feat: Use LRUCache instead of Map in MemoryCache (#774)

Author: ishaanxgupta

packages/tools/package.json

@@ -14,6 +14,7 @@
     "@ai-sdk/anthropic": "^2.0.25",
     "@ai-sdk/openai": "^2.0.23",
     "ai": "^5.0.29",
+    "lru-cache": "^11.2.6",
     "openai": "^4.104.0",
     "supermemory": "^3.0.0-alpha.26",
     "zod": "^4.1.5"

packages/tools/src/shared/cache.ts

@@ -1,11 +1,12 @@
+import { LRUCache } from "lru-cache"
 import type { MemoryMode } from "./types"
 
 /**
  * Generic memory cache for storing per-turn memories to avoid redundant API calls.
  * Used to cache memory retrieval results during tool-call loops within the same turn.
  */
 export class MemoryCache<T = string> {
-	private cache: Map<string, T> = new Map()
+	private cache: LRUCache<string, T> = new LRUCache({ max: 100 })
 
 	/**
 	 * Generates a cache key for the current turn based on context parameters.