feat: add clientName to SessionConfig across all SDKs

dotnet/src/Client.cs

@@ -371,6 +371,7 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig? config = nul
         var request = new CreateSessionRequest(
             config?.Model,
             config?.SessionId,
+            config?.ClientName,
             config?.ReasoningEffort,
             config?.Tools?.Select(ToolDefinition.FromAIFunction).ToList(),
             config?.SystemMessage,
@@ -454,6 +455,7 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
 
         var request = new ResumeSessionRequest(
             sessionId,
+            config?.ClientName,
             config?.Model,
             config?.ReasoningEffort,
             config?.Tools?.Select(ToolDefinition.FromAIFunction).ToList(),
@@ -1375,6 +1377,7 @@ public static string Escape(string arg)
     internal record CreateSessionRequest(
         string? Model,
         string? SessionId,
+        string? ClientName,
         string? ReasoningEffort,
         List<ToolDefinition>? Tools,
         SystemMessageConfig? SystemMessage,
@@ -1409,6 +1412,7 @@ internal record CreateSessionResponse(
 
     internal record ResumeSessionRequest(
         string SessionId,
+        string? ClientName,
         string? Model,
         string? ReasoningEffort,
         List<ToolDefinition>? Tools,

dotnet/src/Types.cs

@@ -745,6 +745,7 @@ protected SessionConfig(SessionConfig? other)
         if (other is null) return;
 
         AvailableTools = other.AvailableTools is not null ? [.. other.AvailableTools] : null;
+        ClientName = other.ClientName;
         ConfigDir = other.ConfigDir;
         CustomAgents = other.CustomAgents is not null ? [.. other.CustomAgents] : null;
         DisabledSkills = other.DisabledSkills is not null ? [.. other.DisabledSkills] : null;
@@ -768,6 +769,13 @@ protected SessionConfig(SessionConfig? other)
     }
 
     public string? SessionId { get; set; }
+
+    /// <summary>
+    /// Client name to identify the application using the SDK.
+    /// Included in the User-Agent header for API requests.
+    /// </summary>
+    public string? ClientName { get; set; }
+
     public string? Model { get; set; }
 
     /// <summary>
@@ -874,6 +882,7 @@ protected ResumeSessionConfig(ResumeSessionConfig? other)
         if (other is null) return;
 
         AvailableTools = other.AvailableTools is not null ? [.. other.AvailableTools] : null;
+        ClientName = other.ClientName;
         ConfigDir = other.ConfigDir;
         CustomAgents = other.CustomAgents is not null ? [.. other.CustomAgents] : null;
         DisabledSkills = other.DisabledSkills is not null ? [.. other.DisabledSkills] : null;
@@ -896,6 +905,12 @@ protected ResumeSessionConfig(ResumeSessionConfig? other)
         WorkingDirectory = other.WorkingDirectory;
     }
 
+    /// <summary>
+    /// Client name to identify the application using the SDK.
+    /// Included in the User-Agent header for API requests.
+    /// </summary>
+    public string? ClientName { get; set; }
+
     /// <summary>
     /// Model to use for this session. Can change the model when resuming.
     /// </summary>

dotnet/test/CloneTests.cs

@@ -78,6 +78,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
         var original = new SessionConfig
         {
             SessionId = "test-session",
+            ClientName = "my-app",
             Model = "gpt-4",
             ReasoningEffort = "high",
             ConfigDir = "/config",
@@ -94,6 +95,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
         var clone = original.Clone();
 
         Assert.Equal(original.SessionId, clone.SessionId);
+        Assert.Equal(original.ClientName, clone.ClientName);
         Assert.Equal(original.Model, clone.Model);
         Assert.Equal(original.ReasoningEffort, clone.ReasoningEffort);
         Assert.Equal(original.ConfigDir, clone.ConfigDir);

go/client.go

@@ -455,6 +455,7 @@ func (c *Client) CreateSession(ctx context.Context, config *SessionConfig) (*Ses
 	if config != nil {
 		req.Model = config.Model
 		req.SessionID = config.SessionID
+		req.ClientName = config.ClientName
 		req.ReasoningEffort = config.ReasoningEffort
 		req.ConfigDir = config.ConfigDir
 		req.Tools = config.Tools
@@ -552,6 +553,7 @@ func (c *Client) ResumeSessionWithOptions(ctx context.Context, sessionID string,
 	var req resumeSessionRequest
 	req.SessionID = sessionID
 	if config != nil {
+		req.ClientName = config.ClientName
 		req.Model = config.Model
 		req.ReasoningEffort = config.ReasoningEffort
 		req.SystemMessage = config.SystemMessage

