Rename experimental mode session option across SDKs

Copilot · SteveSandersonMS · web-flow · commit 1e90676fa790 · 2026-06-12T16:02:47.000Z
Co-authored-by: SteveSandersonMS &lt;1101362+SteveSandersonMS@users.noreply.github.com&gt;
diff --git a/dotnet/src/Client.cs b/dotnet/src/Client.cs
@@ -896,7 +896,7 @@ public async Task<CopilotSession> CreateSessionAsync(SessionConfig config, Cance
                 toolFilter.ExcludedTools,
                 config.Provider,
                 config.EnableSessionTelemetry,
-                config.IsExperimentalMode,
+                config.EnableExperimentalMode,
                 config.OnPermissionRequest != null ? true : null,
                 config.OnUserInputRequest != null ? true : null,
                 config.OnExitPlanModeRequest != null ? true : null,
@@ -1092,7 +1092,7 @@ public async Task<CopilotSession> ResumeSessionAsync(string sessionId, ResumeSes
                 toolFilter.ExcludedTools,
                 config.Provider,
                 config.EnableSessionTelemetry,
-                config.IsExperimentalMode,
+                config.EnableExperimentalMode,
                 config.OnPermissionRequest != null ? true : null,
                 config.OnUserInputRequest != null ? true : null,
                 config.OnExitPlanModeRequest != null ? true : null,
diff --git a/dotnet/src/Types.cs b/dotnet/src/Types.cs
@@ -2474,7 +2474,7 @@ protected SessionConfigBase(SessionConfigBase? other)
         OnUserInputRequest = other.OnUserInputRequest;
         Provider = other.Provider;
         EnableSessionTelemetry = other.EnableSessionTelemetry;
-        IsExperimentalMode = other.IsExperimentalMode;
+        EnableExperimentalMode = other.EnableExperimentalMode;
         SkipCustomInstructions = other.SkipCustomInstructions;
         CustomAgentsLocalOnly = other.CustomAgentsLocalOnly;
         CoauthorEnabled = other.CoauthorEnabled;
@@ -2649,7 +2649,7 @@ protected SessionConfigBase(SessionConfigBase? other)
     /// experimental were off. Leave <see langword="null"/> to inherit the runtime
     /// process defaults unchanged.
     /// </remarks>
-    public bool? IsExperimentalMode { get; set; }
+    public bool? EnableExperimentalMode { get; set; }
 
     /// <summary>
     /// When <see langword="true"/>, suppresses loading of custom instruction files
diff --git a/dotnet/test/Unit/CloneTests.cs b/dotnet/test/Unit/CloneTests.cs
@@ -76,7 +76,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
             WorkingDirectory = "/workspace",
             Streaming = true,
             EnableSessionTelemetry = false,
-            IsExperimentalMode = true,
+            EnableExperimentalMode = true,
             EnableOnDemandInstructionDiscovery = true,
             IncludeSubAgentStreamingEvents = false,
             McpServers = new Dictionary<string, McpServerConfig> { ["server1"] = new McpStdioServerConfig { Command = "echo" } },
@@ -116,7 +116,7 @@ public void SessionConfig_Clone_CopiesAllProperties()
         Assert.Equal(original.WorkingDirectory, clone.WorkingDirectory);
         Assert.Equal(original.Streaming, clone.Streaming);
         Assert.Equal(original.EnableSessionTelemetry, clone.EnableSessionTelemetry);
-        Assert.Equal(original.IsExperimentalMode, clone.IsExperimentalMode);
+        Assert.Equal(original.EnableExperimentalMode, clone.EnableExperimentalMode);
         Assert.Equal(original.EnableOnDemandInstructionDiscovery, clone.EnableOnDemandInstructionDiscovery);
         Assert.Equal(original.IncludeSubAgentStreamingEvents, clone.IncludeSubAgentStreamingEvents);
         Assert.Equal(original.McpServers.Count, clone.McpServers!.Count);
@@ -358,16 +358,16 @@ public void ResumeSessionConfig_Clone_CopiesEnableSessionTelemetry()
     }
 
     [Fact]
-    public void ResumeSessionConfig_Clone_CopiesIsExperimentalMode()
+    public void ResumeSessionConfig_Clone_CopiesEnableExperimentalMode()
     {
         var original = new ResumeSessionConfig
         {
-            IsExperimentalMode = true,
+            EnableExperimentalMode = true,
         };
 
         var clone = original.Clone();
 
-        Assert.True(clone.IsExperimentalMode);
+        Assert.True(clone.EnableExperimentalMode);
     }
 
