feat: add skillDirectories and disabledSkills to all SDKs

dotnet/src/Client.cs

@@ -344,7 +344,9 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig? config = nul
             config?.Streaming == true ? true : null,
             config?.McpServers,
             config?.CustomAgents,
-            config?.ConfigDir);
+            config?.ConfigDir,
+            config?.SkillDirectories,
+            config?.DisabledSkills);
 
         var response = await connection.Rpc.InvokeWithCancellationAsync<CreateSessionResponse>(
             "session.create", [request], cancellationToken);
@@ -399,7 +401,9 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
             config?.OnPermissionRequest != null ? true : null,
             config?.Streaming == true ? true : null,
             config?.McpServers,
-            config?.CustomAgents);
+            config?.CustomAgents,
+            config?.SkillDirectories,
+            config?.DisabledSkills);
 
         var response = await connection.Rpc.InvokeWithCancellationAsync<ResumeSessionResponse>(
             "session.resume", [request], cancellationToken);
@@ -927,7 +931,9 @@ private record CreateSessionRequest(
         bool? Streaming,
         Dictionary<string, object>? McpServers,
         List<CustomAgentConfig>? CustomAgents,
-        string? ConfigDir);
+        string? ConfigDir,
+        List<string>? SkillDirectories,
+        List<string>? DisabledSkills);
 
     private record ToolDefinition(
         string Name,
@@ -948,7 +954,9 @@ private record ResumeSessionRequest(
         bool? RequestPermission,
         bool? Streaming,
         Dictionary<string, object>? McpServers,
-        List<CustomAgentConfig>? CustomAgents);
+        List<CustomAgentConfig>? CustomAgents,
+        List<string>? SkillDirectories,
+        List<string>? DisabledSkills);
 
     private record ResumeSessionResponse(
         string SessionId);

dotnet/src/Types.cs

@@ -329,6 +329,16 @@ public class SessionConfig
     /// Custom agent configurations for the session.
     /// </summary>
     public List<CustomAgentConfig>? CustomAgents { get; set; }
+
+    /// <summary>
+    /// Directories to load skills from.
+    /// </summary>
+    public List<string>? SkillDirectories { get; set; }
+
+    /// <summary>
+    /// List of skill names to disable.
+    /// </summary>
+    public List<string>? DisabledSkills { get; set; }
 }
 
 public class ResumeSessionConfig
@@ -359,6 +369,16 @@ public class ResumeSessionConfig
     /// Custom agent configurations for the session.
     /// </summary>
     public List<CustomAgentConfig>? CustomAgents { get; set; }
+
+    /// <summary>
+    /// Directories to load skills from.
+    /// </summary>
+    public List<string>? SkillDirectories { get; set; }
+
+    /// <summary>
+    /// List of skill names to disable.
+    /// </summary>
+    public List<string>? DisabledSkills { get; set; }
 }
 
