Add entity resolution (#58)

core/config.py

@@ -67,6 +67,7 @@ class Settings(BaseSettings):
     # Graph configuration
     GRAPH_PROVIDER: Literal["ollama", "openai"]
     GRAPH_MODEL: str
+    ENABLE_ENTITY_RESOLUTION: bool = True
 
     # Reranker configuration
     USE_RERANKING: bool
@@ -301,6 +302,7 @@ def get_settings() -> Settings:
     graph_config = {
         "GRAPH_PROVIDER": config["graph"]["provider"],
         "GRAPH_MODEL": config["graph"]["model_name"],
+        "ENABLE_ENTITY_RESOLUTION": config["graph"].get("enable_entity_resolution", True),
     }
     
     # load telemetry config

core/services/entity_resolution.py

@@ -0,0 +1,344 @@
+import httpx
+import logging
+import json
+from typing import List, Dict, Any, Tuple
+from pydantic import BaseModel, ConfigDict
+
+from core.config import get_settings
+from core.models.graph import Entity
+from openai import AsyncOpenAI
+
+logger = logging.getLogger(__name__)
+
+
+# Define Pydantic models for structured output
+class EntityGroup(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+    canonical: str
+    variants: List[str]
+
+
+class EntityResolutionResult(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+    entity_groups: List[EntityGroup]
+
+
+class EntityResolver:
+    """
+    Resolves and normalizes entities by identifying different variants of the same entity.
+    Handles cases like "Trump" vs "Donald J Trump" or "JFK" vs "Kennedy".
+    """
+
+    def __init__(self):
+        """Initialize the entity resolver"""
+        self.settings = get_settings()
+
+    async def resolve_entities(self, entities: List[Entity]) -> Tuple[List[Entity], Dict[str, str]]:
+        """
+        Resolves entities by identifying and grouping entities that refer to the same real-world entity.
+
+        Args:
+            entities: List of extracted entities
+
+        Returns:
+            Tuple containing:
+            - List of normalized entities
+            - Dictionary mapping original entity text to canonical entity text
+        """
+        if not entities:
+            return [], {}
+
+        # Extract entity labels to deduplicate
+        entity_labels = [e.label for e in entities]
+
+        # If there's only one entity, no need to resolve
+        if len(entity_labels) <= 1:
+            return entities, {entity_labels[0]: entity_labels[0]} if entity_labels else {}
+        
+        # Use LLM to identify and group similar entities
+        resolved_entities = await self._resolve_with_llm(entity_labels)
+        
+        # Create mapping from original to canonical forms
+        entity_mapping = {}
+        for group in resolved_entities:
+            canonical = group["canonical"]
+            for variant in group["variants"]:
+                entity_mapping[variant] = canonical
+        
+        # Deduplicate entities based on mapping
+        unique_entities = []
+        label_to_entity_map = {}
+        
+        # First, create a map from labels to entities
+        for entity in entities:
+            canonical_label = entity_mapping.get(entity.label, entity.label)
+            
+            # If we haven't seen this canonical label yet, add the entity to our map
+            if canonical_label not in label_to_entity_map:
+                label_to_entity_map[canonical_label] = entity
+            else:
+                # If we have seen it, merge chunk sources
+                existing_entity = label_to_entity_map[canonical_label]
+                
+                # Merge document IDs
+                for doc_id in entity.document_ids:
+                    if doc_id not in existing_entity.document_ids:
+                        existing_entity.document_ids.append(doc_id)
+                
+                # Merge chunk sources
+                for doc_id, chunk_numbers in entity.chunk_sources.items():
+                    if doc_id not in existing_entity.chunk_sources:
+                        existing_entity.chunk_sources[doc_id] = list(chunk_numbers)
+                    else:
+                        for chunk_num in chunk_numbers:
+                            if chunk_num not in existing_entity.chunk_sources[doc_id]:
+                                existing_entity.chunk_sources[doc_id].append(chunk_num)
+                
+                # Merge properties (optional)
+                for key, value in entity.properties.items():
+                    if key not in existing_entity.properties:
+                        existing_entity.properties[key] = value
+    
+        # Now, update the labels and create unique entities list
+        for canonical_label, entity in label_to_entity_map.items():
+            # Update the entity label to the canonical form
+            entity.label = canonical_label
+            
+            # Add aliases property if there are variants
+            variants = [variant for variant, canon in entity_mapping.items() 
