Add configurable custom CLI launcher support

PolyPilot.Provider.Abstractions/IProviderHostContext.cs

@@ -47,5 +47,6 @@ public enum ProviderConnectionMode
 public enum ProviderCliSource
 {
     BuiltIn,
-    System
+    System,
+    Custom
 }

PolyPilot.Tests/CliPathResolutionTests.cs

@@ -26,6 +26,12 @@ public void CliSourceMode_System_IsOne()
         Assert.Equal(1, (int)CliSourceMode.System);
     }
 
+    [Fact]
+    public void CliSourceMode_Custom_IsTwo()
+    {
+        Assert.Equal(2, (int)CliSourceMode.Custom);
+    }
+
     [Fact]
     public void CopilotClientOptions_CliPath_AcceptsNonExistentPath()
     {
@@ -410,6 +416,22 @@ public void ResolveCopilotCliPath_System_ReturnsNonNull()
             "(system install or bundled fallback)");
     }
 
+    [Fact]
+    public void ResolveCopilotCliPath_Custom_ReturnsConfiguredPath()
+    {
+        var path = CopilotService.ResolveCopilotCliPath(CliSourceMode.Custom, "/tmp/custom-copilot");
+
+        Assert.Equal("/tmp/custom-copilot", path);
+    }
+
+    [Fact]
+    public void ResolveCopilotCliPath_Custom_Blank_ReturnsNull()
+    {
+        var path = CopilotService.ResolveCopilotCliPath(CliSourceMode.Custom, "   ");
+
+        Assert.Null(path);
+    }
+
     [Fact]
     public void GetCliSourceInfo_ReturnsBuiltInPath()
     {

PolyPilot.Tests/ConnectionSettingsTests.cs

@@ -142,6 +142,8 @@ public void DefaultValues_NewFields_AreCorrect()
         Assert.Null(settings.ServerPassword);
         Assert.False(settings.DirectSharingEnabled);
         Assert.Equal(CliSourceMode.BuiltIn, settings.CliSource);
+        Assert.Null(settings.CustomCliPath);
+        Assert.Null(settings.CustomCliArguments);
         Assert.Null(settings.RepositoryStorageRoot);
     }
 
@@ -155,7 +157,9 @@ public void Save_Load_RoundTrip_WithNewFields()
             Port = 4321,
             ServerPassword = "mypass",
             DirectSharingEnabled = true,
-            CliSource = CliSourceMode.System,
+            CliSource = CliSourceMode.Custom,
+            CustomCliPath = "/custom/copilot-wrapper",
+            CustomCliArguments = "copilot --profile work",
             RepositoryStorageRoot = "D:\\DevDrive\\PolyPilot"
         };
 
@@ -165,7 +169,9 @@ public void Save_Load_RoundTrip_WithNewFields()
         Assert.NotNull(loaded);
         Assert.Equal("mypass", loaded!.ServerPassword);
         Assert.True(loaded.DirectSharingEnabled);
-        Assert.Equal(CliSourceMode.System, loaded.CliSource);
+        Assert.Equal(CliSourceMode.Custom, loaded.CliSource);
+        Assert.Equal("/custom/copilot-wrapper", loaded.CustomCliPath);
+        Assert.Equal("copilot --profile work", loaded.CustomCliArguments);
         Assert.Equal("D:\\DevDrive\\PolyPilot", loaded.RepositoryStorageRoot);
     }
 
@@ -181,6 +187,8 @@ public void BackwardCompatibility_OldJsonWithoutNewFields()
         Assert.Null(loaded.ServerPassword);
         Assert.False(loaded.DirectSharingEnabled);
         Assert.Equal(CliSourceMode.BuiltIn, loaded.CliSource);
+        Assert.Null(loaded.CustomCliPath);
+        Assert.Null(loaded.CustomCliArguments);
         Assert.Null(loaded.RepositoryStorageRoot);
     }
 
@@ -196,6 +204,58 @@ public void NormalizeRepositoryStorageRoot_TrimmedPath_ReturnsTrimmed()
         Assert.Equal("C:\\Dev", ConnectionSettings.NormalizeRepositoryStorageRoot("  C:\\Dev  "));
     }
 