 public class MessageOptions

dotnet/test/SkillsTests.cs

@@ -0,0 +1,115 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *--------------------------------------------------------------------------------------------*/
+
+using GitHub.Copilot.SDK.Test.Harness;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace GitHub.Copilot.SDK.Test;
+
+public class SkillsTests : E2ETestBase
+{
+    private const string SkillMarker = "PINEAPPLE_COCONUT_42";
+    private static int _skillDirCounter = 0;
+
+    private readonly string _workDir;
+
+    public SkillsTests(E2ETestFixture fixture, ITestOutputHelper output) : base(fixture, "skills", output)
+    {
+        _workDir = fixture.Ctx.WorkDir;
+    }
+
+    private string CreateSkillDir()
+    {
+        var skillsDir = Path.Join(_workDir, ".test_skills", $"copilot-skills-test-{++_skillDirCounter}");
+        Directory.CreateDirectory(skillsDir);
+
+        // Create a skill subdirectory with SKILL.md
+        var skillSubdir = Path.Join(skillsDir, "test-skill");
+        Directory.CreateDirectory(skillSubdir);
+
+        // Create a skill that instructs the model to include a specific marker in responses
+        var skillContent = $@"---
+name: test-skill
+description: A test skill that adds a marker to responses
+---
+
+# Test Skill Instructions
+
+IMPORTANT: You MUST include the exact text ""{SkillMarker}"" somewhere in EVERY response you give. This is a mandatory requirement. Include it naturally in your response.
+".ReplaceLineEndings("\n");
+        File.WriteAllText(Path.Join(skillSubdir, "SKILL.md"), skillContent);
+
+        return skillsDir;
+    }
+
+    [Fact(Skip = "Skills tests temporarily skipped")]
+    public async Task Should_Load_And_Apply_Skill_From_SkillDirectories()
+    {
+        var skillsDir = CreateSkillDir();
+        var session = await Client.CreateSessionAsync(new SessionConfig
+        {
+            SkillDirectories = [skillsDir]
+        });
+
+        Assert.Matches(@"^[a-f0-9-]+$", session.SessionId);
+
+        // The skill instructs the model to include a marker - verify it appears
+        var message = await session.SendAndWaitAsync(new MessageOptions { Prompt = "Say hello briefly using the test skill." });
+        Assert.NotNull(message);
+        Assert.Contains(SkillMarker, message!.Data.Content);
+
+        await session.DisposeAsync();
+    }
+
+    [Fact(Skip = "Skills tests temporarily skipped")]
+    public async Task Should_Not_Apply_Skill_When_Disabled_Via_DisabledSkills()
+    {
+        var skillsDir = CreateSkillDir();
+        var session = await Client.CreateSessionAsync(new SessionConfig
+        {
+            SkillDirectories = [skillsDir],
+            DisabledSkills = ["test-skill"]
+        });
+
+        Assert.Matches(@"^[a-f0-9-]+$", session.SessionId);
+
+        // The skill is disabled, so the marker should NOT appear
+        var message = await session.SendAndWaitAsync(new MessageOptions { Prompt = "Say hello briefly using the test skill." });
+        Assert.NotNull(message);
+        Assert.DoesNotContain(SkillMarker, message!.Data.Content);
+
+        await session.DisposeAsync();
+    }
+
+    [Fact(Skip = "Skills tests temporarily skipped")]
+    public async Task Should_Apply_Skill_On_Session_Resume_With_SkillDirectories()
+    {
+        var skillsDir = CreateSkillDir();
+
+        // Create a session without skills first
+        var session1 = await Client.CreateSessionAsync();
+        var sessionId = session1.SessionId;
+
+        // First message without skill - marker should not appear
+        var message1 = await session1.SendAndWaitAsync(new MessageOptions { Prompt = "Say hi." });
+        Assert.NotNull(message1);
+        Assert.DoesNotContain(SkillMarker, message1!.Data.Content);
+
+        // Resume with skillDirectories - skill should now be active
+        var session2 = await Client.ResumeSessionAsync(sessionId, new ResumeSessionConfig
+        {
+            SkillDirectories = [skillsDir]
+        });
+
+        Assert.Equal(sessionId, session2.SessionId);
+
+        // Now the skill should be applied
+        var message2 = await session2.SendAndWaitAsync(new MessageOptions { Prompt = "Say hello again using the test skill." });
+        Assert.NotNull(message2);
+        Assert.Contains(SkillMarker, message2!.Data.Content);
+
+        await session2.DisposeAsync();
+    }
+}

go/client.go

@@ -536,6 +536,14 @@ func (c *Client) CreateSession(config *SessionConfig) (*Session, error) {
 		if config.ConfigDir != "" {
 			params["configDir"] = config.ConfigDir
 		}
+		// Add skill directories configuration
+		if len(config.SkillDirectories) > 0 {
+			params["skillDirectories"] = config.SkillDirectories
+		}
+		// Add disabled skills configuration
+		if len(config.DisabledSkills) > 0 {
+			params["disabledSkills"] = config.DisabledSkills
+		}
 	}
 
 	result, err := c.client.Request("session.create", params)
@@ -664,6 +672,14 @@ func (c *Client) ResumeSessionWithOptions(sessionID string, config *ResumeSessio
 			}
 			params["customAgents"] = customAgents
 		}
+		// Add skill directories configuration
+		if len(config.SkillDirectories) > 0 {
+			params["skillDirectories"] = config.SkillDirectories
+		}
+		// Add disabled skills configuration
+		if len(config.DisabledSkills) > 0 {
+			params["disabledSkills"] = config.DisabledSkills
+		}
 	}
 
 	result, err := c.client.Request("session.resume", params)