     [Fact]
@@ -456,23 +456,23 @@ public void ResumeSessionConfig_Clone_PreservesEnableSessionTelemetryDefault()
     }
 
     [Fact]
-    public void SessionConfig_Clone_PreservesIsExperimentalModeDefault()
+    public void SessionConfig_Clone_PreservesEnableExperimentalModeDefault()
     {
         var original = new SessionConfig();
 
         var clone = original.Clone();
 
-        Assert.Null(clone.IsExperimentalMode);
+        Assert.Null(clone.EnableExperimentalMode);
     }
 
     [Fact]
-    public void ResumeSessionConfig_Clone_PreservesIsExperimentalModeDefault()
+    public void ResumeSessionConfig_Clone_PreservesEnableExperimentalModeDefault()
     {
         var original = new ResumeSessionConfig();
 
         var clone = original.Clone();
 
-        Assert.Null(clone.IsExperimentalMode);
+        Assert.Null(clone.EnableExperimentalMode);
     }
 
     [Fact]
diff --git a/dotnet/test/Unit/SerializationTests.cs b/dotnet/test/Unit/SerializationTests.cs
@@ -300,7 +300,7 @@ public void ResumeSessionRequest_CanSerializeEnableSessionTelemetry_WithSdkOptio
     }
 
     [Fact]
-    public void SessionRequests_CanSerializeIsExperimentalMode_WithSdkOptions()
+    public void SessionRequests_CanSerializeEnableExperimentalMode_WithSdkOptions()
     {
         var options = GetSerializerOptions();
 
diff --git a/go/client.go b/go/client.go
@@ -629,7 +629,7 @@ func (c *Client) CreateSession(ctx context.Context, config *SessionConfig) (*Ses
 	req.ToolFilterPrecedence = precedence
 	req.Provider = config.Provider
 	req.EnableSessionTelemetry = config.EnableSessionTelemetry
-	req.IsExperimentalMode = config.IsExperimentalMode
+	req.IsExperimentalMode = config.EnableExperimentalMode
 	req.SkipCustomInstructions = config.SkipCustomInstructions
 	req.CustomAgentsLocalOnly = config.CustomAgentsLocalOnly
 	req.CoauthorEnabled = config.CoauthorEnabled
@@ -924,7 +924,7 @@ func (c *Client) ResumeSessionWithOptions(ctx context.Context, sessionID string,
 	req.Tools = config.Tools
 	req.Provider = config.Provider
 	req.EnableSessionTelemetry = config.EnableSessionTelemetry
-	req.IsExperimentalMode = config.IsExperimentalMode
+	req.IsExperimentalMode = config.EnableExperimentalMode
 	req.SkipCustomInstructions = config.SkipCustomInstructions
 	req.CustomAgentsLocalOnly = config.CustomAgentsLocalOnly
 	req.CoauthorEnabled = config.CoauthorEnabled
diff --git a/go/client_test.go b/go/client_test.go
@@ -1242,8 +1242,8 @@ func TestCreateSessionRequest_RequestMCPApps(t *testing.T) {
 	})
 }
 
-func TestSessionRequests_IsExperimentalMode(t *testing.T) {
-	t.Run("create forwards isExperimentalMode when explicitly false", func(t *testing.T) {
+func TestSessionRequests_EnableExperimentalMode(t *testing.T) {
+	t.Run("create forwards enableExperimentalMode when explicitly false", func(t *testing.T) {
 		req := createSessionRequest{
 			IsExperimentalMode: Bool(false),
 		}
@@ -1260,7 +1260,7 @@ func TestSessionRequests_IsExperimentalMode(t *testing.T) {
 		}
 	})
 
-	t.Run("create omits isExperimentalMode when unset", func(t *testing.T) {
+	t.Run("create omits enableExperimentalMode when unset", func(t *testing.T) {
 		req := createSessionRequest{}
 		data, _ := json.Marshal(req)
 		var m map[string]any
@@ -1270,7 +1270,7 @@ func TestSessionRequests_IsExperimentalMode(t *testing.T) {
 		}
 	})
 
-	t.Run("resume forwards isExperimentalMode when explicitly true", func(t *testing.T) {
+	t.Run("resume forwards enableExperimentalMode when explicitly true", func(t *testing.T) {
 		req := resumeSessionRequest{
 			SessionID:          "s1",
 			IsExperimentalMode: Bool(true),
@@ -1288,7 +1288,7 @@ func TestSessionRequests_IsExperimentalMode(t *testing.T) {
 		}
 	})
 
