fix(js/plugins/google-genai): do not enforce API key when apiKey is set to false (#3933)

Author: pavelgj

js/plugins/google-genai/src/googleai/client.ts

@@ -46,7 +46,7 @@ import {
  * @returns A promise that resolves to an array of Model objects.
  */
 export async function listModels(
-  apiKey: string,
+  apiKey: string | undefined,
   clientOptions?: ClientOptions
 ): Promise<Model[]> {
   const url = getGoogleAIUrl({
@@ -75,7 +75,7 @@ export async function listModels(
  * @throws {Error} If the API request fails or the response cannot be parsed.
  */
 export async function generateContent(
-  apiKey: string,
+  apiKey: string | undefined,
   model: string,
   generateContentRequest: GenerateContentRequest,
   clientOptions?: ClientOptions
@@ -108,7 +108,7 @@ export async function generateContent(
  * @throws {Error} If the API request fails.
  */
 export async function generateContentStream(
-  apiKey: string,
+  apiKey: string | undefined,
   model: string,
   generateContentRequest: GenerateContentRequest,
   clientOptions?: ClientOptions
@@ -140,7 +140,7 @@ export async function generateContentStream(
  * @throws {Error} If the API request fails or the response cannot be parsed.
  */
 export async function embedContent(
-  apiKey: string,
+  apiKey: string | undefined,
   model: string,
   embedContentRequest: EmbedContentRequest,
   clientOptions?: ClientOptions
@@ -162,7 +162,7 @@ export async function embedContent(
 }
 
 export async function imagenPredict(
-  apiKey: string,
+  apiKey: string | undefined,
   model: string,
   imagenPredictRequest: ImagenPredictRequest,
   clientOptions?: ClientOptions
@@ -185,7 +185,7 @@ export async function imagenPredict(
 }
 
 export async function veoPredict(
-  apiKey: string,
+  apiKey: string | undefined,
   model: string,
   veoPredictRequest: VeoPredictRequest,
   clientOptions?: ClientOptions
@@ -208,7 +208,7 @@ export async function veoPredict(
 }
 
 export async function veoCheckOperation(
-  apiKey: string,
+  apiKey: string | undefined,
   operation: string,
   clientOptions?: ClientOptions
 ): Promise<VeoOperation> {
@@ -265,7 +265,7 @@ export function getGoogleAIUrl(params: {
 
 function getFetchOptions(params: {
   method: 'POST' | 'GET';
-  apiKey: string;
+  apiKey: string | undefined;
   body?: string;
   clientOptions?: ClientOptions;
 }) {
@@ -310,7 +310,7 @@ function getAbortSignal(
  * @returns {HeadersInit} An object containing the headers to be included in the request.
  */
 function getHeaders(
-  apiKey: string,
+  apiKey?: string,
   clientOptions?: ClientOptions
 ): HeadersInit {
   let customHeaders = {};
@@ -322,10 +322,13 @@ function getHeaders(
   const headers: HeadersInit = {
     ...customHeaders,
     'Content-Type': 'application/json',
-    'x-goog-api-key': apiKey,
     'x-goog-api-client': getGenkitClientHeader(),
   };
 
+  if (apiKey) {
+    headers['x-goog-api-key'] = apiKey;
+  }
+
   return headers;
 }
 

js/plugins/google-genai/src/googleai/embedder.ts

@@ -26,6 +26,7 @@ import { embedderRef } from 'genkit/embedder';
 import { embedder as pluginEmbedder } from 'genkit/plugin';
 import { embedContent } from './client.js';
 import {
+  ClientOptions,
   EmbedContentRequest,
   GoogleAIPluginOptions,
   Model,
@@ -132,6 +133,11 @@ export function defineEmbedder(
 ): EmbedderAction {
   checkApiKey(pluginOptions?.apiKey);
   const ref = model(name);
+  const clientOptions: ClientOptions = {
+    apiVersion: pluginOptions?.apiVersion,
+    baseUrl: pluginOptions?.baseUrl,
+    customHeaders: pluginOptions?.customHeaders,
+  };
 
   return pluginEmbedder(
     {
@@ -148,15 +154,20 @@ export function defineEmbedder(
 
       const embeddings = await Promise.all(
         request.input.map(async (doc) => {
-          const response = await embedContent(embedApiKey, embedVersion, {
-            taskType: request.options?.taskType,
-            title: request.options?.title,
-            content: {
-              role: '',
-              parts: [{ text: doc.text }],
-            },
-            outputDimensionality: request.options?.outputDimensionality,
-          } as EmbedContentRequest);
+          const response = await embedContent(
+            embedApiKey,
+            embedVersion,
+            {
+              taskType: request.options?.taskType,
+              title: request.options?.title,
+              content: {
+                role: '',
+                parts: [{ text: doc.text }],
+              },
+              outputDimensionality: request.options?.outputDimensionality,
+            } as EmbedContentRequest,
+            clientOptions
+          );
           const values = response.embedding.values;
           return { embedding: values };
         })

js/plugins/google-genai/src/googleai/gemini.ts

@@ -575,6 +575,7 @@ export function defineModel(
   const clientOptions: ClientOptions = {
     apiVersion: pluginOptions?.apiVersion,
     baseUrl: pluginOptions?.baseUrl,
+    customHeaders: pluginOptions?.customHeaders,
   };
 
   const middleware: ModelMiddleware[] = [];

js/plugins/google-genai/src/googleai/imagen.ts

@@ -180,6 +180,7 @@ export function defineModel(
   const clientOptions: ClientOptions = {
     apiVersion: pluginOptions?.apiVersion,
     baseUrl: pluginOptions?.baseUrl,
+    customHeaders: pluginOptions?.customHeaders,
   };
 
   return pluginModel(

js/plugins/google-genai/src/googleai/types.ts��

@@ -80,6 +80,10 @@ export interface GoogleAIPluginOptions {
   experimental_debugTraces?: boolean;
   /** Use `responseSchema` field instead of `responseJsonSchema`. */
   legacyResponseSchema?: boolean;
+  /**
+   * Additional headers to send along with the request.
+   */
+  customHeaders?: Record<string, string>;
 }
 
