diff --git a/extensions/slack/src/monitor.threading.missing-thread-ts.test.ts b/extensions/slack/src/monitor.threading.missing-thread-ts.test.ts
index 50cb7e84e7d..8c237041557 100644
--- a/extensions/slack/src/monitor.threading.missing-thread-ts.test.ts
+++ b/extensions/slack/src/monitor.threading.missing-thread-ts.test.ts
@@ -1,117 +1,61 @@
-import { resetInboundDedupe } from "openclaw/plugin-sdk/reply-runtime";
-import { beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
-import {
-  flush,
-  getSlackClient,
-  getSlackHandlerOrThrow,
-  getSlackTestState,
-  resetSlackTestState,
-  startSlackMonitor,
-  stopSlackMonitor,
-} from "./monitor.test-helpers.js";
+import { describe, expect, it, vi } from "vitest";
+import { createSlackThreadTsResolver } from "./monitor/thread-resolution.js";
+import type { SlackMessageEvent } from "./types.js";
 
-let monitorSlackProvider: typeof import("./monitor.js").monitorSlackProvider;
-
-const slackTestState = getSlackTestState();
-
-type SlackConversationsClient = {
-  history: ReturnType<typeof vi.fn>;
-  info: ReturnType<typeof vi.fn>;
-};
-
-function makeThreadReplyEvent() {
+function makeThreadReplyMessage(): SlackMessageEvent {
   return {
-    event: {
-      type: "message",
-      user: "U1",
-      text: "hello",
-      ts: "456",
-      parent_user_id: "U2",
-      channel: "C1",
-      channel_type: "channel",
-    },
+    type: "message",
+    user: "U1",
+    text: "hello",
+    ts: "456",
+    parent_user_id: "U2",
+    channel: "C1",
+    channel_type: "channel",
   };
 }
 
-function getConversationsClient(): SlackConversationsClient {
-  const client = getSlackClient();
-  if (!client) {
-    throw new Error("Slack client not registered");
-  }
-  return client.conversations as SlackConversationsClient;
-}
-
 async function runMissingThreadScenario(params: {
   historyResponse?: { messages: Array<{ ts?: string; thread_ts?: string }> };
   historyError?: Error;
 }) {
-  slackTestState.replyMock.mockResolvedValue({ text: "thread reply" });
-
-  const conversations = getConversationsClient();
+  const history = vi.fn();
   if (params.historyError) {
-    conversations.history.mockRejectedValueOnce(params.historyError);
+    history.mockRejectedValueOnce(params.historyError);
   } else {
-    conversations.history.mockResolvedValueOnce(
-      params.historyResponse ?? { messages: [{ ts: "456" }] },
-    );
+    history.mockResolvedValueOnce(params.historyResponse ?? { messages: [{ ts: "456" }] });
   }
 
-  const { controller, run } = startSlackMonitor(monitorSlackProvider);
-  const handler = await getSlackHandlerOrThrow("message");
-  await handler(makeThreadReplyEvent());
+  const resolver = createSlackThreadTsResolver({
+    client: { conversations: { history } } as never,
+    cacheTtlMs: 60_000,
+    maxSize: 5,
+  });
 
-  await flush();
-  await stopSlackMonitor({ controller, run });
-
-  expect(slackTestState.sendMock).toHaveBeenCalledTimes(1);
-  return slackTestState.sendMock.mock.calls[0]?.[2];
+  return await resolver.resolve({
+    message: makeThreadReplyMessage(),
+    source: "message",
+  });
 }
 
-beforeEach(() => {
-  resetInboundDedupe();
-});
-
-beforeAll(async () => {
-  ({ monitorSlackProvider } = await import("./monitor.js"));
-});
-
-beforeEach(() => {
-  resetInboundDedupe();
-  resetSlackTestState({
-    messages: { responsePrefix: "PFX" },
-    channels: {
-      slack: {
-        dm: { enabled: true, policy: "open", allowFrom: ["*"] },
-        groupPolicy: "open",
-        channels: { C1: { allow: true, requireMention: false } },
-      },
-    },
-  });
-  const conversations = getConversationsClient();
-  conversations.info.mockResolvedValue({
-    channel: { name: "general", is_channel: true },
-  });
-});
-
-describe("monitorSlackProvider threading", () => {
+describe("Slack missing thread_ts recovery", () => {
   it("recovers missing thread_ts when parent_user_id is present", async () => {
-    const options = await runMissingThreadScenario({
+    const message = await runMissingThreadScenario({
       historyResponse: { messages: [{ ts: "456", thread_ts: "111.222" }] },
     });
-    expect(options).toMatchObject({ threadTs: "111.222" });
+    expect(message).toMatchObject({ thread_ts: "111.222" });
   });
 
   it("continues without thread_ts when history lookup returns no thread result", async () => {
-    const options = await runMissingThreadScenario({
+    const message = await runMissingThreadScenario({
       historyResponse: { messages: [{ ts: "456" }] },
     });
-    expect(options).not.toMatchObject({ threadTs: "111.222" });
+    expect(message.thread_ts).toBeUndefined();
   });
 
   it("continues without thread_ts when history lookup throws", async () => {
-    const options = await runMissingThreadScenario({
+    const message = await runMissingThreadScenario({
       historyError: new Error("history failed"),
     });
-    expect(options).not.toMatchObject({ threadTs: "111.222" });
+    expect(message.thread_ts).toBeUndefined();
   });
 });