jwt-security

Validate JWT algorithms, claims, and refresh token rotation for backend services.

Updated Mar 29, 2026

Search Tags:#authorization #security #authentication #jwt #token-rotation #token-validation #revocation

Ready to run

npx skills add https://github.com/marquesfelip/agents-and-skills --skill jwt-security-marquesfelip

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: jwt-security
Source: https://github.com/marquesfelip/agents-and-skills/tree/main/skills/jwt-security
Command: npx skills add https://github.com/marquesfelip/agents-and-skills --skill jwt-security-marquesfelip

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

JWTs are commonly misconfigured or poorly validated, exposing services to token forgery, replay, or privilege escalation. This Skill provides a comprehensive approach to safe JWT issuance, validation, rotation, and revocation.

Core Features & Use Cases

Robust algorithm validation and header checks (rejecting alg none and enforcing approved algorithms)
Comprehensive claim validation (exp, iat, iss, aud, sub, and custom claims)
Token lifecycle design (short-lived access tokens with secure refresh token rotation and revocation)
Guidance for secure storage, key management, and JWKS publishing
Use Case: securing a microservice API gateway, user sessions, and service-to-service authentication

Quick Start

Configure your authentication layer to validate alg, exp, iss, aud, and claims, and to rotate refresh tokens on every use.

Frequently Asked Questions about jwt-security

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I validate JWT claims like exp, iss, and aud in a backend API?▼

To validate JWT claims in a backend API, enforce allowed algorithms and verify expiration, issuer, and audience fields. Comprehensive claim validation prevents token forgery and privilege escalation by rejecting misconfigured tokens across web apps and microservices.

What's the best way to implement secure refresh token rotation?▼

Secure refresh token rotation requires issuing short-lived access tokens and rotating the refresh token on every use. This lifecycle design prevents replay attacks by invalidating compromised tokens immediately upon refresh.

How does JWKS key management work for JWT validation?▼

JWKS key management for JWT validation involves publishing public keys via a JSON Web Key Set endpoint. Services fetch these keys to cryptographically verify token signatures, ensuring secure key distribution and revocation strategies across microservices.

Why should I reject the alg none header in JWT authentication?▼

Rejecting the alg none header in JWT authentication prevents token forgery by enforcing approved signing algorithms. Attackers exploit alg none to bypass signature verification, so robust header checks must reject unsecured tokens to protect backend services.

Can I use JWT authentication for service-to-service communication in microservices?▼

JWT authentication secures service-to-service communication in microservices by validating tokens at the API gateway. Enforcing claim verification and algorithm restrictions ensures that only authenticated services can access internal endpoints.

What JWT revocation strategies work for user sessions?▼

JWT revocation strategies for user sessions include maintaining a blocklist of invalidated tokens and using short-lived access tokens with refresh token rotation. This approach ensures compromised sessions are terminated even before the token expires.