Is this skill compatible with frontend libraries like Better Auth?

Yes, it is specifically designed to use the BETTER_AUTH_SECRET for consistent token signing and verification across the entire stack.

How does it prevent users from accessing other people's data?

The skill implements a mandatory check that compares the user_id extracted from the JWT token against the user_id in the URL path, returning a 403 Forbidden error if they don't match.

What hashing algorithm is used for passwords?

It uses the bcrypt algorithm via Passlib, ensuring that plain text passwords are never stored and are resistant to rainbow table attacks.

Does it handle token expiration?

Yes, it includes patterns for setting a 7-day expiration (iat/exp claims) and specific exception handling for ExpiredSignatureError to prompt user re-authentication.

Can I use this for non-FastAPI projects?

While the middleware patterns are optimized for FastAPI's dependency injection system, the core logic for token verification and hashing can be easily adapted for Flask or Django.

Backend JWT Authentication

Name: Backend JWT Authentication
Author: Syedaashnaghazanfar

bySyedaashnaghazanfar

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Desarrollo de API

Implements secure JWT-based authentication and user data isolation for FastAPI backends using shared secret protocols.

This skill provides a standardized framework for implementing robust security in Python-based backends, specifically focusing on FastAPI. It guides the creation of JWT verification middleware, secure password hashing using bcrypt, and critical user isolation patterns that prevent unauthorized data access by matching token subjects to resource paths. By leveraging a shared secret approach compatible with Better Auth, it ensures seamless and secure communication between frontend and backend components in full-stack applications.

Características Principales

01Environment-based configuration for Better Auth secret integration

02Automated user isolation and ID validation in API routes

03Secure password hashing and verification using bcrypt

04JWT token verification middleware for FastAPI dependencies

05Standardized token generation with HS256 and configurable expiration

063 GitHub stars

Casos de Uso

01Securing REST API endpoints for user-specific data like Todo lists

02Building secure signup and signin workflows with multi-claim JWTs

03Implementing shared-secret authentication between a frontend and FastAPI backend

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add syedaashnaghazanfar/full-stack-todo-app backend-jwt-auth

For use in Claude.ai and ChatGPT

Download Skill