 /**

js/plugins/google-genai/src/googleai/utils.ts

@@ -102,7 +102,7 @@ export function checkApiKey(
 export function calculateApiKey(
   pluginApiKey: string | false | undefined,
   requestApiKey: string | undefined
-): string {
+): string | undefined {
   let apiKey: string | undefined;
 
   // Don't get the key from the environment if pluginApiKey is false
@@ -113,7 +113,7 @@ export function calculateApiKey(
   apiKey = requestApiKey || apiKey;
 
   if (pluginApiKey === false && !requestApiKey) {
-    throw API_KEY_FALSE_ERROR;
+    return undefined;
   }
 
   if (!apiKey) {

js/plugins/google-genai/src/googleai/veo.ts

@@ -176,6 +176,7 @@ export function defineModel(
   const clientOptions: ClientOptions = {
     apiVersion: pluginOptions?.apiVersion,
     baseUrl: pluginOptions?.baseUrl,
+    customHeaders: pluginOptions?.customHeaders,
   };
 
   return pluginBackgroundModel({

js/plugins/google-genai/tests/googleai/embedder_test.ts

@@ -15,7 +15,7 @@
  */
 
 import * as assert from 'assert';
-import { Document, GenkitError } from 'genkit';
+import { Document } from 'genkit';
 import { afterEach, beforeEach, describe, it } from 'node:test';
 import * as sinon from 'sinon';
 import {
@@ -144,23 +144,16 @@ describe('defineGoogleAIEmbedder', () => {
     });
 
     it('throws if apiKey is false in pluginOptions and not provided in call options', async () => {
+      mockFetchResponse({ embedding: { values: [] } });
       const embedder = defineEmbedder('text-embedding-004', {
         apiKey: false,
       });
-      await assert.rejects(
-        embedder.run({
+      assert.ok(
+        await embedder.run({
           input: [new Document({ content: [{ text: 'test' }] })],
-        }),
-        (err: GenkitError) => {
-          assert.strictEqual(err.status, 'INVALID_ARGUMENT');
-          assert.match(
-            err.message,
-            /GoogleAI plugin was initialized with \{apiKey: false\}/
-          );
-          return true;
-        }
+        })
       );
-      sinon.assert.notCalled(fetchStub);
+      sinon.assert.calledOnce(fetchStub);
     });
 
     it('uses API key from call options if apiKey is false in pluginOptions', async () => {

js/plugins/google-genai/tests/googleai/gemini_test.ts

@@ -139,13 +139,11 @@ describe('Google AI Gemini', () => {
         );
       });
 
-      it('throws if apiKey is false and not in call config', async () => {
+      it('works if apiKey is false and not in call config', async () => {
+        mockFetchResponse(defaultApiResponse);
         const model = defineModel('gemini-2.0-flash', { apiKey: false });
-        await assert.rejects(
-          model.run(minimalRequest),
-          /GoogleAI plugin was initialized with \{apiKey: false\}/
-        );
-        sinon.assert.notCalled(fetchStub);
+        assert.ok(await model.run(minimalRequest));
+        sinon.assert.calledOnce(fetchStub);
       });
 
       it('uses API key from call config if apiKey is false', async () => {

js/plugins/google-genai/tests/googleai/imagen_test.ts

@@ -33,10 +33,7 @@ import {
   ImagenPredictResponse,
   ImagenPrediction,
 } from '../../src/googleai/types.js';
-import {
-  API_KEY_FALSE_ERROR,
-  MISSING_API_KEY_ERROR,
-} from '../../src/googleai/utils.js';
+import { MISSING_API_KEY_ERROR } from '../../src/googleai/utils.js';
 
 const { toImagenParameters, fromImagenPrediction } = TEST_ONLY;
 
@@ -394,20 +391,22 @@ describe('Google AI Imagen', () => {
       assert.strictEqual(fetchArgs[1].headers['x-goog-api-key'], requestApiKey);
     });
 
-    it('apiKey false at init, missing in request - throws error', async () => {
+    it('works with apiKey false at init, missing in request', async () => {
+      mockFetchResponse({
+        predictions: [{ bytesBase64Encoded: 'jkl', mimeType: 'image/png' }],
+      });
       const modelRunner = captureModelRunner({ apiKey: false });
 
-      await assert.rejects(
-        modelRunner(
+      assert.ok(
+        await modelRunner(
           {
             messages: [{ role: 'user', content: [{ text: 'A car' }] }],
             config: {},
           },
           {}
-        ),
-        API_KEY_FALSE_ERROR
+        )
       );
-      sinon.assert.notCalled(fetchStub);
+      sinon.assert.calledOnce(fetchStub);
     });
 
     it('defineImagenModel throws if key not found in env or args', async () => {