Flask is a lightweight WSGI web application framework. It is designed to make getting started quick and easy, with the ability to scale up to complex applications.

Get started with Installation and then get an overview with the Quickstart. There is also a more detailed Tutorial that shows how to create a small but complete application with Flask. Common patterns are described in the Patterns for Flask section.

Flask depends on the Werkzeug WSGI toolkit, the Jinja template engine, and the Click CLI toolkit. Flask provides configuration and conventions, with sensible defaults, to get started. Beyond Flask itself, look for community-maintained extensions to add even more functionality.

The documentation covers a minimal application, debug mode, routing, static files, rendering templates, accessing request data, redirects and errors, responses, sessions, message flashing, logging, WSGI middleware, using Flask extensions, and deploying to a web server.