+                        if canon == canonical_label and variant != canonical_label]
+            if variants:
+                if 'aliases' not in entity.properties:
+                    entity.properties['aliases'] = []
+                entity.properties['aliases'].extend(variants)
+                # Deduplicate aliases
+                entity.properties['aliases'] = list(set(entity.properties['aliases']))
+            
+            unique_entities.append(entity)
+            
+        return unique_entities, entity_mapping
+    
+    async def _resolve_with_llm(self, entity_labels: List[str]) -> List[Dict[str, Any]]:
+        """
+        Uses LLM to identify and group similar entities.
+        
+        Args:
+            entity_labels: List of entity labels to resolve
+            
+        Returns:
+            List of entity groups, where each group is a dict with:
+            - "canonical": The canonical form of the entity
+            - "variants": List of variant forms of the entity
+        """
+        prompt = self._create_entity_resolution_prompt(entity_labels)
+        
+        if self.settings.GRAPH_PROVIDER == "openai":
+            return await self._resolve_with_openai(prompt, entity_labels)
+        elif self.settings.GRAPH_PROVIDER == "ollama":
+            return await self._resolve_with_ollama(prompt, entity_labels)
+        else:
+            logger.error(f"Unsupported graph provider: {self.settings.GRAPH_PROVIDER}")
+            # Fallback: treat each entity as unique
+            return [{"canonical": label, "variants": [label]} for label in entity_labels]
+
+    async def _resolve_with_openai(self, prompt: str, entity_labels: List[str]) -> List[Dict[str, Any]]:
+        """
+        Resolves entities using OpenAI.
+
+        Args:
+            prompt: Prompt for entity resolution
+            entity_labels: Original entity labels
+
+        Returns:
+            List of entity groups
+        """
+        # Define the schema directly instead of converting from Pydantic model
+        json_schema = {
+            "type": "object",
+            "properties": {
+                "entity_groups": {
+                    "type": "array",
+                    "items": {
+                        "type": "object",
+                        "properties": {
+                            "canonical": {"type": "string"},
+                            "variants": {
+                                "type": "array",
+                                "items": {"type": "string"}
+                            }
+                        },
+                        "required": ["canonical", "variants"],
+                        "additionalProperties": False
+                    }
+                }
+            },
+            "required": ["entity_groups"],
+            "additionalProperties": False
+        }
+        
+        # System and user messages
+        system_message = {
+            "role": "system",
+            "content": "You are an entity resolution expert. Your task is to identify and group different representations of the same real-world entity."
+        }
+        
+        user_message = {
+            "role": "user",
+            "content": prompt
+        }
+        
+        try:
+            client = AsyncOpenAI(api_key=self.settings.OPENAI_API_KEY)
+            
+            response = await client.responses.create(
+                model=self.settings.GRAPH_MODEL,
+                input=[system_message, user_message],
+                text={
+                    "format": {
+                        "type": "json_schema",
+                        "name": "entity_resolution",
+                        "schema": json_schema,
+                        "strict": True
+                    }
+                }
+            )
+            
+            # Process response based on current API structure
+            if hasattr(response, 'output_text') and response.output_text:
+                content = response.output_text
+                
+                try:
+                    # Parse with Pydantic model for validation
+                    parsed_data = json.loads(content)
+                    
+                    # Validate with Pydantic model
+                    resolution_result = EntityResolutionResult.model_validate(parsed_data)
+                    
+                    # Extract entity groups
+                    return [group.model_dump() for group in resolution_result.entity_groups]
+                    
+                except Exception as e:
+                    logger.error("Error parsing entity resolution response: %r", e)
+                    
+                    # Fallback to direct JSON parsing if Pydantic validation fails
+                    try:
+                        parsed_data = json.loads(content)
