TypeSafe · Early Access

LLM as a Judge with Jev

Jev is a structured judgment model by TypeSafe. Ask boolean, choice, or score questions and get exact answers back, with up to 32 independent questions processed in parallel per request.

LLM as a Judge with Jev

A person reviews documents on three monitors at a desk, illustrating evidence-based work with Jev.

Use Jev in agent and CLI workflows.

The Kollab Agent invokes Jev automatically when you ask for structured evaluations. You can also run it manually via the CLI for scripts and pipelines.

Install & call it
npm install -g @kollab/cli
kollab login

echo '{
  "state": "Help! My payouts have been failing for 3 days.",
  "questions": {
    "is_urgent": { "type": "noul", "instructions": "Does this convey urgency?" },
    "department": { "type": "choice", "instructions": "Which team should handle this?",
      "criteria": { "billing": "Payments, invoicing, refunds", "technical": "Bugs, outages, integrations", "sales": "Pricing, upgrades, new accounts" } }
  }
}' | kollab tool run jev --json

Part of the Kollab model armory.

Access Jev alongside a complete suite of models for text, vision, video, and audio tasks.

Images
GPT Image 2
Video
Seedance 2 · Veo 3
Voice
Grok TTS · Grok STT
Vision
Visual Q&A
Search & data
Web search · Deep search · Social data fetch
Chat models
Claude · GPT · Gemini · Grok · Kimi · DeepSeek · GLM

LLM as a judge for moderation, scoring, and reranking.

Run specific evaluation tasks with Jev.

Performance benchmarks.

Fast execution and high consistency for batch classification tasks.

Official Benchmarks
Parallel vs Sequential
10x faster · 12.2x cheaper

13 questions in one call: 0.27s vs 2.71s for 13 separate calls

TypeSafe cookbook
Official Benchmarks
Candidate Reranking Top-10 Accuracy
38% → 62%

CLERC legal dataset, 40 queries, BM25 top-30 shortlist

TypeSafe cookbook
Independent Evaluations
Agreement with Claude Fable 5.1
91.5%

6,003 ratings checked · $160 vs $33,000 per million judgments

Good Start Labs
Independent Evaluations
Writing Defect Detection Speed
25x faster

0.35s median vs 8.83s · detected 6/7 seeded defects

Every.to
Independent Evaluations
Spam Zero-Shot Classification Accuracy
98.64%

5,733-email test set, close to a tuned TF-IDF baseline's 98.87%

bitnovus (independent)

LLM as a judge: common questions.

What does LLM-as-a-judge mean?+

It means using a language model to evaluate text against a question you define, such as "Is this comment abusive?" or "Score this lead from 1 to 5." Teams often use it to grade another model's answers, and the same pattern works for tickets, comments, reviews, and search results. Jev is a structured judgment model that returns exact booleans, choices, and scores instead of conversational text.

How can I use an LLM judge correctly?+

Phrase each question so it has one clear answer: true or false, one of a few choices, or a score on a fixed scale. In Kollab, describe the task and the Agent calls Jev for you, or run `kollab tool run jev` from your terminal. Spot-check a sample of results against your own judgment before relying on them.

How effective is LLM-based judging?+

It depends on the task and how clearly the question is written. The benchmarks above list Jev's official and independent results with their sources, so you can compare them with your own case. Try a small labeled sample first.

What are the limits of an LLM judge?+

Jev's output probabilities are not strictly calibrated, so treat them as relative scores. Accuracy for Chinese, Japanese, and Korean is currently lower than for English. Jev reads plain text up to 80,000 characters, so transcribe audio or extract text from images first; other Kollab models, such as Grok STT, handle audio directly. For high-impact decisions in areas such as finance, law, or hiring, have a person review the results.

What should I look for in an LLM judge framework?+

Look for outputs you can parse, a way to run many questions at once, clear pricing, and a way to inspect confidence. Jev returns structured answers, processes up to 32 independent questions per request, and runs through the Kollab Agent or the CLI.

How is Jev priced?+

Input tokens cost $0.042 per million. Output tokens are completely free.

Start evaluating text with Jev.

Run high-volume classification and scoring tasks directly in your workspace.