diff --git a/nexus/mnemosyne/FEATURES.yaml b/nexus/mnemosyne/FEATURES.yaml
index 8e8cb875..5c3ae14c 100644
--- a/nexus/mnemosyne/FEATURES.yaml
+++ b/nexus/mnemosyne/FEATURES.yaml
@@ -151,13 +151,16 @@ frontend:
 planned:
 
   memory_decay:
-    status: planned
+    status: shipped
+    files: [entry.py, archive.py]
     description: >
       Memories have living energy that fades with neglect and
       brightens with access. Vitality score based on access
-      frequency and recency. Was attempted in PR #1221 but
-      went stale — needs fresh implementation against current main.
+      frequency and recency. Exponential decay with 30-day half-life.
+      Touch boost with diminishing returns.
     priority: medium
+    merged_prs:
+      - "#TBD"  # Will be filled when PR is created
 
   memory_pulse:
     status: planned