diff --git a/CHANGELOG.md b/CHANGELOG.md
index a7e5b520155..d66c0223f52 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -30,6 +30,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- WhatsApp/self-chat response prefix fallback: stop forcing `"[openclaw]"` as the implicit outbound response prefix when no identity name or response prefix is configured, so blank/default prefix settings no longer inject branding text unexpectedly in self-chat flows. (#27962) Thanks @ecanmor.
 - Memory/QMD search result decoding: accept `qmd search` hits that only include `file` URIs (for example `qmd://collection/path.md`) without `docid`, resolve them through managed collection roots, and keep multi-collection results keyed by file fallback so valid QMD hits no longer collapse to empty `memory_search` output. (#28181) Thanks @0x76696265.
 - Memory/QMD collection-name conflict recovery: when `qmd collection add` fails because another collection already occupies the same `path + pattern`, detect the conflicting collection from `collection list`, remove it, and retry add so agent-scoped managed collections are created deterministically instead of being silently skipped; also add warning-only fallback when qmd metadata is unavailable to avoid destructive guesses. (#25496) Thanks @Ramsbaby.
 - Slack/app_mention race dedupe: when `app_mention` dispatch wins while same-`ts` `message` prepare is still in-flight, suppress the later message dispatch so near-simultaneous Slack deliveries do not produce duplicate replies; keep single-retry behavior and add regression coverage for both dropped and successful message-prepare outcomes. (#37033) Thanks @Takhoffman.
diff --git a/src/web/auto-reply/monitor/process-message.inbound-contract.test.ts b/src/web/auto-reply/monitor/process-message.inbound-contract.test.ts
index 8b367640039..94b550b2b2a 100644
--- a/src/web/auto-reply/monitor/process-message.inbound-contract.test.ts
+++ b/src/web/auto-reply/monitor/process-message.inbound-contract.test.ts
@@ -219,6 +219,33 @@ describe("web processMessage inbound contract", () => {
     expect(dispatcherOptions?.responsePrefix).toBe("[Mainbot]");
   });
 
+  it("does not force an [openclaw] response prefix in self-chats when identity is unset", async () => {
+    capturedDispatchParams = undefined;
+
+    await processMessage(
+      makeProcessMessageArgs({
+        routeSessionKey: "agent:main:whatsapp:direct:+1555",
+        groupHistoryKey: "+1555",
+        cfg: {
+          messages: {},
+          session: { store: sessionStorePath },
+        } as unknown as ReturnType<typeof import("../../../config/config.js").loadConfig>,
+        msg: {
+          id: "msg1",
+          from: "+1555",
+          to: "+1555",
+          selfE164: "+1555",
+          chatType: "direct",
+          body: "hi",
+        },
+      }),
+    );
+
+    // oxlint-disable-next-line typescript/no-explicit-any
+    const dispatcherOptions = (capturedDispatchParams as any)?.dispatcherOptions;
+    expect(dispatcherOptions?.responsePrefix).toBeUndefined();
+  });
+
   it("clears pending group history when the dispatcher does not queue a final reply", async () => {
     capturedCtx = undefined;
     const groupHistories = new Map<string, Array<{ sender: string; body: string }>>([
diff --git a/src/web/auto-reply/monitor/process-message.ts b/src/web/auto-reply/monitor/process-message.ts
index e092922a770..ff6d186da56 100644
--- a/src/web/auto-reply/monitor/process-message.ts
+++ b/src/web/auto-reply/monitor/process-message.ts
@@ -279,7 +279,7 @@ export async function processMessage(params: {
   const responsePrefix =
     prefixOptions.responsePrefix ??
     (configuredResponsePrefix === undefined && isSelfChat
-      ? (resolveIdentityNamePrefix(params.cfg, params.route.agentId) ?? "[openclaw]")
+      ? resolveIdentityNamePrefix(params.cfg, params.route.agentId)
       : undefined);
 
   const inboundHistory =