Auth / JWT-based (for JSON Endpoints)

• Axioms-Flask-Py (⭐4) - OAuth2/OIDC authentication and authorization for Flask APIs. Supports authentication and claim-based fine-grained authorization (scopes, roles, permissions) using JWT tokens.

Security / Testing

• Flask-CORS - Cross Origin Resource Sharing (CORS) handling.

Data Validation and Serialization / OAuth

• Flask-Pydantic (⭐434) - Pydantic (⭐28k) support.

Developer Tools / Logging

• Rollbar - Flask error logging with Rollbar.

Developer Tools / Monitoring

• Elastic APM Agent - Elastic APM Flask integration.

Utils / Testing

• Apitally (⭐218) - API monitoring, analytics, and request logging for Flask.

PaaS / Testing

• Google App Engine

IaaS / Testing

• Google Compute Engine

Serverless / Testing

• Google Cloud Functions

Admin

• Flask-Admin (⭐6.1k) - Functional admin panel that provides a user interface for managing data based on your models.

Developer Tools / Tracing

• OpenTelemetry - OpenTelemetry Flask Instrumentation.

Email / Testing

• Flask-Mail - Provides simple email sending capabilities.

Books / Testing

• Explore Flask - Best practices and patterns for developing web applications with Flask.

APIs / RESTful API + Swagger/OpenAPI Documentation Support

• APIFlask (⭐1.1k) - Integrates marshmallow for validation and serialization, and for OpenAPI generation with Swagger UI.

• Flasgger (⭐3.7k) - OpenAPI and Swagger UI. Builds the API from Flasgger models, marshmallow models, dicts, or YAML files.

• flask-smorest (⭐720) - Marshmallow's official Flask REST integration. Uses marshmallow models for request/response validation and serialization, and generates OpenAPI with Swagger UI.

Databases / ODMs

• Flask-MongoEngine - Bridges Flask and MongoEngine for working with MongoDB.

Security / Testing

• Flask-Talisman (⭐86) - HTTPS and security headers.

Task Queues / Testing

• Flask-RQ (⭐232) - RQ (Redis Queue) integration.

APIs / RESTful API Support

• Flask-Classful - Adds support for class-based views for setting up RESTful API route endpoints.

Auth / Basic Auth and Session-based (for HTML Endpoints)

• Flask-Session - Session managment.

Email / Testing

• Flask-Mail-SendGrid (⭐16) - Provides simple email base on Flask-Mail for sending email by SendGrid.

Security / Testing

• Flask-Argon2 (⭐19) - Provides argon2 hashing utilities.

Utils / Testing

• Flask-Injector (⭐283) - Adds support for dependency injection.

• Flask-SSE - Streaming with flask.

External Resources / Testing

• Patrick Kennedy's Blog - Numerous tutorials on learning Python web application development with Flask.

PaaS / Testing

• Microsoft Azure App Service

Serverless / Testing

• Azure Functions

Boilerplates / Testing

• flask-htmx-boilerplate (⭐37) - Boilerplate template for a Python Flask application with HTMX and Tailwind CSS.

Developer Tools / Monitoring

• Airbrake - Airbrake Flask integration.

Conferences / Testing

• FlaskCon - Community driven Flask event intended for speakers and attendees all over the world to participate in technical and evangelical sessions related to Flask.

Utils / Testing

• Flask-Reactize (⭐7) - Hides the Node.js development backend for React behind a Flask application.

Auth / Basic Auth and Session-based (for HTML Endpoints)

• Flask-SimpleLogin (⭐204) - Authentication.

Email / Testing

• Flask-Mailman - A port of django.mail for Flask.

Conferences / Testing

• PyConWeb - Covers Django, Tornado, Flask, API frameworks. AsyncIO, networking, Frontend, JavaScript, and web security.

Utils / Testing

• Flask-Shell2HTTP (⭐189) - RESTful/HTTP wrapper for Python's subprocess API, so you can convert any command-line tool into a RESTful API service.

APIs / RESTful API Support

• Eve - RESTful API framework designed for human beings.

• Flask-MongoRest (⭐519) - RESTful API framework wrapped around MongoEngine (⭐4.4k).

• Flask-RESTful - Quickly build RESTful APIs.

APIs / RESTful API + Swagger/OpenAPI Documentation Support

• Connexion - Open source, OpenAPI-based, REST framework built on top of Flask.

• Flask-Rebar (⭐235) - Combines Flask, marshmallow, and OpenAPI for robust REST services.

• Flask-RESTX - Community-driven fork of Flask-RESTPlus that makes it easy to build and document RESTful APIs with Flask.

APIs / Swagger/OpenAPI Documentation Support

• SAFRS: Python OpenAPI & JSON:API Framework (⭐413) - SAFRS, which is an acronym for SqlAlchemy Flask-Restful Swagger, is meant to help developers create self-documenting JSON APIs for SQLAlchemy database objects and relationships.

Auth / Basic Auth and Session-based (for HTML Endpoints)

• Flask-HTTPAuth - Authentication.

