diff --git a/extensions/nostr/src/channel.inbound.test.ts b/extensions/nostr/src/channel.inbound.test.ts
index 47d0d5379126..1f4843df19a3 100644
--- a/extensions/nostr/src/channel.inbound.test.ts
+++ b/extensions/nostr/src/channel.inbound.test.ts
@@ -52,11 +52,12 @@ function createRuntimeHarness() {
   const dispatchReplyWithBufferedBlockDispatcher = vi.fn(async ({ dispatcherOptions }) => {
     await dispatcherOptions.deliver({ text: "**Table:** [docs](https://example.com)" });
   });
+  const convertMarkdownTables = vi.fn((text: string) => text);
   const runtime = {
     channel: {
       text: {
         resolveMarkdownTableMode: vi.fn(() => "off"),
-        convertMarkdownTables: vi.fn((text: string) => text),
+        convertMarkdownTables,
       },
       commands: {
         shouldComputeCommandAuthorized: vi.fn(() => true),
@@ -91,6 +92,7 @@ function createRuntimeHarness() {
     runtime,
     recordInboundSession,
     dispatchReplyWithBufferedBlockDispatcher,
+    convertMarkdownTables,
   };
 }
 
@@ -227,4 +229,88 @@ describe("nostr inbound gateway path", () => {
 
     await cleanup.stop();
   });
+
+  it.each([
+    {
+      name: "strips an internal tool-failure banner",
+      text: "Done.\n⚠️ 🛠️ `search repos (agent)` failed",
+      expected: "Done.",
+    },
+    {
+      name: "strips internal tool-call XML",
+      text: '<tool_call>{"name":"read","arguments":{"path":"private"}}</tool_call>Done.',
+      expected: "Done.",
+    },
+    {
+      name: "strips multiline tool-response scaffolding",
+      text: [
+        "Before",
+        "<function_response>",
+        "private output",
+        "</function_response>",
+        "After",
+      ].join("\n"),
+      expected: "Before\n\nAfter",
+    },
+    {
+      name: "does not send an internal-trace-only reply",
+      text: "⚠️ 🛠️ `search repos (agent)` failed",
+      expected: null,
+    },
+    {
+      name: "preserves ordinary visible prose",
+      text: "The relay has two active subscriptions.",
+      expected: "The relay has two active subscriptions.",
+    },
+  ])("$name before sending an inbound Nostr DM reply", async ({ text, expected }) => {
+    mocks.dispatchInboundDirectDm.mockImplementationOnce(
+      async (params: Parameters<typeof DispatchInboundDirectDm>[0]) => {
+        await params.deliver({ text });
+      },
+    );
+    const { harness, cleanup } = await startGatewayHarness({
+      account: buildResolvedNostrAccount({
+        publicKey: "bot-pubkey",
+        config: { dmPolicy: "allowlist", allowFrom: ["nostr:sender-pubkey"] },
+      }),
+      cfg: {},
+    });
+    const options = mockCallArg(mocks.startNostrBus) as {
+      onMessage: (
+        senderPubkey: string,
+        text: string,
+        reply: (text: string) => Promise<void>,
+        meta: { eventId: string; createdAt: number },
+        lifecycle: NostrIngressLifecycle,
+      ) => Promise<void>;
+    };
+    const sendReply = vi.fn(async (_text: string) => {});
+    const lifecycle: NostrIngressLifecycle = {
+      abortSignal: new AbortController().signal,
+      onAdopted: vi.fn(async () => {}),
+      onDeferred: vi.fn(),
+      onAdoptionFinalizing: vi.fn(),
+      onAbandoned: vi.fn(async () => {}),
+    };
+
+    try {
+      await options.onMessage(
+        "sender-pubkey",
+        "hello from nostr",
+        sendReply,
+        { eventId: "event-123", createdAt: 1_710_000_000 },
+        lifecycle,
+      );
+
+      if (expected === null) {
+        expect(harness.convertMarkdownTables).not.toHaveBeenCalled();
+        expect(sendReply).not.toHaveBeenCalled();
+      } else {
+        expect(harness.convertMarkdownTables).toHaveBeenCalledWith(expected, "off");
+        expect(sendReply).toHaveBeenCalledWith(expected);
+      }
+    } finally {
+      await cleanup.stop();
+    }
+  });
 });
diff --git a/extensions/nostr/src/channel.outbound.test.ts b/extensions/nostr/src/channel.outbound.test.ts
index db873d6b98e4..12fb56045258 100644
--- a/extensions/nostr/src/channel.outbound.test.ts
+++ b/extensions/nostr/src/channel.outbound.test.ts
@@ -85,6 +85,47 @@ describe("nostr outbound cfg threading", () => {
     mocks.startNostrBus.mockReset();
   });
 
