diff --git a/src/ClaudeDo.Localization/locales/de.json b/src/ClaudeDo.Localization/locales/de.json
index 18e5bb40..8753be16 100644
--- a/src/ClaudeDo.Localization/locales/de.json
+++ b/src/ClaudeDo.Localization/locales/de.json
@@ -266,6 +266,7 @@
     "overviewMode": "Übersicht",
     "closeSession": "Sitzung schließen",
     "conptyLaunchFailed": "ConPTY-Sitzung konnte nicht geöffnet werden: {0}",
+    "planningTitleSuffix": " (Planung)",
     "question": {
       "title": "Claude fragt nach",
       "placeholder": "Antwort eingeben…",
diff --git a/src/ClaudeDo.Localization/locales/en.json b/src/ClaudeDo.Localization/locales/en.json
index 0938797f..9a82ee24 100644
--- a/src/ClaudeDo.Localization/locales/en.json
+++ b/src/ClaudeDo.Localization/locales/en.json
@@ -266,6 +266,7 @@
     "overviewMode": "Overview",
     "closeSession": "Close session",
     "conptyLaunchFailed": "Couldn't open ConPTY session: {0}",
+    "planningTitleSuffix": " (Planning)",
     "question": {
       "title": "Claude is asking",
       "placeholder": "Type your answer…",
diff --git a/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs b/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs
index 64050c2a..b0e32e93 100644
--- a/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs
+++ b/src/ClaudeDo.Ui/Services/Interfaces/IWorkerClient.cs
@@ -82,6 +82,11 @@ public interface IWorkerClient : INotifyPropertyChanged
     /// <summary>Launch spec for an ad-hoc interactive session in an arbitrary directory --
     /// no task, no worktree.</summary>
     Task<LaunchSpec> GetAdHocLaunchSpecAsync(string directory, CancellationToken ct = default);
+    /// <summary>Starts a planning session and returns the launch spec for an embedded ConPTY
+    /// planning terminal (replaces StartPlanningSessionAsync's external wt window).</summary>
+    Task<LaunchSpec> GetPlanningStartLaunchSpecAsync(string taskId, CancellationToken ct = default);
+    /// <summary>Resumes a planning session and returns its embedded-ConPTY launch spec.</summary>
+    Task<LaunchSpec> GetPlanningResumeLaunchSpecAsync(string taskId, CancellationToken ct = default);
     Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default);
     Task<DiscardPlanningOutcome> DiscardPlanningSessionAsync(string taskId, bool dequeueQueuedChildren = false, CancellationToken ct = default);
     Task FinalizePlanningSessionAsync(string taskId, bool queueAgentTasks = true, CancellationToken ct = default);
diff --git a/src/ClaudeDo.Ui/Services/WorkerClient.cs b/src/ClaudeDo.Ui/Services/WorkerClient.cs
index acccd4c1..56768cc4 100644
--- a/src/ClaudeDo.Ui/Services/WorkerClient.cs
+++ b/src/ClaudeDo.Ui/Services/WorkerClient.cs
@@ -519,6 +519,12 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable, IWorkerC
     public async Task<LaunchSpec> GetAdHocLaunchSpecAsync(string directory, CancellationToken ct = default)
         => await _hub.InvokeAsync<LaunchSpec>("GetAdHocLaunchSpec", directory, ct);
 
+    public async Task<LaunchSpec> GetPlanningStartLaunchSpecAsync(string taskId, CancellationToken ct = default)
+        => await _hub.InvokeAsync<LaunchSpec>("GetPlanningStartLaunchSpec", taskId, ct);
+
+    public async Task<LaunchSpec> GetPlanningResumeLaunchSpecAsync(string taskId, CancellationToken ct = default)
+        => await _hub.InvokeAsync<LaunchSpec>("GetPlanningResumeLaunchSpec", taskId, ct);
+
     public async Task<DiscardPlanningOutcome> DiscardPlanningSessionAsync(string taskId, bool dequeueQueuedChildren = false, CancellationToken ct = default)
         => await _hub.InvokeAsync<DiscardPlanningOutcome>("DiscardPlanningSessionAsync", taskId, dequeueQueuedChildren, ct);
 
