diff --git a/apps/mcp/src/ui/mcp-app.ts b/apps/mcp/src/ui/mcp-app.ts
index ba20d89a..6939edcc 100644
--- a/apps/mcp/src/ui/mcp-app.ts
+++ b/apps/mcp/src/ui/mcp-app.ts
@@ -173,9 +173,16 @@ function transformData(data: ToolResultData): {
 } {
 	const nodes: GraphNode[] = []
 	const links: GraphLink[] = []
-	const nodeIds = new Set<string>()
 	const SPREAD = 50
 
+	// Pre-populate all node IDs so edge targets are always resolvable
+	// regardless of iteration order.
+	const nodeIds = new Set<string>()
+	for (const doc of data.documents) {
+		nodeIds.add(doc.id)
+		for (const mem of doc.memories) nodeIds.add(mem.id)
+	}
+
 	for (const doc of data.documents) {
 		const pos = initialPosition(doc.id, SPREAD)
 		nodes.push({
@@ -189,7 +196,6 @@ function transformData(data: ToolResultData): {
 			x: pos.x,
 			y: pos.y,
 		} as DocumentNode)
-		nodeIds.add(doc.id)
 
 		const memCount = doc.memories.length
 		for (let i = 0; i < memCount; i++) {
@@ -211,15 +217,16 @@ function transformData(data: ToolResultData): {
 				x: pos.x + Math.cos(angle) * CLUSTER_SPREAD,
 				y: pos.y + Math.sin(angle) * CLUSTER_SPREAD,
 			} as MemoryNode)
-			nodeIds.add(mem.id)
 
 			// Derives link (doc -> memory)
 			links.push({ source: doc.id, target: mem.id, edgeType: "derives" })
 
 			// Memory-to-memory relation edges from backend data.
 			// Uses memoryRelations as primary source, falls back to parentMemoryId.
+			// Keep in sync with packages/memory-graph/src/hooks/use-graph-data.ts
 			let relations: Record<string, string> = {}
 			if (
+				// Defensive: data comes from structuredContent cast, may be unexpected type
 				mem.memoryRelations &&
 				typeof mem.memoryRelations === "object" &&
 				Object.keys(mem.memoryRelations).length > 0
diff --git a/apps/web/components/memory-graph/hooks/use-graph-api.ts b/apps/web/components/memory-graph/hooks/use-graph-api.ts
index 3984088d..5710f6ca 100644
--- a/apps/web/components/memory-graph/hooks/use-graph-api.ts
+++ b/apps/web/components/memory-graph/hooks/use-graph-api.ts
@@ -6,6 +6,7 @@ import { $fetch } from "@lib/api"
 import type {
 	GraphApiDocument,
 	GraphApiMemory,
+	MemoryRelation,
 } from "@supermemory/memory-graph"
 
 const PAGE_SIZE = 100
@@ -30,10 +31,10 @@ interface ApiMemoryEntry {
 	rootMemoryId?: string | null
 	createdAt: string
 	updatedAt: string
-	relation?: "updates" | "extends" | "derives" | null
+	relation?: MemoryRelation | null
 	updatesMemoryId?: string | null
 	nextVersionId?: string | null
-	memoryRelations?: Record<string, "updates" | "extends" | "derives"> | null
+	memoryRelations?: Record<string, MemoryRelation> | null
 	spaceContainerTag?: string | null
 }
 
diff --git a/packages/memory-graph/src/hooks/use-graph-data.ts b/packages/memory-graph/src/hooks/use-graph-data.ts
index d539e86c..037b989f 100644
--- a/packages/memory-graph/src/hooks/use-graph-data.ts
+++ b/packages/memory-graph/src/hooks/use-graph-data.ts
@@ -200,6 +200,7 @@ export function useGraphData(
 			for (const mem of doc.memories) {
 				let relations: Record<string, string> = {}
 
+				// Defensive: API may return unexpected types at runtime
 				if (
 					mem.memoryRelations &&
 					typeof mem.memoryRelations === "object" &&
diff --git a/packages/memory-graph/src/mock-data.ts b/packages/memory-graph/src/mock-data.ts
index e32adb13..9cd25a1c 100644
--- a/packages/memory-graph/src/mock-data.ts
+++ b/packages/memory-graph/src/mock-data.ts
@@ -361,7 +361,7 @@ export function generateMockGraphData(options: MockGraphOptions = {}): {
 					if (targetMem) {
 						const relType = random() < 0.5 ? "extends" : "derives"
 						memoryRelations = {
-							[targetMem.id]: relType as "extends" | "derives",
+							[targetMem.id]: relType,
 						}
 					}
 				}
diff --git a/packages/memory-graph/src/types.ts b/packages/memory-graph/src/types.ts
index 447c17ee..6fa5b9ff 100644
--- a/packages/memory-graph/src/types.ts
+++ b/packages/memory-graph/src/types.ts
@@ -39,7 +39,7 @@ export interface GraphApiDocument {
 export interface GraphApiEdge {
 	source: string
 	target: string
-	edgeType: "derives" | "updates" | "extends"
+	edgeType: MemoryRelation
 }
 
 // Typed node data
@@ -98,7 +98,7 @@ export interface GraphEdge {
 		opacity: number
 		thickness: number
 	}
-	edgeType: "derives" | "updates" | "extends"
+	edgeType: MemoryRelation
 }
 
 export interface GraphThemeColors {
@@ -221,5 +221,4 @@ export type {
 	DocumentWithMemories,
 	MemoryEntry,
 	DocumentsResponse,
-	MemoryRelation,
 } from "./api-types"