go/e2e/skills_test.go

@@ -0,0 +1,151 @@
+package e2e
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	copilot "github.com/github/copilot-sdk/go"
+	"github.com/github/copilot-sdk/go/e2e/testharness"
+)
+
+const skillMarker = "PINEAPPLE_COCONUT_42"
+
+var skillDirCounter = 0
+
+func createTestSkillDir(t *testing.T, workDir string, marker string) string {
+	skillDirCounter++
+	skillsDir := filepath.Join(workDir, ".test_skills", fmt.Sprintf("copilot-skills-test-%d", skillDirCounter))
+	if err := os.MkdirAll(skillsDir, 0755); err != nil {
+		t.Fatalf("Failed to create skills directory: %v", err)
+	}
+
+	skillSubdir := filepath.Join(skillsDir, "test-skill")
+	if err := os.MkdirAll(skillSubdir, 0755); err != nil {
+		t.Fatalf("Failed to create skill subdirectory: %v", err)
+	}
+
+	skillContent := `---
+name: test-skill
+description: A test skill that adds a marker to responses
+---
+
+# Test Skill Instructions
+
+IMPORTANT: You MUST include the exact text "` + marker + `" somewhere in EVERY response you give. This is a mandatory requirement. Include it naturally in your response.
+`
+	if err := os.WriteFile(filepath.Join(skillSubdir, "SKILL.md"), []byte(skillContent), 0644); err != nil {
+		t.Fatalf("Failed to write SKILL.md: %v", err)
+	}
+
+	return skillsDir
+}
+
+func TestSkillBehavior(t *testing.T) {
+	t.Skip("Skills tests temporarily skipped")
+	ctx := testharness.NewTestContext(t)
+	client := ctx.NewClient()
+	t.Cleanup(func() { client.ForceStop() })
+
+	t.Run("load and apply skill from skillDirectories", func(t *testing.T) {
+		ctx.ConfigureForTest(t)
+		skillsDir := createTestSkillDir(t, ctx.WorkDir, skillMarker)
+
+		session, err := client.CreateSession(&copilot.SessionConfig{
+			SkillDirectories: []string{skillsDir},
+		})
+		if err != nil {
+			t.Fatalf("Failed to create session: %v", err)
+		}
+
+		// The skill instructs the model to include a marker - verify it appears
+		message, err := session.SendAndWait(copilot.MessageOptions{
+			Prompt: "Say hello briefly using the test skill.",
+		}, 60*time.Second)
+		if err != nil {
+			t.Fatalf("Failed to send message: %v", err)
+		}
+
+		if message.Data.Content == nil || !strings.Contains(*message.Data.Content, skillMarker) {
+			t.Errorf("Expected message to contain skill marker '%s', got: %v", skillMarker, message.Data.Content)
+		}
+
+		session.Destroy()
+	})
+
+	t.Run("not apply skill when disabled via disabledSkills", func(t *testing.T) {
+		ctx.ConfigureForTest(t)
+		skillsDir := createTestSkillDir(t, ctx.WorkDir, skillMarker)
+
+		session, err := client.CreateSession(&copilot.SessionConfig{
+			SkillDirectories: []string{skillsDir},
+			DisabledSkills:   []string{"test-skill"},
+		})
+		if err != nil {
+			t.Fatalf("Failed to create session: %v", err)
+		}
+
+		// The skill is disabled, so the marker should NOT appear
+		message, err := session.SendAndWait(copilot.MessageOptions{
+			Prompt: "Say hello briefly using the test skill.",
+		}, 60*time.Second)
+		if err != nil {
+			t.Fatalf("Failed to send message: %v", err)
+		}
+
+		if message.Data.Content != nil && strings.Contains(*message.Data.Content, skillMarker) {
+			t.Errorf("Expected message to NOT contain skill marker '%s' when disabled, got: %v", skillMarker, *message.Data.Content)
+		}
+
+		session.Destroy()
+	})
+
+	t.Run("apply skill on session resume with skillDirectories", func(t *testing.T) {
+		ctx.ConfigureForTest(t)
+		skillsDir := createTestSkillDir(t, ctx.WorkDir, skillMarker)
+
+		// Create a session without skills first
+		session1, err := client.CreateSession(nil)
+		if err != nil {
+			t.Fatalf("Failed to create session: %v", err)
+		}
+		sessionID := session1.SessionID
+
+		// First message without skill - marker should not appear
+		message1, err := session1.SendAndWait(copilot.MessageOptions{Prompt: "Say hi."}, 60*time.Second)
+		if err != nil {
+			t.Fatalf("Failed to send message: %v", err)
+		}
+
+		if message1.Data.Content != nil && strings.Contains(*message1.Data.Content, skillMarker) {
+			t.Errorf("Expected message to NOT contain skill marker before skill was added, got: %v", *message1.Data.Content)
+		}
+
+		// Resume with skillDirectories - skill should now be active
+		session2, err := client.ResumeSessionWithOptions(sessionID, &copilot.ResumeSessionConfig{
+			SkillDirectories: []string{skillsDir},
+		})
+		if err != nil {
+			t.Fatalf("Failed to resume session: %v", err)
+		}
+
+		if session2.SessionID != sessionID {
+			t.Errorf("Expected session ID %s, got %s", sessionID, session2.SessionID)
+		}
+
+		// Now the skill should be applied
+		message2, err := session2.SendAndWait(copilot.MessageOptions{Prompt: "Say hello again using the test skill."}, 60*time.Second)
+		if err != nil {
+			t.Fatalf("Failed to send message: %v", err)
+		}
+
+		if message2.Data.Content == nil || !strings.Contains(*message2.Data.Content, skillMarker) {
+			t.Errorf("Expected message to contain skill marker '%s' after resume, got: %v", skillMarker, message2.Data.Content)
+		}
+
+		session2.Destroy()
+	})
+}

go/types.go

@@ -163,6 +163,10 @@ type SessionConfig struct {
 	MCPServers map[string]MCPServerConfig
 	// CustomAgents configures custom agents for the session
 	CustomAgents []CustomAgentConfig
+	// SkillDirectories is a list of directories to load skills from
+	SkillDirectories []string
+	// DisabledSkills is a list of skill names to disable
+	DisabledSkills []string
 }
 
 // Tool describes a caller-implemented tool that can be invoked by Copilot
@@ -211,6 +215,10 @@ type ResumeSessionConfig struct {
 	MCPServers map[string]MCPServerConfig
 	// CustomAgents configures custom agents for the session
 	CustomAgents []CustomAgentConfig
+	// SkillDirectories is a list of directories to load skills from
+	SkillDirectories []string
+	// DisabledSkills is a list of skill names to disable
+	DisabledSkills []string
 }
 
 // ProviderConfig configures a custom model provider