SKILL.md
Flask API Development
Table of Contents
- [Overview](#overview)
- [When to Use](#when-to-use)
- [Quick Start](#quick-start)
- [Reference Guides](#reference-guides)
- [Best Practices](#best-practices)
Overview
Create efficient Flask APIs with blueprints for modular organization, SQLAlchemy for ORM, JWT authentication, comprehensive error handling, and proper request validation following REST principles.
When to Use
- Building RESTful APIs with Flask
- Creating microservices with minimal overhead
- Implementing lightweight authentication systems
- Designing API endpoints with proper validation
- Integrating with relational databases
- Building request/response handling systems
Quick Start
Minimal working example:
# app.py
from flask import Flask, request, jsonify
from flask_cors import CORS
from flask_sqlalchemy import SQLAlchemy
from flask_jwt_extended import JWTManager
import os
app = Flask(__name__)
app.config['SQLALCHEMY_DATABASE_URI'] = os.getenv('DATABASE_URL', 'sqlite:///app.db')
app.config['JWT_SECRET_KEY'] = os.getenv('JWT_SECRET_KEY', 'dev-secret')
app.config['JSON_SORT_KEYS'] = False
db = SQLAlchemy(app)
jwt = JWTManager(app)
CORS(app)
# Request ID middleware
@app.before_request
def assign_request_id():
import uuid
request.request_id = str(uuid.uuid4())
# Error handlers
@app.errorhandler(400)
def bad_request(error):
// ... (see reference guides for full implementation)Reference Guides
Detailed implementations in the references/ directory:
| Guide | Contents |
|---|---|
| Flask Application Setup | Flask Application Setup |
| Database Models with SQLAlchemy | Database Models with SQLAlchemy |
| Authentication and JWT | Authentication and JWT |
| Blueprints for Modular API Design | Blueprints for Modular API Design |
| Request Validation | Request Validation |
| Application Factory and Configuration | Application Factory and Configuration |
Best Practices
✅ DO
- Use blueprints for modular organization
- Implement proper authentication with JWT
- Validate all user input
- Use SQLAlchemy ORM for database operations
- Implement comprehensive error handling
- Use pagination for collection endpoints
- Log errors and important events
- Return appropriate HTTP status codes
- Implement CORS properly
- Use environment variables for configuration
❌ DON'T
- Store secrets in code
- Use global variables for shared state
- Ignore database transactions
- Trust user input without validation
- Return stack traces in production
- Use mutable default arguments
- Forget to handle database connection errors
- Implement authentication in route handlers