kataras-jwt

A development guide for the JWT library for Go. JSON Web Tokens are signed data packages commonly used to represent a user's login or other claims between services.

In plain words
What is it for?
Use it to sign and verify tokens, handle claims and expiry, choose signing algorithms, rotate keys, use JWKS keys, block tokens, and test JWT code.
Why use it?
It provides guidance for the security and maintenance details that can make token-based authentication error-prone.

Plugin for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Claude Code
/plugin marketplace add kataras/jwt
agentmods
npx agentmods add plugins/kataras/jwt/marketplace
Clone the repo
git clone --depth 1 https://github.com/kataras/jwt

Made for: Claude Code.

Per session not measured What this adds to a session before it is invoked.
When invoked not measured Not applicable: nothing here is loaded into a session.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Security

Grade A, and why

kataras-jwt scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude-plugin/marketplace.json · 16 lines

What it actually says

{
  "name": "kataras-jwt",
  "owner": {
    "name": "Gerasimos (Makis) Maropoulos",
    "url": "https://github.com/kataras"
  },
  "description": "The jwt skill: a development guide for the jwt JSON Web Token library for Go.",
  "plugins": [
    {
      "name": "jwt",
      "source": ".",
      "description": "Development guide for the jwt JSON Web Token library for Go: signing and verifying tokens, claims and expiry, algorithm choice (HMAC/RSA/RSA-PSS/ECDSA/EdDSA), kid-based key rotation, JWKS fetch/refresh/publish, blocklisting and testing."
    }
  ]
}
Files

What ships with it

1 file beside marketplace.json in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 16 lines scan A e5fec0202ebe

Subscribe to this mod's changes

kataras-jwt is a plugin published in the GitHub repository kataras/jwt (211 stars, last pushed 11d ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.