+    [Fact]
+    public void NormalizeCustomCliPath_Whitespace_ReturnsNull()
+    {
+        Assert.Null(ConnectionSettings.NormalizeCustomCliPath("   "));
+    }
+
+    [Fact]
+    public void NormalizeCustomCliArguments_Trimmed_ReturnsTrimmed()
+    {
+        Assert.Equal("--flag value", ConnectionSettings.NormalizeCustomCliArguments("  --flag value  "));
+    }
+
+    [Fact]
+    public void SplitCommandLineArguments_HandlesQuotesAndSpaces()
+    {
+        var args = ConnectionSettings.SplitCommandLineArguments("wrapper subcommand --label \"two words\" 'three words'");
+
+        Assert.Equal(new[] { "wrapper", "subcommand", "--label", "two words", "three words" }, args);
+    }
+
+    [Fact]
+    public void SplitCommandLineArguments_PreservesBackslashesInUnquotedPaths()
+    {
+        var args = ConnectionSettings.SplitCommandLineArguments("--launcher C:\\Tools\\wrapper.exe --flag");
+
+        Assert.Equal(new[] { "--launcher", "C:\\Tools\\wrapper.exe", "--flag" }, args);
+    }
+
+    [Fact]
+    public void SplitCommandLineArguments_PreservesBackslashesInDoubleQuotedPaths()
+    {
+        var args = ConnectionSettings.SplitCommandLineArguments("--config \"C:\\Users\\me\\.copilot\\config.json\"");
+
+        Assert.Equal(new[] { "--config", "C:\\Users\\me\\.copilot\\config.json" }, args);
+    }
+
+    [Fact]
+    public void SplitCommandLineArguments_PreservesBackslashesInQuotedUncPaths()
+    {
+        var args = ConnectionSettings.SplitCommandLineArguments("--config \"\\\\server\\share\\tool.json\"");
+
+        Assert.Equal(new[] { "--config", "\\\\server\\share\\tool.json" }, args);
+    }
+
+    [Fact]
+    public void SplitCommandLineArguments_StillSupportsEscapedWhitespace()
+    {
+        var args = ConnectionSettings.SplitCommandLineArguments("one\\ two three");
+
+        Assert.Equal(new[] { "one two", "three" }, args);
+    }
+
     [Fact]
     public void ServerPassword_NotInCliUrl()
     {

PolyPilot.Tests/ProtocolVersionMismatchTests.cs

@@ -37,10 +37,10 @@ public void StubServerManager_StopServer_ClearsIsServerRunning()
     public async Task StubServerManager_StartServerAsync_ReturnsConfiguredResult()
     {
         _serverManager.StartServerResult = true;
-        Assert.True(await _serverManager.StartServerAsync(4321));
+        Assert.True(await _serverManager.StartServerAsync(new ConnectionSettings { Port = 4321 }));
 
         _serverManager.StartServerResult = false;
-        Assert.False(await _serverManager.StartServerAsync(4321));
+        Assert.False(await _serverManager.StartServerAsync(new ConnectionSettings { Port = 4321 }));
     }
 
     [Fact]

PolyPilot.Tests/ProviderPluginTests.cs

@@ -136,6 +136,21 @@ public void ProviderHostContext_Maps_Embedded()
         Assert.Equal(ProviderCliSource.BuiltIn, ctx.CliSource);
     }
 
+    [Fact]
+    public void ProviderHostContext_Maps_CustomCliSource()
+    {
+        var settings = new ConnectionSettings
+        {
+            Mode = ConnectionMode.Embedded,
+            CliSource = CliSourceMode.Custom,
+            CustomCliPath = "/custom/copilot-wrapper"
+        };
+        var ctx = new ProviderHostContext(settings);
+
+        Assert.Equal(ProviderConnectionMode.Embedded, ctx.ConnectionMode);
+        Assert.Equal(ProviderCliSource.Custom, ctx.CliSource);
+    }
+
     [Fact]
     public void ProviderHostContext_Maps_Persistent()
     {