diff --git a/src/ClaudeDo.Ui/ViewModels/Islands/TasksIslandViewModel.cs b/src/ClaudeDo.Ui/ViewModels/Islands/TasksIslandViewModel.cs
index 0d8a6b3a..3c600eed 100644
--- a/src/ClaudeDo.Ui/ViewModels/Islands/TasksIslandViewModel.cs
+++ b/src/ClaudeDo.Ui/ViewModels/Islands/TasksIslandViewModel.cs
@@ -813,19 +813,24 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
     private void OpenListSettings() => OpenListSettingsRequested?.Invoke(this, EventArgs.Empty);
 
     [RelayCommand]
-    private async Task OpenPlanningSessionAsync(TaskRowViewModel? row)
+    private void OpenPlanningSession(TaskRowViewModel? row)
     {
         if (row is null) return;
         if (row.Status != TaskStatus.Idle || row.PlanningPhase != PlanningPhase.None) return;
-        ForegroundHelper.AllowAny();
-        try { await _worker!.StartPlanningSessionAsync(row.Id); }
-        catch (Exception ex) { ErrorReported?.Invoke(Loc.T("vm.tasksIsland.planningOpenFailed", ex.Message)); }
+        // Planning now runs as an embedded ConPTY pane in the Command Center (not an external wt
+        // window). The shell owns Mission Control, so raise an event; the actual StartAsync happens
+        // server-side inside GetPlanningStartLaunchSpec when the pane opens.
+        OpenPlanningConPtyRequested?.Invoke(row.Id, false);
     }
 
     // Opens the task in an embedded ConPTY terminal pane in the Command Center. The shell owns
     // the Mission Control view model, so this just raises an event for it to act on.
     public event Action<string>? OpenConPtySessionRequested;
 
+    // Opens (resume=false) or resumes (resume=true) a planning session as an embedded ConPTY
+    // pane in the Command Center.
+    public event Action<string, bool>? OpenPlanningConPtyRequested;
+
     [RelayCommand]
     private void OpenConPtySession(TaskRowViewModel? row)
     {
@@ -865,8 +870,9 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
             switch (choice)
             {
                 case UnfinishedPlanningModalResult.Resume:
-                    ForegroundHelper.AllowAny();
-                    await _worker.ResumePlanningSessionAsync(row.Id);
+                    // Resume as an embedded ConPTY pane (server-side ResumeAsync runs inside
+                    // GetPlanningResumeLaunchSpec when the pane opens).
+                    OpenPlanningConPtyRequested?.Invoke(row.Id, true);
                     break;
                 case UnfinishedPlanningModalResult.FinalizeNow:
                     await _worker.FinalizePlanningSessionAsync(row.Id, queueAgentTasks: false);
diff --git a/src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs b/src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs
index 8066f6c4..649f7a06 100644
--- a/src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs
+++ b/src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs
@@ -234,6 +234,11 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
             OpenMissionControl();
             _ = MissionControl.OpenConPtySessionAsync(taskId);
         };
+        Tasks.OpenPlanningConPtyRequested += (taskId, resume) =>
+        {
+            OpenMissionControl();
+            _ = MissionControl.OpenPlanningConPtySessionAsync(taskId, resume);
+        };
         Tasks.TasksChanged     += (_, _) => _ = Lists.RefreshCountsAsync();
         Tasks.OpenListSettingsRequested += (_, _) =>
         {
diff --git a/src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs b/src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs
index c65a8032..b7a3966e 100644
--- a/src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs
+++ b/src/ClaudeDo.Ui/ViewModels/MissionControlViewModel.cs
@@ -256,6 +256,45 @@ public sealed partial class MissionControlViewModel : ViewModelBase, IDisposable
         }
     }
 
