diff --git a/.custodian-brief.md b/.custodian-brief.md
index 0fa8c40..e716569 100644
--- a/.custodian-brief.md
+++ b/.custodian-brief.md
@@ -2,11 +2,17 @@
 # Custodian Brief — user-engine
 
 **Domain:** communication  
-**Last synced:** 2026-08-15 23:28 UTC  
+**Last synced:** 2026-08-18 05:29 UTC  
 **State Hub:** http://127.0.0.1:8000 *(adjust if running on a remote machine)*
 
 ## Active Workstreams
 
+### Bind user-engine to flex-auth with rotating workload identity
+Progress: 2/3 done  |  workplan_id: `014d0886-b690-4860-8337-c718e440f678`
+
+**Open tasks:**
+- ! USER-WP-0023 — flex-auth caller identity  `0499c65b`
+
 ### Expand user-engine portal beyond the proven Binky MVP
 Progress: 4/5 done  |  workplan_id: `ba217f48-5fa5-4178-9c79-73aa225f3f2e`