diff --git a/packages/server/src/server/agent/providers/omp/agent.test.ts b/packages/server/src/server/agent/providers/omp/agent.test.ts
index 35020ca45..f0adadee7 100644
--- a/packages/server/src/server/agent/providers/omp/agent.test.ts
+++ b/packages/server/src/server/agent/providers/omp/agent.test.ts
@@ -277,6 +277,35 @@ describe("OMP agent client and session", () => {
     ]);
   });
 
+  test("renders a live system-notice custom message as a synthetic tool call", async () => {
+    const omp = new OmpHarness();
+    await omp.start();
+
+    await omp.runPrompt("hello OMP", "done");
+    omp
+      .runtime()
+      .acceptCustomMessage(
+        [
+          "<system-notice>",
+          "Background job DocsSmokeTwo has completed.",
+          '<task-result id="DocsSmokeTwo" agent="explore" status="completed" duration="21.6s">',
+          "<output>done</output>",
+          "</task-result>",
+          "</system-notice>",
+        ].join("\n"),
+      );
+    omp.runtime().acceptCustomMessage("plain custom status text");
+
+    expect(omp.timeline().filter((item) => item.type === "tool_call")).toMatchObject([
+      { callId: "omp-notice:DocsSmokeTwo", name: "task_notification", status: "completed" },
+    ]);
+    // Non-notice custom messages still fall through as assistant messages.
+    expect(omp.timeline().filter((item) => item.type === "assistant_message")).toMatchObject([
+      { text: "done" },
+      { text: "plain custom status text" },
+    ]);
+  });
+
   test("does not complete a queued model turn from OMP's local-only hint", async () => {
     const omp = new OmpHarness();
     await omp.start();
diff --git a/packages/server/src/server/agent/providers/omp/agent.ts b/packages/server/src/server/agent/providers/omp/agent.ts
index c0654a627..8337c250a 100644
--- a/packages/server/src/server/agent/providers/omp/agent.ts
+++ b/packages/server/src/server/agent/providers/omp/agent.ts
@@ -68,6 +68,7 @@ export { formatOmpVersionSupport, resolveOmpDiagnosticPaths } from "./provider-c
 import { OmpSubagentCardTracker, type OmpSubagentCardScheduler } from "./subagent-card-tracker.js";
 import { shouldDisplayOmpCustomMessage } from "./custom-message.js";
 import { getUserMessageText } from "./message-history.js";
+import { mapOmpSystemNoticeToToolCall } from "./system-notice.js";
 import { materializeProviderImage } from "../provider-image-output.js";
 import { OmpCliRuntime } from "./cli-runtime.js";
 import { listOmpImportableSessions, readOmpImportSessionConfig } from "./session-descriptor.js";
@@ -2068,12 +2069,14 @@ export class OmpAgentSession implements AgentSession {
       if (shouldDisplayOmpCustomMessage(event.message)) {
         const text = getUserMessageText(event.message.content);
         if (text) {
-          const advisorItem = mapOmpAdvisorMessageToToolCall(event.message, text);
+          const item =
+            mapOmpAdvisorMessageToToolCall(event.message, text) ??
+            mapOmpSystemNoticeToToolCall(text);
           this.emit({
             type: "timeline",
             provider: this.provider,
             turnId,
-            item: advisorItem ?? { type: "assistant_message", text },
+            item: item ?? { type: "assistant_message", text },
           });
         }
       }