From 1973c80dcacae82e7c7cb8b2342942142a183059 Mon Sep 17 00:00:00 2001
From: yangdx <gzdaniel@me.com>
Date: Mon, 23 Jun 2025 22:14:50 +0800
Subject: [PATCH] Feat: Add entity and relation deletion endpoints

---
 lightrag/api/routers/document_routes.py | 105 +++++++++++++++++++++++-
 1 file changed, 104 insertions(+), 1 deletion(-)

diff --git a/lightrag/api/routers/document_routes.py b/lightrag/api/routers/document_routes.py
index f5bdf01d..2d66ae1c 100644
--- a/lightrag/api/routers/document_routes.py
+++ b/lightrag/api/routers/document_routes.py
@@ -23,7 +23,7 @@ from fastapi import (
 from pydantic import BaseModel, Field, field_validator
 
 from lightrag import LightRAG
-from lightrag.base import DocProcessingStatus, DocStatus
+from lightrag.base import DeletionResult, DocProcessingStatus, DocStatus
 from lightrag.api.utils_api import get_combined_auth_dependency
 from ..config import global_args
 
@@ -262,6 +262,36 @@ Attributes:
 class DeleteDocRequest(BaseModel):
     doc_id: str = Field(..., description="The ID of the document to delete.")
 
+    @field_validator("doc_id", mode="after")
+    @classmethod
+    def validate_doc_id(cls, doc_id: str) -> str:
+        if not doc_id or not doc_id.strip():
+            raise ValueError("Document ID cannot be empty")
+        return doc_id.strip()
+
+
+class DeleteEntityRequest(BaseModel):
+    entity_name: str = Field(..., description="The name of the entity to delete.")
+
+    @field_validator("entity_name", mode="after")
+    @classmethod
+    def validate_entity_name(cls, entity_name: str) -> str:
+        if not entity_name or not entity_name.strip():
+            raise ValueError("Entity name cannot be empty")
+        return entity_name.strip()
+
+
+class DeleteRelationRequest(BaseModel):
+    source_entity: str = Field(..., description="The name of the source entity.")
+    target_entity: str = Field(..., description="The name of the target entity.")
+
+    @field_validator("source_entity", "target_entity", mode="after")
+    @classmethod
+    def validate_entity_names(cls, entity_name: str) -> str:
+        if not entity_name or not entity_name.strip():
+            raise ValueError("Entity name cannot be empty")
+        return entity_name.strip()
+
 
 class DocStatusResponse(BaseModel):
     id: str = Field(description="Document identifier")
@@ -1478,4 +1508,77 @@ def create_document_routes(
             logger.error(traceback.format_exc())
             raise HTTPException(status_code=500, detail=str(e))
 
+    @router.delete(
+        "/delete_entity",
+        response_model=DeletionResult,
+        dependencies=[Depends(combined_auth)],
+    )
+    async def delete_entity(request: DeleteEntityRequest):
+        """
+        Delete an entity and all its relationships from the knowledge graph.
+
+        Args:
+            request (DeleteEntityRequest): The request body containing the entity name.
+
+        Returns:
+            DeletionResult: An object containing the outcome of the deletion process.
+
+        Raises:
+            HTTPException: If the entity is not found (404) or an error occurs (500).
+        """
+        try:
+            result = await rag.adelete_by_entity(entity_name=request.entity_name)
+            if result.status == "not_found":
+                raise HTTPException(status_code=404, detail=result.message)
+            if result.status == "fail":
+                raise HTTPException(status_code=500, detail=result.message)
+            # Set doc_id to empty string since this is an entity operation, not document
+            result.doc_id = ""
+            return result
+        except HTTPException:
+            raise
+        except Exception as e:
+            error_msg = f"Error deleting entity '{request.entity_name}': {str(e)}"
+            logger.error(error_msg)
+            logger.error(traceback.format_exc())
+            raise HTTPException(status_code=500, detail=error_msg)
+
+    @router.delete(
+        "/delete_relation",
+        response_model=DeletionResult,
+        dependencies=[Depends(combined_auth)],
+    )
+    async def delete_relation(request: DeleteRelationRequest):
+        """
+        Delete a relationship between two entities from the knowledge graph.
+
+        Args:
+            request (DeleteRelationRequest): The request body containing the source and target entity names.
+
+        Returns:
+            DeletionResult: An object containing the outcome of the deletion process.
+
+        Raises:
+            HTTPException: If the relation is not found (404) or an error occurs (500).
+        """
+        try:
+            result = await rag.adelete_by_relation(
+                source_entity=request.source_entity,
+                target_entity=request.target_entity,
+            )
+            if result.status == "not_found":
+                raise HTTPException(status_code=404, detail=result.message)
+            if result.status == "fail":
+                raise HTTPException(status_code=500, detail=result.message)
+            # Set doc_id to empty string since this is a relation operation, not document
+            result.doc_id = ""
+            return result
+        except HTTPException:
+            raise
+        except Exception as e:
+            error_msg = f"Error deleting relation from '{request.source_entity}' to '{request.target_entity}': {str(e)}"
+            logger.error(error_msg)
+            logger.error(traceback.format_exc())
+            raise HTTPException(status_code=500, detail=error_msg)
+
     return router