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 OpenHands/extensions --skill use-jevgit clone --depth 1 https://github.com/OpenHands/extensionsWrote 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/openhands/extensions/use-jev)<a href="https://agentmods.dev/skills/openhands/extensions/use-jev"><img src="https://agentmods.dev/badge/skills/openhands/extensions/use-jev/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/openhands/extensions/use-jev"><img src="https://agentmods.dev/badge/skills/openhands/extensions/use-jev.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 | $0.00025 | $0.00721 |
| Opus 5.5 | $0.00010 | $0.00288 |
| Sonnet 5.5 | $0.00005 | $0.00144 |
| Haiku 4.5 | $0.00003 | $0.00072 |
Grade A, and why
use-jev 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 15d 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.
What it actually says
Jev is a newly released general classifier. Give it text or application state and typed questions; it returns decisions and probabilities your code can use for routing, ranking, extraction, or verification.
Read the upstream llms.txt to find current documentation, then follow the pages relevant to the task:
- Use cases: explore applications; see worked examples for function calling, reranking, and citation checks.
- Best practices: provide relevant state, ask focused questions, define clear criteria, and batch independent questions. Keep workflow logic in code.
- Confidence: use uncertainty to decide when to escalate, and validate thresholds on representative data.
- Python SDK, JavaScript SDK, or HTTP API: read before integrating.
Choice, Score, and Noul
| Primitive | Example use | Result |
|---|---|---|
| Choice | Route a support request to a team | One option, option probabilities, and confidence |
| Score | Rate a bug's impact | Probability-weighted position on ordered levels, plus confidence |
| Noul | Check whether a refund is requested | Probability of yes; 0.5 means uncertainty, not medium intensity |
Install typesafe-sdk and check that JEV_API_KEY is set in the environment,
otherwise ask the user to provide it.
This Python example asks one question of each type in a single call:
import os
from typesafe_sdk import Choice, Noul, Score, TypeSafeClient
with TypeSafeClient(api_key=os.environ["JEV_API_KEY"]) as client:
result = client.system_one(
state={"ticket": "PDF export fails, but CSV works. Please refund this month."},
questions={
"team": Choice(
instructions="Which team should handle the main issue in the ticket?",
criteria={"billing": "Charges and payments",
"technical": "Broken product features", "other": "Neither"},
),
"impact": Score(
instructions="How much does the reported bug affect functionality?",
criteria=["Cosmetic only", "Feature broken; workaround available",
"Work blocked; no workaround available"],
),
"refund": Noul(instructions="Does the ticket explicitly request a refund?"),
},
)
print(result.choices["team"].choice)
print(result.scores["impact"].score)
print(result.nouls["refund"].noul)
What ships with it
4 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.
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.
- 15d ago First seen · 67 lines · 25 tokens per session scan A 56bd6d2c1003
use-jev is a skill published in the GitHub repository OpenHands/extensions (167 stars, last pushed today), licensed MIT. It adds 25 tokens to every session and 721 once invoked, about $0.0001 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 2026-10-02.
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