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 agentmods add skills/yunseo-kim/agent-toolbox/javascript-testing-patternsnpx skills add yunseo-kim/agent-toolbox --skill javascript-testing-patternsgit clone --depth 1 https://github.com/yunseo-kim/agent-toolboxWhat 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 | $0.00063 | $0.06337 |
| Opus 5 | $0.00032 | $0.03168 |
| Sonnet 5 | $0.00013 | $0.01267 |
| Haiku 4.5 | $0.00006 | $0.00634 |
Grade B, and why
javascript-testing-patterns scanned grade B 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 yesterday.
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.
Sends data to an external URLmediumData exfiltration
A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.
const response = await fetch("https://api.example.com/users", { method: "POST", The source is not reproduced here
No licence file
A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.
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.
- yesterday First seen · 1,022 lines · 63 tokens per session scan B 5fc959e9123e
javascript-testing-patterns is a skill published in the GitHub repository yunseo-kim/agent-toolbox (1 stars, last pushed 2d ago), with no licence file. It adds 63 tokens to every session and 6,337 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it B with 1 finding (sends data to an external url). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.
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