+    // Starts (or resumes) a planning session and hosts it as an embedded ConPTY Command Center
+    // pane — the ConPTY replacement for the old external wt planning window. Deduped by TaskId
+    // like OpenConPtySessionAsync.
+    public async System.Threading.Tasks.Task OpenPlanningConPtySessionAsync(string taskId, bool resume)
+    {
+        if (string.IsNullOrEmpty(taskId)) return;
+        if (ConPtySessions.FirstOrDefault(s => s.TaskId == taskId) is { } existing)
+        {
+            FocusedPane = existing;
+            return;
+        }
+
+        var title = taskId;
+        try
+        {
+            await using var ctx = await _dbFactory.CreateDbContextAsync();
+            var entity = await ctx.Tasks.AsNoTracking().FirstOrDefaultAsync(t => t.Id == taskId);
+            if (entity?.Title is { Length: > 0 } t) title = t;
+        }
+        catch { /* best-effort title lookup */ }
+        title += Loc.T("missionControl.planningTitleSuffix");
+
+        try
+        {
+            var spec = resume
+                ? await _worker.GetPlanningResumeLaunchSpecAsync(taskId)
+                : await _worker.GetPlanningStartLaunchSpecAsync(taskId);
+            var descriptor = new TerminalLaunchDescriptor(spec.Cwd, spec.Exe, spec.Args, spec.Env);
+            var pane = new ConPtyPaneViewModel(taskId, title, descriptor);
+            pane.ErrorReported += OnConPtyPaneError;
+            pane.CloseRequested += CloseConPtySession;
+            ConPtySessions.Add(pane);
+        }
+        catch (Exception ex)
+        {
+            ErrorReported?.Invoke(Loc.T("missionControl.conptyLaunchFailed", ex.Message));
+        }
+    }
+
     // Ad-hoc (task-less) ConPTY session in a user-chosen directory. Never deduped — every call
     // opens a fresh pane, unlike the task-based OpenConPtySessionAsync above.
     public async System.Threading.Tasks.Task OpenAdHocConPtySessionAsync(string directory)
diff --git a/src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs b/src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs
index 316e74e6..cc096214 100644
--- a/src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs
+++ b/src/ClaudeDo.Ui/Views/Islands/TaskRowView.axaml.cs
@@ -55,10 +55,10 @@ public partial class TaskRowView : UserControl
             await vm.RemoveFromMyDayCommand.ExecuteAsync(row);
     }
 
-    private async void OnOpenPlanningSessionClick(object? sender, RoutedEventArgs e)
+    private void OnOpenPlanningSessionClick(object? sender, RoutedEventArgs e)
     {
         if (DataContext is TaskRowViewModel row && FindTasksVm() is { } vm)
-            await vm.OpenPlanningSessionCommand.ExecuteAsync(row);
+            vm.OpenPlanningSessionCommand.Execute(row);
     }
 
     private void OnOpenConPtySessionClick(object? sender, RoutedEventArgs e)
diff --git a/src/ClaudeDo.Worker/Hub/WorkerHub.cs b/src/ClaudeDo.Worker/Hub/WorkerHub.cs
index 3dffca1a..79c97dd8 100644
--- a/src/ClaudeDo.Worker/Hub/WorkerHub.cs
+++ b/src/ClaudeDo.Worker/Hub/WorkerHub.cs
@@ -673,6 +673,38 @@ public sealed class WorkerHub : Microsoft.AspNetCore.SignalR.Hub
         return _interactiveLaunchSpec.BuildForDirectoryAsync(directory, Context.ConnectionAborted);
     });
 