+                        return parsed_data.get("entity_groups", [])
+                    except Exception:
+                        logger.error("JSON parsing failed, falling back to default resolution")
+                        
+            elif hasattr(response, 'refusal') and response.refusal:
+                logger.warning("OpenAI refused to resolve entities")
+                        
+        except Exception as e:
+            logger.error("Error during entity resolution with OpenAI: %r", e)
+        
+        # Fallback: treat each entity as unique
+        logger.info("Falling back to treating each entity as unique")
+        return [{"canonical": label, "variants": [label]} for label in entity_labels]
+    
+    async def _resolve_with_ollama(self, prompt: str, entity_labels: List[str]) -> List[Dict[str, Any]]:
+        """
+        Resolves entities using Ollama.
+        
+        Args:
+            prompt: Prompt for entity resolution
+            entity_labels: Original entity labels
+            
+        Returns:
+            List of entity groups
+        """
+        system_message = {
+            "role": "system",
+            "content": "You are an entity resolution expert. Your task is to identify and group different representations of the same real-world entity."
+        }
+        
+        user_message = {
+            "role": "user",
+            "content": prompt
+        }
+        
+        try:
+            async with httpx.AsyncClient(timeout=60.0) as client:
+                # Create the schema for structured output
+                format_schema = EntityResolutionResult.model_json_schema()
+                
+                response = await client.post(
+                    f"{self.settings.EMBEDDING_OLLAMA_BASE_URL}/api/chat",
+                    json={
+                        "model": self.settings.GRAPH_MODEL,
+                        "messages": [system_message, user_message],
+                        "stream": False,
+                        "format": format_schema
+                    },
+                )
+                response.raise_for_status()
+                result = response.json()
+                
+                # Parse with Pydantic model for validation
+                resolution_result = EntityResolutionResult.model_validate_json(result["message"]["content"])
+                return [group.model_dump() for group in resolution_result.entity_groups]
+                
+        except Exception as e:
+            logger.error("Error during entity resolution with Ollama: %r", e)
+            
+        # Fallback: treat each entity as unique
+        return [{"canonical": label, "variants": [label]} for label in entity_labels]
+    
+    def _create_entity_resolution_prompt(self, entity_labels: List[str]) -> str:
+        """
+        Creates a prompt for the LLM to resolve entities.
+        
+        Args:
+            entity_labels: List of entity labels to resolve
+            
+        Returns:
+            Prompt string for the LLM
+        """
+        entities_str = "\n".join([f"- {label}" for label in entity_labels])
+        entities_example_dict = {
+            "entity_groups": [
+                {
+                    "canonical": "John F. Kennedy",
+                    "variants": ["John F. Kennedy", "JFK", "Kennedy"]
+                },
+                {
+                    "canonical": "United States of America",
+                    "variants": ["United States of America", "USA", "United States"]
+                }
+            ]
+        }
+        
+        prompt = f"""
+Below is a list of entities extracted from a document:
+
+{entities_str}
+
+Some of these entities may refer to the same real-world entity but with different names or spellings.
+For example, "JFK" and "John F. Kennedy" refer to the same person.
+
+Please analyze this list and group entities that refer to the same real-world entity.
+For each group, provide:
+1. A canonical (standard) form of the entity
+2. All variant forms found in the list
+
+Format your response as a JSON object with an "entity_groups" array, where each item in the array is an object with:
+- "canonical": The canonical form (choose the most complete and formal name)
+- "variants": Array of all variants (including the canonical form)
+
+The exact format of the JSON structure should be:
+```json
+{str(entities_example_dict)}
+```
+
+Only include entities in your response that have multiple variants or are grouped with other entities.
+If an entity has no variants and doesn't belong to any group, don't include it in your response.
+
+Focus on identifying:
+- Different names for the same person (e.g., full names vs. nicknames)
+- Different forms of the same organization
+- The same concept expressed differently
+- Abbreviations and their full forms
+- Spelling variations and typos
+"""
+        return prompt

