Flask API Development

Flask API Development

Table of Contents

• Overview
• When to Use
• Quick Start
• Reference Guides
• 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:

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