fix(gemini): raise incomplete transcription interactions as non-retryable 400 and drop response bodies from Vertex transcription errors

litellm/llms/gemini/audio_transcription/transformation.py

@@ -38,6 +38,7 @@ from litellm.types.utils import (
 INTERACTIONS_API_REVISION: Final = "2026-05-20"
 WORD_INFO_ANNOTATION_TYPE: Final = "word_info"
 _DECODED_JSON: Final = TypeAdapter(object)
+_RETRYABLE_INTERACTION_STATUSES: Final = frozenset({"failed"})
 
 
 class GeminiAudioTranscriptionConfig(BaseAudioTranscriptionConfig):
@@ -143,7 +144,7 @@ class GeminiAudioTranscriptionConfig(BaseAudioTranscriptionConfig):
         parsed: Final = GeminiTranscriptionInteractionResponse.model_validate(response_json)
         if parsed.status != "completed":
             raise GeminiError(
-                status_code=raw_response.status_code,
+                status_code=500 if parsed.status in _RETRYABLE_INTERACTION_STATUSES else 400,
                 message=f"Gemini transcription interaction did not complete (status={parsed.status})",
             )
         text_contents: Final = tuple(

litellm/llms/vertex_ai/audio_transcription/gemini_transcribe_transformation.py

@@ -183,7 +183,7 @@ class VertexGeminiAudioTranscriptionConfig(BaseAudioTranscriptionConfig, VertexB
         except ValueError:
             raise VertexAIError(
                 status_code=raw_response.status_code,
-                message=f"Received non-JSON response from Vertex AI Gemini transcription: {raw_response.text}",
+                message="Received non-JSON response from Vertex AI Gemini transcription",
             )
         parsed: Final = VertexGeminiTranscriptionResponse.model_validate(response_json)
         texts: Final = tuple(

litellm/llms/vertex_ai/audio_transcription/transformation.py

@@ -172,7 +172,7 @@ class VertexAIAudioTranscriptionConfig(BaseAudioTranscriptionConfig, VertexBase)
         except ValueError:
             raise VertexAIError(
                 status_code=raw_response.status_code,
-                message=f"Received non-JSON response from Google Speech-to-Text: {raw_response.text}",
+                message="Received non-JSON response from Google Speech-to-Text",
             )
         parsed: Final = VertexSpeechToTextRecognizeResponse.model_validate(response_json)
         transcripts: Final = tuple(

tests/unit/llms/gemini/audio_transcription/test_gemini_audio_transcription_transformation.py

@@ -3,6 +3,7 @@ import json
 
 import httpx
 import pytest
+import respx
 
 import litellm
 from litellm.llms.gemini.audio_transcription.transformation import (
@@ -264,6 +265,52 @@ class TestTransformResponse:
         assert response.get("duration") is None
 
 
+
+class TestNonCompletedInteractionThroughRouter:
+    @pytest.fixture
+    def router(self, monkeypatch):
+        monkeypatch.setattr(litellm, "disable_aiohttp_transport", True)
+        return litellm.Router(
+            model_list=[
+                {
+                    "model_name": "transcribe",
+                    "litellm_params": {"model": "gemini/gemini-3.5-transcribe", "api_key": "test-gemini-key"},
+                }
+            ],
+            num_retries=2,
+        )
+
+    def _interaction(self, status):
+        payload = json.loads(json.dumps(COMPLETED_RESPONSE))
+        payload["status"] = status
+        payload["steps"][0]["content"][0]["text"] = "sensitive transcript text"
+        return payload
+
+    @pytest.mark.asyncio
+    @respx.mock
+    async def test_incomplete_interaction_fails_once_as_bad_request_without_transcript(self, router):
+        route = respx.post("https://generativelanguage.googleapis.com/v1beta/interactions").mock(
+            return_value=httpx.Response(200, json=self._interaction("incomplete"))
+        )
+        with pytest.raises(litellm.BadRequestError) as excinfo:
+            await router.atranscription(model="transcribe", file=("call.wav", AUDIO_BYTES, "audio/wav"))
+        assert route.call_count == 1
+        assert excinfo.value.status_code == 400
+        assert "status=incomplete" in str(excinfo.value)
+        assert "sensitive transcript text" not in str(excinfo.value)
+
+    @pytest.mark.asyncio
+    @respx.mock
+    async def test_failed_interaction_is_retried(self, router):
+        route = respx.post("https://generativelanguage.googleapis.com/v1beta/interactions").mock(
+            return_value=httpx.Response(200, json=self._interaction("failed"))
+        )
+        with pytest.raises(litellm.InternalServerError) as excinfo:
+            await router.atranscription(model="transcribe", file=("call.wav", AUDIO_BYTES, "audio/wav"))
+        assert route.call_count == 3
+        assert "sensitive transcript text" not in str(excinfo.value)
+
+
 class TestSubtitleSynthesisThroughHandler:
     def _transform(self, config, response_format):
         from unittest.mock import Mock

tests/unit/llms/vertex_ai/audio_transcription/test_vertex_ai_audio_transcription_transformation.py

@@ -208,6 +208,12 @@ class TestTransformResponse:
         response = config.transform_audio_transcription_response(raw_response)
         assert response.text == ""
 
+    def test_non_json_error_omits_response_body(self, config):
+        raw_response = httpx.Response(status_code=200, text='{"results": [{"alternatives": [{"transcript": "sensitive')
+        with pytest.raises(VertexAIError, match="non-JSON") as excinfo:
+            config.transform_audio_transcription_response(raw_response)
+        assert "sensitive" not in str(excinfo.value)
+
     def test_fractional_billed_duration(self, config):
         raw_response = httpx.Response(
             status_code=200,

tests/unit/llms/vertex_ai/audio_transcription/test_vertex_ai_gemini_transcribe_transformation.py

@@ -255,6 +255,12 @@ class TestTransformResponse:
         with pytest.raises(VertexAIError, match="non-JSON"):
             config.transform_audio_transcription_response(raw_response)
 
+    def test_non_json_error_omits_response_body(self, config):
+        raw_response = httpx.Response(status_code=200, text='{"candidates": [{"content": {"parts": [{"text": "sensitive')
+        with pytest.raises(VertexAIError) as excinfo:
+            config.transform_audio_transcription_response(raw_response)
+        assert "sensitive" not in str(excinfo.value)
+
 
 class TestValidateEnvironment:
     def test_sets_oauth_headers(self):