core/services/graph_service.py

@@ -12,6 +12,7 @@ from core.completion.base_completion import BaseCompletionModel
 from core.database.base_database import BaseDatabase
 from core.models.documents import Document, ChunkResult
 from core.config import get_settings
+from core.services.entity_resolution import EntityResolver
 from openai import AsyncOpenAI
 
 logger = logging.getLogger(__name__)
@@ -49,6 +50,7 @@ class GraphService:
         self.db = db
         self.embedding_model = embedding_model
         self.completion_model = completion_model
+        self.entity_resolver = EntityResolver()
 
     async def create_graph(
         self,
@@ -140,6 +142,8 @@ class GraphService:
         entities = {}
         # List to collect all relationships
         relationships = []
+        # List to collect all extracted entities for resolution
+        all_entities = []
 
         # Collect all chunk sources from documents.
         chunk_sources = [
@@ -162,11 +166,12 @@ class GraphService:
                     chunk.chunk_number
                 )
 
-                # Add entities to the collection, avoiding duplicates
+                # Add entities to the collection, avoiding duplicates based on exact label match
                 for entity in chunk_entities:
                     if entity.label not in entities:
                         # For new entities, initialize chunk_sources with the current chunk
                         entities[entity.label] = entity
+                        all_entities.append(entity)
                     else:
                         # If entity already exists, add this chunk source if not already present
                         existing_entity = entities[entity.label]
@@ -197,6 +202,58 @@ class GraphService:
                 logger.error(f"Fatal error processing chunk {chunk.chunk_number} in document {chunk.document_id}: {e}")
                 raise
 
+        # Check if entity resolution is enabled in settings
+        settings = get_settings()
+        
+        # Resolve entities to handle variations like "Trump" vs "Donald J Trump"
+        if settings.ENABLE_ENTITY_RESOLUTION:
+            logger.info("Resolving %d entities using LLM...", len(all_entities))
+            resolved_entities, entity_mapping = await self.entity_resolver.resolve_entities(all_entities)
+            logger.info("Entity resolution completed successfully")
+        else:
+            logger.info("Entity resolution is disabled in settings.")
+            # Return identity mapping (each entity maps to itself)
+            entity_mapping = {entity.label: entity.label for entity in all_entities}
+            resolved_entities = all_entities
+        
+        if entity_mapping:
+            logger.info("Entity resolution complete. Found %d mappings.", len(entity_mapping))
+            # Create a new entities dictionary with resolved entities
+            resolved_entities_dict = {}
+            # Build new entities dictionary with canonical labels
+            for entity in resolved_entities:
+                resolved_entities_dict[entity.label] = entity
+            # Update relationships to use canonical entity labels
+            updated_relationships = []
+            
+            # Create an entity index by ID for efficient lookups
+            entity_by_id = {entity.id: entity for entity in all_entities}
+            
+            for relationship in relationships:
+                # Lookup entities by ID directly from the index
+                source_entity = entity_by_id.get(relationship.source_id)
+                target_entity = entity_by_id.get(relationship.target_id)
+                
+                if source_entity and target_entity:
+                    # Get canonical labels
+                    source_canonical = entity_mapping.get(source_entity.label, source_entity.label)
+                    target_canonical = entity_mapping.get(target_entity.label, target_entity.label)
+                    # Get canonical entities
+                    canonical_source = resolved_entities_dict.get(source_canonical)
+                    canonical_target = resolved_entities_dict.get(target_canonical)
+                    if canonical_source and canonical_target:
+                        # Update relationship to point to canonical entities
+                        relationship.source_id = canonical_source.id
+                        relationship.target_id = canonical_target.id
+                        updated_relationships.append(relationship)
+                    else:
+                        # Skip relationships that can't be properly mapped
+                        logger.warning("Skipping relationship between '%s' and '%s' - canonical entities not found", source_entity.label, target_entity.label)
+                else:
+                    # Keep relationship as is if we can't find the entities
+                    updated_relationships.append(relationship)
+            return resolved_entities_dict, updated_relationships
+        # If no entity resolution occurred, return original entities and relationships
         return entities, relationships
 
     async def extract_entities_from_text(
@@ -328,7 +385,7 @@ class GraphService:
                 result = response.json()
 
