What is competition-jwt-claim-confusion?

A capture-the-flag security-testing workflow for checking how applications validate JSON Web Tokens (JWTs), signed tokens, and encrypted tokens.

Use it to inspect key selection, audience and issuer checks, role derivation, and bugs where a token is treated as belonging to the wrong identity.

It helps reveal mismatches between token headers, keys, claims, and the identity or role an application accepts.

competition-jwt-claim-confusion — Skill for Codex by ryfineZ

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.

Any agent

npx skills add ryfineZ/my-ai-skills --skill competition-jwt-claim-confusion

Clone the repo

git clone --depth 1 https://github.com/ryfineZ/my-ai-skills

Made for: Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/ryfinez/my-ai-skills/competition-jwt-claim-confusion/github.svg)](https://agentmods.dev/skills/ryfinez/my-ai-skills/competition-jwt-claim-confusion)

Your own site

<a href="https://agentmods.dev/skills/ryfinez/my-ai-skills/competition-jwt-claim-confusion"><img src="https://agentmods.dev/badge/skills/ryfinez/my-ai-skills/competition-jwt-claim-confusion/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/ryfinez/my-ai-skills/competition-jwt-claim-confusion"><img src="https://agentmods.dev/badge/skills/ryfinez/my-ai-skills/competition-jwt-claim-confusion.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 128 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 655 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin unknown No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00128	$0.00655
Opus 5.5	$0.00051	$0.00262
Sonnet 5.5	$0.00026	$0.00131
Haiku 4.5	$0.00013	$0.00065

Measured 2mo ago against content hash f470a0467fdf, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

competition-jwt-claim-confusion 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 2mo 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.

packages/community/GALIAIS__CTF-Sandbox-Orchestrator/competition-jwt-claim-confusion/SKILL.md · 51 lines

The source is not reproduced here

No licence file

Read it on GitHub

Files

What ships with it

3 files beside SKILL.md 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.

2mo ago First seen · 51 lines · 128 tokens per session scan A f470a0467fdf

Subscribe to this mod's changes

competition-jwt-claim-confusion is a skill published in the GitHub repository ryfineZ/my-ai-skills (127 stars, last pushed 7mo ago), with no licence file. It adds 128 tokens to every session and 655 once invoked, about $0.0005 per session on Opus 5.5. 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.