diff --git a/extensions/whatsapp/src/inbound/dedupe.ts b/extensions/whatsapp/src/inbound/dedupe.ts
index 676717fa137..765623acc46 100644
--- a/extensions/whatsapp/src/inbound/dedupe.ts
+++ b/extensions/whatsapp/src/inbound/dedupe.ts
@@ -1,4 +1,3 @@
-import { createDedupeCache } from "openclaw/plugin-sdk/core";
 import { createClaimableDedupe } from "openclaw/plugin-sdk/persistent-dedupe";
 
 const RECENT_WEB_MESSAGE_TTL_MS = 20 * 60_000;
@@ -6,19 +5,69 @@ const RECENT_WEB_MESSAGE_MAX = 5000;
 const RECENT_OUTBOUND_MESSAGE_TTL_MS = 20 * 60_000;
 const RECENT_OUTBOUND_MESSAGE_MAX = 5000;
 
-const recentInboundMessages = createDedupeCache({
-  ttlMs: RECENT_WEB_MESSAGE_TTL_MS,
-  maxSize: RECENT_WEB_MESSAGE_MAX,
-});
 const claimableInboundMessages = createClaimableDedupe({
   ttlMs: RECENT_WEB_MESSAGE_TTL_MS,
   memoryMaxSize: RECENT_WEB_MESSAGE_MAX,
 });
-const recentOutboundMessages = createDedupeCache({
+const recentOutboundMessages = createRecentMessageCache({
   ttlMs: RECENT_OUTBOUND_MESSAGE_TTL_MS,
   maxSize: RECENT_OUTBOUND_MESSAGE_MAX,
 });
 
+function createRecentMessageCache(options: { ttlMs: number; maxSize: number }) {
+  const ttlMs = Math.max(0, options.ttlMs);
+  const maxSize = Math.max(0, Math.floor(options.maxSize));
+  const cache = new Map<string, number>();
+
+  const prune = (now: number) => {
+    if (ttlMs > 0) {
+      const cutoff = now - ttlMs;
+      for (const [key, timestamp] of cache) {
+        if (timestamp < cutoff) {
+          cache.delete(key);
+        }
+      }
+    }
+    while (cache.size > maxSize) {
+      const oldest = cache.keys().next().value;
+      if (!oldest) {
+        break;
+      }
+      cache.delete(oldest);
+    }
+  };
+
+  const peek = (key: string | null, now = Date.now()): boolean => {
+    if (!key) {
+      return false;
+    }
+    const timestamp = cache.get(key);
+    if (timestamp === undefined) {
+      return false;
+    }
+    if (ttlMs > 0 && now - timestamp >= ttlMs) {
+      cache.delete(key);
+      return false;
+    }
+    return true;
+  };
+
+  return {
+    check: (key: string | null, now = Date.now()): boolean => {
+      if (!key) {
+        return false;
+      }
+      const existed = peek(key, now);
+      cache.delete(key);
+      cache.set(key, now);
+      prune(now);
+      return existed;
+    },
+    peek,
+    clear: () => cache.clear(),
+  };
+}
+
 export class WhatsAppRetryableInboundError extends Error {
   constructor(message: string, options?: ErrorOptions) {
     super(message, options);
@@ -41,7 +90,6 @@ function buildMessageKey(params: {
 }
 
 export function resetWebInboundDedupe(): void {
-  recentInboundMessages.clear();
   claimableInboundMessages.clearMemory();
   recentOutboundMessages.clear();
 }
@@ -53,7 +101,6 @@ export async function claimRecentInboundMessage(key: string): Promise<boolean> {
 
 export async function commitRecentInboundMessage(key: string): Promise<void> {
   await claimableInboundMessages.commit(key);
-  recentInboundMessages.check(key);
 }
 
 export function releaseRecentInboundMessage(key: string, error?: unknown): void {