Add /api/transcribe endpoint with Whisper

app/routes.py

@@ -2,10 +2,15 @@
 
 from datetime import datetime, timezone
 
-from fastapi import APIRouter
+from fastapi import APIRouter, File, HTTPException, UploadFile
+
+from app.services.transcriber import transcribe_bytes
 
 router = APIRouter(prefix="/api")
 
+# File size limit: 10 MB
+MAX_UPLOAD_SIZE = 10 * 1024 * 1024
+
 
 @router.get("/health")
 async def health():
@@ -16,3 +21,52 @@ async def health():
         "version": "0.1.0",
         "timestamp": datetime.now(timezone.utc).isoformat(),
     }
+
+
+@router.post("/transcribe")
+async def transcribe_audio(
+    file: UploadFile = File(...),
+    model: str = "base",
+):
+    """Transcribe an audio file using Whisper.
+
+    Supported formats: wav, mp3, m4a, ogg, flac, webm.
+    Model options: tiny, base, small, medium (default: base).
+    """
+    # Validate model
+    valid_models = {"tiny", "base", "small", "medium"}
+    if model not in valid_models:
+        raise HTTPException(
+            status_code=400,
+            detail=f"Invalid model '{model}'. Use: {', '.join(sorted(valid_models))}",
+        )
+
+    # Validate file type
+    allowed = {"audio/wav", "audio/mpeg", "audio/mp4", "audio/x-m4a",
+               "audio/ogg", "audio/flac", "audio/webm", "audio/x-wav"}
+    if file.content_type and file.content_type not in allowed:
+        raise HTTPException(
+            status_code=400,
+            detail=f"Unsupported format: {file.content_type}. Supported: wav, mp3, m4a, ogg, flac, webm",
+        )
+
+    # Read file
+    contents = await file.read()
+    if len(contents) > MAX_UPLOAD_SIZE:
+        raise HTTPException(
+            status_code=413,
+            detail=f"File too large. Max {MAX_UPLOAD_SIZE // (1024*1024)} MB.",
+        )
+    if len(contents) == 0:
+        raise HTTPException(400, detail="Empty file.")
+
+    # Transcribe
+    try:
+        result = transcribe_bytes(contents, model_name=model)
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=f"Transcription failed: {str(e)}")
+
+    return {
+        "filename": file.filename,
+        **result,
+    }