• Flask-Login - Account management and authentication.

• Flask Principal - Authorization.

• Flask-Security-Too - Account management, authentication, authorization.

• Flask-User - Account management, authentication, authorization.

Auth / JWT-based (for JSON Endpoints)

• Flask-JWT - Basic support for working with JWTs.

• Flask-JWT-Extended - Advanced support for working with JWTs.

• Flask-JWT-Router (⭐56) - Adds authorized routes to a Flask app.

• Flask-Praetorian - Authentication and authorization for Flask APIs.

Auth / OAuth

• Authlib - Library for building OAuth and OpenID clients and servers.

• Authomatic (⭐1.1k) - Framework agnostic library for Python web applications that simplifies authentication and authorization of users via OAuth and OpenID.

• Flask-Dance (⭐1k) - OAuth support via OAuthLib.

Cache / OAuth

• Flask-Caching - Caching support.

Data Validation and Serialization / OAuth

• Flask-Marshmallow - Thin integration layer for Flask and marshmallow (an object serialization /deserialization library) that adds additional features to marshmallow.

Databases / ORMs

• Flask-Peewee - Support for Peewee, an ORM and database migration tool.

• Flask-Pony - Support for Pony ORM.

• Flask-SQLAlchemy - Support for SQLAlchemy, a SQL toolkit and ORM.

Databases / ODMs

• Flask-PyMongo - Bridges Flask and PyMongo for working with MongoDB.

Databases / Migrations

• Flask-Alembic - Configurable Alembic migration environment around a Flask-SQLAlchemy database for handling database migrations.

• Flask-DB (⭐77) - Flask CLI extension that helps you migrate, drop, create and seed your SQL database.

• Flask-Migrate - Handles SQLAlchemy database migrations via Alembic.

Databases / Other Tools

• Flask-Excel (⭐264) - Uses pyexcel (⭐1.3k) to read, manipulate, and write data in different Excel formats: csv, ods, xls, xlsx and xlsm.

Developer Tools / Debugging

• Flask-DebugToolbar - Port of Django's debug toolbar for Flask.

• Flask-Profiler (⭐755) - Endpoint analyzer/profiler.

Developer Tools / Fixtures

• Flask-Fixtures (⭐64) - Create database fixtures from JSON or YAML.

• Mixer - Object generation tool.

Developer Tools / Monitoring

• Flask Monitoring Dashboard - Dashboard for automatic monitoring of Flask web-services.

• Sentry Python SDK - Sentry SDK Flask integration.

Developer Tools / Testing

• Flask-Testing - Unittest extensions.

• Pytest-Flask (⭐500) - Pytest support for testing Flask applications.

Forms / Testing

• Flask-WTF - Integrates Flask with WTForms (provides CSRF protection as well).

Full-text Search / Testing

• flask-msearch (⭐225) - Full-text search.

• Flask-WhooshAlchemy3 (⭐29) - Full-text search + Whoosh indexing capabilities for Flask-SQLAlchemy.

• SQLAlchemy-Searchable - Provides full-text search capabilities for SQLAlchemy models.

Security / Testing

• Flask-Bcrypt - Provides bcrypt hashing utilities.

• Flask-SeaSurf (⭐195) - Cross-site request forgery (CSRF) prevention.

Task Queues / Testing

• Celery - The most commonly used Python library for handling asynchronous tasks and scheduling.

• Dramatiq - Fast and reliable alternative to Celery.

• Huey - Redis-based task queue that aims to provide a simple, yet flexible framework for executing tasks.

Utils / Testing

• Flask-Babel (⭐453) - Support for internationalization (i18n) and localization (l10n).

• Flask-File-Upload (⭐154) - Easy file uploads.

• Flask-FlatPages - Provides flat static pages based on text files.

• Frozen-Flask (⭐800) - Freezes a Flask application into a set of static files.

• Flask-GraphQL (⭐1.3k) - GraphQL support.

• Flask-Limiter - Rate limiting features to Flask routes.

• Flask-Moment (⭐381) - Moment.js date and time formatting helpers for Jinja2 templates.

• Flask-Paginate - Pagination support.

• Flask-Sitemap - Sitemap generation.

• Flask-SocketIO - Socket.IO integration.

Official Resources / Testing

• Project Website - Official Flask website.

• Documentation - Comprehensive documentation for all Flask versions.

• Flaskr Tutorial - Build a basic blog application called Flaskr.

• Source Code (⭐72k) - Hosted on GitHub.

External Resources / Testing

• Full Stack Python's Flask Page - Explanation of Flask philosophy and links to other resources and tutorials.

• Miguel Grinberg's Blog - Multiple Flask-specific tutorials.

• Nick Janetakis's Blog - Flask Tips, Tricks and Tutorials.

• RealPython - Many high-quality tutorials on Flask.

• TestDriven.io - Up-to-date tutorials on Flask.

Community / Testing

• Discord - Pallets Projects community on Discord (use the #get-help channel for Flask support).