+    // Starts a planning session (worktree + prompt files + token, task -> Planning) and returns
+    // the launch spec for an embedded ConPTY planning terminal -- the ConPTY replacement for
+    // StartPlanningSessionAsync's external wt window. On any spec-build failure the just-started
+    // session is discarded (no children exist yet), mirroring StartPlanningSessionAsync.
+    public Task<LaunchSpec> GetPlanningStartLaunchSpec(string taskId) => HubGuard(async () =>
+    {
+        if (_interactiveLaunchSpec is null)
+            throw new InvalidOperationException("Interactive launch spec service is not configured.");
+        var ctx = await _planning.StartAsync(taskId, Context.ConnectionAborted);
+        try
+        {
+            var spec = _interactiveLaunchSpec.BuildPlanningStart(ctx);
+            await Clients.All.SendAsync("TaskUpdated", taskId);
+            return spec;
+        }
+        catch
+        {
+            await _planning.DiscardAsync(taskId, dequeueQueuedChildren: true, Context.ConnectionAborted);
+            throw;
+        }
+    });
+
+    // Resumes a planning session and returns the ConPTY launch spec (--permission-mode plan
+    // --resume). ConPTY replacement for ResumePlanningSessionAsync's external wt window.
+    public Task<LaunchSpec> GetPlanningResumeLaunchSpec(string taskId) => HubGuard(async () =>
+    {
+        if (_interactiveLaunchSpec is null)
+            throw new InvalidOperationException("Interactive launch spec service is not configured.");
+        var ctx = await _planning.ResumeAsync(taskId, Context.ConnectionAborted);
+        return _interactiveLaunchSpec.BuildPlanningResume(ctx);
+    });
+
     public async Task<DiscardPlanningOutcome> DiscardPlanningSessionAsync(string taskId, bool dequeueQueuedChildren = false)
     {
         var outcome = await _planning.DiscardAsync(taskId, dequeueQueuedChildren, Context.ConnectionAborted);
diff --git a/src/ClaudeDo.Worker/Planning/WindowsTerminalLauncher.cs b/src/ClaudeDo.Worker/Planning/WindowsTerminalLauncher.cs
index f2c08797..6cad82a2 100644
--- a/src/ClaudeDo.Worker/Planning/WindowsTerminalLauncher.cs
+++ b/src/ClaudeDo.Worker/Planning/WindowsTerminalLauncher.cs
@@ -74,11 +74,7 @@ public sealed class WindowsTerminalLauncher : ITerminalLauncher
         var resolvedWt = ResolveWtOrThrow();
         var resolvedClaude = ResolveClaudeOrThrow();
 
-        var command = BuildPwshCommand(resolvedClaude, new[]
-        {
-            "--permission-mode", "plan",
-            "--resume", ctx.ClaudeSessionId,
-        });
+        var command = BuildPwshCommand(resolvedClaude, BuildPlanningResumeArgs(ctx.ClaudeSessionId));
 
         StartInWindowsTerminal(resolvedWt, ctx.WorkingDir, command, env =>
         {
@@ -117,13 +113,21 @@ public sealed class WindowsTerminalLauncher : ITerminalLauncher
     // Arg order matters: variadic flags (--allowedTools, --add-dir) come first; the
     // single-line kickoff prompt is positional, so it must follow a single-value flag
     // (--append-system-prompt-file) or a variadic flag would swallow it.
-    internal static string BuildPlanningStartCommand(string claudePath, PlanningSessionStartContext ctx)
+    internal static string BuildPlanningStartCommand(string claudePath, PlanningSessionStartContext ctx) =>
+        BuildPwshCommand(claudePath, BuildPlanningStartArgs(ctx));
+
+    // The raw claude CLI args for an interactive planning START, shared with the embedded-ConPTY
+    // planning path (InteractiveLaunchSpecService), which needs the bare Exe/Args pair rather than
+    // a pwsh-wrapped command line. Arg order matters: variadic flags (--allowedTools, --add-dir)
+    // come first; the single-line kickoff prompt is positional, so it must follow a single-value
+    // flag (--append-system-prompt-file) or a variadic flag would swallow it.
+    internal static IReadOnlyList<string> BuildPlanningStartArgs(PlanningSessionStartContext ctx)
     {
         var kickoff =
             $"Read the file {ctx.Files.InitialPromptPath} first. It contains the task you must plan. " +
             "After reading it, begin the planning session as your instructions describe.";
 
