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. Thje bridge can be created either with create_window(..., js_api=Api()) or 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

• Finally you can do without a web server altogther by loading HTML using webview.create_window(...html='') or window.load_html. This approach has got limitations though, as file system does not exist in the context of the loaded page. Images and other assets can be loaded only inline using Base64.