diff --git a/packages/core/src/code_assist/converter.test.ts b/packages/core/src/code_assist/converter.test.ts
index 17dba1e4da..31e66bcd17 100644
--- a/packages/core/src/code_assist/converter.test.ts
+++ b/packages/core/src/code_assist/converter.test.ts
@@ -331,6 +331,16 @@ describe('converter', () => {
       const genaiRes = fromGenerateContentResponse(codeAssistRes);
       expect(genaiRes.responseId).toBeUndefined();
     });
+
+    it('should handle missing response property gracefully', () => {
+      const invalidRes = {
+        traceId: 'some-trace-id',
+      } as unknown as CaGenerateContentResponse;
+
+      const genaiRes = fromGenerateContentResponse(invalidRes);
+      expect(genaiRes.responseId).toEqual('some-trace-id');
+      expect(genaiRes.candidates).toEqual([]);
+    });
   });
 
   describe('toContents', () => {
diff --git a/packages/core/src/code_assist/converter.ts b/packages/core/src/code_assist/converter.ts
index 2b8b0a3a33..8dcfe80d78 100644
--- a/packages/core/src/code_assist/converter.ts
+++ b/packages/core/src/code_assist/converter.ts
@@ -133,14 +133,18 @@ export function toGenerateContentRequest(
 export function fromGenerateContentResponse(
   res: CaGenerateContentResponse,
 ): GenerateContentResponse {
-  const inres = res.response;
   const out = new GenerateContentResponse();
-  out.candidates = inres.candidates;
+  out.responseId = res.traceId;
+  const inres = res.response;
+  if (!inres) {
+    out.candidates = [];
+    return out;
+  }
+  out.candidates = inres.candidates ?? [];
   out.automaticFunctionCallingHistory = inres.automaticFunctionCallingHistory;
   out.promptFeedback = inres.promptFeedback;
   out.usageMetadata = inres.usageMetadata;
   out.modelVersion = inres.modelVersion;
-  out.responseId = res.traceId;
   return out;
 }