-	t.Run("resume omits isExperimentalMode when unset", func(t *testing.T) {
+	t.Run("resume omits enableExperimentalMode when unset", func(t *testing.T) {
 		req := resumeSessionRequest{SessionID: "s1"}
 		data, _ := json.Marshal(req)
 		var m map[string]any
diff --git a/go/types.go b/go/types.go
@@ -980,12 +980,12 @@ type SessionConfig struct {
 	// regardless of this setting. This is independent of the OpenTelemetry
 	// configuration in ClientOptions.Telemetry.
 	EnableSessionTelemetry *bool
-	// IsExperimentalMode, when non-nil, overrides the session's experimental
+	// EnableExperimentalMode, when non-nil, overrides the session's experimental
 	// feature-flag tier resolution. Use Bool(true) to force-enable the
 	// experimental tier for this session, Bool(false) to resolve feature flags
 	// as if experimental were off, or nil to inherit the runtime process
 	// defaults unchanged.
-	IsExperimentalMode *bool
+	EnableExperimentalMode *bool
 	// SkipCustomInstructions, when non-nil, controls whether the runtime loads
 	// custom instruction files. See also [ClientOptions.Mode] = [ModeEmpty].
 	SkipCustomInstructions *bool
@@ -1301,12 +1301,12 @@ type ResumeSessionConfig struct {
 	// regardless of this setting. This is independent of the OpenTelemetry
 	// configuration in ClientOptions.Telemetry.
 	EnableSessionTelemetry *bool
-	// IsExperimentalMode, when non-nil, overrides the resumed session's
+	// EnableExperimentalMode, when non-nil, overrides the resumed session's
 	// experimental feature-flag tier resolution. Use Bool(true) to force-enable
 	// the experimental tier for this session, Bool(false) to resolve feature
 	// flags as if experimental were off, or nil to inherit the runtime process
 	// defaults unchanged.
-	IsExperimentalMode *bool
+	EnableExperimentalMode *bool
 	// SkipCustomInstructions, when non-nil, controls whether the runtime loads
 	// custom instruction files. See also [ClientOptions.Mode] = [ModeEmpty].
 	SkipCustomInstructions *bool
diff --git a/java/src/main/java/com/github/copilot/SessionRequestBuilder.java b/java/src/main/java/com/github/copilot/SessionRequestBuilder.java
@@ -114,7 +114,7 @@ static CreateSessionRequest buildCreateRequest(SessionConfig config, String sess
         request.setExcludedTools(config.getExcludedTools());
         request.setProvider(config.getProvider());
         config.getEnableSessionTelemetry().ifPresent(request::setEnableSessionTelemetry);
-        config.getIsExperimentalMode().ifPresent(request::setIsExperimentalMode);
+        config.getEnableExperimentalMode().ifPresent(request::setIsExperimentalMode);
         if (config.getOnUserInputRequest() != null) {
             request.setRequestUserInput(true);
         }
@@ -226,7 +226,7 @@ static ResumeSessionRequest buildResumeRequest(String sessionId, ResumeSessionCo
         request.setExcludedTools(config.getExcludedTools());
         request.setProvider(config.getProvider());
         config.getEnableSessionTelemetry().ifPresent(request::setEnableSessionTelemetry);
-        config.getIsExperimentalMode().ifPresent(request::setIsExperimentalMode);
+        config.getEnableExperimentalMode().ifPresent(request::setIsExperimentalMode);
         if (config.getOnUserInputRequest() != null) {
             request.setRequestUserInput(true);
         }
diff --git a/java/src/main/java/com/github/copilot/rpc/ResumeSessionConfig.java b/java/src/main/java/com/github/copilot/rpc/ResumeSessionConfig.java
@@ -46,7 +46,7 @@ public class ResumeSessionConfig {
     private List<String> excludedTools;
     private ProviderConfig provider;
     private Boolean enableSessionTelemetry;
-    private Boolean isExperimentalMode;
+    private Boolean enableExperimentalMode;
     private Boolean skipCustomInstructions;
     private Boolean customAgentsLocalOnly;
     private Boolean coauthorEnabled;
@@ -306,32 +306,32 @@ public ResumeSessionConfig clearEnableSessionTelemetry() {
      *         inherit the runtime process defaults unchanged
      */
     @JsonIgnore
-    public Optional<Boolean> getIsExperimentalMode() {
-        return Optional.ofNullable(isExperimentalMode);
+    public Optional<Boolean> getEnableExperimentalMode() {
+        return Optional.ofNullable(enableExperimentalMode);
     }
 
