Backend on the dev server

On the UI5 door the dev server is already the UI5 CLI's, and what has to join it is the backend the app calls: forwarded to over the network, or run inside the dev server, so the app and its service answer on one origin. Live reload, transpiling and the rest of the dev server's middleware are UI5 build tooling.

Overview

SAP SHIPS

The UI5 CLI's server serves a UI5 project for local development and takes custom middleware. SAP's backend-proxy-middleware is one: it forwards every request under a configured path, /sap in its examples, to a backend URL or a destination, so the app and the service it calls answer on the dev server's origin.

Not covered: At forwarding to a backend that already runs somewhere: one URL or destination per path, reached over the network. Running the services inside the dev server is left to custom middleware.

SourceUI5 CLI documentation — UI5 Serverchecked 2026-10-19