diff --git a/extensions/slack/src/actions.download-file.test.ts b/extensions/slack/src/actions.download-file.test.ts
index c73bad4e397..5e8765d0f4d 100644
--- a/extensions/slack/src/actions.download-file.test.ts
+++ b/extensions/slack/src/actions.download-file.test.ts
@@ -12,6 +12,7 @@ vi.mock("./monitor/media.js", () => ({
 vi.mock("./client.js", () => ({
   createSlackWebClient: createSlackWebClientMock,
   createSlackWriteClient: createSlackWebClientMock,
+  getSlackWriteClient: createSlackWebClientMock,
 }));
 
 let downloadSlackFile: typeof import("./actions.js").downloadSlackFile;
diff --git a/extensions/slack/src/actions.ts b/extensions/slack/src/actions.ts
index 5034b01faec..88057e808ec 100644
--- a/extensions/slack/src/actions.ts
+++ b/extensions/slack/src/actions.ts
@@ -4,7 +4,7 @@ import { logVerbose } from "openclaw/plugin-sdk/runtime-env";
 import { resolveSlackAccount } from "./accounts.js";
 import { buildSlackBlocksFallbackText } from "./blocks-fallback.js";
 import { validateSlackBlocksArray } from "./blocks-input.js";
-import { createSlackWebClient, createSlackWriteClient } from "./client.js";
+import { createSlackWebClient, getSlackWriteClient } from "./client.js";
 import { resolveSlackMedia } from "./monitor/media.js";
 import type { SlackMediaResult } from "./monitor/media.js";
 import { sendMessageSlack } from "./send.js";
@@ -81,7 +81,7 @@ async function getClient(opts: SlackActionClientOpts = {}, mode: "read" | "write
     return opts.client;
   }
   const token = resolveToken(opts.token, opts.accountId, opts.cfg);
-  return mode === "write" ? createSlackWriteClient(token) : createSlackWebClient(token);
+  return mode === "write" ? getSlackWriteClient(token) : createSlackWebClient(token);
 }
 
 async function resolveBotUserId(client: WebClient) {
diff --git a/extensions/slack/src/client.test.ts b/extensions/slack/src/client.test.ts
index e4368b45598..e4ada517b43 100644
--- a/extensions/slack/src/client.test.ts
+++ b/extensions/slack/src/client.test.ts
@@ -14,6 +14,8 @@ vi.mock("@slack/web-api", () => {
 
 let createSlackWebClient: typeof import("./client.js").createSlackWebClient;
 let createSlackWriteClient: typeof import("./client.js").createSlackWriteClient;
+let getSlackWriteClient: typeof import("./client.js").getSlackWriteClient;
+let clearSlackWriteClientCacheForTest: typeof import("./client.js").clearSlackWriteClientCacheForTest;
 let resolveSlackWebClientOptions: typeof import("./client.js").resolveSlackWebClientOptions;
 let resolveSlackWriteClientOptions: typeof import("./client.js").resolveSlackWriteClientOptions;
 let SLACK_DEFAULT_RETRY_OPTIONS: typeof import("./client.js").SLACK_DEFAULT_RETRY_OPTIONS;
@@ -25,6 +27,8 @@ beforeAll(async () => {
   ({
     createSlackWebClient,
     createSlackWriteClient,
+    getSlackWriteClient,
+    clearSlackWriteClientCacheForTest,
     resolveSlackWebClientOptions,
     resolveSlackWriteClientOptions,
     SLACK_DEFAULT_RETRY_OPTIONS,
@@ -35,6 +39,7 @@ beforeAll(async () => {
 
 beforeEach(() => {
   WebClient.mockClear();
+  clearSlackWriteClientCacheForTest();
 });
 
