diff --git a/CHANGELOG.md b/CHANGELOG.md
index d793a0ad7..9bb494b94 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@
 * [WIDGET-WORKS] Fix `PrismaClientValidationError` in `messages.update` (missing `Message` relation) by guarding `messageUpdate.create` calls.
 * [WIDGET-WORKS] Guard `messages.update` cache cleanup with a derived key and optional `MESSAGE_UPDATE_CACHE_DELETE_DISABLED` flag to prevent cache.delete crash-loops.
 * [WIDGET-WORKS] Save messages before Chatwoot sync in `/message/sendText` to avoid missing `chatwootMessageId` and log async sync failures.
+* [WIDGET-WORKS] Cache sent message keys in Baileys so WhatsApp echoes are ignored (prevents Chatwoot automation duplicates when `isIntegration=true`).
 * [WIDGET-WORKS] Skip Chatwoot sync in `messages.upsert` when a message key already has `chatwootMessageId` (handles Chatwoot automation echoes/duplicates).
 * [WIDGET-WORKS] Avoid dropping group conversations when Chatwoot `updateContact` fails by logging the error and continuing with the existing contact.
 
diff --git a/src/api/integrations/channel/whatsapp/whatsapp.baileys.service.ts b/src/api/integrations/channel/whatsapp/whatsapp.baileys.service.ts
index 98832cc04..ac221411f 100644
--- a/src/api/integrations/channel/whatsapp/whatsapp.baileys.service.ts
+++ b/src/api/integrations/channel/whatsapp/whatsapp.baileys.service.ts
@@ -2212,6 +2212,16 @@ export class BaileysStartupService extends ChannelStartupService {
 
       const messageRaw = this.prepareMessage(messageSent);
 
+      // [WIDGET-WORKS] Cache sent message key so messages.upsert treats the WhatsApp echo as duplicate
+      try {
+        const messageKey = `${this.instance.id}_${messageRaw.key.id}`;
+        await this.baileysCache.set(messageKey, true, 5 * 60);
+      } catch (error) {
+        this.logger.warn(
+          `[WIDGET-WORKS] Failed to cache sent message ${messageRaw?.key?.id ?? 'unknown'}: ${error?.message}`,
+        );
+      }
+
       const isMedia =
         messageSent?.message?.imageMessage ||
         messageSent?.message?.videoMessage ||