     /**
      * Overrides the resumed session's experimental feature-flag tier resolution.
      *
-     * @param isExperimentalMode
+     * @param enableExperimentalMode
      *            {@code true} to force-enable the experimental tier for this
      *            session, {@code false} to resolve feature flags as if experimental
      *            were off
      * @return this config for method chaining
      */
-    public ResumeSessionConfig setIsExperimentalMode(boolean isExperimentalMode) {
-        this.isExperimentalMode = isExperimentalMode;
+    public ResumeSessionConfig setEnableExperimentalMode(boolean enableExperimentalMode) {
+        this.enableExperimentalMode = enableExperimentalMode;
         return this;
     }
 
     /**
-     * Clears the isExperimentalMode setting, reverting to the runtime default
+     * Clears the enableExperimentalMode setting, reverting to the runtime default
      * behavior.
      *
      * @return this instance for method chaining
      */
-    public ResumeSessionConfig clearIsExperimentalMode() {
-        this.isExperimentalMode = null;
+    public ResumeSessionConfig clearEnableExperimentalMode() {
+        this.enableExperimentalMode = null;
         return this;
     }
 
@@ -1565,7 +1565,7 @@ public ResumeSessionConfig clone() {
         copy.excludedTools = this.excludedTools != null ? new ArrayList<>(this.excludedTools) : null;
         copy.provider = this.provider;
         copy.enableSessionTelemetry = this.enableSessionTelemetry;
-        copy.isExperimentalMode = this.isExperimentalMode;
+        copy.enableExperimentalMode = this.enableExperimentalMode;
         copy.reasoningEffort = this.reasoningEffort;
         copy.reasoningSummary = this.reasoningSummary;
         copy.contextTier = this.contextTier;
diff --git a/java/src/main/java/com/github/copilot/rpc/SessionConfig.java b/java/src/main/java/com/github/copilot/rpc/SessionConfig.java
@@ -50,7 +50,7 @@ public class SessionConfig {
     private List<String> excludedTools;
     private ProviderConfig provider;
     private Boolean enableSessionTelemetry;
-    private Boolean isExperimentalMode;
+    private Boolean enableExperimentalMode;
     private Boolean skipCustomInstructions;
     private Boolean customAgentsLocalOnly;
     private Boolean coauthorEnabled;
@@ -407,32 +407,32 @@ public SessionConfig clearEnableSessionTelemetry() {
      *         inherit the runtime process defaults unchanged
      */
     @JsonIgnore
-    public Optional<Boolean> getIsExperimentalMode() {
-        return Optional.ofNullable(isExperimentalMode);
+    public Optional<Boolean> getEnableExperimentalMode() {
+        return Optional.ofNullable(enableExperimentalMode);
     }
 
     /**
      * Overrides the session's experimental feature-flag tier resolution.
      *
-     * @param isExperimentalMode
+     * @param enableExperimentalMode
      *            {@code true} to force-enable the experimental tier for this
      *            session, {@code false} to resolve feature flags as if experimental
      *            were off
      * @return this config instance for method chaining
      */
-    public SessionConfig setIsExperimentalMode(boolean isExperimentalMode) {
-        this.isExperimentalMode = isExperimentalMode;
+    public SessionConfig setEnableExperimentalMode(boolean enableExperimentalMode) {
+        this.enableExperimentalMode = enableExperimentalMode;
         return this;
     }
 
     /**
-     * Clears the isExperimentalMode setting, reverting to the runtime default
+     * Clears the enableExperimentalMode setting, reverting to the runtime default
      * behavior.
      *
      * @return this instance for method chaining
      */
-    public SessionConfig clearIsExperimentalMode() {
-        this.isExperimentalMode = null;
+    public SessionConfig clearEnableExperimentalMode() {
+        this.enableExperimentalMode = null;
         return this;
     }
 
@@ -1688,7 +1688,7 @@ public SessionConfig clone() {
         copy.excludedTools = this.excludedTools != null ? new ArrayList<>(this.excludedTools) : null;
         copy.provider = this.provider;
         copy.enableSessionTelemetry = this.enableSessionTelemetry;
-        copy.isExperimentalMode = this.isExperimentalMode;
+        copy.enableExperimentalMode = this.enableExperimentalMode;
         copy.skipCustomInstructions = this.skipCustomInstructions;
         copy.customAgentsLocalOnly = this.customAgentsLocalOnly;
         copy.coauthorEnabled = this.coauthorEnabled;
diff --git a/java/src/test/java/com/github/copilot/SessionRequestBuilderTest.java b/java/src/test/java/com/github/copilot/SessionRequestBuilderTest.java
@@ -99,14 +99,14 @@ void testBuildCreateRequestSetsReasoningSummary() {
     }
 
