From e4aae2ee6eeec9a18734cce8d29889ff662c30bb Mon Sep 17 00:00:00 2001
From: Ratish1 <formula733@gmail.com>
Date: Tue, 21 Oct 2025 22:29:53 +0400
Subject: [PATCH] fix(models/gemini): handle non-JSON error messages from
 Gemini API

---
 src/strands/models/gemini.py        |  8 +++++++-
 tests/strands/models/test_gemini.py | 16 ++++++++++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/strands/models/gemini.py b/src/strands/models/gemini.py
index c288595e1..c24d91a0d 100644
--- a/src/strands/models/gemini.py
+++ b/src/strands/models/gemini.py
@@ -408,7 +408,13 @@ async def stream(
             if not error.message:
                 raise
 
-            message = json.loads(error.message)
+            try:
+                message = json.loads(error.message) if error.message else {}
+            except json.JSONDecodeError as e:
+                logger.warning("error_message=<%s> | Gemini API returned non-JSON error", error.message)
+                # Re-raise the original ClientError (not JSONDecodeError) and make the JSON error the explicit cause
+                raise error from e
+
             match message["error"]["status"]:
                 case "RESOURCE_EXHAUSTED" | "UNAVAILABLE":
                     raise ModelThrottledException(error.message) from error
diff --git a/tests/strands/models/test_gemini.py b/tests/strands/models/test_gemini.py
index 9eb5a9a7f..a8f5351cc 100644
--- a/tests/strands/models/test_gemini.py
+++ b/tests/strands/models/test_gemini.py
@@ -1,4 +1,5 @@
 import json
+import logging
 import unittest.mock
 
 import pydantic
@@ -621,3 +622,18 @@ async def test_structured_output(gemini_client, model, messages, model_id, weath
         "model": model_id,
     }
     gemini_client.aio.models.generate_content.assert_called_with(**exp_request)
+
+
+@pytest.mark.asyncio
+async def test_stream_handles_non_json_error(gemini_client, model, messages, caplog, alist):
+    error_message = "Invalid API key"
+    gemini_client.aio.models.generate_content_stream.side_effect = genai.errors.ClientError(
+        error_message, {"message": error_message}
+    )
+
+    with caplog.at_level(logging.WARNING):
+        with pytest.raises(genai.errors.ClientError, match=error_message):
+            await alist(model.stream(messages))
+
+    assert "Gemini API returned non-JSON error" in caplog.text
+    assert f"error_message=<{error_message}>" in caplog.text