+  it.each([
+    {
+      name: "strips an internal tool-failure banner",
+      text: "Done.\n⚠️ 🛠️ `search repos (agent)` failed",
+      expected: "Done.",
+    },
+    {
+      name: "strips internal tool-call XML",
+      text: '<tool_call>{"name":"read","arguments":{"path":"private"}}</tool_call>Done.',
+      expected: "Done.",
+    },
+    {
+      name: "strips multiline tool-response scaffolding",
+      text: [
+        "Before",
+        "<function_response>",
+        "private output",
+        "</function_response>",
+        "After",
+      ].join("\n"),
+      expected: "Before\n\nAfter",
+    },
+    {
+      name: "suppresses an internal-trace-only reply",
+      text: "⚠️ 🛠️ `search repos (agent)` failed",
+      expected: "",
+    },
+    {
+      name: "preserves ordinary visible prose",
+      text: "The relay has two active subscriptions.",
+      expected: "The relay has two active subscriptions.",
+    },
+  ])("$name through the Nostr outbound sanitizer", ({ text, expected }) => {
+    const sanitizeText = nostrPlugin.outbound?.sanitizeText;
+    expect(sanitizeText).toBeTypeOf("function");
+    if (!sanitizeText) {
+      throw new Error("Expected Nostr outbound assistant-visible text sanitizer");
+    }
+    expect(sanitizeText({ text, payload: { text } })).toBe(expected);
+  });
+
   it("converts tables before projecting markdown to Nostr plain text", async () => {
     const { resolveMarkdownTableMode, convertMarkdownTables } = installOutboundRuntime(
       vi.fn((text: string) => (text === "***" ? text : "**Table:** [docs](https://example.com)")),
diff --git a/extensions/nostr/src/gateway.ts b/extensions/nostr/src/gateway.ts
index 08fc4015e3dd..4cdb37d5597a 100644
--- a/extensions/nostr/src/gateway.ts
+++ b/extensions/nostr/src/gateway.ts
@@ -10,7 +10,7 @@ import {
 import { createChannelPairingController } from "openclaw/plugin-sdk/channel-pairing";
 import { attachChannelToResult } from "openclaw/plugin-sdk/channel-send-result";
 import type { OpenClawConfig } from "openclaw/plugin-sdk/config-contracts";
-import { stripMarkdown } from "openclaw/plugin-sdk/text-chunking";
+import { sanitizeAssistantVisibleText, stripMarkdown } from "openclaw/plugin-sdk/text-chunking";
 import type { ChannelOutboundAdapter, ChannelPlugin } from "./channel-api.js";
 import type { MetricEvent, MetricsSnapshot } from "./metrics.js";
 import { startNostrBus, type NostrBusHandle } from "./nostr-bus.js";
@@ -26,6 +26,7 @@ type NostrOutboundAdapter = Pick<
   "deliveryCapabilities" | "deliveryMode" | "textChunkLimit" | "sendText"
 > & {
   sendText: NonNullable<ChannelOutboundAdapter["sendText"]>;
+  sanitizeText: NonNullable<ChannelOutboundAdapter["sanitizeText"]>;
 };
 
 const activeBuses = new Map<string, NostrBusHandle>();
@@ -194,7 +195,10 @@ export const startNostrGatewayAccount: NostrGatewayStart = async (ctx) => {
                 payload && typeof payload === "object" && "text" in payload
                   ? ((payload as { text?: string }).text ?? "")
                   : "";
-              if (!outboundText.trim()) {
+              // Inbound DM replies bypass the outbound adapter; sanitize before
+              // Markdown conversion so private tool traces cannot reach a relay.
+              const sanitizedText = sanitizeAssistantVisibleText(outboundText);
+              if (!sanitizedText) {
                 return;
               }
               const tableMode = runtime.channel.text.resolveMarkdownTableMode({
@@ -203,7 +207,7 @@ export const startNostrGatewayAccount: NostrGatewayStart = async (ctx) => {
                 accountId: account.accountId,
               });
               const message = stripMarkdown(
-                runtime.channel.text.convertMarkdownTables(outboundText, tableMode),
+                runtime.channel.text.convertMarkdownTables(sanitizedText, tableMode),
               );
               if (message) {
                 await reply(message);
@@ -312,6 +316,7 @@ export const nostrPairingTextAdapter = {
 export const nostrOutboundAdapter: NostrOutboundAdapter = {
   deliveryMode: "direct",
   textChunkLimit: 4000,
+  sanitizeText: ({ text }) => sanitizeAssistantVisibleText(text),
   deliveryCapabilities: {
     durableFinal: {
       text: true,