diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0a95d7fd09c..a30e57c5f0a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -77,6 +77,7 @@ Docs: https://docs.openclaw.ai
 
 ### Fixes
 
+- Web UI/Assistant text: strip internal `<relevant-memories>...</relevant-memories>` scaffolding from rendered assistant messages (while preserving code-fence literals), preventing memory-context leakage in chat output for models that echo internal blocks. (#29851) Thanks @Valkster70.
 - Dashboard/Sessions: allow authenticated Control UI clients to delete and patch sessions while still blocking regular webchat clients from session mutation RPCs, fixing Dashboard session delete failures. (#21264) Thanks @jskoiz.
 - Podman/Quadlet setup: fix `sed` escaping and UID mismatch in Podman Quadlet setup. (#26414) Thanks @KnHack and @vincentkoc.
 - Browser/Navigate: resolve the correct `targetId` in navigate responses after renderer swaps. (#25326) Thanks @stone-jin and @vincentkoc.
diff --git a/src/shared/text/assistant-visible-text.test.ts b/src/shared/text/assistant-visible-text.test.ts
new file mode 100644
index 00000000000..234d37b96da
--- /dev/null
+++ b/src/shared/text/assistant-visible-text.test.ts
@@ -0,0 +1,49 @@
+import { describe, expect, it } from "vitest";
+import { stripAssistantInternalScaffolding } from "./assistant-visible-text.js";
+
+describe("stripAssistantInternalScaffolding", () => {
+  it("strips reasoning tags", () => {
+    const input = ["<thinking>", "secret", "</thinking>", "Visible"].join("\n");
+    expect(stripAssistantInternalScaffolding(input)).toBe("Visible");
+  });
+
+  it("strips relevant-memories scaffolding blocks", () => {
+    const input = [
+      "<relevant-memories>",
+      "The following memories may be relevant to this conversation:",
+      "- Internal memory note",
+      "</relevant-memories>",
+      "",
+      "User-visible answer",
+    ].join("\n");
+    expect(stripAssistantInternalScaffolding(input)).toBe("User-visible answer");
+  });
+
+  it("supports relevant_memories tag variants", () => {
+    const input = [
+      "<relevant_memories>",
+      "Internal memory note",
+      "</relevant_memories>",
+      "Visible",
+    ].join("\n");
+    expect(stripAssistantInternalScaffolding(input)).toBe("Visible");
+  });
+
+  it("keeps relevant-memories tags inside fenced code", () => {
+    const input = [
+      "```xml",
+      "<relevant-memories>",
+      "sample",
+      "</relevant-memories>",
+      "```",
+      "",
+      "Visible text",
+    ].join("\n");
+    expect(stripAssistantInternalScaffolding(input)).toBe(input);
+  });
+
+  it("hides unfinished relevant-memories blocks", () => {
+    const input = ["Hello", "<relevant-memories>", "internal-only"].join("\n");
+    expect(stripAssistantInternalScaffolding(input)).toBe("Hello\n");
+  });
+});
diff --git a/src/shared/text/assistant-visible-text.ts b/src/shared/text/assistant-visible-text.ts
new file mode 100644
index 00000000000..38bcd5ff995
--- /dev/null
+++ b/src/shared/text/assistant-visible-text.ts
@@ -0,0 +1,47 @@
+import { findCodeRegions, isInsideCode } from "./code-regions.js";
+import { stripReasoningTagsFromText } from "./reasoning-tags.js";
+
+const MEMORY_TAG_RE = /<\s*(\/?)\s*relevant[-_]memories\b[^<>]*>/gi;
+const MEMORY_TAG_QUICK_RE = /<\s*\/?\s*relevant[-_]memories\b/i;
+
+function stripRelevantMemoriesTags(text: string): string {
+  if (!text || !MEMORY_TAG_QUICK_RE.test(text)) {
+    return text;
+  }
+  MEMORY_TAG_RE.lastIndex = 0;
+
+  const codeRegions = findCodeRegions(text);
+  let result = "";
+  let lastIndex = 0;
+  let inMemoryBlock = false;
+
+  for (const match of text.matchAll(MEMORY_TAG_RE)) {
+    const idx = match.index ?? 0;
+    if (isInsideCode(idx, codeRegions)) {
+      continue;
+    }
+
+    const isClose = match[1] === "/";
+    if (!inMemoryBlock) {
+      result += text.slice(lastIndex, idx);
+      if (!isClose) {
+        inMemoryBlock = true;
+      }
+    } else if (isClose) {
+      inMemoryBlock = false;
+    }
+
+    lastIndex = idx + match[0].length;
+  }
+
+  if (!inMemoryBlock) {
+    result += text.slice(lastIndex);
+  }
+
+  return result;
+}
+
+export function stripAssistantInternalScaffolding(text: string): string {
+  const withoutReasoning = stripReasoningTagsFromText(text, { mode: "preserve", trim: "start" });
+  return stripRelevantMemoriesTags(withoutReasoning).trimStart();
+}
diff --git a/ui/src/ui/chat/message-extract.test.ts b/ui/src/ui/chat/message-extract.test.ts
index 70dd28e001f..93df4b371af 100644
--- a/ui/src/ui/chat/message-extract.test.ts
+++ b/ui/src/ui/chat/message-extract.test.ts
@@ -23,6 +23,25 @@ describe("extractTextCached", () => {
     expect(extractTextCached(message)).toBe("plain text");
     expect(extractTextCached(message)).toBe("plain text");
   });
+
+  it("strips assistant relevant-memories scaffolding", () => {
+    const message = {
+      role: "assistant",
+      content: [
+        {
+          type: "text",
+          text: [
+            "<relevant-memories>",
+            "Internal memory context",
+            "</relevant-memories>",
+            "Final user answer",
+          ].join("\n"),
+        },
+      ],
+    };
+    expect(extractText(message)).toBe("Final user answer");
+    expect(extractTextCached(message)).toBe("Final user answer");
+  });
 });
 