go/client_test.go

@@ -1,6 +1,7 @@
 package copilot
 
 import (
+	"encoding/json"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -389,3 +390,57 @@ func fileExistsForTest(path string) bool {
 	_, err := os.Stat(path)
 	return err == nil
 }
+
+func TestCreateSessionRequest_ClientName(t *testing.T) {
+	t.Run("includes clientName in JSON when set", func(t *testing.T) {
+		req := createSessionRequest{ClientName: "my-app"}
+		data, err := json.Marshal(req)
+		if err != nil {
+			t.Fatalf("Failed to marshal: %v", err)
+		}
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("Failed to unmarshal: %v", err)
+		}
+		if m["clientName"] != "my-app" {
+			t.Errorf("Expected clientName to be 'my-app', got %v", m["clientName"])
+		}
+	})
+
+	t.Run("omits clientName from JSON when empty", func(t *testing.T) {
+		req := createSessionRequest{}
+		data, _ := json.Marshal(req)
+		var m map[string]any
+		json.Unmarshal(data, &m)
+		if _, ok := m["clientName"]; ok {
+			t.Error("Expected clientName to be omitted when empty")
+		}
+	})
+}
+
+func TestResumeSessionRequest_ClientName(t *testing.T) {
+	t.Run("includes clientName in JSON when set", func(t *testing.T) {
+		req := resumeSessionRequest{SessionID: "s1", ClientName: "my-app"}
+		data, err := json.Marshal(req)
+		if err != nil {
+			t.Fatalf("Failed to marshal: %v", err)
+		}
+		var m map[string]any
+		if err := json.Unmarshal(data, &m); err != nil {
+			t.Fatalf("Failed to unmarshal: %v", err)
+		}
+		if m["clientName"] != "my-app" {
+			t.Errorf("Expected clientName to be 'my-app', got %v", m["clientName"])
+		}
+	})
+
+	t.Run("omits clientName from JSON when empty", func(t *testing.T) {
+		req := resumeSessionRequest{SessionID: "s1"}
+		data, _ := json.Marshal(req)
+		var m map[string]any
+		json.Unmarshal(data, &m)
+		if _, ok := m["clientName"]; ok {
+			t.Error("Expected clientName to be omitted when empty")
+		}
+	})
+}

go/types.go

@@ -330,6 +330,9 @@ type InfiniteSessionConfig struct {
 type SessionConfig struct {
 	// SessionID is an optional custom session ID
 	SessionID string
+	// ClientName identifies the application using the SDK.
+	// Included in the User-Agent header for API requests.
+	ClientName string
 	// Model to use for this session
 	Model string
 	// ReasoningEffort level for models that support it.
@@ -409,6 +412,9 @@ type ToolResult struct {
 
 // ResumeSessionConfig configures options when resuming a session
 type ResumeSessionConfig struct {
+	// ClientName identifies the application using the SDK.
+	// Included in the User-Agent header for API requests.
+	ClientName string
 	// Model to use for this session. Can change the model when resuming.
 	Model string
 	// Tools exposes caller-implemented tools to the CLI
@@ -626,6 +632,7 @@ type permissionRequestResponse struct {
 type createSessionRequest struct {
 	Model             string                     `json:"model,omitempty"`
 	SessionID         string                     `json:"sessionId,omitempty"`
+	ClientName        string                     `json:"clientName,omitempty"`
 	ReasoningEffort   string                     `json:"reasoningEffort,omitempty"`
 	Tools             []Tool                     `json:"tools,omitempty"`
 	SystemMessage     *SystemMessageConfig       `json:"systemMessage,omitempty"`
@@ -655,6 +662,7 @@ type createSessionResponse struct {
 // resumeSessionRequest is the request for session.resume
 type resumeSessionRequest struct {
 	SessionID         string                     `json:"sessionId"`
+	ClientName        string                     `json:"clientName,omitempty"`
 	Model             string                     `json:"model,omitempty"`
 	ReasoningEffort   string                     `json:"reasoningEffort,omitempty"`
 	Tools             []Tool                     `json:"tools,omitempty"`

nodejs/src/client.ts

@@ -513,6 +513,7 @@ export class CopilotClient {
         const response = await this.connection!.sendRequest("session.create", {
             model: config.model,
             sessionId: config.sessionId,
+            clientName: config.clientName,
             reasoningEffort: config.reasoningEffort,
             tools: config.tools?.map((tool) => ({
                 name: tool.name,
@@ -594,6 +595,7 @@ export class CopilotClient {
 
         const response = await this.connection!.sendRequest("session.resume", {
             sessionId,
+            clientName: config.clientName,
             model: config.model,
             reasoningEffort: config.reasoningEffort,
             systemMessage: config.systemMessage,

nodejs/src/types.ts

@@ -615,6 +615,12 @@ export interface SessionConfig {
      */
     sessionId?: string;
 
