Application architecture

There are several way to build your application using pywebview:

Pure web server

• The most simple case is pointing to a url. This requires a running web server either remotely or locally

webview.create_window('Simple browser', 'https://pywebview.flowrl.com')
webview.start()

If you point to a local web server, you can start an external HTTP server in a background thread manually and or giving a WSGIRef server instance to the url parameter.

server = Flask(__name__, static_folder='.', template_folder='.')
webview.create_window('My first pywebview application', server)
webview.start()

See a complete example Flask-based application

When using a local web server, you should protect your API calls against CSRF attacks. See security for more information.

While the file:// protocol is possible, its use is discouraged as it comes with a number of inherit limitations and is not well supported.

JS API with internal HTTP server

Another approach is using JS API bridge and serving static content with a built-in HTTP server. JS API bridge allows communication between Python and Javascript domains without a web server. The bridge can be created either with create_window(..., js_api=Api()) or window.expose function. To serve static contents, set entrypoint url to a local relative path. This will start a built-in HTTP server automatically. For more details on communication between Python and Javascript refer to interdomain communication. See an example serverless application for a complete implementation.

Serverless

By loading HTML using webview.create_window(...html='') or window.load_html you can avoid using a web server altogether. This approach has limitations however, as the file system does not exist in the context of the loaded page. Images and other assets can be loaded only inline using Base64.