diff --git a/app.py b/app.py
index dedc9fd..96df09c 100644
--- a/app.py
+++ b/app.py
@@ -70,7 +70,7 @@ def sync_team(client=None, owner=None, team_id=None, slug=None):
         try:
             directory_group = get_directory_from_slug(slug, custom_map, org)
             # If we're filtering on group prefix, skip if the group doesn't match
-            if group_prefix.length() > 0 and not directory_group.startswith(
+            if len(group_prefix) > 0 and not directory_group.startswith(
                 tuple(group_prefix)
             ):
                 print(f"skipping team {team.slug} - not in group prefix")
diff --git a/githubapp/core.py b/githubapp/core.py
index 07fced3..2684192 100644
--- a/githubapp/core.py
+++ b/githubapp/core.py
@@ -89,6 +89,11 @@ def init_app(self, app):
             methods=["POST"],
         )
 
+        app.add_url_rule("/health_check", endpoint="health_check")
+        @app.endpoint("health_check")
+        def health_check():
+            return "Web server is running.", 200
+
     @property
     def id(self):
         return current_app.config["GITHUBAPP_ID"]