-        return BuildPwshCommand(claudePath, new[]
+        return new[]
         {
             "--model", Model,
             "--permission-mode", "plan",
@@ -131,9 +135,14 @@ public sealed class WindowsTerminalLauncher : ITerminalLauncher
             "--add-dir", ctx.Files.SessionDirectory,
             "--append-system-prompt-file", ctx.Files.SystemPromptPath,
             kickoff,
-        });
+        };
     }
 
+    // The raw claude CLI args for an interactive planning RESUME, shared with the embedded-ConPTY
+    // planning path. Pins --permission-mode plan (unlike a plain --resume pickup).
+    internal static IReadOnlyList<string> BuildPlanningResumeArgs(string claudeSessionId) =>
+        new[] { "--permission-mode", "plan", "--resume", claudeSessionId };
+
     private string ResolveWtOrThrow() =>
         Resolve(_wtPath) ?? throw new TerminalLaunchException($"Windows Terminal not found: {_wtPath}");
 
diff --git a/src/ClaudeDo.Worker/Runner/InteractiveLaunchSpecService.cs b/src/ClaudeDo.Worker/Runner/InteractiveLaunchSpecService.cs
index 65a5ea65..0c5c1651 100644
--- a/src/ClaudeDo.Worker/Runner/InteractiveLaunchSpecService.cs
+++ b/src/ClaudeDo.Worker/Runner/InteractiveLaunchSpecService.cs
@@ -107,6 +107,40 @@ public sealed class InteractiveLaunchSpecService : IInteractiveLaunchSpecService
         return new LaunchSpec(worktree.Path, resolvedClaude, args, env);
     }
 
+    public LaunchSpec BuildPlanningStart(PlanningSessionStartContext ctx)
+    {
+        var resolvedClaude = WindowsTerminalLauncher.Resolve(_claudePath)
+            ?? throw new InvalidOperationException($"claude executable not found: {_claudePath}");
+
+        // Mirrors the env the wt planning launcher set (MAX_THINKING_TOKENS + the per-session
+        // planning token); MCP_TOOL_TIMEOUT matches the other embedded-ConPTY specs. Applied to
+        // the UI process env at spawn time (see PtyTerminalSession) — process-global by design.
+        var env = new Dictionary<string, string>
+        {
+            ["MAX_THINKING_TOKENS"] = "20000",
+            ["CLAUDEDO_PLANNING_TOKEN"] = ctx.Token,
+            ["MCP_TOOL_TIMEOUT"] = "200000",
+        };
+
+        return new LaunchSpec(
+            ctx.WorkingDir, resolvedClaude, WindowsTerminalLauncher.BuildPlanningStartArgs(ctx), env);
+    }
+
+    public LaunchSpec BuildPlanningResume(PlanningSessionResumeContext ctx)
+    {
+        var resolvedClaude = WindowsTerminalLauncher.Resolve(_claudePath)
+            ?? throw new InvalidOperationException($"claude executable not found: {_claudePath}");
+
+        var env = new Dictionary<string, string>
+        {
+            ["CLAUDEDO_PLANNING_TOKEN"] = ctx.Token,
+            ["MCP_TOOL_TIMEOUT"] = "200000",
+        };
+
+        return new LaunchSpec(
+            ctx.WorkingDir, resolvedClaude, WindowsTerminalLauncher.BuildPlanningResumeArgs(ctx.ClaudeSessionId), env);
+    }
+
     public Task<LaunchSpec> BuildForDirectoryAsync(string directory, CancellationToken ct)
     {
         if (!Directory.Exists(directory))
diff --git a/src/ClaudeDo.Worker/Runner/Interfaces/IInteractiveLaunchSpecService.cs b/src/ClaudeDo.Worker/Runner/Interfaces/IInteractiveLaunchSpecService.cs
index 8a3719c9..bfca55e7 100644
--- a/src/ClaudeDo.Worker/Runner/Interfaces/IInteractiveLaunchSpecService.cs
+++ b/src/ClaudeDo.Worker/Runner/Interfaces/IInteractiveLaunchSpecService.cs
@@ -1,7 +1,18 @@
+using ClaudeDo.Worker.Planning;
+
 namespace ClaudeDo.Worker.Runner;
 
