Info, DateTime.UtcNow);
+        return DescribeClaudeBin();
+    }
+
+    private ClaudeBinDto DescribeClaudeBin() =>
+        new(_cfg.ClaudeBin, ExecutableResolver.Resolve(_cfg.ClaudeBin)?.Path);
+
 #pragma warning disable CA1416 // ClaudeDo.Worker is Windows-only; DPAPI calls are safe here.
     public OnlineInboxStateDto GetOnlineInboxState()
     {
diff --git a/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs b/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs
index 69ff19a1..df0e4ee5 100644
--- a/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs
+++ b/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs
@@ -172,6 +172,8 @@ public abstract class StubWorkerClient : IWorkerClient
     public virtual Task<WorkerBuildInfoDto?> GetWorkerBuildInfoAsync() => Task.FromResult(WorkerBuildInfo);
     public virtual Task RefineTaskAsync(string taskId) => Task.CompletedTask;
 
+    public virtual Task<ClaudeBinDto?> GetClaudeBinAsync() => Task.FromResult<ClaudeBinDto?>(null);
+    public virtual Task<ClaudeBinDto?> SetClaudeBinAsync(string? value) => Task.FromResult<ClaudeBinDto?>(null);
     public virtual Task<OnlineInboxStateDto?> GetOnlineInboxStateAsync() => Task.FromResult<OnlineInboxStateDto?>(null);
     public virtual Task SetOnlineInboxConfigAsync(OnlineInboxConfigInputDto input) => Task.CompletedTask;
     public virtual Task SetOnlineInboxAuthAsync(string refreshToken) => Task.CompletedTask;
diff --git a/tests/ClaudeDo.Worker.Tests/Config/WorkerConfigSaveTests.cs b/tests/ClaudeDo.Worker.Tests/Config/WorkerConfigSaveTests.cs
new file mode 100644
index 00000000..4431ec24
--- /dev/null
+++ b/tests/ClaudeDo.Worker.Tests/Config/WorkerConfigSaveTests.cs
@@ -0,0 +1,46 @@
+using ClaudeDo.Worker.Config;
+using Xunit;
+
+namespace ClaudeDo.Worker.Tests.Config;
+
+/// SaveClaudeBin/SaveOnlineInbox are read-modify-write on a file the user also hand-edits, so the
+/// one thing that must hold is: every other key survives.
+public sealed class WorkerConfigSaveTests : IDisposable
+{
+    private readonly string _path = Path.Combine(
+        Path.GetTempPath(), $"cd_workercfg_{Guid.NewGuid():N}.json");
+
+    public void Dispose() { try { File.Delete(_path); } catch { } }
+
+    [Fact]
+    public void SaveClaudeBin_keeps_every_other_key()
+    {
+        File.WriteAllText(_path, """
+            {
+              "claude_bin": "claude",
+              "signalr_port": 12345,
+              "external_mcp_api_key": "secret",
+              "online_inbox": { "enabled": true }
+            }
+            """);
+
+        var cfg = WorkerConfig.Load(_path);
+        cfg.ClaudeBin = @"C:\tools\claude.cmd";
+        cfg.SaveClaudeBin(_path);
+
+        var reloaded = WorkerConfig.Load(_path);
+        Assert.Equal(@"C:\tools\claude.cmd", reloaded.ClaudeBin);
+        Assert.Equal(12345, reloaded.SignalRPort);
+        Assert.Equal("secret", reloaded.ExternalMcpApiKey);
+        Assert.True(reloaded.OnlineInbox.Enabled);
+    }
+
+    [Fact]
+    public void SaveClaudeBin_creates_the_file_when_missing()
+    {
+        var cfg = new WorkerConfig { ClaudeBin = "claude-next" };
+        cfg.SaveClaudeBin(_path);
+
+        Assert.Equal("claude-next", WorkerConfig.Load(_path).ClaudeBin);
+    }
+}
diff --git a/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs b/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
index 6bd31701..27df187d 100644
--- a/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
+++ b/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
@@ -159,6 +159,8 @@ sealed class FakeWorkerClient : IWorkerClient
     public Task<string> GetLastPrepLogAsync() => Task.FromResult(string.Empty);
     public Task<WorkerBuildInfoDto?> GetWorkerBuildInfoAsync() => Task.FromResult<WorkerBuildInfoDto?>(null);
     public Task RefineTaskAsync(string taskId) => Task.CompletedTask;
+    public Task<ClaudeBinDto?> GetClaudeBinAsync() => Task.FromResult<ClaudeBinDto?>(null);
+    public Task<ClaudeBinDto?> SetClaudeBinAsync(string? value) => Task.FromResult<ClaudeBinDto?>(null);
     public Task<OnlineInboxStateDto?> GetOnlineInboxStateAsync() => Task.FromResult<OnlineInboxStateDto?>(null);
     public Task SetOnlineInboxConfigAsync(OnlineInboxConfigInputDto input) => Task.CompletedTask;
     public Task SetOnlineInboxAuthAsync(string refreshToken) => Task.CompletedTask;