fix: harden routing/session isolation for followups and heartbeat

src/infra/heartbeat-runner.returns-default-unset.test.ts

@@ -591,6 +591,8 @@ describe("runHeartbeatOnce", () => {
           SessionKey: sessionKey,
           From: "+1555",
           To: "+1555",
+          OriginatingChannel: "whatsapp",
+          OriginatingTo: "+1555",
           Provider: "heartbeat",
         }),
         expect.objectContaining({ isHeartbeat: true, suppressToolErrorWarnings: false }),

src/infra/heartbeat-runner.ts

@@ -663,6 +663,10 @@ export async function runHeartbeatOnce(opts: {
     Body: appendCronStyleCurrentTimeLine(prompt, cfg, startedAt),
     From: sender,
     To: sender,
+    OriginatingChannel: delivery.channel !== "none" ? delivery.channel : undefined,
+    OriginatingTo: delivery.to,
+    AccountId: delivery.accountId,
+    MessageThreadId: delivery.threadId,
     Provider: hasExecCompletion ? "exec-event" : hasCronEvents ? "cron-event" : "heartbeat",
     SessionKey: sessionKey,
   };

src/infra/outbound/targets.test.ts

@@ -1,6 +1,10 @@
 import { describe, expect, it } from "vitest";
 import type { OpenClawConfig } from "../../config/config.js";
-import { resolveOutboundTarget, resolveSessionDeliveryTarget } from "./targets.js";
+import {
+  resolveHeartbeatDeliveryTarget,
+  resolveOutboundTarget,
+  resolveSessionDeliveryTarget,
+} from "./targets.js";
 import {
   installResolveOutboundTargetPluginRegistryHooks,
   runResolveOutboundTargetCoreTests,
@@ -175,6 +179,22 @@ describe("resolveSessionDeliveryTarget", () => {
     expect(resolved.threadId).toBe(999);
   });
 
+  it("does not inherit lastThreadId in heartbeat mode", () => {
+    const resolved = resolveSessionDeliveryTarget({
+      entry: {
+        sessionId: "sess-heartbeat-thread",
+        updatedAt: 1,
+        lastChannel: "slack",
+        lastTo: "user:U123",
+        lastThreadId: "1739142736.000100",
+      },
+      requestedChannel: "last",
+      mode: "heartbeat",
+    });
+
+    expect(resolved.threadId).toBeUndefined();
+  });
+
   it("falls back to a provided channel when requested is unsupported", () => {
     const resolved = resolveSessionDeliveryTarget({
       entry: {
@@ -280,4 +300,25 @@ describe("resolveSessionDeliveryTarget", () => {
     expect(resolved.threadId).toBe(42);
     expect(resolved.to).toBe("63448508");
   });
+
+  it("does not return inherited threadId from resolveHeartbeatDeliveryTarget", () => {
+    const cfg: OpenClawConfig = {};
+    const resolved = resolveHeartbeatDeliveryTarget({
+      cfg,
+      entry: {
+        sessionId: "sess-heartbeat-outbound",
+        updatedAt: 1,
+        lastChannel: "slack",
+        lastTo: "user:U123",
+        lastThreadId: "1739142736.000100",
+      },
+      heartbeat: {
+        target: "last",
+      },
+    });
+
+    expect(resolved.channel).toBe("slack");
+    expect(resolved.to).toBe("user:U123");
+    expect(resolved.threadId).toBeUndefined();
+  });
 });

src/infra/outbound/targets.ts

@@ -115,9 +115,10 @@ export function resolveSessionDeliveryTarget(params: {
     }
   }
 
-  const accountId = channel && channel === lastChannel ? lastAccountId : undefined;
-  const threadId = channel && channel === lastChannel ? lastThreadId : undefined;
   const mode = params.mode ?? (explicitTo ? "explicit" : "implicit");
+  const accountId = channel && channel === lastChannel ? lastAccountId : undefined;
+  const threadId =
+    mode !== "heartbeat" && channel && channel === lastChannel ? lastThreadId : undefined;
 
   const resolvedThreadId = explicitThreadId ?? threadId;
   return {