                 # Log the raw response for debugging
-                logger.info(f"Raw Ollama response for entity extraction: {result['message']['content']}")
+                logger.debug(f"Raw Ollama response for entity extraction: {result['message']['content']}")
 
                 # Parse the JSON response - Pydantic will handle validation
                 extraction_result = ExtractionResult.model_validate_json(result["message"]["content"])
@@ -459,14 +516,36 @@ class GraphService:
             # Find similar entities using embedding similarity
             top_entities = await self._find_similar_entities(query, graph.entities, k)
         else:
-            # Use extracted entities directly
-            entity_map = {entity.label.lower(): entity for entity in graph.entities}
+            # Use entity resolution to handle variants of the same entity
+            settings = get_settings()
+            
+            # First, create combined list of query entities and graph entities for resolution
+            combined_entities = query_entities + graph.entities
+            
+            # Resolve entities to identify variants if enabled
+            if settings.ENABLE_ENTITY_RESOLUTION:
+                logger.info(f"Resolving {len(combined_entities)} entities from query and graph...")
+                resolved_entities, entity_mapping = await self.entity_resolver.resolve_entities(combined_entities)
+            else:
+                logger.info("Entity resolution is disabled in settings.")
+                # Return identity mapping (each entity maps to itself)
+                entity_mapping = {entity.label: entity.label for entity in combined_entities}
+                resolved_entities = combined_entities
+            
+            # Create a mapping of resolved entity labels to graph entities
+            entity_map = {}
+            for entity in graph.entities:
+                # Get canonical form for this entity
+                canonical_label = entity_mapping.get(entity.label, entity.label)
+                entity_map[canonical_label.lower()] = entity
+            
             matched_entities = []
-
-            # Match extracted entities with graph entities
+            # Match extracted entities with graph entities using canonical labels
             for query_entity in query_entities:
-                if query_entity.label.lower() in entity_map:
-                    matched_entities.append(entity_map[query_entity.label.lower()])
+                # Get canonical form for this query entity
+                canonical_query = entity_mapping.get(query_entity.label, query_entity.label)
+                if canonical_query.lower() in entity_map:
+                    matched_entities.append(entity_map[canonical_query.lower()])
 
             # If no matches, fallback to embedding similarity
             if matched_entities:

databridge.toml

@@ -105,10 +105,12 @@ mode = "self_hosted"  # "cloud" or "self_hosted"
 [graph]
 provider = "ollama"
 model_name = "llama3.2"
+enable_entity_resolution = true
 
 # [graph]
 # provider = "openai"
 # model_name = "gpt-4o-mini"
+# enable_entity_resolution = true
 
 [telemetry]
 enabled = true

sdks/python/databridge/__init__.py

@@ -12,4 +12,4 @@ __all__ = [
     "Document",
 ]
 
-__version__ = "0.2.6"
+__version__ = "0.2.7"

sdks/python/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "databridge-client"
-version = "0.2.6"
+version = "0.2.7"
 authors = [
     { name = "DataBridge", email = "databridgesuperuser@gmail.com" },
 ]

ui-component/components/ForceGraphComponent.tsx

@@ -92,12 +92,10 @@ const ForceGraphComponent: React.FC<ForceGraphComponentProps> = ({
             .linkDirectionalArrowLength(3)
             .linkDirectionalArrowRelPos(1);
           
-          // Add node labels if enabled
-          if (showNodeLabels && graph.nodeCanvasObject) {
+          // Always use nodeCanvasObject to have consistent rendering regardless of label visibility
+          if (graph.nodeCanvasObject) {
             graph.nodeCanvasObject((node: NodeObject, ctx: CanvasRenderingContext2D, globalScale: number) => {
               // Draw the node circle
-              const label = node.label;
-              const fontSize = 12/globalScale;
               const nodeR = 5;
               
               if (typeof node.x !== 'number' || typeof node.y !== 'number') return;
@@ -110,31 +108,35 @@ const ForceGraphComponent: React.FC<ForceGraphComponentProps> = ({
               ctx.fillStyle = node.color;
               ctx.fill();
               
