From 7bfa261c42ebdb60562a7b1a62d69037dcc24354 Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Sun, 22 Mar 2026 19:12:25 -0700
Subject: [PATCH] perf(reply): lazy-load media path normalization

---
 src/auto-reply/reply/agent-runner-execution.ts    | 11 ++++++++++-
 src/auto-reply/reply/agent-runner.ts              | 10 +++++++++-
 src/auto-reply/reply/reply-media-paths.runtime.ts |  1 +
 3 files changed, 20 insertions(+), 2 deletions(-)
 create mode 100644 src/auto-reply/reply/reply-media-paths.runtime.ts

diff --git a/src/auto-reply/reply/agent-runner-execution.ts b/src/auto-reply/reply/agent-runner-execution.ts
index 7e6a4cfa6bc..8af99882709 100644
--- a/src/auto-reply/reply/agent-runner-execution.ts
+++ b/src/auto-reply/reply/agent-runner-execution.ts
@@ -47,9 +47,17 @@ import {
 import { type BlockReplyPipeline } from "./block-reply-pipeline.js";
 import type { FollowupRun } from "./queue.js";
 import { createBlockReplyDeliveryHandler } from "./reply-delivery.js";
-import { createReplyMediaPathNormalizer } from "./reply-media-paths.js";
 import type { TypingSignaler } from "./typing-mode.js";
 
+let replyMediaPathsRuntimePromise: Promise<
+  typeof import("./reply-media-paths.runtime.js")
+> | null = null;
+
+function loadReplyMediaPathsRuntime() {
+  replyMediaPathsRuntimePromise ??= import("./reply-media-paths.runtime.js");
+  return replyMediaPathsRuntimePromise;
+}
+
 export type RuntimeFallbackAttempt = {
   provider: string;
   model: string;
@@ -109,6 +117,7 @@ export async function runAgentTurnWithFallback(params: {
   const directlySentBlockKeys = new Set<string>();
 
   const runId = params.opts?.runId ?? crypto.randomUUID();
+  const { createReplyMediaPathNormalizer } = await loadReplyMediaPathsRuntime();
   const normalizeReplyMediaPaths = createReplyMediaPathNormalizer({
     cfg: params.followupRun.run.config,
     sessionKey: params.sessionKey,
diff --git a/src/auto-reply/reply/agent-runner.ts b/src/auto-reply/reply/agent-runner.ts
index 6ce2b0321fb..2a634016c9e 100644
--- a/src/auto-reply/reply/agent-runner.ts
+++ b/src/auto-reply/reply/agent-runner.ts
@@ -48,7 +48,6 @@ import { readPostCompactionContext } from "./post-compaction-context.js";
 import { resolveActiveRunQueueAction } from "./queue-policy.js";
 import { enqueueFollowupRun } from "./queue/enqueue.js";
 import type { FollowupRun, QueueSettings } from "./queue/types.js";
-import { createReplyMediaPathNormalizer } from "./reply-media-paths.js";
 import { createReplyToModeFilterForChannel, resolveReplyToMode } from "./reply-threading.js";
 import { incrementRunCompactionCount, persistRunSessionUsage } from "./session-run-accounting.js";
 import { createTypingSignaler } from "./typing-mode.js";
@@ -68,6 +67,9 @@ let usageCostRuntimePromise: Promise<typeof import("./usage-cost.runtime.js")> |
 let contextTokensRuntimePromise: Promise<
   typeof import("../../agents/context-tokens.runtime.js")
 > | null = null;
+let replyMediaPathsRuntimePromise: Promise<
+  typeof import("./reply-media-paths.runtime.js")
+> | null = null;
 
 function loadPiEmbeddedQueueRuntime() {
   piEmbeddedQueueRuntimePromise ??= import("../../agents/pi-embedded-queue.runtime.js");
@@ -94,6 +96,11 @@ function loadContextTokensRuntime() {
   return contextTokensRuntimePromise;
 }
 
+function loadReplyMediaPathsRuntime() {
+  replyMediaPathsRuntimePromise ??= import("./reply-media-paths.runtime.js");
+  return replyMediaPathsRuntimePromise;
+}
+
 export async function runReplyAgent(params: {
   commandBody: string;
   followupRun: FollowupRun;
@@ -189,6 +196,7 @@ export async function runReplyAgent(params: {
   );
   const applyReplyToMode = createReplyToModeFilterForChannel(replyToMode, replyToChannel);
   const cfg = followupRun.run.config;
+  const { createReplyMediaPathNormalizer } = await loadReplyMediaPathsRuntime();
   const normalizeReplyMediaPaths = createReplyMediaPathNormalizer({
     cfg,
     sessionKey,
diff --git a/src/auto-reply/reply/reply-media-paths.runtime.ts b/src/auto-reply/reply/reply-media-paths.runtime.ts
new file mode 100644
index 00000000000..904ada489cb
--- /dev/null
+++ b/src/auto-reply/reply/reply-media-paths.runtime.ts
@@ -0,0 +1 @@
+export { createReplyMediaPathNormalizer } from "./reply-media-paths.js";