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Jev Benchmark — themsquared

Runnable benchmark putting Jev, jev-preview and Claude Sonnet 5 through one real agent task — classifying a tool call as readonly, destructive, privileged or exfiltration — on the same 60 labelled cases, with raw per-call results committed.

Stars
1
Language
Python
License
APACHE-2.0
Published by
Community
Author
themsquared
Last verified
Oct 2026

This is one of several Jev listings for the same project. The canonical entry is Jev Benchmark — YidiDev.

About this project

A reproducible benchmark for TypeSafe AI's Jev on a real agent-infrastructure task: classifying an agent tool call as readonly, destructive, privileged, or exfiltration. Everything here is runnable. The task set is published, the harness is 200 lines, and the raw per-call results are committed. If you disagree with a label, edit tasks.jsonl and re-run.

Quoted from the project's README. Read the full README.

Highlights

  • 60 hand-labelled cases split 34 clear, 14 ambiguous and 12 adversarial, with destructive calls wrapped in benign wording.
  • All three backends tie at 55/60, with the same 100% / 71.4% / 91.7% split by difficulty across every model.
  • Measured 3.25x-3.62x faster and about 40.6x cheaper per call than Claude Sonnet 5, far short of the launch multipliers.
  • Confidence reaches exactly 1.000 on 40 of 60 Jev answers and on none of Claude's, and every miss came back hedged.

Watch out

The 0.9-1.0 confidence bin holds 50 of 60 predictions, so most of the ECE figure rests on one bin and the occupancy matters as much as the number. An earlier six-case probe of the same API returned confidence of exactly 1.000 on five of six, which looked like a saturated softmax; the README treats that as an artifact of an easy sample rather than a property of the model. The two Jev variants are not separable at this sample size, and an earlier run had jev-preview at 93.3% and 100% on the adversarial slice, which the author reads as run-to-run variance. Some ambiguous labels are arguably mislabels — kubectl port-forward into a production database is labelled readonly and classified privileged by every backend — and the repo reports the disagreement instead of adjudicating it. Measurements come from one residential connection, prices are only as current as that run, and the Anthropic adapter explicitly disables extended thinking. Copy reviewed against the repository README on 2026-10-04, not from running it.

Questions about this entry

Short answers drawn from the linked project or page.

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