CLI (#12284)

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

libs/cli/langchain_cli/dev_scripts.py

@@ -0,0 +1,17 @@
+"""
+Development Scripts for Hub Packages
+"""
+
+from fastapi import FastAPI
+from langserve.packages import add_package_route
+from langchain_cli.utils.packages import get_package_root
+
+
+def create_demo_server():
+    """
+    Creates a demo server for the current hub package.
+    """
+    app = FastAPI()
+    package_root = get_package_root()
+    add_package_route(app, package_root, "")
+    return app