diff --git a/src/config/types.signal.ts b/src/config/types.signal.ts
index cf45fa340..cc31ea869 100644
--- a/src/config/types.signal.ts
+++ b/src/config/types.signal.ts
@@ -6,6 +6,8 @@ export type SignalReactionLevel = "off" | "ack" | "minimal" | "extensive";
 export type SignalAccountConfig = CommonChannelMessagingConfig & {
   /** Optional explicit E.164 account for signal-cli. */
   account?: string;
+  /** Optional account UUID for signal-cli (used for loop protection). */
+  accountUuid?: string;
   /** Optional full base URL for signal-cli HTTP daemon. */
   httpUrl?: string;
   /** HTTP host for signal-cli daemon (default 127.0.0.1). */
diff --git a/src/signal/monitor.ts b/src/signal/monitor.ts
index d874fea11..13812593c 100644
--- a/src/signal/monitor.ts
+++ b/src/signal/monitor.ts
@@ -423,6 +423,7 @@ export async function monitorSignalProvider(opts: MonitorSignalOpts = {}): Promi
       cfg,
       baseUrl,
       account,
+      accountUuid: accountInfo.config.accountUuid,
       accountId: accountInfo.accountId,
       blockStreaming: accountInfo.config.blockStreaming,
       historyLimit,
diff --git a/src/signal/monitor/event-handler.inbound-contract.test.ts b/src/signal/monitor/event-handler.inbound-contract.test.ts
index ecb5c270b..c47db1b57 100644
--- a/src/signal/monitor/event-handler.inbound-contract.test.ts
+++ b/src/signal/monitor/event-handler.inbound-contract.test.ts
@@ -172,4 +172,33 @@ describe("signal createSignalEventHandler inbound contract", () => {
     expect(capture.ctx).toBeTruthy();
     expect(capture.ctx?.CommandAuthorized).toBe(false);
   });
+
+  it("drops own UUID inbound messages when only accountUuid is configured", async () => {
+    const ownUuid = "123e4567-e89b-12d3-a456-426614174000";
+    const handler = createSignalEventHandler(
+      createBaseSignalEventHandlerDeps({
+        cfg: {
+          messages: { inbound: { debounceMs: 0 } },
+          channels: { signal: { dmPolicy: "open", allowFrom: ["*"], accountUuid: ownUuid } },
+        },
+        account: undefined,
+        accountUuid: ownUuid,
+        historyLimit: 0,
+      }),
+    );
+
+    await handler(
+      createSignalReceiveEvent({
+        sourceNumber: null,
+        sourceUuid: ownUuid,
+        dataMessage: {
+          message: "self message",
+          attachments: [],
+        },
+      }),
+    );
+
+    expect(capture.ctx).toBeUndefined();
+    expect(dispatchInboundMessageMock).not.toHaveBeenCalled();
+  });
 });
diff --git a/src/signal/monitor/event-handler.ts b/src/signal/monitor/event-handler.ts
index 583328f8a..a3e51323b 100644
--- a/src/signal/monitor/event-handler.ts
+++ b/src/signal/monitor/event-handler.ts
@@ -420,18 +420,28 @@ export function createSignalEventHandler(deps: SignalEventHandlerDeps) {
     if (!envelope) {
       return;
     }
-    if (envelope.syncMessage) {
-      return;
-    }
 
+    // Check for syncMessage (e.g., sentTranscript from other devices)
+    // We need to check if it's from our own account to prevent self-reply loops
     const sender = resolveSignalSender(envelope);
     if (!sender) {
       return;
     }
-    if (deps.account && sender.kind === "phone") {
-      if (sender.e164 === normalizeE164(deps.account)) {
-        return;
-      }
+
+    // Check if the message is from our own account to prevent loop/self-reply
+    // This handles both phone number and UUID based identification
+    const normalizedAccount = deps.account ? normalizeE164(deps.account) : undefined;
+    const isOwnMessage =
+      (sender.kind === "phone" && normalizedAccount != null && sender.e164 === normalizedAccount) ||
+      (sender.kind === "uuid" && deps.accountUuid != null && sender.raw === deps.accountUuid);
+    if (isOwnMessage) {
+      return;
+    }
+
+    // For non-own sync messages (e.g., messages synced from other devices),
+    // we could process them but for now we skip to be conservative
+    if (envelope.syncMessage) {
+      return;
     }
 
     const dataMessage = envelope.dataMessage ?? envelope.editMessage?.dataMessage;
diff --git a/src/signal/monitor/event-handler.types.ts b/src/signal/monitor/event-handler.types.ts
index 480e7ad49..a7f3c6b1d 100644
--- a/src/signal/monitor/event-handler.types.ts
+++ b/src/signal/monitor/event-handler.types.ts
@@ -72,6 +72,7 @@ export type SignalEventHandlerDeps = {
   cfg: OpenClawConfig;
   baseUrl: string;
   account?: string;
+  accountUuid?: string;
   accountId: string;
   blockStreaming?: boolean;
   historyLimit: number;