fix: add transcription provider fallback

openrouter_client.py

@@ -19,10 +19,15 @@ load_dotenv()
 logger = logging.getLogger(__name__)
 
 OPENROUTER_BASE = "https://openrouter.ai/api/v1"
+OPENAI_BASE = "https://api.openai.com/v1"
 TRANSCRIPTION_MODELS = [
     "openai/gpt-4o-mini-transcribe",
     "openai/whisper-large-v3",
 ]
+DIRECT_OPENAI_TRANSCRIPTION_MODELS = [
+    "gpt-4o-mini-transcribe",
+    "whisper-1",
+]
 TRANSCRIPTION_CHUNK_SECONDS = 600
 MAX_TRANSCRIPTION_FILE_BYTES = 25 * 1024 * 1024
 SUMMARY_TRANSCRIPT_CHAR_LIMIT = 12000
@@ -32,6 +37,10 @@ def _api_key() -> str:
     return os.getenv("OPENROUTER_API_KEY", "")
 
 
+def _openai_api_key() -> str:
+    return os.getenv("OPENAI_API_KEY", "")
+
+
 def _auth_headers() -> dict[str, str]:
     api_key = _api_key()
     if not api_key:
@@ -177,7 +186,7 @@ async def _split_audio_for_transcription(audio_path: str) -> list[str]:
     return chunk_paths
 
 
-async def _transcribe_chunk(client: httpx.AsyncClient, audio_path: str, headers: dict[str, str]) -> str:
+async def _transcribe_chunk_with_openrouter(client: httpx.AsyncClient, audio_path: str, headers: dict[str, str]) -> str:
     failures: list[str] = []
     for model in TRANSCRIPTION_MODELS:
         resp = await client.post(
@@ -193,7 +202,7 @@ async def _transcribe_chunk(client: httpx.AsyncClient, audio_path: str, headers:
             suffix = f"; generation_id={generation_id}" if generation_id else ""
             failures.append(f"{model}: HTTP {resp.status_code}: {detail}{suffix}")
             logger.warning(
-                "Transcription model failed: model=%s chunk=%s status=%s detail=%s generation_id=%s",
+                "Transcription model failed: provider=openrouter model=%s chunk=%s status=%s detail=%s generation_id=%s",
                 model,
                 Path(audio_path).name,
                 resp.status_code,
@@ -206,7 +215,7 @@ async def _transcribe_chunk(client: httpx.AsyncClient, audio_path: str, headers:
         text = data.get("text", "")
         if text.strip():
             logger.info(
-                "Transcription chunk completed: chunk=%s model=%s transcript_chars=%s",
+                "Transcription chunk completed: provider=openrouter chunk=%s model=%s transcript_chars=%s",
                 Path(audio_path).name,
                 model,
                 len(text.strip()),
@@ -215,7 +224,7 @@ async def _transcribe_chunk(client: httpx.AsyncClient, audio_path: str, headers:
 
         failures.append(f"{model}: returned empty text")
         logger.warning(
-            "Transcription model returned empty text: model=%s chunk=%s",
+            "Transcription model returned empty text: provider=openrouter model=%s chunk=%s",
             model,
             Path(audio_path).name,
         )
@@ -223,6 +232,83 @@ async def _transcribe_chunk(client: httpx.AsyncClient, audio_path: str, headers:
     raise RuntimeError("OpenRouter transcription failed across all models: " + " | ".join(failures))
 
 
+async def _transcribe_chunk_with_openai(client: httpx.AsyncClient, audio_path: str) -> str:
+    api_key = _openai_api_key()
+    if not api_key:
+        raise RuntimeError("OPENAI_API_KEY not set")
+
+    failures: list[str] = []
+    headers = {"Authorization": f"Bearer {api_key}"}
+    for model in DIRECT_OPENAI_TRANSCRIPTION_MODELS:
+        with open(audio_path, "rb") as audio_file:
+            files = {"file": (Path(audio_path).name, audio_file, "audio/wav")}
+            data = {"model": model}
+            resp = await client.post(
+                f"{OPENAI_BASE}/audio/transcriptions",
+                headers=headers,
+                data=data,
+                files=files,
+            )
+        try:
+            resp.raise_for_status()
+        except httpx.HTTPStatusError:
+            detail = summarize_error(_safe_json(resp), fallback=resp.text)
+            request_id = resp.headers.get("x-request-id")
+            suffix = f"; request_id={request_id}" if request_id else ""
+            failures.append(f"{model}: HTTP {resp.status_code}: {detail}{suffix}")
+            logger.warning(
+                "Transcription model failed: provider=openai model=%s chunk=%s status=%s detail=%s request_id=%s",
+                model,
+                Path(audio_path).name,
+                resp.status_code,
+                detail,
+                request_id,
+            )
+            continue
+
+        data = resp.json()
+        text = data.get("text", "")
+        if text.strip():
+            logger.info(
+                "Transcription chunk completed: provider=openai chunk=%s model=%s transcript_chars=%s",
+                Path(audio_path).name,
+                model,
+                len(text.strip()),
+            )
+            return text.strip()
+
+        failures.append(f"{model}: returned empty text")
+        logger.warning(
+            "Transcription model returned empty text: provider=openai model=%s chunk=%s",
+            model,
+            Path(audio_path).name,
+        )
+
+    raise RuntimeError("Direct OpenAI transcription failed across all models: " + " | ".join(failures))
+
+
+async def _transcribe_chunk(client: httpx.AsyncClient, audio_path: str, headers: dict[str, str]) -> str:
+    failures: list[str] = []
+    try:
+        return await _transcribe_chunk_with_openrouter(client, audio_path, headers)
+    except RuntimeError as exc:
+        failures.append(str(exc))
+        logger.warning(
+            "OpenRouter transcription provider failed for chunk=%s; checking direct OpenAI fallback",
+            Path(audio_path).name,
+        )
+
+    if _openai_api_key():
+        try:
+            return await _transcribe_chunk_with_openai(client, audio_path)
+        except RuntimeError as exc:
+            failures.append(str(exc))
+    else:
+        failures.append("direct OpenAI fallback skipped: OPENAI_API_KEY not set")
+
+    raise RuntimeError("Transcription failed across providers: " + " | ".join(failures))
+
+
 async def transcribe(audio_path: str) -> str:
     """Send audio to OpenRouter STT models and return transcript text."""
     logger.info(