From e30e9e84aa3ba1d1bd3610088812eed4b94fd669 Mon Sep 17 00:00:00 2001
From: lyon <liang6516@outlook.com>
Date: Sun, 21 Jun 2026 03:08:14 +0800
Subject: [PATCH] fix: keep turn timing independent from sessions

---
 internal/cloud/workbench-turn-projection.ts | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/internal/cloud/workbench-turn-projection.ts b/internal/cloud/workbench-turn-projection.ts
index 42ae0c69..d81dd0a8 100644
--- a/internal/cloud/workbench-turn-projection.ts
+++ b/internal/cloud/workbench-turn-projection.ts
@@ -48,7 +48,10 @@ export function createWorkbenchTurnTimingProjection({ result = null, session = n
   const firstEvent = events[0] ?? null;
   const lastEvent = traceLastEvent(trace);
   const terminalEvent = terminalTraceEventForTiming(events);
-  const directTiming = objectValue(result?.timing) ?? objectValue(trace?.timing) ?? objectValue(session?.timing) ?? null;
+  // Session lifecycle timing is not turn timing authority. Mixing session
+  // startedAt/createdAt with turn terminal duration makes the running timer
+  // jump backwards when the turn completes.
+  const directTiming = objectValue(result?.timing) ?? objectValue(trace?.timing) ?? null;
   const agentRun = objectValue(result?.agentRun ?? trace?.agentRun);
   const traceSummary = objectValue(result?.traceSummary ?? trace?.traceSummary);
   const sessionSnapshot = objectValue(session?.session);
@@ -63,11 +66,7 @@ export function createWorkbenchTurnTimingProjection({ result = null, session = n
     agentRun?.startedAt,
     firstEvent?.startedAt,
     firstEvent?.createdAt,
-    firstEvent?.occurredAt,
-    session?.startedAt,
-    session?.createdAt,
-    sessionSnapshot?.startedAt,
-    sessionSnapshot?.createdAt
+    firstEvent?.occurredAt
   );
   const lastEventAt = firstTimestamp(
     result?.lastEventAt,