From dc692aa6f6a20da289f21c76da3cd0cc816ac45e Mon Sep 17 00:00:00 2001
From: Shakker <shakkerdroid@gmail.com>
Date: Mon, 25 May 2026 21:41:58 +0100
Subject: [PATCH] perf: avoid duplicate transcript idempotency scans

---
 extensions/codex/src/app-server/transcript-mirror.ts | 1 +
 src/config/sessions/transcript-append.ts             | 9 ++++++---
 src/config/sessions/transcript.ts                    | 1 +
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/extensions/codex/src/app-server/transcript-mirror.ts b/extensions/codex/src/app-server/transcript-mirror.ts
index 4c5971aba5b..b91eef56273 100644
--- a/extensions/codex/src/app-server/transcript-mirror.ts
+++ b/extensions/codex/src/app-server/transcript-mirror.ts
@@ -186,6 +186,7 @@ export async function mirrorCodexAppServerTranscript(params: {
       const { messageId, message: appendedMessage } = await appendSessionTranscriptMessage({
         transcriptPath: params.sessionFile,
         message: messageToAppend,
+        idempotencyLookup: idempotencyKey ? "caller-checked" : "scan",
         config: params.config,
       });
       if (appendedMessage.role === "user") {
diff --git a/src/config/sessions/transcript-append.ts b/src/config/sessions/transcript-append.ts
index 6ef3448385c..b631883a841 100644
--- a/src/config/sessions/transcript-append.ts
+++ b/src/config/sessions/transcript-append.ts
@@ -241,6 +241,8 @@ type AppendSessionTranscriptMessageParams<TMessage = unknown> = {
   sessionId?: string;
   cwd?: string;
   useRawWhenLinear?: boolean;
+  /** Use only when the caller already checked this idempotency key under the session write lock. */
+  idempotencyLookup?: "scan" | "caller-checked";
   config?: OpenClawConfig;
 };
 
@@ -305,9 +307,10 @@ async function appendSessionTranscriptMessageLocked<TMessage>(
     ...(params.cwd ? { cwd: params.cwd } : {}),
   });
   const idempotencyKey = readMessageIdempotencyKey(params.message);
-  const existing = idempotencyKey
-    ? await findTranscriptMessageByIdempotencyKey<TMessage>(params.transcriptPath, idempotencyKey)
-    : undefined;
+  const existing =
+    idempotencyKey && params.idempotencyLookup !== "caller-checked"
+      ? await findTranscriptMessageByIdempotencyKey<TMessage>(params.transcriptPath, idempotencyKey)
+      : undefined;
   if (existing) {
     return { ...existing, appended: false };
   }
diff --git a/src/config/sessions/transcript.ts b/src/config/sessions/transcript.ts
index 8aece357ee5..ab96abc52f7 100644
--- a/src/config/sessions/transcript.ts
+++ b/src/config/sessions/transcript.ts
@@ -353,6 +353,7 @@ export async function appendExactAssistantMessageToSessionTranscript(params: {
             return await appendSessionTranscriptMessage({
               transcriptPath: sessionFile,
               message,
+              idempotencyLookup: explicitIdempotencyKey ? "caller-checked" : "scan",
               config: params.config,
             });
           },