diff --git a/.custodian-brief.md b/.custodian-brief.md
index d0d0a9d..a775080 100644
--- a/.custodian-brief.md
+++ b/.custodian-brief.md
@@ -7,6 +7,9 @@
 
 ## Active Workstreams
 
+### Cross-Repo E2E Sandbox Framework
+Progress: 8/8 done  |  workstream_id: `b68de20b-e397-4f97-b1be-ad30711fc2a6`
+
 ### Haskell Build Machine — VirtualBox Image & State-Hub Integration
 Progress: 0/15 done  |  workstream_id: `f2bfac74-de8a-4c86-9aa9-4d95a92336e2`