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Jev vs LLM: a phishing decision benchmark with a calibration audit

A public benchmark comparing Jev with Claude Haiku 4.5 on whether an email agent should click a link, over 2,000 PhishNChips emails, with calibration, latency, cost, and five signal questions.
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Python
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Author
anisselbd
Last verified
Sep 2026

Jev (TypeSafe) vs Claude Haiku 4.5 on 2 000 phishing emails: accuracy, calibration, latency, cost. Reproducible benchmark.

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Updated Sep 2026

Repo stats from the GitHub API, cached Oct 2026.

About this project

Public, reproducible comparison of Jev (TypeSafe AI's System One model, launched 15 September 2026) against a classic LLM on one security decision: should an email agent click the link in this email? The question this repo answers with numbers: is Jev accurate enough, are its probabilities calibrated, and how much faster and cheaper is it than an LLM on the same 2 000 emails?

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

Highlights

  • Both systems saw the same 2,000 PhishNChips v5.2 emails in seeded order, one call per email, no concurrency.
  • Jev was 62.6% accurate with AUROC 0.689 and ECE 0.154; Claude Haiku 4.5 was 81.3% accurate with AUROC 0.837.
  • Jev won on cost and speed: $0.038 per 1,000 emails at list price and 239 ms p50 from France versus $0.462 and 687 ms for Haiku.
  • A cross-validated logistic regression on Jev's five signals reached 95.0% on held-out half B, against 91.8% for a two-feature regex regression.
  • The signal result was re-controlled after review: Jev's best single signal lost to both the regex (89.4% vs 91.8%) and Haiku asked the same question (94.2%).

Quickstart

bash
cp .env.example .env            # fill in the TypeSafe and Anthropic keys
uv run run_jev.py --limit 10    # smoke test, prints raw answers
uv run run_llm.py --limit 10

Watch out

No license file, so reuse terms are unclear. Needs Python 3.13, uv, and both TypeSafe and Anthropic keys; published recall on the dataset varies with the system prompt, and one pass per arm limits stability claims.

Questions about this entry

Short answers drawn from the linked project or page.

Reactions & coverage

Posts, threads, and videos about this entry from around the web.

YouTube: Kubernetes admission control with a decision model, fail-closed.

Hacker News: SafeDep Gryph plus Jev checks for compromised coding-agent behavior.

2 pointsDetecting Compromised AI Coding Agents with Jev and GryphRead the thread on Hacker News

X: Jev and Laya on security queries

X: Testing Jev for prompt injection

From the Jev guides

Original write-ups on what this entry is for.

From the Jev AI model community

Posts from builders shipping with Jev right now.

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