     @Test
-    void testBuildCreateRequestSetsIsExperimentalMode() {
-        var config = new SessionConfig().setIsExperimentalMode(false);
+    void testBuildCreateRequestSetsEnableExperimentalMode() {
+        var config = new SessionConfig().setEnableExperimentalMode(false);
         CreateSessionRequest request = SessionRequestBuilder.buildCreateRequest(config);
         assertFalse(request.getIsExperimentalMode());
     }
 
     @Test
-    void testBuildCreateRequestOmitsIsExperimentalModeWhenNotSet() {
+    void testBuildCreateRequestOmitsEnableExperimentalModeWhenNotSet() {
         CreateSessionRequest request = SessionRequestBuilder.buildCreateRequest(new SessionConfig());
         assertNull(request.getIsExperimentalMode());
     }
@@ -190,14 +190,14 @@ void testBuildResumeRequestOmitsEnableSessionTelemetryWhenNotSet() {
     }
 
     @Test
-    void testBuildResumeRequestSetsIsExperimentalMode() {
-        var config = new ResumeSessionConfig().setIsExperimentalMode(true);
+    void testBuildResumeRequestSetsEnableExperimentalMode() {
+        var config = new ResumeSessionConfig().setEnableExperimentalMode(true);
         ResumeSessionRequest request = SessionRequestBuilder.buildResumeRequest("sid-1", config);
         assertTrue(request.getIsExperimentalMode());
     }
 
     @Test
-    void testBuildResumeRequestOmitsIsExperimentalModeWhenNotSet() {
+    void testBuildResumeRequestOmitsEnableExperimentalModeWhenNotSet() {
         var config = new ResumeSessionConfig();
         ResumeSessionRequest request = SessionRequestBuilder.buildResumeRequest("sid-1", config);
         assertNull(request.getIsExperimentalMode());
diff --git a/nodejs/src/client.ts b/nodejs/src/client.ts
@@ -1100,7 +1100,7 @@ export class CopilotClient {
                 clientName: config.clientName,
                 reasoningEffort: config.reasoningEffort,
                 reasoningSummary: config.reasoningSummary,
-                isExperimentalMode: config.isExperimentalMode,
+                isExperimentalMode: config.enableExperimentalMode,
                 contextTier: config.contextTier,
                 tools: config.tools?.map((tool) => ({
                     name: tool.name,
@@ -1282,7 +1282,7 @@ export class CopilotClient {
                 model: config.model,
                 reasoningEffort: config.reasoningEffort,
                 reasoningSummary: config.reasoningSummary,
-                isExperimentalMode: config.isExperimentalMode,
+                isExperimentalMode: config.enableExperimentalMode,
                 contextTier: config.contextTier,
                 systemMessage: wireSystemMessage,
                 availableTools: toolFilterOptions.availableTools,
diff --git a/nodejs/src/types.ts b/nodejs/src/types.ts
@@ -1593,7 +1593,7 @@ export interface SessionConfigBase {
      * `false` to resolve feature flags as if experimental were off. Leave
      * unset to inherit the runtime process defaults unchanged.
      */
-    isExperimentalMode?: boolean;
+    enableExperimentalMode?: boolean;
 
     /**
      * Context window tier for models that support it. Use "long_context" to pin
diff --git a/nodejs/test/client.test.ts b/nodejs/test/client.test.ts
diff --git a/python/copilot/client.py b/python/copilot/client.py
diff --git a/python/test_client.py b/python/test_client.py
diff --git a/rust/src/types.rs b/rust/src/types.rs

Original file line number	Diff line number	Diff line change
`@@ -300,7 +300,7 @@ public void ResumeSessionRequest_CanSerializeEnableSessionTelemetry_WithSdkOptio`
`300`	`300`	`}`
`301`	`301`
`302`	`302`	`[Fact]`
`303`		`- public void SessionRequests_CanSerializeIsExperimentalMode_WithSdkOptions()`
	`303`	`+ public void SessionRequests_CanSerializeEnableExperimentalMode_WithSdkOptions()`
`304`	`304`	`{`
`305`	`305`	`var options = GetSerializerOptions();`
`306`	`306`