diff --git a/api/app.py b/api/app.py
index 4ed743dcb4..99f70f32d5 100644
--- a/api/app.py
+++ b/api/app.py
@@ -1,7 +1,7 @@
 import sys
 
 
-def is_db_command():
+def is_db_command() -> bool:
     if len(sys.argv) > 1 and sys.argv[0].endswith("flask") and sys.argv[1] == "db":
         return True
     return False
diff --git a/dev/basedpyright-check b/dev/basedpyright-check
index 1c87b27d6f..1b3d1df7ad 100755
--- a/dev/basedpyright-check
+++ b/dev/basedpyright-check
@@ -8,9 +8,14 @@ cd "$SCRIPT_DIR/.."
 # Get the path argument if provided
 PATH_TO_CHECK="$1"
 
-# run basedpyright checks
-if [ -n "$PATH_TO_CHECK" ]; then
-    uv run --directory api --dev -- basedpyright --threads $(nproc) "$PATH_TO_CHECK"
-else
-    uv run --directory api --dev -- basedpyright --threads $(nproc)
-fi
+# Determine CPU core count based on OS
+CPU_CORES=$(
+  if [[ "$(uname -s)" == "Darwin" ]]; then
+    sysctl -n hw.ncpu 2>/dev/null
+  else
+    nproc
+  fi
+)
+
+# Run basedpyright checks
+uv run --directory api --dev -- basedpyright --threads "$CPU_CORES" $PATH_TO_CHECK