fix(mattermost): strip internal tool-trace banners from outbound text

ZengWen-DT · cursoragent · ZengWen-DT · commit dce31a1f056f · 2026-07-01T15:37:00.000Z
Co-authored-by: Cursor &lt;cursoragent@cursor.com&gt;
diff --git a/extensions/mattermost/src/channel.ts b/extensions/mattermost/src/channel.ts
@@ -33,6 +33,7 @@ import {
   createDefaultChannelRuntimeState,
 } from "openclaw/plugin-sdk/status-helpers";
 import { normalizeOptionalString } from "openclaw/plugin-sdk/string-coerce-runtime";
+import { sanitizeAssistantVisibleText } from "openclaw/plugin-sdk/text-chunking";
 import { mattermostApprovalAuth } from "./approval-auth.js";
 import {
   chunkTextForOutbound,
@@ -627,6 +628,7 @@ const mattermostOutbound: ChannelOutboundAdapter = {
   chunker: chunkTextForOutbound,
   chunkerMode: "markdown",
   textChunkLimit: 4000,
+  sanitizeText: ({ text }) => sanitizeAssistantVisibleText(text),
   deliveryCapabilities: {
     durableFinal: {
       text: true,
diff --git a/extensions/mattermost/src/outbound-tool-trace-sanitize.test.ts b/extensions/mattermost/src/outbound-tool-trace-sanitize.test.ts
@@ -0,0 +1,19 @@
+// Mattermost outbound must strip assistant internal tool-trace scaffolding,
+// matching the sibling channel fixes tracked under #90684 (Slack / Telegram /
+// Google Chat / IRC / SMS). sanitizeAssistantVisibleText keeps Markdown prose.
+import { describe, expect, it } from "vitest";
+import { mattermostPlugin } from "./channel.js";
+
+describe("mattermost outbound sanitizeText", () => {
+  it("strips internal tool-trace banners before outbound delivery", () => {
+    const text = "Done.\n⚠️ 🛠️ `search repos (agent)` failed";
+
+    expect(mattermostPlugin.outbound?.sanitizeText?.({ text, payload: { text } })).toBe("Done.");
+  });
+
+  it("preserves ordinary assistant prose while sanitizing", () => {
+    const text = "The pipeline has 3 open deals.";
+
+    expect(mattermostPlugin.outbound?.sanitizeText?.({ text, payload: { text } })).toBe(text);
+  });
+});
