Welcome to Flask

Welcome to Flask’s documentation. Get started with Installation and then get an overview with the . 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 section. The rest of the docs describe each component of Flask in detail, with a full reference in the API section.

This part of the documentation, which is mostly prose, begins with some background information about Flask, then focuses on step-by-step instructions for web development with Flask.

• Foreword
  • Configuration and Conventions
• Foreword for Experienced Programmers
  • Develop for the Web with Caution
• • Python Version
  • Virtual environments
• Quickstart
  • What to do if the Server does not Start
  • HTML Escaping
  • Static Files
  • Accessing Request Data
  • About Responses
  • Message Flashing
  • Hooking in WSGI Middleware
  • Deploying to a Web Server
• • Project Layout
  • Define and Access the Database
  • Templates
  • Blog Blueprint
  • Test Coverage
  • Keep Developing!
• • Jinja Setup
  • Controlling Autoescaping
  • Context Processors
• • The Application
  • The First Test
  • Test Adding Messages
  • Faking Resources and Context
  • Accessing and Modifying Sessions
  • Testing CLI Commands
• • Error Logging Tools
  • Custom Error Pages
  • Returning API Errors as JSON
  • Debugging
• • In Production
  • External Debuggers
• • Basic Configuration
  • Injecting Request Information
• Configuration Handling
  • Environment and Debug Features
  • Configuring from Python Files
  • Configuring from Environment Variables
  • Development / Production
• Signals
  • Creating Signals
  • Signals and Flask’s Request Context
• Pluggable Views
  • Method Hints
  • Decorating Views
• The Application Context
  • Lifetime of the Context
  • Storing Data
• The Request Context
  • Lifetime of the Context
  • How the Context Works
  • Context Preservation on Error
• Modular Applications with Blueprints
  • The Concept of Blueprints
  • Registering Blueprints
  • Blueprint Resources
  • Blueprint Error Handlers
• • Finding Extensions
  • Building Extensions
• • Application Discovery
  • Open a Shell
  • Debug Mode
  • Environment Variables From virtualenv
  • Plugins
  • PyCharm Integration
• • Command Line
• Working with the Shell
  • Creating a Request Context
  • Further Improving the Shell Experience
• • Large Applications as Packages
  • Application Dispatching
  • Deploying with Setuptools
  • Using SQLite 3 with Flask
  • Uploading Files
  • View Decorators
  • Template Inheritance
  • AJAX with jQuery
  • MongoDB with MongoEngine
  • Streaming Contents
  • Adding HTTP Method Overrides
  • Celery Background Tasks
  • Single-Page Applications
• • Hosted options
• Becoming Big
  • Hook. Extend.
  • Wrap with middleware.
  • Scale like a pro.
• Using and await
  • Background tasks
  • Extensions

• • Application Object
  • Incoming Request Data
  • Sessions
  • Test Client
  • Application Globals
  • Message Flashing
  • Template Rendering
  • Stream Helpers
  • Signals
  • URL Route Registrations
  • Command Line Interface

Design notes, legal information and changelog are here for the interested.

• • The Explicit Application Object
  • One Template Engine
  • Thread Locals
  • What Flask is, What Flask is Not
• • History of XHTML
  • HTML versus XHTML
  • New technologies in HTML5
• Security Considerations
  • Cross-Site Request Forgery (CSRF)
  • Security Headers
• Flask Extension Development
  • “Hello Flaskext!”
  • The Extension Code
  • Learn from Others
• How to contribute to Flask
  • Reporting issues
• License
  • Artwork License
• • Version 2.0.2
  • Version 2.0.0
  • Version 1.1.3
  • Version 1.1.1
  • Version 1.0.4
  • Version 1.0.2
  • Version 1.0
  • Version 0.12.4
  • Version 0.12.2
  • Version 0.12
  • Version 0.11
  • Version 0.10
  • Version 0.8.1
  • Version 0.7.2
  • Version 0.7
  • Version 0.6
  • Version 0.5.1
  • Version 0.4
  • Version 0.3