From 21d850dd6656bd97fa9174c0756d2186040396c8 Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Mon, 13 Apr 2026 16:40:54 +0100
Subject: [PATCH] perf(cron): lazy-load embedded runtime branch

---
 src/cron/isolated-agent/run-embedded.runtime.ts  |  3 +++
 src/cron/isolated-agent/run-execution.runtime.ts |  3 ---
 src/cron/isolated-agent/run-executor.ts          | 12 +++++++++---
 src/cron/isolated-agent/run.test-harness.ts      |  6 ++++++
 4 files changed, 18 insertions(+), 6 deletions(-)
 create mode 100644 src/cron/isolated-agent/run-embedded.runtime.ts

diff --git a/src/cron/isolated-agent/run-embedded.runtime.ts b/src/cron/isolated-agent/run-embedded.runtime.ts
new file mode 100644
index 00000000000..6828dd4e0c2
--- /dev/null
+++ b/src/cron/isolated-agent/run-embedded.runtime.ts
@@ -0,0 +1,3 @@
+export { resolveFastModeState } from "../../agents/fast-mode.js";
+export { resolveNestedAgentLane } from "../../agents/lanes.js";
+export { runEmbeddedPiAgent } from "../../agents/pi-embedded.js";
diff --git a/src/cron/isolated-agent/run-execution.runtime.ts b/src/cron/isolated-agent/run-execution.runtime.ts
index e8f73a5fc25..039fd107838 100644
--- a/src/cron/isolated-agent/run-execution.runtime.ts
+++ b/src/cron/isolated-agent/run-execution.runtime.ts
@@ -1,11 +1,8 @@
 export { resolveEffectiveModelFallbacks } from "../../agents/agent-scope.js";
 export { resolveBootstrapWarningSignaturesSeen } from "../../agents/bootstrap-budget.js";
-export { resolveFastModeState } from "../../agents/fast-mode.js";
-export { resolveNestedAgentLane } from "../../agents/lanes.js";
 export { LiveSessionModelSwitchError } from "../../agents/live-model-switch.js";
 export { runWithModelFallback } from "../../agents/model-fallback.js";
 export { isCliProvider } from "../../agents/model-selection.js";
-export { runEmbeddedPiAgent } from "../../agents/pi-embedded.js";
 export { normalizeVerboseLevel } from "../../auto-reply/thinking.js";
 export { resolveSessionTranscriptPath } from "../../config/sessions/paths.js";
 export { registerAgentRunContext } from "../../infra/agent-events.js";
diff --git a/src/cron/isolated-agent/run-executor.ts b/src/cron/isolated-agent/run-executor.ts
index a3e298726d8..e2d075a5b20 100644
--- a/src/cron/isolated-agent/run-executor.ts
+++ b/src/cron/isolated-agent/run-executor.ts
@@ -12,11 +12,8 @@ import {
   normalizeVerboseLevel,
   registerAgentRunContext,
   resolveBootstrapWarningSignaturesSeen,
-  resolveFastModeState,
-  resolveNestedAgentLane,
   resolveSessionTranscriptPath,
   runCliAgent,
-  runEmbeddedPiAgent,
   runWithModelFallback,
 } from "./run-execution.runtime.js";
 import { resolveCronFallbacksOverride } from "./run-fallback-policy.js";
@@ -30,10 +27,17 @@ import { isLikelyInterimCronMessage } from "./subagent-followup-hints.js";
 
 type AgentTurnPayload = Extract<CronJob["payload"], { kind: "agentTurn" }> | null;
 type CronPromptRunResult = Awaited<ReturnType<typeof runCliAgent>>;
+type CronEmbeddedRuntime = typeof import("./run-embedded.runtime.js");
 type CronSubagentRegistryRuntime = typeof import("./run-subagent-registry.runtime.js");
 
+let cronEmbeddedRuntimePromise: Promise<CronEmbeddedRuntime> | undefined;
 let cronSubagentRegistryRuntimePromise: Promise<CronSubagentRegistryRuntime> | undefined;
 
+async function loadCronEmbeddedRuntime() {
+  cronEmbeddedRuntimePromise ??= import("./run-embedded.runtime.js");
+  return await cronEmbeddedRuntimePromise;
+}
+
 async function loadCronSubagentRegistryRuntime() {
   cronSubagentRegistryRuntimePromise ??= import("./run-subagent-registry.runtime.js");
   return await cronSubagentRegistryRuntimePromise;
@@ -135,6 +139,8 @@ export function createCronPromptExecutor(params: {
           );
           return result;
         }
+        const { resolveFastModeState, resolveNestedAgentLane, runEmbeddedPiAgent } =
+          await loadCronEmbeddedRuntime();
         const result = await runEmbeddedPiAgent({
           sessionId: params.cronSession.sessionEntry.sessionId,
           sessionKey: params.agentSessionKey,
diff --git a/src/cron/isolated-agent/run.test-harness.ts b/src/cron/isolated-agent/run.test-harness.ts
index 61830c09cf5..d855369eea5 100644
--- a/src/cron/isolated-agent/run.test-harness.ts
+++ b/src/cron/isolated-agent/run.test-harness.ts
@@ -160,6 +160,12 @@ vi.mock("./run-auth-profile.runtime.js", () => ({
   resolveSessionAuthProfileOverride: resolveSessionAuthProfileOverrideMock,
 }));
 
+vi.mock("./run-embedded.runtime.js", () => ({
+  resolveFastModeState: resolveFastModeStateMock,
+  resolveNestedAgentLane: resolveNestedAgentLaneMock,
+  runEmbeddedPiAgent: runEmbeddedPiAgentMock,
+}));
+
 vi.mock("./run-subagent-registry.runtime.js", () => ({
   countActiveDescendantRuns: countActiveDescendantRunsMock,
   listDescendantRunsForRequester: listDescendantRunsForRequesterMock,