From 36b6cd1493c01c8e6a32f611a1ec2c26c2e8f902 Mon Sep 17 00:00:00 2001
From: William FH <13333726+hinthornw@users.noreply.github.com>
Date: Mon, 2 Dec 2024 18:20:19 -0800
Subject: [PATCH] fix: Handle empty store similarity (numpy) (#2602)

---
 libs/checkpoint/langgraph/store/memory/__init__.py | 2 ++
 libs/checkpoint/pyproject.toml                     | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/libs/checkpoint/langgraph/store/memory/__init__.py b/libs/checkpoint/langgraph/store/memory/__init__.py
index 40011a7ba..eec511ac8 100644
--- a/libs/checkpoint/langgraph/store/memory/__init__.py
+++ b/libs/checkpoint/langgraph/store/memory/__init__.py
@@ -413,6 +413,8 @@ def _cosine_similarity(X: list[float], Y: list[list[float]]) -> list[float]:
     Compute cosine similarity between a vector X and a matrix Y.
     Lazy import numpy for efficiency.
     """
+    if not Y:
+        return []
     if _check_numpy():
         import numpy as np  # type: ignore
 
diff --git a/libs/checkpoint/pyproject.toml b/libs/checkpoint/pyproject.toml
index ef12f2052..f48f46a1f 100644
--- a/libs/checkpoint/pyproject.toml
+++ b/libs/checkpoint/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "langgraph-checkpoint"
-version = "2.0.7"
+version = "2.0.8"
 description = "Library with base interfaces for LangGraph checkpoint savers."
 authors = []
 license = "MIT"