 describe("extractThinkingCached", () => {
diff --git a/ui/src/ui/format.test.ts b/ui/src/ui/format.test.ts
index 239bdd213ec..e272b5c6ca4 100644
--- a/ui/src/ui/format.test.ts
+++ b/ui/src/ui/format.test.ts
@@ -68,4 +68,34 @@ describe("stripThinkingTags", () => {
     expect(stripThinkingTags("<final\nHello")).toBe("<final\nHello");
     expect(stripThinkingTags("Hello</final>")).toBe("Hello");
   });
+
+  it("strips <relevant-memories> blocks", () => {
+    const input = [
+      "<relevant-memories>",
+      "The following memories may be relevant to this conversation:",
+      "- Internal memory note",
+      "</relevant-memories>",
+      "",
+      "User-visible answer",
+    ].join("\n");
+    expect(stripThinkingTags(input)).toBe("User-visible answer");
+  });
+
+  it("keeps relevant-memories tags in fenced code blocks", () => {
+    const input = [
+      "```xml",
+      "<relevant-memories>",
+      "sample",
+      "</relevant-memories>",
+      "```",
+      "",
+      "Visible text",
+    ].join("\n");
+    expect(stripThinkingTags(input)).toBe(input);
+  });
+
+  it("hides unfinished <relevant-memories> block tails", () => {
+    const input = ["Hello", "<relevant-memories>", "internal-only"].join("\n");
+    expect(stripThinkingTags(input)).toBe("Hello\n");
+  });
 });
diff --git a/ui/src/ui/format.ts b/ui/src/ui/format.ts
index da3d544f199..1d3f24bfadf 100644
--- a/ui/src/ui/format.ts
+++ b/ui/src/ui/format.ts
@@ -1,6 +1,6 @@
 import { formatDurationHuman } from "../../../src/infra/format-time/format-duration.ts";
 import { formatRelativeTimestamp } from "../../../src/infra/format-time/format-relative.ts";
-import { stripReasoningTagsFromText } from "../../../src/shared/text/reasoning-tags.js";
+import { stripAssistantInternalScaffolding } from "../../../src/shared/text/assistant-visible-text.js";
 
 export { formatRelativeTimestamp, formatDurationHuman };
 
@@ -56,5 +56,5 @@ export function parseList(input: string): string[] {
 }
 
 export function stripThinkingTags(value: string): string {
-  return stripReasoningTagsFromText(value, { mode: "preserve", trim: "start" });
+  return stripAssistantInternalScaffolding(value);
 }