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.
npx skills add withcrux/agentHack-skills --skill analyzing-jwt-token-securitygit clone --depth 1 https://github.com/withcrux/agentHack-skillsWrote 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.
[](https://agentmods.dev/skills/withcrux/agenthack-skills/analyzing-jwt-token-security)<a href="https://agentmods.dev/skills/withcrux/agenthack-skills/analyzing-jwt-token-security"><img src="https://agentmods.dev/badge/skills/withcrux/agenthack-skills/analyzing-jwt-token-security/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.
<a href="https://agentmods.dev/skills/withcrux/agenthack-skills/analyzing-jwt-token-security"><img src="https://agentmods.dev/badge/skills/withcrux/agenthack-skills/analyzing-jwt-token-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00062 | $0.01856 |
| Opus 5 | $0.00031 | $0.00928 |
| Sonnet 5 | $0.00012 | $0.00371 |
| Haiku 4.5 | $0.00006 | $0.00186 |
Grade A, and why
analyzing-jwt-token-security scanned grade A with 1 finding 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 10d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
- **Software:** Docker + Docker Compose, browser or curl The source is not reproduced here
A licence we could not identify
The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.
What ships with it
1 file 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.
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.
- 10d ago First seen · 199 lines · 62 tokens per session scan A 807a5f2c09e3
analyzing-jwt-token-security is a skill published in the GitHub repository withcrux/agentHack-skills (5 stars, last pushed 5mo ago), with no licence file. It adds 62 tokens to every session and 1,856 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
Other skills, from other repositories
exploiting-jwt-algorithm-confusion-attack
Exploits JWT algorithm confusion vulnerabilities where the server's token verification library accepts the algorithm specified in the JWT header rather than enforcing a fixed algorithm. The tester manipulates the alg header to switch from RS256 to HS256 (using the RSA public key as the HMAC secret), sets alg to none…
testing-jwt-token-security
Assessing JSON Web Token implementations for cryptographic weaknesses, algorithm confusion attacks, and authorization bypass vulnerabilities during security engagements.
testing-jwt-token-security
Assessing JSON Web Token implementations for cryptographic weaknesses, algorithm confusion attacks, and authorization bypass vulnerabilities during security engagements.
testing-for-json-web-token-vulnerabilities
Test JWT implementations for critical vulnerabilities including algorithm confusion, none algorithm bypass, kid parameter injection, and weak secret exploitation to achieve authentication bypass and privilege escalation.
testing-api-authentication-weaknesses
Tests API authentication mechanisms for weaknesses including broken token validation, missing authentication on endpoints, weak password policies, credential stuffing susceptibility, token leakage in URLs or logs, and session management flaws. The tester evaluates JWT implementation, API key handling, OAuth flows, and…
performing-jwt-none-algorithm-attack
Execute and test the JWT none algorithm attack to bypass signature verification by manipulating the alg header field in JSON Web Tokens.