diff --git a/src/ai_memory_protocol/__init__.py b/src/ai_memory_protocol/__init__.py
index 3cfb310..8fb678f 100644
--- a/src/ai_memory_protocol/__init__.py
+++ b/src/ai_memory_protocol/__init__.py
@@ -1,3 +1,3 @@
 """AI Memory Protocol — versioned, graph-based memory for AI agents."""
 
-__version__ = "0.3.1"
+__version__ = "0.4.0"