fix(agents): preserve cron heartbeat suppression during compaction

Protocol-zero-0 · Protocol-zero-0 · commit dee66a96f874 · 2026-03-24T06:29:32.000Z
Carry the original embedded-run trigger into overflow compaction so cron-origin sessions do not regain the heartbeat prompt when the system prompt is rebuilt.

Made-with: Cursor
diff --git a/src/agents/pi-embedded-runner/compact.hooks.test.ts b/src/agents/pi-embedded-runner/compact.hooks.test.ts
@@ -107,6 +107,32 @@ beforeEach(() => {
   resetCompactHooksHarnessMocks();
 });
 
+describe("compaction heartbeat prompt policy", () => {
+  it("suppresses heartbeat prompt rebuilds for cron-origin compaction", () => {
+    expect(
+      compactTesting.shouldInjectHeartbeatPromptDuringCompaction({
+        isDefaultAgent: true,
+        sourceTrigger: "cron",
+      }),
+    ).toBe(false);
+  });
+
+  it("preserves heartbeat prompt rebuilds for non-cron compaction", () => {
+    expect(
+      compactTesting.shouldInjectHeartbeatPromptDuringCompaction({
+        isDefaultAgent: true,
+        sourceTrigger: "memory",
+      }),
+    ).toBe(true);
+    expect(
+      compactTesting.shouldInjectHeartbeatPromptDuringCompaction({
+        isDefaultAgent: false,
+        sourceTrigger: "cron",
+      }),
+    ).toBe(false);
+  });
+});
+
 describe("compactEmbeddedPiSessionDirect hooks", () => {
   beforeEach(() => {
     ensureRuntimePluginsLoaded.mockReset();
diff --git a/src/agents/pi-embedded-runner/compact.ts b/src/agents/pi-embedded-runner/compact.ts
@@ -99,6 +99,8 @@ import { resolveGlobalLane, resolveSessionLane } from "./lanes.js";
 import { log } from "./logger.js";
 import { buildEmbeddedMessageActionDiscoveryInput } from "./message-action-discovery-input.js";
 import { buildModelAliasLines, resolveModelAsync } from "./model.js";
+import type { EmbeddedRunTrigger } from "./run/params.js";
+import { shouldInjectHeartbeatPromptForTrigger } from "./run/trigger-policy.js";
 import { buildEmbeddedSandboxInfo } from "./sandbox-info.js";
 import { prewarmSessionFile, trackSessionManagerAccess } from "./session-manager-cache.js";
 import { truncateSessionAfterCompaction } from "./session-truncation.js";
@@ -153,6 +155,7 @@ export type CompactEmbeddedPiSessionParams = {
   tokenBudget?: number;
   force?: boolean;
   trigger?: "overflow" | "manual";
+  sourceTrigger?: EmbeddedRunTrigger;
   diagId?: string;
   attempt?: number;
   maxAttempts?: number;
@@ -165,6 +168,13 @@ export type CompactEmbeddedPiSessionParams = {
   allowGatewaySubagentBinding?: boolean;
 };
 
+function shouldInjectHeartbeatPromptDuringCompaction(params: {
+  isDefaultAgent: boolean;
+  sourceTrigger?: EmbeddedRunTrigger;
+}): boolean {
+  return params.isDefaultAgent && shouldInjectHeartbeatPromptForTrigger(params.sourceTrigger);
+}
+
 type CompactionMessageMetrics = {
   messages: number;
   historyTextChars: number;
@@ -958,7 +968,10 @@ export async function compactEmbeddedPiSessionDirect(
       ownerDisplay: ownerDisplay.ownerDisplay,
       ownerDisplaySecret: ownerDisplay.ownerDisplaySecret,
       reasoningTagHint,
-      heartbeatPrompt: isDefaultAgent
+      heartbeatPrompt: shouldInjectHeartbeatPromptDuringCompaction({
+        isDefaultAgent,
+        sourceTrigger: params.sourceTrigger,
+      })
         ? resolveHeartbeatPrompt(params.config?.agents?.defaults?.heartbeat?.prompt)
         : undefined,
       skillsPrompt,
@@ -1422,6 +1435,7 @@ export const __testing = {
   hasMeaningfulConversationContent,
   containsRealConversationMessages,
   estimateTokensAfterCompaction,
+  shouldInjectHeartbeatPromptDuringCompaction,
   buildBeforeCompactionHookMetrics,
   runBeforeCompactionHooks,
   runAfterCompactionHooks,
diff --git a/src/agents/pi-embedded-runner/run.ts b/src/agents/pi-embedded-runner/run.ts
@@ -1156,6 +1156,7 @@ export async function runEmbeddedPiAgent(
                   }),
                   runId: params.runId,
                   trigger: "overflow",
+                  sourceTrigger: params.trigger,
                   ...(observedOverflowTokens !== undefined
                     ? { currentTokenCount: observedOverflowTokens }
                     : {}),