-              // Draw the text label
-              ctx.font = `${fontSize}px Sans-Serif`;
-              ctx.textAlign = 'center';
-              ctx.textBaseline = 'middle';
-              ctx.fillStyle = 'black';
-              
-              // Add a background for better readability
-              const textWidth = ctx.measureText(label).width;
-              const bckgDimensions = [textWidth, fontSize].map(n => n + fontSize * 0.2);
-              
-              ctx.fillStyle = 'rgba(255, 255, 255, 0.8)';
-              ctx.fillRect(
-                x - bckgDimensions[0] / 2,
-                y - bckgDimensions[1] / 2,
-                bckgDimensions[0],
-                bckgDimensions[1]
-              );
-              
-              ctx.fillStyle = 'black';
-              ctx.fillText(label, x, y);
+              // Only draw the text label if showNodeLabels is true
+              if (showNodeLabels) {
+                const label = node.label;
+                const fontSize = 12/globalScale;
+                
+                ctx.font = `${fontSize}px Sans-Serif`;
+                ctx.textAlign = 'center';
+                ctx.textBaseline = 'middle';
+                
+                // Add a background for better readability
+                const textWidth = ctx.measureText(label).width;
+                const bckgDimensions = [textWidth, fontSize].map(n => n + fontSize * 0.2);
+                
+                ctx.fillStyle = 'rgba(255, 255, 255, 0.8)';
+                ctx.fillRect(
+                  x - bckgDimensions[0] / 2,
+                  y - bckgDimensions[1] / 2,
+                  bckgDimensions[0],
+                  bckgDimensions[1]
+                );
+                
+                ctx.fillStyle = 'black';
+                ctx.fillText(label, x, y);
+              }
             });
           }
           
-          // Add link labels if enabled
-          if (showLinkLabels && graph.linkCanvasObject) {
+          // Always use linkCanvasObject for consistent rendering
+          if (graph.linkCanvasObject) {
             graph.linkCanvasObject((link: LinkObject, ctx: CanvasRenderingContext2D, globalScale: number) => {
               // Draw the link line
               const start = link.source as NodeObject;
@@ -155,55 +157,59 @@ const ForceGraphComponent: React.FC<ForceGraphComponentProps> = ({
               ctx.lineWidth = 1;
               ctx.stroke();
               
