diff --git a/3ca0-announcements-purgatory.md b/3ca0-announcements-purgatory.md
index e985258..d66558b 100644
--- a/3ca0-announcements-purgatory.md
+++ b/3ca0-announcements-purgatory.md
@@ -65,6 +65,18 @@ This prevents serving announcements for repositories that may never receive stat
 - Created worktree: worktrees/3ca0-announcements-purgatory
 - Ready to begin implementation
 
+### 2026-01-23 [Design Session]
+- Conducted extensive architectural review with multiple iterations
+- Clarified requirements based on user feedback:
+  - Problem: Prevent serving empty bare repos indefinitely (misleads clients)
+  - Trigger: Git data arrival promotes announcements (not state events)
+  - Indexing: Must use (pubkey, identifier) tuple (identifier not unique)
+  - Expiry extension: Two places (state event arrival AND git auth)
+  - Edge cases: Newer announcements replace older, service list changes
+- Created design document: `docs/explanation/announcements-purgatory-design.md`
+- OpenCode conversation: https://opencode.ai/c/01JJBXPFVVQVX5RVQF2KQBQZJR
+- Next: User to review design document before implementation begins
+
 ## Implementation Considerations
 
 - **Data Structure**: Need separate storage for purgatory announcements (HashMap keyed by repo identifier?)