Add apiVersion configuration support for Gemini API client

src/adapters/impl/gemini/GeminiClient.ts

@@ -27,11 +27,18 @@ const DEFAULT_TOOL_CALL_LIMIT: ToolCallLimitConfig = {
 
 export type GeminiClientOptions = BaseClientOptions & {
   toolCallLimit?: ToolCallLimitConfig
+  /** Optional. The API version to use. 
+   * If unset, the default API version will be used. 
+   */
+  apiVersion?: string
 }
 export class GeminiClient extends AbstractClient {
+  private readonly apiVersion?: string
+
   constructor(options: GeminiClientOptions | Partial<GeminiClientOptions>, context?: ChaiteContext) {
     super(options, context)
     this.name = 'gemini'
+    this.apiVersion = (options as Partial<GeminiClientOptions>)?.apiVersion
     const providedLimit = (options as Partial<GeminiClientOptions>)?.toolCallLimit
     const effectiveLimit = {
       ...DEFAULT_TOOL_CALL_LIMIT,
@@ -58,6 +65,7 @@ export class GeminiClient extends AbstractClient {
     }
     const ai = new GoogleGenAI({
       apiKey,
+      apiVersion: this.apiVersion,
       httpOptions: {
         baseUrl: this.baseUrl,
         headers: {
@@ -144,6 +152,7 @@ export class GeminiClient extends AbstractClient {
       const model = options.model || 'text-embedding-004'
       const ai = new GoogleGenAI({
         apiKey,
+        apiVersion: this.apiVersion,
         httpOptions: {
           baseUrl: this.baseUrl,
           headers: {

src/adapters/impl/gemini/gemini.test.ts

@@ -101,4 +101,29 @@ describe('GeminiClient', () => {
 
     expect(response.contents[0].type).toBe('text')
   }, 60000);
+
+  test('GeminiClient accepts apiVersion configuration', () => {
+    const geminiClient = new GeminiClient({
+      apiKey: 'test-api-key',
+      baseUrl: 'https://test.example.com',
+      features: ['chat'],
+      historyManager: DefaultHistoryManager,
+      apiVersion: 'v1alpha'
+    })
+    // Verify the client is created successfully with apiVersion
+    expect(geminiClient).toBeDefined()
+    expect(geminiClient.name).toBe('gemini')
+  });
+
+  test('GeminiClient works without apiVersion (uses default)', () => {
+    const geminiClient = new GeminiClient({
+      apiKey: 'test-api-key',
+      baseUrl: 'https://test.example.com',
+      features: ['chat'],
+      historyManager: DefaultHistoryManager
+    })
+    // Verify the client is created successfully without apiVersion
+    expect(geminiClient).toBeDefined()
+    expect(geminiClient.name).toBe('gemini')
+  });
 });