-              // Draw the label at the middle of the link
-              const label = link.type;
-              if (label) {
-                const fontSize = 10/globalScale;
-                ctx.font = `${fontSize}px Sans-Serif`;
-                
-                // Calculate middle point
-                const middleX = startX + (endX - startX) / 2;
-                const middleY = startY + (endY - startY) / 2;
-                
-                // Add a background for better readability
-                const textWidth = ctx.measureText(label).width;
-                const bckgDimensions = [textWidth, fontSize].map(n => n + fontSize * 0.2);
-                
-                ctx.fillStyle = 'rgba(255, 255, 255, 0.8)';
-                ctx.fillRect(
-                  middleX - bckgDimensions[0] / 2,
-                  middleY - bckgDimensions[1] / 2,
-                  bckgDimensions[0],
-                  bckgDimensions[1]
-                );
-                
-                ctx.textAlign = 'center';
-                ctx.textBaseline = 'middle';
-                ctx.fillStyle = 'black';
-                ctx.fillText(label, middleX, middleY);
-                
-                // Draw arrow
-                const arrowLength = 5;
-                const dx = endX - startX;
-                const dy = endY - startY;
-                const angle = Math.atan2(dy, dx);
-                
-                const arrowX = middleX + Math.cos(angle) * arrowLength;
-                const arrowY = middleY + Math.sin(angle) * arrowLength;
-                
-                ctx.beginPath();
-                ctx.moveTo(arrowX, arrowY);
-                ctx.lineTo(
-                  arrowX - arrowLength * Math.cos(angle - Math.PI / 6),
-                  arrowY - arrowLength * Math.sin(angle - Math.PI / 6)
-                );
-                ctx.lineTo(
-                  arrowX - arrowLength * Math.cos(angle + Math.PI / 6),
-                  arrowY - arrowLength * Math.sin(angle + Math.PI / 6)
-                );
-                ctx.closePath();
-                ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';
-                ctx.fill();
+              // Draw arrowhead regardless of label visibility
+              const arrowLength = 5;
+              const dx = endX - startX;
+              const dy = endY - startY;
+              const angle = Math.atan2(dy, dx);
+              
+              // Calculate a position near the target for the arrow
+              const arrowDistance = 15; // Distance from target node
+              const arrowX = endX - Math.cos(angle) * arrowDistance;
+              const arrowY = endY - Math.sin(angle) * arrowDistance;
+              
+              ctx.beginPath();
+              ctx.moveTo(arrowX, arrowY);
+              ctx.lineTo(
+                arrowX - arrowLength * Math.cos(angle - Math.PI / 6),
+                arrowY - arrowLength * Math.sin(angle - Math.PI / 6)
+              );
+              ctx.lineTo(
+                arrowX - arrowLength * Math.cos(angle + Math.PI / 6),
+                arrowY - arrowLength * Math.sin(angle + Math.PI / 6)
+              );
+              ctx.closePath();
+              ctx.fillStyle = 'rgba(0, 0, 0, 0.5)';
+              ctx.fill();
+              
+              // Only draw label if showLinkLabels is true
+              if (showLinkLabels) {
+                const label = link.type;
+                if (label) {
+                  const fontSize = 10/globalScale;
+                  ctx.font = `${fontSize}px Sans-Serif`;
+                  
+                  // Calculate middle point
+                  const middleX = startX + (endX - startX) / 2;
+                  const middleY = startY + (endY - startY) / 2;
+                  
+                  // Add a background for better readability
+                  const textWidth = ctx.measureText(label).width;
+                  const bckgDimensions = [textWidth, fontSize].map(n => n + fontSize * 0.2);
+                  
+                  ctx.fillStyle = 'rgba(255, 255, 255, 0.8)';
+                  ctx.fillRect(
+                    middleX - bckgDimensions[0] / 2,
+                    middleY - bckgDimensions[1] / 2,
+                    bckgDimensions[0],
+                    bckgDimensions[1]
+                  );
+                  
+                  ctx.textAlign = 'center';
+                  ctx.textBaseline = 'middle';
+                  ctx.fillStyle = 'black';
+                  ctx.fillText(label, middleX, middleY);
+                }
               }
             });
           }

ui-component/components/GraphSection.tsx

@@ -98,11 +98,17 @@ const GraphSection: React.FC<GraphSectionProps> = ({ apiBaseUrl }) => {
       color: entityTypeColors[entity.type.toLowerCase()] || entityTypeColors.default
     }));
 
-    const links = graph.relationships.map(rel => ({
-      source: rel.source_id,
-      target: rel.target_id,
-      type: rel.type
-    }));
+    // Create a Set of all entity IDs for faster lookups
+    const nodeIdSet = new Set(graph.entities.map(entity => entity.id));
+
+    // Filter relationships to only include those where both source and target nodes exist
+    const links = graph.relationships
+      .filter(rel => nodeIdSet.has(rel.source_id) && nodeIdSet.has(rel.target_id))
+      .map(rel => ({
+        source: rel.source_id,
+        target: rel.target_id,
+        type: rel.type
+      }));
 
     return { nodes, links };
   }, []);
@@ -251,7 +257,7 @@ const GraphSection: React.FC<GraphSectionProps> = ({ apiBaseUrl }) => {
         initializeGraph();
       }, 100);
     }
-  }, [selectedGraph, activeTab, initializeGraph]);
+  }, [selectedGraph, activeTab, initializeGraph, showNodeLabels, showLinkLabels]);
 
   // Handle tab change
   const handleTabChange = (value: string) => {