diff --git a/packages/core/src/core/contentGenerator.test.ts b/packages/core/src/core/contentGenerator.test.ts
index 57ce1fed23..4bacd1b488 100644
--- a/packages/core/src/core/contentGenerator.test.ts
+++ b/packages/core/src/core/contentGenerator.test.ts
@@ -725,6 +725,26 @@ describe('createContentGeneratorConfig', () => {
     expect(config.apiKey).toBeUndefined();
     expect(config.vertexai).toBeUndefined();
   });
+  it('should configure for GATEWAY using dummy placeholder if GEMINI_API_KEY is set', async () => {
+    vi.stubEnv('GEMINI_API_KEY', 'env-gemini-key');
+    const config = await createContentGeneratorConfig(
+      mockConfig,
+      AuthType.GATEWAY,
+    );
+    expect(config.apiKey).toBe('gateway-placeholder-key');
+    expect(config.vertexai).toBe(false);
+  });
+
+  it('should configure for GATEWAY using dummy placeholder if GEMINI_API_KEY is not set', async () => {
+    vi.stubEnv('GEMINI_API_KEY', '');
+    vi.mocked(loadApiKey).mockResolvedValue(null);
+    const config = await createContentGeneratorConfig(
+      mockConfig,
+      AuthType.GATEWAY,
+    );
+    expect(config.apiKey).toBe('gateway-placeholder-key');
+    expect(config.vertexai).toBe(false);
+  });
 });
 
 describe('validateBaseUrl', () => {
diff --git a/packages/core/src/core/contentGenerator.ts b/packages/core/src/core/contentGenerator.ts
index 60641abdeb..ff1739c04b 100644
--- a/packages/core/src/core/contentGenerator.ts
+++ b/packages/core/src/core/contentGenerator.ts
@@ -150,6 +150,13 @@ export async function createContentGeneratorConfig(
     return contentGeneratorConfig;
   }
 
+  if (authType === AuthType.GATEWAY) {
+    contentGeneratorConfig.apiKey = apiKey || 'gateway-placeholder-key';
+    contentGeneratorConfig.vertexai = false;
+
+    return contentGeneratorConfig;
+  }
+
   return contentGeneratorConfig;
 }