From b7f778d686d4f321795575aaab1f22d55907510a Mon Sep 17 00:00:00 2001
From: Aishanee Shah <aishaneeshah@google.com>
Date: Tue, 10 Mar 2026 02:39:34 +0000
Subject: [PATCH] feat(core): add 'Incomplete JSON segment' to retryable errors

---
 packages/core/src/utils/retry.test.ts | 19 +++++++++++++++++++
 packages/core/src/utils/retry.ts      |  9 +++++++--
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/utils/retry.test.ts b/packages/core/src/utils/retry.test.ts
index f63a5ed723..77fce2a1cb 100644
--- a/packages/core/src/utils/retry.test.ts
+++ b/packages/core/src/utils/retry.test.ts
@@ -350,6 +350,25 @@ describe('retryWithBackoff', () => {
       expect(mockFn).toHaveBeenCalledTimes(2);
     });
 
+    it("should retry on 'Incomplete JSON segment' when retryFetchErrors is true", async () => {
+      const mockFn = vi.fn();
+      mockFn.mockRejectedValueOnce(
+        new Error('Incomplete JSON segment at the end'),
+      );
+      mockFn.mockResolvedValueOnce('success');
+
+      const promise = retryWithBackoff(mockFn, {
+        retryFetchErrors: true,
+        initialDelayMs: 10,
+      });
+
+      await vi.runAllTimersAsync();
+
+      const result = await promise;
+      expect(result).toBe('success');
+      expect(mockFn).toHaveBeenCalledTimes(2);
+    });
+
     it('should retry on common network error codes (ECONNRESET)', async () => {
       const mockFn = vi.fn();
       const error = new Error('read ECONNRESET');
diff --git a/packages/core/src/utils/retry.ts b/packages/core/src/utils/retry.ts
index a16e823e74..8ce8e1934a 100644
--- a/packages/core/src/utils/retry.ts
+++ b/packages/core/src/utils/retry.ts
@@ -100,6 +100,7 @@ function getNetworkErrorCode(error: unknown): string | undefined {
 }
 
 const FETCH_FAILED_MESSAGE = 'fetch failed';
+const INCOMPLETE_JSON_MESSAGE = 'incomplete json segment';
 
 /**
  * Default predicate function to determine if a retry should be attempted.
@@ -119,8 +120,12 @@ export function isRetryableError(
   }
 
   if (retryFetchErrors && error instanceof Error) {
-    // Check for generic fetch failed message (case-insensitive)
-    if (error.message.toLowerCase().includes(FETCH_FAILED_MESSAGE)) {
+    const lowerMessage = error.message.toLowerCase();
+    // Check for generic fetch failed message or incomplete JSON segment (common stream error)
+    if (
+      lowerMessage.includes(FETCH_FAILED_MESSAGE) ||
+      lowerMessage.includes(INCOMPLETE_JSON_MESSAGE)
+    ) {
       return true;
     }
   }