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CommunityPractices & Patterns74 starsVerified 2026-09-22

JevBench

Independent cross-model benchmark for Jev-class decision models, running 534 frozen cases per complete entrant with scoring code and a four-axis score of accuracy, calibration, latency and cost.

Category
Practices & Patterns
Published by
Community
Author
fstandhartinger
Added
2026-09-22
Tagscommunitypythonbenchmarksevaluationcalibration

Highlights

  • Each complete entrant runs 534 frozen cases, including 220 hard decisions written by Claude Opus 5 and GPT-5.6 Sol and hashed before any system ran.
  • The JevBench Score is the geometric mean of chance-corrected Intelligence, Calibration, Speed and Cost, 25% each.
  • Jev 1.13.0 ranks second at 74.4 behind Hopper at 75.4 on the 66-row board, reading 950 input tokens per decision.
  • Cost is dollars per 1,000 decisions, not tokens: Jev's $0.0399 comes from 950 tokens at $0.042 per million.
  • Small models are option-order sensitive: reversing A and B order dropped open-alternative-jev from 72% to 21% on answer judging.

Watch out

MIT for the harness and 72 original public decisions; other artifacts keep their own licences. Not affiliated with TypeSafe AI, some self-hosted latency is adjusted by assumption, and held-out cases were exposed to the services measured.

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From the community

Posts from builders shipping with Jev right now.

Follow @typesafeai

The launch post

Trading bot, one decision per block

Classifying 1,500 real emails

this model is actually insane at email classification i tested it on 1500 of my own emails to see how well it works and I am blown away

Diogo Almeida
Diogo Almeida
TypeSafe AI
@CompleteSkeptic

After co-inventing ChatGPT, I kept asking myself: why have superhuman chat models not led to AGI? I’ve spent the last 2 years in stealth building a new way to train models (RLCD), and a new type of frontier AI model that we are releasing today: Jev • 20-200x faster • 40-400x

Reply

Fast browser use with Stagehand

we built blazing fast computer/browser use with Jev + @Stagehanddev. this task cost $0.001 and executed at near instant speed (in a remote browser btw) the loop: observe the page, send a11y tree as state + actions as questions, Jev decides the next action, then Stagehand Show more

Diogo Almeida
Diogo Almeida
TypeSafe AI
@CompleteSkeptic

After co-inventing ChatGPT, I kept asking myself: why have superhuman chat models not led to AGI? I’ve spent the last 2 years in stealth building a new way to train models (RLCD), and a new type of frontier AI model that we are releasing today: Jev • 20-200x faster • 40-400x

Reply

LLM-as-a-judge, sped up

Jev has spoken. It picked which model is AGI. 20–200x faster. 40–400x cheaper. This could make things like LLM-as-a-judge insanely fast and nearly free. (I tried a bunch of prompts and still didn’t burn through $0.10.)

Image
Diogo Almeida
Diogo Almeida
TypeSafe AI
@CompleteSkeptic

After co-inventing ChatGPT, I kept asking myself: why have superhuman chat models not led to AGI? I’ve spent the last 2 years in stealth building a new way to train models (RLCD), and a new type of frontier AI model that we are releasing today: Jev • 20-200x faster • 40-400x

Reply

Instant compaction with Jev