diff --git a/backend/local_rag.py b/backend/local_rag.py
index ab5def3..81581dc 100644
--- a/backend/local_rag.py
+++ b/backend/local_rag.py
@@ -25,6 +25,14 @@ router = APIRouter(tags=["local-rag"])
 LIB_ROOT = Path(__file__).parent / "libraries"
 LIB_ROOT.mkdir(parents=True, exist_ok=True)
 
+RAW_CORPUS_PROFILE = "per-file-default-v1"
+PREPARE_PROFILE = "selective-enrich-v1"
+DEFAULT_EMBED_MODEL = "dengcao/Qwen3-Embedding-0.6B:F16"
+DEFAULT_ENRICH_MODEL = "qwen3:4b"
+DEFAULT_ENRICH_MIN_CHARS = 240
+DEFAULT_ENRICH_MAX_TEXT = 6000
+DEFAULT_ENRICH_CONCURRENCY = max(1, min(4, (os.cpu_count() or 4) // 2))
+
 JOB_EXECUTOR = ThreadPoolExecutor(max_workers=2)
 JOBS: Dict[str, Dict[str, Any]] = {}
 LIB_LOCKS: Dict[str, asyncio.Lock] = {}
@@ -46,8 +54,13 @@ class RemoveFileRequest(BaseModel):
     rel: str
 
 
+class UpdateFileEnrichmentRequest(BaseModel):
+    rel: str
+    enabled: bool
+
+
 class EmbedLibraryRequest(BaseModel):
-    embed_model: str = "dengcao/Qwen3-Embedding-0.6B:F16"
+    embed_model: str = DEFAULT_EMBED_MODEL
     ollama: str = "http://localhost:11434"
     target_chars: int = 2000
     overlap_chars: int = 200
@@ -58,7 +71,7 @@ class LibraryContextRequest(BaseModel):
     prompt: str
     top_k: int = 5
     ollama: str = "http://localhost:11434"
-    embed_model: str = "dengcao/Qwen3-Embedding-0.6B:F16"
+    embed_model: str = DEFAULT_EMBED_MODEL
     gen_model: str = "qwen3:4b"