diff --git a/databricks-builder-app/.python-version b/databricks-builder-app/.python-version
new file mode 100644
index 00000000..e4fba218
--- /dev/null
+++ b/databricks-builder-app/.python-version
@@ -0,0 +1 @@
+3.12
diff --git a/databricks-builder-app/pyproject.toml b/databricks-builder-app/pyproject.toml
index 9ea7c17e..ac9c97f9 100644
--- a/databricks-builder-app/pyproject.toml
+++ b/databricks-builder-app/pyproject.toml
@@ -12,7 +12,7 @@ name = "databricks-builder-app"
 version = "0.1.0"
 description = "Claude Code MCP Application"
 readme = "README.md"
-requires-python = ">=3.11"
+requires-python = ">=3.11,<3.14"
 dependencies = [
   "fastapi[standard]>=0.115.8",
   "python-dotenv>=1.0.1",
diff --git a/databricks-builder-app/scripts/start_dev.sh b/databricks-builder-app/scripts/start_dev.sh
index 24af7b83..063e7ab3 100755
--- a/databricks-builder-app/scripts/start_dev.sh
+++ b/databricks-builder-app/scripts/start_dev.sh
@@ -36,7 +36,7 @@ trap cleanup SIGINT SIGTERM
 
 # Start backend
 echo "Starting backend on http://localhost:8000..."
-uvicorn server.app:app --reload --port 8000 --reload-dir server &
+uv run uvicorn server.app:app --reload --port 8000 --reload-dir server &
 BACKEND_PID=$!
 
 # Wait a moment for backend to start