• IRC Channel - Chat with other Flask users on IRC channel #pocoo on FreeNode.

• Reddit - Flask subreddit.

• Stack Overflow - Questions tagged flask.

• Twitter - For official announcements on updates, security fixes, etc.

Conferences / Testing

• Flask Conf Brazil - Conference for the developers and users of Flask.

• PyCon US - The largest annual gathering for the community using and developing the open-source Python programming language.

• PyCon Australia - National conference organized for the Python Programming Community.

• Euro Python - The largest Python conference in Europe.

• PyCon - Complete listing of all PyCons globally.

Meetups / Testing

• Flask - 40+ groups in 20 countries.

• Python Web Development - 600+ groups in 81 countries.

• Python - 2,400+ groups in 100 countries.

Podcasts / Testing

• TalkPython - The leading Python podcast with several episodes on Flask.

• Podcast Init - A popular Python podcast that features Flask guests on occasion.

• Python Bytes - Another Python podcast that discusses Flask from time to time.

• Full Stack Python's Best Python Podcasts Page - A list of active Python-specific podcasts.

Tutorials / Testing

• Flask Mega-Tutorial - Overarching tutorial for Python beginner and intermediate developers that teaches web development with the Flask framework.

• Flaskr TDD (⭐2.3k) - Intro to Flask, Test-Driven Development (TDD), and JavaScript.

• Make a Web App Using Python & Flask! - Creating a Python Website from the Bottom Up.

Courses / Testing

• Developing Web Applications with Python and Flask - This course focuses on teaching the fundamentals of Flask by building and testing a web application using Test-Driven Development (TDD).

• Test-Driven Development with Python, Flask, and Docker - Learn how to build, test, and deploy a production-grade microservice powered by Python, Flask, and Docker.

• Authentication with Flask, React, and Docker - Learn how to add authentication to a Flask and React microservice!.

• Deploying a Flask and React Microservice to AWS ECS - Learn how to deploy microservices to Amazon ECS powered by Flask, React, and Docker.

• Build a SAAS App with Flask - Learn to build web applications with Flask and Docker.

• Full Stack Foundations - Build a data-driven web app with Python.

• Designing RESTful APIs - Build and Secure a backend API server.

Books / Testing

• Flask Web Development - Learn the framework from the ground up by developing, step-by-step, a real-world project.

• Real Python - Learn Python programming, by example.

Boilerplates / Testing

• cookiecutter-flask (⭐4.7k) - With Bootstrap 4, asset bundling annd minification with webpack, starter templates, and registration/authentication.

• Cookiecutter Flask Skeleton (⭐67) - Flask starter project for Cookiecutter (⭐25k).

• Flask-AppBuilder (⭐5k) - Simple and rapid application development framework that includes detailed security, auto CRUD generation for your models, Google charts, and much more.

• flask-base - Includes SQLAlchemy, Redis, User Authentication, and more.

• Flask-Bootstrap (⭐211) - Integrated SQLAlchemy, authentication, and Bootstrap frontend.

• uwsgi-nginx-flask-docker (⭐3k) - Docker image with uWSGI and Nginx for Flask applications in Python running in a single container.

• React-Redux-Flask (⭐1.5k) - Boilerplate application for a Flask JWT Backend and a React/Redux Front-End with Material UI.

Open Source Projects / Testing

• ActorCloud (⭐197) - Open-source IoT Platform.

• Busy Beaver (⭐71) - Chicago Python's Community Engagement Slack bot.

• FlaskBB (⭐2.7k) - Classic forum software.

• Indico (⭐2.1k) - Feature-rich event management system, made at CERN.

• Quokka CMS - The happiest CMS in the world.

• PythonBuddy (⭐282) - Online Python Editor with live syntax checking and execution.

• Redash (⭐29k) - Designed to enable anyone, regardless of the level of technical sophistication, to harness the power of data big and small.

• SkyLines (⭐404) - Live tracking, flight database, and competition framework.

• Security Monkey (⭐4.4k) - Monitors AWS, GCP, OpenStack, and GitHub orgs for assets and their changes over time.

• SecureDrop (⭐3.8k) - Open-source whistleblower submission system that media organizations can use to securely accept documents from, and communicate with anonymous sources.

• SimpleLogin (⭐6.6k) - Protect your online identity with email alias.

• sr.ht - Git hosting service (check out Why I chose Flask to build sr.ht's mini-services as well).

• Timesketch (⭐3.3k) - Collaborative forensic timeline analysis.

Videos / Testing

• PyVideo

• Practical Flask Web Development Tutorials

• Python Flask Tutorial: Full-Featured Web App

• Discover Flask - Full Stack Web Development with Flask (⭐4.5k)

PaaS / Testing

• Heroku

• PythonAnywhere

• AWS Elastic Beanstalk

• Divio

• Render

IaaS / Testing

• AWS EC2

• Digital Ocean

• Linode

Serverless / Testing

• Zappa (⭐12k)

• Chalice (⭐11k)

• AWS Lambda