diff --git a/PLAN.md b/PLAN.md
index 0f94cbd..fd95aed 100644
--- a/PLAN.md
+++ b/PLAN.md
@@ -59,12 +59,12 @@ Check off items as completed. Each phase builds on the previous.
 - [x] **Commit checkpoint** (262739d)
 
 ### Step 2.2: Event Store Core
-- [ ] Create `events/store.py` with append_event, get_event, list_events
-- [ ] Implement nonce validation (reject duplicates)
-- [ ] Implement clock skew guard (reject ts_utc > now + 5 min)
-- [ ] Create `events/types.py` with event type constants
-- [ ] Write tests for event storage, nonce rejection, clock skew
-- [ ] **Commit checkpoint**
+- [x] Create `events/store.py` with append_event, get_event, list_events
+- [x] Implement nonce validation (reject duplicates)
+- [x] Implement clock skew guard (reject ts_utc > now + 5 min)
+- [x] Create `events/types.py` with event type constants
+- [x] Write tests for event storage, nonce rejection, clock skew
+- [x] **Commit checkpoint** (29d5d3f)
 
 ### Step 2.3: Event Type Payloads
 - [ ] Create Pydantic models for all event payloads (spec §6):