PolyPilot.Tests/ServerManagerTests.cs

@@ -1,5 +1,6 @@
 using System.Net;
 using System.Net.Sockets;
+using PolyPilot.Models;
 using PolyPilot.Services;
 
 namespace PolyPilot.Tests;
@@ -88,4 +89,33 @@ public void CheckServerRunning_DefaultPort_UsesServerPort()
         Assert.True(defaultResult || !defaultResult); // completed without throwing
         Assert.False(customResult);
     }
+
+    [Fact]
+    public void BuildLaunchArguments_PrependsCustomArgs_BeforeHeadlessFlags()
+    {
+        var settings = new ConnectionSettings
+        {
+            CliSource = CliSourceMode.Custom,
+            CustomCliPath = "/custom/copilot-wrapper",
+            CustomCliArguments = "copilot --profile work"
+        };
+
+        var args = ServerManager.BuildLaunchArguments(settings, 4567);
+
+        Assert.Equal("copilot", args[0]);
+        Assert.Equal("--profile", args[1]);
+        Assert.Equal("work", args[2]);
+        Assert.Contains("--headless", args);
+        Assert.Contains("4567", args);
+    }
+
+    [Fact]
+    public void CreateStartInfo_ForwardsGitHubToken()
+    {
+        var settings = new ConnectionSettings();
+        var psi = ServerManager.CreateStartInfo(settings, "/tmp/copilot", 4321, "token-123");
+
+        Assert.Equal("/tmp/copilot", psi.FileName);
+        Assert.Equal("token-123", psi.Environment["COPILOT_GITHUB_TOKEN"]);
+    }
 }

PolyPilot.Tests/ServerRecoveryTests.cs

@@ -211,7 +211,7 @@ public void ServerManager_AcceptsGitHubToken_InStartServerAsync()
         // Verify the stub properly records the token parameter
         var mgr = new StubServerManager();
         mgr.StartServerResult = true;
-        mgr.StartServerAsync(4321, "test-token-123").GetAwaiter().GetResult();
+        mgr.StartServerAsync(new ConnectionSettings { Port = 4321 }, "test-token-123").GetAwaiter().GetResult();
         Assert.Equal("test-token-123", mgr.LastGitHubToken);
     }
 
@@ -220,7 +220,7 @@ public void ServerManager_AcceptsNullGitHubToken_InStartServerAsync()
     {
         var mgr = new StubServerManager();
         mgr.StartServerResult = true;
-        mgr.StartServerAsync(4321).GetAwaiter().GetResult();
+        mgr.StartServerAsync(new ConnectionSettings { Port = 4321 }).GetAwaiter().GetResult();
         Assert.Null(mgr.LastGitHubToken);
     }
 

PolyPilot.Tests/SettingsRegistryTests.cs

@@ -51,6 +51,26 @@ public void ForCategory_RespectsVisibilityPredicate()
         Assert.DoesNotContain(cliSettings, s => s.Id == "cli.source");
     }
 
+    [Fact]
+    public void CustomCliSettings_Hidden_WhenSourceIsNotCustom()
+    {
+        var ctx = CreateContext(new ConnectionSettings { CliSource = CliSourceMode.BuiltIn });
+        var devSettings = SettingsRegistry.ForCategory("Developer", ctx).ToList();
+
+        Assert.DoesNotContain(devSettings, s => s.Id == "cli.customPath");
+        Assert.DoesNotContain(devSettings, s => s.Id == "cli.customArguments");
+    }
+
+    [Fact]
+    public void CustomCliSettings_Visible_WhenSourceIsCustom()
+    {
+        var ctx = CreateContext(new ConnectionSettings { CliSource = CliSourceMode.Custom });
+        var devSettings = SettingsRegistry.ForCategory("Developer", ctx).ToList();
+
+        Assert.Contains(devSettings, s => s.Id == "cli.customPath");
+        Assert.Contains(devSettings, s => s.Id == "cli.customArguments");
+    }
+
     [Fact]
     public void Search_MatchesByLabel()
     {

PolyPilot.Tests/TestStubs.cs

@@ -46,13 +46,15 @@ internal class StubServerManager : IServerManager
 
     public bool CheckServerRunning(string host = "localhost", int? port = null) => IsServerRunning;
 
