FastAPI JWT Middleware Skill

What problem does it solve?

This Skill provides a secure JWT verification middleware pattern for FastAPI applications, simplifying authentication against Better Auth secrets and protecting route access.

Core Features & Use Cases

• Secure JWT extraction from the Authorization header
• Signature verification using BETTER_AUTH_SECRET
• Decoding payload to extract user_id and email
• Route-level ownership validation by matching user_id in path to JWT payload
• Dependency injection patterns for FastAPI routes
• Standardized error handling with 401/403

Quick Start

Add the FastAPI JWT middleware to your application and configure it with your BETTER_AUTH_SECRET. Use route paths like /users/{user_id}/profile with appropriate dependencies to enforce ownership.