From 5a431f57fc1883dc097b28fbff6028cb64eeb569 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Fri, 13 Feb 2026 16:50:57 +0000
Subject: [PATCH] refactor(infra): split heartbeat event filters

---
 src/infra/heartbeat-events-filter.ts | 62 +++++++++++++++++++++++++
 src/infra/heartbeat-runner.ts        | 67 +++-------------------------
 2 files changed, 68 insertions(+), 61 deletions(-)
 create mode 100644 src/infra/heartbeat-events-filter.ts

diff --git a/src/infra/heartbeat-events-filter.ts b/src/infra/heartbeat-events-filter.ts
new file mode 100644
index 0000000000..f5042bb0bd
--- /dev/null
+++ b/src/infra/heartbeat-events-filter.ts
@@ -0,0 +1,62 @@
+import { HEARTBEAT_TOKEN } from "../auto-reply/tokens.js";
+
+// Build a dynamic prompt for cron events by embedding the actual event content.
+// This ensures the model sees the reminder text directly instead of relying on
+// "shown in the system messages above" which may not be visible in context.
+export function buildCronEventPrompt(pendingEvents: string[]): string {
+  const eventText = pendingEvents.join("\n").trim();
+  if (!eventText) {
+    return (
+      "A scheduled cron event was triggered, but no event content was found. " +
+      "Reply HEARTBEAT_OK."
+    );
+  }
+  return (
+    "A scheduled reminder has been triggered. The reminder content is:\n\n" +
+    eventText +
+    "\n\nPlease relay this reminder to the user in a helpful and friendly way."
+  );
+}
+
+const HEARTBEAT_OK_PREFIX = HEARTBEAT_TOKEN.toLowerCase();
+
+// Detect heartbeat-specific noise so cron reminders don't trigger on non-reminder events.
+function isHeartbeatAckEvent(evt: string): boolean {
+  const trimmed = evt.trim();
+  if (!trimmed) {
+    return false;
+  }
+  const lower = trimmed.toLowerCase();
+  if (!lower.startsWith(HEARTBEAT_OK_PREFIX)) {
+    return false;
+  }
+  const suffix = lower.slice(HEARTBEAT_OK_PREFIX.length);
+  if (suffix.length === 0) {
+    return true;
+  }
+  return !/[a-z0-9_]/.test(suffix[0]);
+}
+
+function isHeartbeatNoiseEvent(evt: string): boolean {
+  const lower = evt.trim().toLowerCase();
+  if (!lower) {
+    return false;
+  }
+  return (
+    isHeartbeatAckEvent(lower) ||
+    lower.includes("heartbeat poll") ||
+    lower.includes("heartbeat wake")
+  );
+}
+
+export function isExecCompletionEvent(evt: string): boolean {
+  return evt.toLowerCase().includes("exec finished");
+}
+
+// Returns true when a system event should be treated as real cron reminder content.
+export function isCronSystemEvent(evt: string) {
+  if (!evt.trim()) {
+    return false;
+  }
+  return !isHeartbeatNoiseEvent(evt) && !isExecCompletionEvent(evt);
+}
diff --git a/src/infra/heartbeat-runner.ts b/src/infra/heartbeat-runner.ts
index fe5783fd0e..d90a978bde 100644
--- a/src/infra/heartbeat-runner.ts
+++ b/src/infra/heartbeat-runner.ts
@@ -41,6 +41,11 @@ import { normalizeAgentId, toAgentStoreSessionKey } from "../routing/session-key
 import { defaultRuntime, type RuntimeEnv } from "../runtime.js";
 import { formatErrorMessage } from "./errors.js";
 import { isWithinActiveHours } from "./heartbeat-active-hours.js";
+import {
+  buildCronEventPrompt,
+  isCronSystemEvent,
+  isExecCompletionEvent,
+} from "./heartbeat-events-filter.js";
 import { emitHeartbeatEvent, resolveIndicatorType } from "./heartbeat-events.js";
 import { resolveHeartbeatVisibility } from "./heartbeat-visibility.js";
 import {
@@ -95,67 +100,7 @@ const EXEC_EVENT_PROMPT =
   "An async command you ran earlier has completed. The result is shown in the system messages above. " +
   "Please relay the command output to the user in a helpful way. If the command succeeded, share the relevant output. " +
   "If it failed, explain what went wrong.";
-
-// Build a dynamic prompt for cron events by embedding the actual event content.
-// This ensures the model sees the reminder text directly instead of relying on
-// "shown in the system messages above" which may not be visible in context.
-function buildCronEventPrompt(pendingEvents: string[]): string {
-  const eventText = pendingEvents.join("\n").trim();
-  if (!eventText) {
-    return (
-      "A scheduled cron event was triggered, but no event content was found. " +
-      "Reply HEARTBEAT_OK."
-    );
-  }
-  return (
-    "A scheduled reminder has been triggered. The reminder content is:\n\n" +
-    eventText +
-    "\n\nPlease relay this reminder to the user in a helpful and friendly way."
-  );
-}
-
-const HEARTBEAT_OK_PREFIX = HEARTBEAT_TOKEN.toLowerCase();
-
-// Detect heartbeat-specific noise so cron reminders don't trigger on non-reminder events.
-function isHeartbeatAckEvent(evt: string): boolean {
-  const trimmed = evt.trim();
-  if (!trimmed) {
-    return false;
-  }
-  const lower = trimmed.toLowerCase();
-  if (!lower.startsWith(HEARTBEAT_OK_PREFIX)) {
-    return false;
-  }
-  const suffix = lower.slice(HEARTBEAT_OK_PREFIX.length);
-  if (suffix.length === 0) {
-    return true;
-  }
-  return !/[a-z0-9_]/.test(suffix[0]);
-}
-
-function isHeartbeatNoiseEvent(evt: string): boolean {
-  const lower = evt.trim().toLowerCase();
-  if (!lower) {
-    return false;
-  }
-  return (
-    isHeartbeatAckEvent(lower) ||
-    lower.includes("heartbeat poll") ||
-    lower.includes("heartbeat wake")
-  );
-}
-
-function isExecCompletionEvent(evt: string): boolean {
-  return evt.toLowerCase().includes("exec finished");
-}
-
-// Returns true when a system event should be treated as real cron reminder content.
-export function isCronSystemEvent(evt: string) {
-  if (!evt.trim()) {
-    return false;
-  }
-  return !isHeartbeatNoiseEvent(evt) && !isExecCompletionEvent(evt);
-}
+export { isCronSystemEvent };
 
 type HeartbeatAgentState = {
   agentId: string;