 public interface IInteractiveLaunchSpecService
 {
+    /// <summary>Maps an already-prepared planning START context (worktree + prompt files + token,
+    /// produced by PlanningSessionManager.StartAsync) into a LaunchSpec for an embedded ConPTY
+    /// planning session — same planning CLI args as the wt launcher, planning env carried in Env.</summary>
+    LaunchSpec BuildPlanningStart(PlanningSessionStartContext ctx);
+
+    /// <summary>Maps a planning RESUME context (from PlanningSessionManager.ResumeAsync) into a
+    /// LaunchSpec for an embedded ConPTY planning session (--permission-mode plan --resume).</summary>
+    LaunchSpec BuildPlanningResume(PlanningSessionResumeContext ctx);
+
     /// <summary>Builds a LaunchSpec for opening an interactive session in a task's worktree.
     /// Throws KeyNotFoundException if the task doesn't exist, InvalidOperationException
     /// if it's Running/Queued. If the task has no usable worktree yet, one is created on
diff --git a/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs b/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs
index 44c00c05..d0b399a9 100644
--- a/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs
+++ b/tests/ClaudeDo.Ui.Tests/StubWorkerClient.cs
@@ -99,6 +99,10 @@ public abstract class StubWorkerClient : IWorkerClient
         => Task.FromResult(new LaunchSpec(".", "claude", Array.Empty<string>(), new Dictionary<string, string>()));
     public virtual Task<LaunchSpec> GetAdHocLaunchSpecAsync(string directory, CancellationToken ct = default)
         => Task.FromResult(new LaunchSpec(directory, "claude", Array.Empty<string>(), new Dictionary<string, string>()));
+    public virtual Task<LaunchSpec> GetPlanningStartLaunchSpecAsync(string taskId, CancellationToken ct = default)
+        => Task.FromResult(new LaunchSpec(".", "claude", Array.Empty<string>(), new Dictionary<string, string>()));
+    public virtual Task<LaunchSpec> GetPlanningResumeLaunchSpecAsync(string taskId, CancellationToken ct = default)
+        => Task.FromResult(new LaunchSpec(".", "claude", Array.Empty<string>(), new Dictionary<string, string>()));
     public virtual Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default) => Task.CompletedTask;
     public virtual Task<DiscardPlanningOutcome> DiscardPlanningSessionAsync(string taskId, bool dequeueQueuedChildren = false, CancellationToken ct = default)
         => Task.FromResult(new DiscardPlanningOutcome(DiscardPlanningResult.Discarded, 0, 0));
diff --git a/tests/ClaudeDo.Worker.Tests/Planning/WindowsTerminalLauncherTests.cs b/tests/ClaudeDo.Worker.Tests/Planning/WindowsTerminalLauncherTests.cs
index 2a302aa7..6c0ad077 100644
--- a/tests/ClaudeDo.Worker.Tests/Planning/WindowsTerminalLauncherTests.cs
+++ b/tests/ClaudeDo.Worker.Tests/Planning/WindowsTerminalLauncherTests.cs
@@ -70,6 +70,31 @@ public sealed class WindowsTerminalLauncherTests
         Assert.DoesNotContain("CLAUDEDO_LAUNCH_PROMPT", command);
     }
 
