diff --git a/api/core/rag/retrieval/retrieval_methods.py b/api/core/rag/retrieval/retrieval_methods.py
index eaa00bca88..c7c6e60c8d 100644
--- a/api/core/rag/retrieval/retrieval_methods.py
+++ b/api/core/rag/retrieval/retrieval_methods.py
@@ -5,6 +5,7 @@ class RetrievalMethod(Enum):
     SEMANTIC_SEARCH = "semantic_search"
     FULL_TEXT_SEARCH = "full_text_search"
     HYBRID_SEARCH = "hybrid_search"
+    KEYWORD_SEARCH = "keyword_search"
 
     @staticmethod
     def is_support_semantic_search(retrieval_method: str) -> bool:
diff --git a/api/core/workflow/nodes/knowledge_index/entities.py b/api/core/workflow/nodes/knowledge_index/entities.py
index f342dbfb3d..18a4f93970 100644
--- a/api/core/workflow/nodes/knowledge_index/entities.py
+++ b/api/core/workflow/nodes/knowledge_index/entities.py
@@ -63,7 +63,7 @@ class RetrievalSetting(BaseModel):
     Retrieval Setting.
     """
 
-    search_method: Literal["semantic_search", "keyword_search", "hybrid_search"]
+    search_method: Literal["semantic_search", "keyword_search", "fulltext_search", "hybrid_search"]
     top_k: int
     score_threshold: Optional[float] = 0.5
     score_threshold_enabled: bool = False
diff --git a/api/services/entities/knowledge_entities/knowledge_entities.py b/api/services/entities/knowledge_entities/knowledge_entities.py
index bb3be61f85..603064ca07 100644
--- a/api/services/entities/knowledge_entities/knowledge_entities.py
+++ b/api/services/entities/knowledge_entities/knowledge_entities.py
@@ -101,7 +101,7 @@ class WeightModel(BaseModel):
 
 
 class RetrievalModel(BaseModel):
-    search_method: Literal["hybrid_search", "semantic_search", "full_text_search"]
+    search_method: Literal["hybrid_search", "semantic_search", "full_text_search", "keyword_search"]
     reranking_enable: bool
     reranking_model: Optional[RerankingModel] = None
     reranking_mode: Optional[str] = None
diff --git a/api/services/entities/knowledge_entities/rag_pipeline_entities.py b/api/services/entities/knowledge_entities/rag_pipeline_entities.py
index 778c394d5b..8da2e4aade 100644
--- a/api/services/entities/knowledge_entities/rag_pipeline_entities.py
+++ b/api/services/entities/knowledge_entities/rag_pipeline_entities.py
@@ -83,7 +83,7 @@ class RetrievalSetting(BaseModel):
     Retrieval Setting.
     """
 
-    search_method: Literal["semantic_search", "keyword_search", "hybrid_search"]
+    search_method: Literal["semantic_search", "fulltext_search", "keyword_search", "hybrid_search"]
     top_k: int
     score_threshold: Optional[float] = 0.5
     score_threshold_enabled: bool = False