[Fix] OCI sync streaming missing split_chunks causes JSONDecodeError (#24819)

Add _split_sse_text helper to split batched SSE events on "\n\n" boundaries,
used by both sync and async streaming paths. The sync path was missing this
logic, causing json.loads() to fail when the OCI endpoint batched multiple
SSE events into a single HTTP chunk.

litellm/llms/oci/chat/transformation.py

@@ -8,6 +8,7 @@ from typing import (
     Any,
     AsyncIterator,
     Dict,
+    Iterator,
     List,
     Optional,
     Protocol,
@@ -190,6 +191,13 @@ def get_vendor_from_model(model: str) -> OCIVendors:
 STREAMING_TIMEOUT = 60 * 5
 
 
+def _split_sse_text(text: str) -> Iterator[str]:
+    """Split a possibly-batched SSE text block into individual event strings."""
+    for chunk in text.split("\n\n"):
+        if chunk:
+            yield chunk.strip()
+
+
 class OCIChatConfig(BaseConfig):
     """
     Configuration class for OCI's API interface.
@@ -1110,8 +1118,12 @@ class OCIChatConfig(BaseConfig):
 
         completion_stream = response.iter_text()
 
+        def split_chunks(stream: Iterator[str]) -> Iterator[str]:
+            for item in stream:
+                yield from _split_sse_text(item)
+
         streaming_response = OCIStreamWrapper(
-            completion_stream=completion_stream,
+            completion_stream=split_chunks(completion_stream),
             model=model,
             custom_llm_provider=custom_llm_provider,
             logging_obj=logging_obj,
@@ -1155,12 +1167,10 @@ class OCIChatConfig(BaseConfig):
 
         completion_stream = response.aiter_text()
 
-        async def split_chunks(completion_stream: AsyncIterator[str]):
-            async for item in completion_stream:
-                for chunk in item.split("\n\n"):
-                    if not chunk:
-                        continue
-                    yield chunk.strip()
+        async def split_chunks(stream: AsyncIterator[str]) -> AsyncIterator[str]:
+            async for item in stream:
+                for chunk in _split_sse_text(item):
+                    yield chunk
 
         streaming_response = OCIStreamWrapper(
             completion_stream=split_chunks(completion_stream),

tests/test_litellm/llms/oci/chat/test_oci_chat_transformation.py

@@ -11,7 +11,7 @@ import litellm
 sys.path.insert(0, os.path.abspath("../../../../.."))
 
 from litellm import ModelResponse
-from litellm.llms.oci.chat.transformation import OCIChatConfig, OCIRequestWrapper, version
+from litellm.llms.oci.chat.transformation import OCIChatConfig, OCIRequestWrapper, version, _split_sse_text
 
 TEST_MODEL_NAME = "xai.grok-4"
 TEST_MODEL = f"oci/{TEST_MODEL_NAME}"
@@ -741,3 +741,73 @@ class TestOCISignerSupport:
         )
 
         assert wrapper.path_url == "/api/v1/chat"
+
+
+class TestSplitSseText:
+    """Tests for the _split_sse_text helper used by both sync and async streaming."""
+
+    def test_single_event(self):
+        result = list(_split_sse_text("data: {\"id\": \"1\"}"))
+        assert result == ["data: {\"id\": \"1\"}"]
+
+    def test_multiple_events(self):
+        text = "data: {\"id\": \"1\"}\n\ndata: {\"id\": \"2\"}"
+        result = list(_split_sse_text(text))
+        assert result == ["data: {\"id\": \"1\"}", "data: {\"id\": \"2\"}"]
+
+    def test_empty_string(self):
+        assert list(_split_sse_text("")) == []
+
+    def test_only_separators(self):
+        assert list(_split_sse_text("\n\n\n\n")) == []
+
+    def test_strips_whitespace(self):
+        text = "  data: {\"id\": \"1\"}  \n\n  data: {\"id\": \"2\"}  "
+        result = list(_split_sse_text(text))
+        assert result == ["data: {\"id\": \"1\"}", "data: {\"id\": \"2\"}"]
+
+    def test_three_events(self):
+        text = "data: {\"a\":1}\n\ndata: {\"b\":2}\n\ndata: {\"c\":3}"
+        result = list(_split_sse_text(text))
+        assert len(result) == 3
+
+
+class TestSyncStreamSplitChunks:
+    """Tests that the sync streaming path correctly splits batched SSE chunks."""
+
+    def test_sync_stream_wrapper_splits_batched_chunks(self):
+        """Verify get_sync_custom_stream_wrapper splits multi-event HTTP chunks."""
+        from unittest.mock import MagicMock, patch
+
+        config = OCIChatConfig()
+
+        # Simulate an HTTP response whose iter_text() yields a batched chunk
+        mock_response = MagicMock()
+        mock_response.status_code = 200
+        mock_response.iter_text.return_value = iter([
+            "data: {\"id\":\"1\"}\n\ndata: {\"id\":\"2\"}",
+            "data: {\"id\":\"3\"}",
+        ])
+
+        mock_client = MagicMock()
+        mock_client.post.return_value = mock_response
+
+        with patch("litellm.llms.oci.chat.transformation.track_llm_api_timing", lambda: lambda f: f):
+            result = config.get_sync_custom_stream_wrapper(
+                model=TEST_MODEL_NAME,
+                custom_llm_provider="oci",
+                logging_obj=MagicMock(),
+                api_base="https://example.com/chat",
+                headers={},
+                data={"test": "data"},
+                messages=[],
+                client=mock_client,
+            )
+
+        # Consume the stream wrapper's completion_stream to verify splitting
+        chunks = list(result.completion_stream)
+        assert chunks == [
+            "data: {\"id\":\"1\"}",
+            "data: {\"id\":\"2\"}",
+            "data: {\"id\":\"3\"}",
+        ]