+    [Fact]
+    public void BuildPlanningStartArgs_HasPlanningFlagsAndKickoffLast()
+    {
+        var ctx = MakeStartCtx();
+
+        var args = WindowsTerminalLauncher.BuildPlanningStartArgs(ctx);
+
+        Assert.Equal("--model", args[0]);
+        var permIdx = args.ToList().IndexOf("--permission-mode");
+        Assert.True(permIdx >= 0);
+        Assert.Equal("plan", args[permIdx + 1]);
+        Assert.Contains("--allowedTools", args);
+        Assert.Contains(ctx.Files.SessionDirectory, args);
+        Assert.Contains(ctx.Files.SystemPromptPath, args);
+        // Kickoff positional is the last token and points at the brief file.
+        Assert.Contains(ctx.Files.InitialPromptPath, args[^1]);
+    }
+
+    [Fact]
+    public void BuildPlanningResumeArgs_PinsPlanModeAndResume()
+    {
+        var args = WindowsTerminalLauncher.BuildPlanningResumeArgs("sess-9");
+        Assert.Equal(new[] { "--permission-mode", "plan", "--resume", "sess-9" }, args);
+    }
+
     [Fact]
     public void BuildResumeCommand_ResumesSessionSingleQuoted()
     {
diff --git a/tests/ClaudeDo.Worker.Tests/Runner/InteractiveLaunchSpecServiceTests.cs b/tests/ClaudeDo.Worker.Tests/Runner/InteractiveLaunchSpecServiceTests.cs
index 0d777388..5c65ffc2 100644
--- a/tests/ClaudeDo.Worker.Tests/Runner/InteractiveLaunchSpecServiceTests.cs
+++ b/tests/ClaudeDo.Worker.Tests/Runner/InteractiveLaunchSpecServiceTests.cs
@@ -2,6 +2,7 @@ using ClaudeDo.Data.Git;
 using ClaudeDo.Data.Models;
 using ClaudeDo.Data.Repositories;
 using ClaudeDo.Worker.Config;
+using ClaudeDo.Worker.Planning;
 using ClaudeDo.Worker.Runner;
 using ClaudeDo.Worker.Skills;
 using ClaudeDo.Worker.Tests.Infrastructure;
@@ -342,4 +343,40 @@ public sealed class InteractiveLaunchSpecServiceTests : IDisposable
         await Assert.ThrowsAsync<InvalidOperationException>(
             () => svc.BuildForDirectoryAsync(Path.Combine(_tempDir, "does-not-exist"), CancellationToken.None));
     }
+
+    [Fact]
+    public void BuildPlanningStart_MapsPlanningArgsAndEnv()
+    {
+        var sessionDir = Path.Combine(_tempDir, "sess");
+        Directory.CreateDirectory(sessionDir);
+        var ctx = new PlanningSessionStartContext(
+            ParentTaskId: "p1", WorkingDir: _worktreeDir, Token: "tok-1",
+            WorktreePath: _worktreeDir, BranchName: "claudedo/planning/p1",
+            Files: new PlanningSessionFiles(sessionDir,
+                Path.Combine(sessionDir, "system-prompt.md"),
+                Path.Combine(sessionDir, "initial-prompt.txt")));
+
+        var spec = BuildService().BuildPlanningStart(ctx);
+
+        Assert.Equal(_worktreeDir, spec.Cwd);
+        Assert.Equal(_claudeStubPath, spec.Exe);
+        Assert.Contains("--permission-mode", spec.Args);
+        Assert.Contains("plan", spec.Args);
+        Assert.Equal("tok-1", spec.Env["CLAUDEDO_PLANNING_TOKEN"]);
+        Assert.Equal("20000", spec.Env["MAX_THINKING_TOKENS"]);
+    }
+
+    [Fact]
+    public void BuildPlanningResume_MapsResumeArgsAndToken()
+    {
+        var ctx = new PlanningSessionResumeContext(
+            ParentTaskId: "p1", WorkingDir: _worktreeDir,
+            ClaudeSessionId: "sess-42", Token: "tok-2", WorktreePath: _worktreeDir);
+
+        var spec = BuildService().BuildPlanningResume(ctx);
+
+        Assert.Equal(new[] { "--permission-mode", "plan", "--resume", "sess-42" }, spec.Args);
+        Assert.Equal("tok-2", spec.Env["CLAUDEDO_PLANNING_TOKEN"]);
+        Assert.Equal(_worktreeDir, spec.Cwd);
+    }
 }
diff --git a/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs b/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
index d1a31dc6..dd877a7d 100644
--- a/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
+++ b/tests/ClaudeDo.Worker.Tests/UiVm/TasksIslandViewModelPlanningTests.cs
@@ -76,6 +76,12 @@ sealed class FakeWorkerClient : IWorkerClient
         => Task.FromResult(new LaunchSpec(".", "claude", Array.Empty<string>(), new Dictionary<string, string>()));
     public Task<LaunchSpec> GetAdHocLaunchSpecAsync(string directory, CancellationToken ct = default)
         => Task.FromResult(new LaunchSpec(directory, "claude", Array.Empty<string>(), new Dictionary<string, string>()));
+    public int PlanningStartSpecCalls { get; private set; }
+    public int PlanningResumeSpecCalls { get; private set; }
+    public Task<LaunchSpec> GetPlanningStartLaunchSpecAsync(string taskId, CancellationToken ct = default)
+    { PlanningStartSpecCalls++; return Task.FromResult(new LaunchSpec(".", "claude", Array.Empty<string>(), new Dictionary<string, string>())); }
+    public Task<LaunchSpec> GetPlanningResumeLaunchSpecAsync(string taskId, CancellationToken ct = default)
+    { PlanningResumeSpecCalls++; return Task.FromResult(new LaunchSpec(".", "claude", Array.Empty<string>(), new Dictionary<string, string>())); }
     public Task QueuePlanningSubtasksAsync(string parentTaskId, CancellationToken ct = default) => Task.CompletedTask;
     public Task ResumePlanningSessionAsync(string taskId, CancellationToken ct = default) { ResumePlanningCalls++; return Task.CompletedTask; }
     public Task<DiscardPlanningOutcome> DiscardPlanningSessionAsync(string taskId, bool dequeueQueuedChildren = false, CancellationToken ct = default)
@@ -224,25 +230,29 @@ public class TasksIslandViewModelPlanningTests
     }
 