-    public Task<bool> StartServerAsync(int port, string? githubToken = null)
+    public Task<bool> StartServerAsync(ConnectionSettings settings, string? githubToken = null)
     {
-        ServerPort = port;
+        ServerPort = settings.Port;
         LastGitHubToken = githubToken;
+        LastStartSettings = settings;
         return Task.FromResult(StartServerResult);
     }
     public string? LastGitHubToken { get; private set; }
+    public ConnectionSettings? LastStartSettings { get; private set; }
 
     public void StopServer() { IsServerRunning = false; StopServerCallCount++; }
     public int StopServerCallCount { get; private set; }

PolyPilot/Components/Pages/Settings.razor

@@ -576,7 +576,7 @@
             }
             @if (cliSourceChanged)
             {
-                <div class="cli-restart-hint">⟳ Restart the app to apply the change</div>
+                <div class="cli-restart-hint">⟳ Reconnect or restart the persistent server to apply the change</div>
             }
         </div>
         }
@@ -831,7 +831,7 @@
         {
             "connection" => SectionVisible("transport mode embedded persistent remote server port start stop pid devtunnel share tunnel mobile qr url token connect save reconnect"),
             "ui" => SectionVisible("chat message layout default reversed both left theme font size text zoom"),
-            "developer" => SectionVisible("auto update main git watch relaunch rebuild cli source built-in system repository repo clone worktree storage root directory dev drive"),
+            "developer" => SectionVisible("auto update main git watch relaunch rebuild cli source built-in system custom executable path launcher wrapper repository repo clone worktree storage root directory dev drive"),
             "plugins" => SectionVisible("plugins provider extension dll assembly trust enable disable"),
             "diagnostics" => SectionVisible("logs diagnostics troubleshoot crash event console"),
             _ => true
@@ -1121,7 +1121,7 @@
     private void SetCliSource(CliSourceMode source)
     {
         // Only block selection if no CLI is available at all (both modes have fallback logic)
-        if (cliInfo.builtInPath == null && cliInfo.systemPath == null) return;
+        if (source != CliSourceMode.Custom && cliInfo.builtInPath == null && cliInfo.systemPath == null) return;
         settings.CliSource = source;
         cliSourceChanged = source != _initialCliSource;
         settings.Save();
@@ -1141,6 +1141,31 @@
     private static bool IsStorageRootValid(string? path) =>
         string.IsNullOrWhiteSpace(path) || Path.IsPathRooted(path.Trim());
 
+    private bool ValidateCustomCliConfiguration()
+    {
+        settings.CustomCliPath = ConnectionSettings.NormalizeCustomCliPath(settings.CustomCliPath);
+        settings.CustomCliArguments = ConnectionSettings.NormalizeCustomCliArguments(settings.CustomCliArguments);
+
+        if (settings.CliSource != CliSourceMode.Custom
+            || settings.Mode == ConnectionMode.Remote
+            || settings.Mode == ConnectionMode.Demo)
+            return true;
+
+        if (string.IsNullOrWhiteSpace(settings.CustomCliPath))
+        {
+            ShowStatus("Enter a custom CLI path or executable name first", "error", 5000);
+            return false;
+        }
+
+        if (Path.IsPathRooted(settings.CustomCliPath) && !File.Exists(settings.CustomCliPath))
+        {
+            ShowStatus($"Custom CLI path not found: {settings.CustomCliPath}", "error", 8000);
+            return false;
+        }
+
+        return true;
+    }
+
     private async Task BrowseRepositoryStorageRoot()
     {
 #if MACCATALYST || WINDOWS
@@ -1293,10 +1318,14 @@
 
     private async Task StartServer()
     {
+        if (!ValidateCustomCliConfiguration())
+            return;
+
+        settings.Save();
         starting = true;
         StateHasChanged();
 
-        var success = await ServerManager.StartServerAsync(settings.Port);
+        var success = await ServerManager.StartServerAsync(settings);
         serverAlive = success;
         starting = false;
 
@@ -1657,6 +1686,9 @@
             return;
         }
 
+        if (!ValidateCustomCliConfiguration())
+            return;
+
         if (settings.Mode == ConnectionMode.Persistent && !serverAlive)
         {
             ShowStatus("Start the persistent server first", "error", 5000);