fix: use final heartbeat payload

CHANGELOG.md

@@ -21,6 +21,7 @@
 
 ### Fixes
 - Heartbeat replies now strip repeated `HEARTBEAT_OK` tails to avoid accidental “OK OK” spam.
+- Heartbeat delivery now uses the last non-empty payload, preventing tool preambles from swallowing the final reply.
 - Heartbeat failure logs now include the error reason instead of `[object Object]`.
 - Duration strings now accept `h` (hours) where durations are parsed (e.g., heartbeat intervals).
 - WhatsApp inbound now normalizes more wrapper types so quoted reply bodies are extracted reliably.

src/infra/heartbeat-runner.test.ts

@@ -1,7 +1,12 @@
-import { describe, expect, it } from "vitest";
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { describe, expect, it, vi } from "vitest";
 import { HEARTBEAT_PROMPT } from "../auto-reply/heartbeat.js";
+import * as replyModule from "../auto-reply/reply.js";
 import type { ClawdisConfig } from "../config/config.js";
 import {
+  runHeartbeatOnce,
   resolveHeartbeatDeliveryTarget,
   resolveHeartbeatIntervalMs,
   resolveHeartbeatPrompt,
@@ -113,3 +118,60 @@ describe("resolveHeartbeatDeliveryTarget", () => {
     });
   });
 });
+
+describe("runHeartbeatOnce", () => {
+  it("uses the last non-empty payload for delivery", async () => {
+    const tmpDir = await fs.mkdtemp(path.join(os.tmpdir(), "clawdis-hb-"));
+    const storePath = path.join(tmpDir, "sessions.json");
+    const replySpy = vi.spyOn(replyModule, "getReplyFromConfig");
+    try {
+      await fs.writeFile(
+        storePath,
+        JSON.stringify(
+          {
+            main: {
+              sessionId: "sid",
+              updatedAt: Date.now(),
+              lastChannel: "whatsapp",
+              lastTo: "+1555",
+            },
+          },
+          null,
+          2,
+        ),
+      );
+
+      const cfg: ClawdisConfig = {
+        agent: {
+          heartbeat: { every: "5m", target: "whatsapp", to: "+1555" },
+        },
+        routing: { allowFrom: ["*"] },
+        session: { store: storePath },
+      };
+
+      replySpy.mockResolvedValue([
+        { text: "Let me check..." },
+        { text: "Final alert" },
+      ]);
+      const sendWhatsApp = vi.fn().mockResolvedValue({
+        messageId: "m1",
+        toJid: "jid",
+      });
+
+      await runHeartbeatOnce({
+        cfg,
+        deps: { sendWhatsApp, getQueueSize: () => 0, nowMs: () => 0 },
+      });
+
+      expect(sendWhatsApp).toHaveBeenCalledTimes(1);
+      expect(sendWhatsApp).toHaveBeenCalledWith(
+        "+1555",
+        "Final alert",
+        expect.any(Object),
+      );
+    } finally {
+      replySpy.mockRestore();
+      await fs.rm(tmpDir, { recursive: true, force: true });
+    }
+  });
+});

src/infra/heartbeat-runner.ts

@@ -93,6 +93,25 @@ function resolveHeartbeatSession(cfg: ClawdisConfig) {
   return { sessionKey, storePath, store, entry };
 }
 
+function resolveHeartbeatReplyPayload(
+  replyResult: ReplyPayload | ReplyPayload[] | undefined,
+): ReplyPayload | undefined {
+  if (!replyResult) return undefined;
+  if (!Array.isArray(replyResult)) return replyResult;
+  for (let idx = replyResult.length - 1; idx >= 0; idx -= 1) {
+    const payload = replyResult[idx];
+    if (!payload) continue;
+    if (
+      payload.text ||
+      payload.mediaUrl ||
+      (payload.mediaUrls && payload.mediaUrls.length > 0)
+    ) {
+      return payload;
+    }
+  }
+  return undefined;
+}
+
 function resolveHeartbeatSender(params: {
   allowFrom: Array<string | number>;
   lastTo?: string;
@@ -318,9 +337,7 @@ export async function runHeartbeatOnce(opts: {
       { isHeartbeat: true },
       cfg,
     );
-    const replyPayload = Array.isArray(replyResult)
+    const replyPayload = resolveHeartbeatReplyPayload(replyResult);
-      ? replyResult[0]
-      : replyResult;
 
     if (
       !replyPayload ||

src/web/auto-reply.ts

@@ -190,6 +190,25 @@ function isSilentReply(payload?: ReplyPayload): boolean {
   return true;
 }
 
+function resolveHeartbeatReplyPayload(
+  replyResult: ReplyPayload | ReplyPayload[] | undefined,
+): ReplyPayload | undefined {
+  if (!replyResult) return undefined;
+  if (!Array.isArray(replyResult)) return replyResult;
+  for (let idx = replyResult.length - 1; idx >= 0; idx -= 1) {
+    const payload = replyResult[idx];
+    if (!payload) continue;
+    if (
+      payload.text ||
+      payload.mediaUrl ||
+      (payload.mediaUrls && payload.mediaUrls.length > 0)
+    ) {
+      return payload;
+    }
+  }
+  return undefined;
+}
+
 export async function runWebHeartbeatOnce(opts: {
   cfg?: ReturnType<typeof loadConfig>;
   to: string;
@@ -291,9 +310,7 @@ export async function runWebHeartbeatOnce(opts: {
       { isHeartbeat: true },
       cfg,
     );
-    const replyPayload = Array.isArray(replyResult)
+    const replyPayload = resolveHeartbeatReplyPayload(replyResult);
-      ? replyResult[0]
-      : replyResult;
 
     if (
       !replyPayload ||