     [Fact]
-    public async Task OpenPlanningSession_IgnoresNonIdleRow()
+    public void OpenPlanningSession_IgnoresNonIdleRow()
     {
         var row = MakeRow("t1", TaskStatus.Queued);
-        var (vm, worker) = VmFactory.Create([row]);
+        var (vm, _) = VmFactory.Create([row]);
+        (string TaskId, bool Resume)? raised = null;
+        vm.OpenPlanningConPtyRequested += (id, resume) => raised = (id, resume);
 
-        await ((IAsyncRelayCommand<TaskRowViewModel?>)vm.OpenPlanningSessionCommand).ExecuteAsync(row);
+        vm.OpenPlanningSessionCommand.Execute(row);
 
-        Assert.Equal(0, worker.StartPlanningCalls);
+        Assert.Null(raised);
     }
 
     [Fact]
-    public async Task OpenPlanningSession_CallsWorkerForIdleRow()
+    public void OpenPlanningSession_RequestsConPtyPaneForIdleRow()
     {
         var row = MakeRow("t1", TaskStatus.Idle);
-        var (vm, worker) = VmFactory.Create([row]);
+        var (vm, _) = VmFactory.Create([row]);
+        (string TaskId, bool Resume)? raised = null;
+        vm.OpenPlanningConPtyRequested += (id, resume) => raised = (id, resume);
 
-        await ((IAsyncRelayCommand<TaskRowViewModel?>)vm.OpenPlanningSessionCommand).ExecuteAsync(row);
+        vm.OpenPlanningSessionCommand.Execute(row);
 
-        Assert.Equal(1, worker.StartPlanningCalls);
+        Assert.Equal(("t1", false), raised);
     }
 
     [Fact]