feat: launch Gemini 3 in Gemini CLI 🚀🚀🚀 (in main) (#13287)

Co-authored-by: Adam Weidman <65992621+adamfweidman@users.noreply.github.com>
Co-authored-by: Sehoon Shon <sshon@google.com>
Co-authored-by: Adib234 <30782825+Adib234@users.noreply.github.com>
Co-authored-by: Sandy Tao <sandytao520@icloud.com>
Co-authored-by: Abhi <43648792+abhipatel12@users.noreply.github.com>
Co-authored-by: Aishanee Shah <aishaneeshah@gmail.com>
Co-authored-by: gemini-cli-robot <gemini-cli-robot@google.com>
Co-authored-by: Gal Zahavi <38544478+galz10@users.noreply.github.com>
Co-authored-by: Jacob Richman <jacob314@gmail.com>
Co-authored-by: joshualitt <joshualitt@google.com>
Co-authored-by: Jenna Inouye <jinouye@google.com>

packages/core/src/config/config.ts

@@ -305,6 +305,7 @@ export interface ConfigParameters {
   hooks?: {
     [K in HookEventName]?: HookDefinition[];
   };
+  previewFeatures?: boolean;
 }
 
 export class Config {
@@ -357,6 +358,7 @@ export class Config {
   private readonly cwd: string;
   private readonly bugCommand: BugCommandSettings | undefined;
   private model: string;
+  private previewFeatures: boolean | undefined;
   private readonly noBrowser: boolean;
   private readonly folderTrust: boolean;
   private ideMode: boolean;
@@ -419,6 +421,9 @@ export class Config {
   private experiments: Experiments | undefined;
   private experimentsPromise: Promise<void> | undefined;
 
+  private previewModelFallbackMode = false;
+  private previewModelBypassMode = false;
+
   constructor(params: ConfigParameters) {
     this.sessionId = params.sessionId;
     this.embeddingModel =
@@ -475,6 +480,7 @@ export class Config {
     this.fileDiscoveryService = params.fileDiscoveryService ?? null;
     this.bugCommand = params.bugCommand;
     this.model = params.model;
+    this.previewFeatures = params.previewFeatures ?? undefined;
     this.maxSessionTurns = params.maxSessionTurns ?? -1;
     this.experimentalZedIntegration =
       params.experimentalZedIntegration ?? false;
@@ -649,7 +655,7 @@ export class Config {
     // thoughtSignature from Genai to Vertex will fail, we need to strip them
     if (
       this.contentGeneratorConfig?.authType === AuthType.USE_GEMINI &&
-      authMethod === AuthType.LOGIN_WITH_GOOGLE
+      authMethod !== AuthType.USE_GEMINI
     ) {
       // Restore the conversation history to the new client
       this.geminiClient.stripThoughtsFromHistory();
@@ -670,11 +676,22 @@ export class Config {
     // Initialize BaseLlmClient now that the ContentGenerator is available
     this.baseLlmClient = new BaseLlmClient(this.contentGenerator, this);
 
+    const previewFeatures = this.getPreviewFeatures();
+
     const codeAssistServer = getCodeAssistServer(this);
     if (codeAssistServer) {
       this.experimentsPromise = getExperiments(codeAssistServer)
         .then((experiments) => {
           this.setExperiments(experiments);
+
+          // If preview features have not been set and the user authenticated through Google, we enable preview based on remote config only if it's true
+          if (previewFeatures === undefined) {
+            const remotePreviewFeatures =
+              experiments.flags[ExperimentFlags.ENABLE_PREVIEW]?.boolValue;
+            if (remotePreviewFeatures === true) {
+              this.setPreviewFeatures(remotePreviewFeatures);
+            }
+          }
         })
         .catch((e) => {
           debugLogger.error('Failed to fetch experiments', e);
@@ -760,6 +777,26 @@ export class Config {
     this.fallbackModelHandler = handler;
   }
 
+  getFallbackModelHandler(): FallbackModelHandler | undefined {
+    return this.fallbackModelHandler;
+  }
+
+  isPreviewModelFallbackMode(): boolean {
+    return this.previewModelFallbackMode;
+  }
+
+  setPreviewModelFallbackMode(active: boolean): void {
+    this.previewModelFallbackMode = active;
+  }
+
+  isPreviewModelBypassMode(): boolean {
+    return this.previewModelBypassMode;
+  }
+
+  setPreviewModelBypassMode(active: boolean): void {
+    this.previewModelBypassMode = active;
+  }
+
   getMaxSessionTurns(): number {
     return this.maxSessionTurns;
   }
@@ -822,6 +859,14 @@ export class Config {
     return this.question;
   }
 
+  getPreviewFeatures(): boolean | undefined {
+    return this.previewFeatures;
+  }
+
+  setPreviewFeatures(previewFeatures: boolean) {
+    this.previewFeatures = previewFeatures;
+  }
+
   getCoreTools(): string[] | undefined {
     return this.coreTools;
   }
@@ -1169,6 +1214,22 @@ export class Config {
     return this.experiments?.flags[ExperimentFlags.USER_CACHING]?.boolValue;
   }
 
+  async getBannerTextNoCapacityIssues(): Promise<string> {
+    await this.ensureExperimentsLoaded();
+    return (
+      this.experiments?.flags[ExperimentFlags.BANNER_TEXT_NO_CAPACITY_ISSUES]
+        ?.stringValue ?? ''
+    );
+  }
+
+  async getBannerTextCapacityIssues(): Promise<string> {
+    await this.ensureExperimentsLoaded();
+    return (
+      this.experiments?.flags[ExperimentFlags.BANNER_TEXT_CAPACITY_ISSUES]
+        ?.stringValue ?? ''
+    );
+  }
+
   private async ensureExperimentsLoaded(): Promise<void> {
     if (!this.experimentsPromise) {
       return;