Application Dispatcher — Werkzeug Documentation (3.1.x)

# Application Dispatcher

This middleware creates a single WSGI application that dispatches to multiple other WSGI applications mounted at different URL paths.

A common example is writing a Single Page Application, where you have a backend API and a frontend written in JavaScript that does the routing in the browser rather than requesting different pages from the server. The frontend is a single HTML and JS file that should be served for any path besides “/api”.

This example dispatches to an API app under “/api”, an admin app under “/admin”, and an app that serves frontend files for all other requests:

    app = DispatcherMiddleware(serve_frontend, {
        '/api': api_app,
        '/admin': admin_app,
    })

In production, you might instead handle this at the HTTP server level, serving files or proxying to application servers based on location. The API and admin apps would each be deployed with a separate WSGI server, and the static files would be served directly by the HTTP server.

class werkzeug.middleware.dispatcher.DispatcherMiddleware(app, mounts=None)

  Combine multiple applications as a single WSGI application. Requests are dispatched to an application based on the path it is mounted under.

  Parameters:

    - app (WSGIApplication) – The WSGI application to dispatch to if the request doesn’t match a mounted path.

    - mounts (dict[str, WSGIApplication] | None) – Maps path prefixes to applications for dispatching.