diff --git a/src/cli/deps.ts b/src/cli/deps.ts
index 41a1118d0..9c38d2949 100644
--- a/src/cli/deps.ts
+++ b/src/cli/deps.ts
@@ -1,6 +1,7 @@
 import { sendMessageDiscord } from "../discord/send.js";
 import { sendMessageIMessage } from "../imessage/send.js";
 import { logWebSelfId, sendMessageWhatsApp } from "../providers/web/index.js";
+import { sendMessageSlack } from "../slack/send.js";
 import { sendMessageSignal } from "../signal/send.js";
 import { sendMessageSlack } from "../slack/send.js";
 import { sendMessageTelegram } from "../telegram/send.js";
diff --git a/src/cron/isolated-agent.ts b/src/cron/isolated-agent.ts
index ada657638..1ed28b298 100644
--- a/src/cron/isolated-agent.ts
+++ b/src/cron/isolated-agent.ts
@@ -464,12 +464,15 @@ export async function runCronIsolatedAgentTurn(params: {
         };
       }
       const slackTarget = resolvedDelivery.to;
+      const textLimit = resolveTextChunkLimit(params.cfg, "slack");
       try {
         for (const payload of payloads) {
           const mediaList =
             payload.mediaUrls ?? (payload.mediaUrl ? [payload.mediaUrl] : []);
           if (mediaList.length === 0) {
-            await params.deps.sendMessageSlack(slackTarget, payload.text ?? "");
+            for (const chunk of chunkText(payload.text ?? "", textLimit)) {
+              await params.deps.sendMessageSlack(slackTarget, chunk);
+            }
           } else {
             let first = true;
             for (const url of mediaList) {
diff --git a/src/gateway/hooks.ts b/src/gateway/hooks.ts
index a0c038479..ef32d5d26 100644
--- a/src/gateway/hooks.ts
+++ b/src/gateway/hooks.ts
@@ -137,7 +137,14 @@ export type HookAgentPayload = {
   wakeMode: "now" | "next-heartbeat";
   sessionKey: string;
   deliver: boolean;
-  channel: "last" | "whatsapp" | "telegram" | "discord" | "signal" | "imessage";
+  channel:
+    | "last"
+    | "whatsapp"
+    | "telegram"
+    | "discord"
+    | "slack"
+    | "signal"
+    | "imessage";
   to?: string;
   thinking?: string;
   timeoutSeconds?: number;
@@ -171,6 +178,7 @@ export function normalizeAgentPayload(
     channelRaw === "whatsapp" ||
     channelRaw === "telegram" ||
     channelRaw === "discord" ||
+    channelRaw === "slack" ||
     channelRaw === "signal" ||
     channelRaw === "imessage" ||
     channelRaw === "last"
@@ -183,7 +191,8 @@ export function normalizeAgentPayload(
   if (channel === null) {
     return {
       ok: false,
-      error: "channel must be last|whatsapp|telegram|discord|signal|imessage",
+      error:
+        "channel must be last|whatsapp|telegram|discord|slack|signal|imessage",
     };
   }
   const toRaw = payload.to;
diff --git a/src/infra/heartbeat-runner.ts b/src/infra/heartbeat-runner.ts
index 3a18ffbbf..3b74a3012 100644
--- a/src/infra/heartbeat-runner.ts
+++ b/src/infra/heartbeat-runner.ts
@@ -21,6 +21,7 @@ import { createSubsystemLogger } from "../logging.js";
 import { getQueueSize } from "../process/command-queue.js";
 import { webAuthExists } from "../providers/web/index.js";
 import { defaultRuntime, type RuntimeEnv } from "../runtime.js";
+import { sendMessageSlack } from "../slack/send.js";
 import { sendMessageSignal } from "../signal/send.js";
 import { sendMessageSlack } from "../slack/send.js";
 import { sendMessageTelegram } from "../telegram/send.js";
@@ -391,7 +392,9 @@ async function deliverHeartbeatReply(params: {
 
   if (channel === "slack") {
     if (mediaUrls.length === 0) {
-      await deps.sendSlack(to, text);
+      for (const chunk of chunkText(text, textLimit)) {
+        await deps.sendSlack(to, chunk);
+      }
       return;
     }
     let first = true;
@@ -402,7 +405,6 @@ async function deliverHeartbeatReply(params: {
     }
     return;
   }
-
   if (mediaUrls.length === 0) {
     await deps.sendDiscord(to, text, { verbose: false });
     return;