jwt-tool-skill

Automate JWT token decoding, verification, cracking, tampering, and endpoint scans with jwt_tool.

1|Updated Jun 26, 2026
One-click install
npx skills add https://github.com/xijunww/Pentest --skill jwt-tool-skill
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: jwt-tool-skill
Source: https://github.com/xijunww/Pentest/tree/main/packages/core/src/config/skills/builtin/jwt-tool-skill
Command: npx skills add https://github.com/xijunww/Pentest --skill jwt-tool-skill

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires python, jwt_tool, and includes scripts (resource) and references (resource) components.

What problem does it solve?

This Skill assists with authorized JWT assessment and manipulation using ticarpi/jwt_tool, providing quick access to decoding, verification, and exploitation commands.

Core Features & Use Cases

  • JWT Decoding and Verification: Quick access to decode, verify signatures, and crack HMAC secrets.
  • Exploitation Commands: Test 'alg:none', key confusion, JWKS spoofing, and inline JWK attacks.
  • Interactive Tampering: Manual token editing for in-depth testing.
  • Playbook Scanning: Automated scans of live endpoints for common JWT vulnerabilities.
  • Use Case: For a security auditor examining a web application that uses JWT tokens for authentication, this Skill can be used to verify token integrity, crack secrets, and test for vulnerabilities in real-time.

Quick Start

Use the jwt-tool-skill to decode a JWT token: python3 jwt_tool.py '<JWT>'

Frequently Asked Questions about jwt-tool-skill

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

FAQPage Schema
How do I decode a JWT token and verify its signature?▼

To decode a JWT token and verify its signature, use the jwt-tool-skill to automate decoding and signature verification via the jwt_tool package. It provides quick commands to inspect token payloads and validate HMAC integrity.

Can I test for JWT alg:none and key confusion vulnerabilities?▼

Yes, you can test for JWT alg:none and key confusion vulnerabilities using the jwt-tool-skill. It provides built-in exploitation commands to probe these specific authentication weaknesses and assess token manipulation risks.

What is the best way to crack HMAC secrets for JWT authentication?▼

The best way to crack HMAC secrets for JWT authentication is using the jwt-tool-skill, which automates secret cracking via jwt_tool. It performs dictionary attacks against the token signature to recover the secret key.

Do I need Python and jwt_tool installed to perform endpoint scans for JWT vulnerabilities?▼

Yes, you need Python and the jwt_tool package installed to perform endpoint scans for JWT vulnerabilities. The jwt-tool-skill relies on these dependencies to execute its playbook scans against live web application endpoints.

How does interactive JWT tampering work for exploitation testing?▼

Interactive JWT tampering allows manual token editing for in-depth exploitation testing. The jwt-tool-skill enables you to modify payload claims and headers directly, facilitating real-time security auditing of token integrity.