+    /**
+     * Client name to identify the application using the SDK.
+     * Included in the User-Agent header for API requests.
+     */
+    clientName?: string;
+
     /**
      * Model to use for this session
      */
@@ -730,6 +736,7 @@ export interface SessionConfig {
  */
 export type ResumeSessionConfig = Pick<
     SessionConfig,
+    | "clientName"
     | "model"
     | "tools"
     | "systemMessage"

nodejs/test/client.test.ts

@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/no-explicit-any */
-import { describe, expect, it, onTestFinished } from "vitest";
+import { describe, expect, it, onTestFinished, vi } from "vitest";
 import { CopilotClient } from "../src/index.js";
 
 // This file is for unit tests. Where relevant, prefer to add e2e tests in e2e/*.test.ts instead
@@ -27,6 +27,35 @@ describe("CopilotClient", () => {
         });
     });
 
+    it("forwards clientName in session.create request", async () => {
+        const client = new CopilotClient();
+        await client.start();
+        onTestFinished(() => client.forceStop());
+
+        const spy = vi.spyOn((client as any).connection!, "sendRequest");
+        await client.createSession({ clientName: "my-app" });
+
+        expect(spy).toHaveBeenCalledWith(
+            "session.create",
+            expect.objectContaining({ clientName: "my-app" })
+        );
+    });
+
+    it("forwards clientName in session.resume request", async () => {
+        const client = new CopilotClient();
+        await client.start();
+        onTestFinished(() => client.forceStop());
+
+        const session = await client.createSession();
+        const spy = vi.spyOn((client as any).connection!, "sendRequest");
+        await client.resumeSession(session.sessionId, { clientName: "my-app" });
+
+        expect(spy).toHaveBeenCalledWith(
+            "session.resume",
+            expect.objectContaining({ clientName: "my-app", sessionId: session.sessionId })
+        );
+    });
+
     describe("URL parsing", () => {
         it("should parse port-only URL format", () => {
             const client = new CopilotClient({

python/copilot/client.py

@@ -467,6 +467,8 @@ async def create_session(self, config: Optional[SessionConfig] = None) -> Copilo
             payload["model"] = cfg["model"]
         if cfg.get("session_id"):
             payload["sessionId"] = cfg["session_id"]
+        if cfg.get("client_name"):
+            payload["clientName"] = cfg["client_name"]
         if cfg.get("reasoning_effort"):
             payload["reasoningEffort"] = cfg["reasoning_effort"]
         if tool_defs:
@@ -629,6 +631,11 @@ async def resume_session(
 
         payload: dict[str, Any] = {"sessionId": session_id}
 
+        # Add client name if provided
+        client_name = cfg.get("client_name")
+        if client_name:
+            payload["clientName"] = client_name
+
         # Add model if provided
         model = cfg.get("model")
         if model:

python/copilot/types.py

@@ -462,6 +462,9 @@ class SessionConfig(TypedDict, total=False):
     """Configuration for creating a session"""
 
     session_id: str  # Optional custom session ID
+    # Client name to identify the application using the SDK.
+    # Included in the User-Agent header for API requests.
+    client_name: str
     model: str  # Model to use for this session. Use client.list_models() to see available models.
     # Reasoning effort level for models that support it.
     # Only valid for models where capabilities.supports.reasoning_effort is True.
@@ -529,6 +532,9 @@ class ProviderConfig(TypedDict, total=False):
 class ResumeSessionConfig(TypedDict, total=False):
     """Configuration for resuming a session"""
 
+    # Client name to identify the application using the SDK.
+    # Included in the User-Agent header for API requests.
+    client_name: str
     # Model to use for this session. Can change the model when resuming.
     model: str
     tools: list[Tool]

python/test_client.py

@@ -147,3 +147,45 @@ def test_use_logged_in_user_with_cli_url_raises(self):
             CopilotClient(
                 {"cli_url": "localhost:8080", "use_logged_in_user": False, "log_level": "error"}
             )
+
+
+class TestSessionConfigForwarding:
+    @pytest.mark.asyncio
+    async def test_create_session_forwards_client_name(self):
+        client = CopilotClient({"cli_path": CLI_PATH})
+        await client.start()
+
+        try:
+            captured = {}
+            original_request = client._client.request
+
+            async def mock_request(method, params):
+                captured[method] = params
+                return await original_request(method, params)
+
+            client._client.request = mock_request
+            await client.create_session({"client_name": "my-app"})
+            assert captured["session.create"]["clientName"] == "my-app"
+        finally:
+            await client.force_stop()
+
+    @pytest.mark.asyncio
+    async def test_resume_session_forwards_client_name(self):
+        client = CopilotClient({"cli_path": CLI_PATH})
+        await client.start()
+
+        try:
+            session = await client.create_session()
+
+            captured = {}
+            original_request = client._client.request
+
+            async def mock_request(method, params):
+                captured[method] = params
+                return await original_request(method, params)
+
+            client._client.request = mock_request
+            await client.resume_session(session.session_id, {"client_name": "my-app"})
+            assert captured["session.resume"]["clientName"] == "my-app"
+        finally:
+            await client.force_stop()