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System One · TypeSafe AI

Jev

Ranks 1 of 7 on noul, 1 of 7 on choice, 1 of 7 on score. Native probabilities, via Vercel AI Gateway.

Jev is TypeSafe AI's hosted decision model, launched on 2026-09-15 and the first System One model: it writes no text. You send a state (any text or JSON) with typed questions and get probabilities back in one parallel pass: noul answers yes or no with P(yes), choice picks one of up to 255 options with a probability for each, and score places the state on an ordered rubric of 2 to 10 levels. It is called at api.typesafe.ai/v1/systemone or through Vercel AI Gateway as typesafe-ai/jev, and costs $0.042 per million input tokens, with output free. The numbers below are Jevals' own measurements against human labels, next to LLMs asked the same questions (how we score). New to Jev? Read what Jev is and how System One models work.

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noul

69.0Decision Score
Rank =1 of 8

Accuracy
91.3%
Calibration gap
5.0
Hand-off at 95%
86%
$ per 1k
$0.029
Speed p95
653 ms
10said 55%, right 58% (48 answers)said 65%, right 73% (109 answers)said 75%, right 82% (170 answers)said 86%, right 91% (371 answers)said 94%, right 98% (802 answers)Said vs right. Squares on the diagonal mean honest confidence; bigger squares hold more answers.
choice

67.8Decision Score
Rank =2 of 8

Accuracy
79.7%
Calibration gap
9.8
Hand-off at 95%
54%
$ per 1k
$0.043
Speed p95
693 ms
10said 29%, right 0% (1 answers)said 35%, right 20% (25 answers)said 44%, right 23% (40 answers)said 54%, right 51% (69 answers)said 64%, right 54% (69 answers)said 74%, right 63% (95 answers)said 85%, right 60% (131 answers)said 98%, right 91% (1070 answers)Said vs right. Squares on the diagonal mean honest confidence; bigger squares hold more answers.
score

9.2Decision Score
Rank =1 of 8

Accuracy
41.3%
Calibration gap
19.7
Hand-off at 95%
—
$ per 1k
$0.036
Speed p95
670 ms
10said 27%, right 47% (34 answers)said 36%, right 31% (118 answers)said 45%, right 31% (261 answers)said 54%, right 31% (339 answers)said 65%, right 41% (324 answers)said 75%, right 53% (222 answers)said 83%, right 61% (157 answers)said 94%, right 76% (45 answers)Said vs right. Squares on the diagonal mean honest confidence; bigger squares hold more answers.

Details

noul
Accuracy91.3%95% range 87.9–94.3%
Calibration gap5.0 ptslower is better · 0.0% of answers at confidence 1.00
10said 55%, right 58% (48 answers)said 65%, right 73% (109 answers)said 75%, right 82% (170 answers)said 86%, right 91% (371 answers)said 94%, right 98% (802 answers)
Automation at 95%86%of decisions, acting at confidence ≥ 0.75 (right 95.0%)shared gate ≥ 0.91: acts on 49%, right 98.6%
Speed438 msmedian · p95 653 ms
Stability0.0%of answers change on an identical rerun
Valid output100.0%0.0% refused · 1,500 of 1,500 answered
Setupai-sdk experimental_evaluate ai@7.0.106 · native probabilities via Vercel AI Gateway · reasoning — · temperature — · 300 items × 5 runs · 2026-09-18 · served as typesafe-ai/jevpubmedqa run log
choice
Accuracy79.7%95% range 75.5–83.8%
Calibration gap9.8 ptslower is better · 41.5% of answers at confidence 1.00
10said 29%, right 0% (1 answers)said 35%, right 20% (25 answers)said 44%, right 23% (40 answers)said 54%, right 51% (69 answers)said 64%, right 54% (69 answers)said 74%, right 63% (95 answers)said 85%, right 60% (131 answers)said 98%, right 91% (1070 answers)
Automation at 95%54%of decisions, acting at confidence ≥ 0.98 (right 95.4%)shared gate ≥ 0.96: acts on 59%, right 94.3%
Speed467 msmedian · p95 693 ms
Stability2.7%of answers change on an identical rerun · 10.3% change when options are reordered
Valid output100.0%0.0% refused · 1,500 of 1,500 answered
Setupai-sdk experimental_evaluate ai@7.0.106 · native probabilities via Vercel AI Gateway · reasoning — · temperature — · 300 items × 5 runs · 2026-09-18 · served as typesafe-ai/jevbanking77 run log
score
Accuracy41.3%95% range 35.9–46.9%
Calibration gap19.7 ptslower is better · 0.3% of answers at confidence 1.00
10said 27%, right 47% (34 answers)said 36%, right 31% (118 answers)said 45%, right 31% (261 answers)said 54%, right 31% (339 answers)said 65%, right 41% (324 answers)said 75%, right 53% (222 answers)said 83%, right 61% (157 answers)said 94%, right 76% (45 answers)
Automation at 95%—never reaches 95% accuracy
Speed478 msmedian · p95 670 ms
Stability2.3%of answers change on an identical rerun
Valid output100.0%0.0% refused · 1,500 of 1,500 answered
Setupai-sdk experimental_evaluate ai@7.0.106 · native probabilities via Vercel AI Gateway · reasoning — · temperature — · 300 items × 5 runs · 2026-09-18 · served as typesafe-ai/jevhelpsteer2 run log
Model id
typesafe-ai/jev
Served as
typesafe-ai/jev
Adapter
ai-sdk experimental_evaluate ai@7.0.106
Host
Vercel AI Gateway
Price as of
2026-09-18
Harness
6d93f79a2310
Release
2026-09-18

See every question Jev answered →