I think monorepo is fairly correct now but I don't know for sure

packages/backend/convex/http.ts

@@ -0,0 +1,9 @@
+import { httpRouter } from 'convex/server';
+
+import { auth } from './auth';
+
+const http = httpRouter();
+
+auth.addHttpRoutes(http);
+
+export default http;