diff --git a/backlog/tasks/task-005 - Automerge-CRDT-Sync.md b/backlog/tasks/task-005 - Automerge-CRDT-Sync.md
new file mode 100644
index 0000000..9cce03b
--- /dev/null
+++ b/backlog/tasks/task-005 - Automerge-CRDT-Sync.md	
@@ -0,0 +1,42 @@
+---
+id: task-005
+title: Automerge CRDT Sync
+status: Done
+assignee: []
+created_date: '2025-12-03'
+updated_date: '2025-12-05 03:41'
+labels:
+  - feature
+  - sync
+  - collaboration
+dependencies: []
+priority: high
+---
+
+## Description
+
+<!-- SECTION:DESCRIPTION:BEGIN -->
+Implement Automerge CRDT-based synchronization for real-time collaborative canvas editing.
+
+## Branch Info
+- **Branch**: `Automerge`
+<!-- SECTION:DESCRIPTION:END -->
+
+## Acceptance Criteria
+<!-- AC:BEGIN -->
+- [ ] #1 Integrate Automerge library
+- [ ] #2 Enable real-time sync between clients
+- [ ] #3 Handle conflict resolution automatically
+- [ ] #4 Persist state across sessions
+<!-- AC:END -->
+
+## Implementation Notes
+
+<!-- SECTION:NOTES:BEGIN -->
+Binary Automerge sync implemented:
+- CloudflareNetworkAdapter sends/receives binary sync messages
+- Worker sends initial sync on connect
+- Message buffering for early server messages
+- documentId tracking for proper Automerge Repo routing
+- Multi-client sync verified working
+<!-- SECTION:NOTES:END -->