Understand-Anything/understand-anything-plugin/skills/understand/frameworks/flask.md

Flask Framework Addendum

Injected into file-analyzer and architecture-analyzer prompts when Flask is detected. Do NOT use as a standalone prompt — always appended to the base prompt template.

Flask Project Structure

When analyzing a Flask project, apply these additional conventions on top of the base analysis rules.

Canonical File Roles

File / Pattern	Role	Tags
app.py, __init__.py (in app package)	Application factory (create_app()) or direct Flask(__name__) instance	entry-point, config
run.py, wsgi.py	Production/dev server entry point	entry-point, config
*/views.py, */routes.py	Route handler functions with @app.route or @blueprint.route	api-handler, routing
*/blueprints/*.py, */api/*.py	Blueprint modules — group routes by feature	api-handler, routing
*/models.py	SQLAlchemy models or other ORM models	data-model
*/forms.py	WTForms form classes	validation, ui
*/schemas.py	Marshmallow serialization schemas	serialization, type-definition
*/config.py	Config classes (DevelopmentConfig, ProductionConfig)	config
*/extensions.py	Flask extension initialization (db = SQLAlchemy(), login_manager = LoginManager())	config, singleton
*/decorators.py	Custom route decorators (auth guards, rate limiting)	middleware, utility
*/utils.py, */helpers.py	Shared utility functions	utility
*/templates/**/*.html	Jinja2 templates	ui
*/static/	CSS, JS, and asset files	assets
*/tests/*.py, test_*.py	pytest or unittest test files	test

Edge Patterns to Look For

Blueprint registration — When app.register_blueprint(bp, url_prefix='/api') appears in the application factory, create depends_on edges from the app factory to each blueprint module.

Extension coupling — When a view imports from extensions.py (e.g., from .extensions import db, login_manager), create imports edges to show which views depend on which extensions.

Before/after request hooks — When @app.before_request or @blueprint.before_request decorates a function, create middleware edges from those functions to the app/blueprint they attach to.

Architectural Layers for Flask

Layer ID	Layer Name	What Goes Here
layer:api	API Layer	Blueprint route files, view functions
layer:data	Data Layer	models.py, database migration files
layer:service	Service Layer	Business logic modules, schemas.py, service classes
layer:ui	UI Layer	templates/, forms.py, static/
layer:config	Config Layer	app.py factory, config.py, extensions.py
layer:middleware	Middleware Layer	decorators.py, before/after request hooks
layer:test	Test Layer	Test files, conftest.py

Notable Patterns to Capture in languageLesson

• Application factory pattern: create_app() functions allow multiple app instances (e.g., for testing) and delay extension initialization — avoids circular imports
• Blueprint modularity: Blueprints group related routes, templates, and static files; they are registered on the app with a URL prefix, making them independently testable
• Flask extension protocol: Extensions follow init_app(app) for lazy initialization — the extension object is created globally but bound to an app instance later