 describe("slack web client config", () => {
@@ -93,6 +98,29 @@ describe("slack web client config", () => {
       }),
     );
   });
+
+  it("reuses default write clients per token", () => {
+    const first = getSlackWriteClient("xoxb-test");
+    const second = getSlackWriteClient("xoxb-test");
+
+    expect(second).toBe(first);
+    expect(WebClient).toHaveBeenCalledTimes(1);
+    expect(WebClient).toHaveBeenCalledWith(
+      "xoxb-test",
+      expect.objectContaining({
+        maxRequestConcurrency: 1,
+        retryConfig: SLACK_WRITE_RETRY_OPTIONS,
+      }),
+    );
+  });
+
+  it("keeps default write clients separated by token", () => {
+    const first = getSlackWriteClient("xoxb-one");
+    const second = getSlackWriteClient("xoxb-two");
+
+    expect(second).not.toBe(first);
+    expect(WebClient).toHaveBeenCalledTimes(2);
+  });
 });
 
 describe("slack proxy agent", () => {
diff --git a/extensions/slack/src/client.ts b/extensions/slack/src/client.ts
index 58ddda289c2..006b9a3e65a 100644
--- a/extensions/slack/src/client.ts
+++ b/extensions/slack/src/client.ts
@@ -1,5 +1,9 @@
 import { type WebClientOptions, WebClient } from "@slack/web-api";
 import { resolveSlackWebClientOptions, resolveSlackWriteClientOptions } from "./client-options.js";
+
+const SLACK_WRITE_CLIENT_CACHE_MAX = 32;
+const slackWriteClientCache = new Map<string, WebClient>();
+
 export {
   resolveSlackWebClientOptions,
   resolveSlackWriteClientOptions,
@@ -14,3 +18,25 @@ export function createSlackWebClient(token: string, options: WebClientOptions =
 export function createSlackWriteClient(token: string, options: WebClientOptions = {}) {
   return new WebClient(token, resolveSlackWriteClientOptions(options));
 }
+
+export function getSlackWriteClient(token: string): WebClient {
+  const cached = slackWriteClientCache.get(token);
+  if (cached) {
+    slackWriteClientCache.delete(token);
+    slackWriteClientCache.set(token, cached);
+    return cached;
+  }
+  const client = createSlackWriteClient(token);
+  if (slackWriteClientCache.size >= SLACK_WRITE_CLIENT_CACHE_MAX) {
+    const oldestToken = slackWriteClientCache.keys().next().value;
+    if (oldestToken) {
+      slackWriteClientCache.delete(oldestToken);
+    }
+  }
+  slackWriteClientCache.set(token, client);
+  return client;
+}
+
+export function clearSlackWriteClientCacheForTest(): void {
+  slackWriteClientCache.clear();
+}
diff --git a/extensions/slack/src/send.ts b/extensions/slack/src/send.ts
index 9a4ec0db4e6..34cfc44a8e4 100644
--- a/extensions/slack/src/send.ts
+++ b/extensions/slack/src/send.ts
@@ -19,7 +19,7 @@ import type { SlackTokenSource } from "./accounts.js";
 import { resolveSlackAccount } from "./accounts.js";
 import { buildSlackBlocksFallbackText } from "./blocks-fallback.js";
 import { validateSlackBlocksArray } from "./blocks-input.js";
-import { createSlackWriteClient } from "./client.js";
+import { getSlackWriteClient } from "./client.js";
 import { markdownToSlackMrkdwnChunks } from "./format.js";
 import { SLACK_TEXT_LIMIT } from "./limits.js";
 import { loadOutboundMediaFromUrl } from "./runtime-api.js";
@@ -397,7 +397,7 @@ async function sendMessageSlackQueued(params: {
   blocks?: (Block | KnownBlock)[];
 }): Promise<SlackSendResult> {
   const { opts, cfg, account, token, recipient, blocks, trimmedMessage } = params;
-  const client = opts.client ?? createSlackWriteClient(token);
+  const client = opts.client ?? getSlackWriteClient(token);
   const { channelId } = await resolveChannelId(client, recipient, {
     accountId: account.accountId,
     token,