Evidence / Benchmarks

Jev benchmarks: what the results actually show.

There is no single Jev benchmark score

Published results vary materially by task, dataset, Jev version, evaluation design, and metric. TypeSafe has vendor evaluations. Independent benchmark evidence also exists. Compare only results that answer the same engineering question.

Current evidence supports a narrower conclusion than “Jev is X% accurate.” Jev can perform strongly on some bounded classification and routing tasks, poorly on others, and differently when label descriptions or code-supplied features change.

Vendor evidence
4 workflow evaluations

Useful for TypeSafe’s intended workflow framing. Not independent reproduction or human-labeled ground truth.

Independent evidence
3 reproducible source sets

Public code and methods; artifact completeness and task quality still vary.

Jev FYI evidence
No first-party benchmark yet

This page synthesizes published work. It does not add a new measurement.

Evidence map

Results checked against original pages, repositories, result files, and benchmark code on September 22, 2026.

EvidenceClassTask and sampleJev versionHeadline result
TypeSafe workflow evals ↗
Sep 15, 2026
A · vendor evaluation4 business workflows; public case count not disclosedNot disclosed67.8% mean reference agreement; 0.4 s and $0.0004 per case
BTZSC pilot v1 ↗
Sep 17, 2026
B · independent, reproducibleZero-shot classification; 300 examples across 3 datasetsjev-1.13.0Accuracy 91%, 87%, and 48%; calibration changed sharply by dataset
Chess + NPC benchmark ↗
Sep 16, 2026
B · independent, reproducibleChess subtests of 25–55 items; 79 labeled NPC utterancesjev-1.13.0Raw-board chess near random; clean NPC addressee F1 0.962
Classifier benchmark ↗
Sep 22, 2026
B · independent, reproducibleSST-2, AG News, Banking77; 500 examples eachtypesafe/jev-1.1395.4%, 84.3%, and 76.4% accuracy; 376–389 ms p50
Benchmark Heaven JevBench ↗
Sep 19–21, 2026
C · community leaderboard534 English typed decisions in 4 tiersjev-1.13.0Tier accuracy 100%, 99.0%, 94.5%, and 74.1%

“Reproducible” means public code and enough method detail to rerun the study. It does not mean every published run exposes every raw prediction. Community leaderboard results remain separate because task authorship, composite scoring, and board revisions add additional judgment.

TypeSafe’s workflow evaluation is a vendor result

Class A

TypeSafe evaluates four code-defined workflows: security incidents, agent-trace observability, invoice processing, and customer service. Each model’s output is compared with consensus probability labels made from GPT-6 Astra and Claude Fable 5.1 at high thinking. The public overview reports an equal-weight mean across the four tasks.

MetricPublished Jev resultInterpretation limit
Reference agreement67.8% meanAgreement with model-generated consensus probabilities, not accuracy against human ground truth
Time0.4 seconds per caseVendor environment; public pages do not disclose case count or Jev model revision
Cost$0.0004 per caseSpecific workflow inputs and TypeSafe’s published pricing basis
Launch ratiosUp to 193.6× faster; 444.6× cheaperTypeSafe calls these the high end of expected real-world gains; not a result for every task or baseline

What it tells you

Jev occupied a favorable cost/time position in TypeSafe’s own decomposed workflow design and reached similar mean reference agreement to some general models in that setup.

What it does not tell you

It does not independently establish ground-truth accuracy, calibration, a universal latency band, or the same speedup on your workload. TypeSafe says team authorship may introduce bias.

Independent results are task-dependent

Class B

BTZSC pilot: 300 zero-shot classifications

AbdelStark compared the same input text and ordered label descriptions with Jev and GLiNER2.5. The protocol was frozen before inference. Each dataset contributes 100 approximately class-balanced held-out examples.

DatasetLabelsJev / GLiNER accuracyJev / GLiNER ECEJev / GLiNER p50
AG News40.910 / 0.7000.064 / 0.124255.9 / 44.9 ms
Banking77 / BTZSC720.870 / 0.6100.054 / 0.062246.4 / 295.5 ms
DAIR Emotion60.480 / 0.4400.351 / 0.117236.3 / 43.3 ms

Jev resolved to jev-1.13.0. Hosted Jev latency from France and local GLiNER CPU latency are not hardware-normalized. On Emotion, Jev assigned zero probability to the true label in 16% of examples; its Brier score was 0.846 versus 0.668 for GLiNER. The repository publishes aggregate JSON and artifact hashes, but not per-example probability files.

Classifier benchmark: 1,500 public-dataset examples

Dhruv Mehra’s harness sampled 500 examples each from SST-2, AG News, and Banking77. It compared Jev through OpenRouter with Laya, two prompted LLMs, zero-shot BART-MNLI, and DistilBERT fine-tuned on up to 10,000 training examples per dataset.

DatasetJev accuracyJev ECEJev p50 / p95Comparison context
SST-295.4%0.026376 / 678 msClaude Sonnet 5: 95.6%; Laya: 92.0%
AG News84.3%0.112381 / 715 msRevised descriptions: 85.8%; fine-tuned DistilBERT: 91.0%
Banking7776.4%0.125389 / 676 msClaude Sonnet 5: 77.4%; fine-tuned DistilBERT: 88.0%

Model: typesafe/jev-1.13. This is a useful zero-shot deployment comparison, not a level training comparison: DistilBERT received supervised task data. The checked revision publishes code, configuration, and a summary, but not the run’s raw per-example result JSON. Latency includes each system’s different serving path.

Chess and NPC speech: task shape changes the answer

Eric Martz tested jev-latest, resolved asjev-1.13.0, on one task outside Jev’s intended shape and one close to bounded real-time routing. Code, labels, reports, and 1,337 raw request/response files are public.

TaskSampleResultWhat it supports
Chess move choice30 middlegame positions per state formRaw ASCII: 409 mean centipawn loss versus 403 random; tactical facts: 90Jev did not infer strong chess play from a raw board; supplied features changed performance materially
Mate in one25 positions per state form24–28% found; random baseline 3.1%Above random on this narrow puzzle set, still missing most forced mates
NPC addressee detection79 utterances; 4 arguable items excluded; 237 NPC decisions per transcript variantClean F1 0.962, exact-set 92% vs 64% heuristic; misheard F1 0.927, exact-set 84% vs 61.3%Strong performance on this author-labeled, closed-world routing task

Benchmark Heaven is a community leaderboard

Class C

JevBench’s current frozen set contains 534 English typed decisions: 72 easy, 96 standard, 146 answer-judging, and 220 hard items. Of the hard items, 109 are held out. The machine-readable artifact reports these Jev 1.13.0 component results:

Easy accuracyStandard accuracyJudge accuracyHard accuracyHard ECE / BrierSerial p50 / p95
100.0%99.0%94.5%74.1%0.0606 / 0.33960.652 / 0.722 s

These values describe one authored suite, not a universal rank. The leaderboard’s composite “JevBench Score” blends custom intelligence, calibration, speed, and cost formulas. Some competing endpoints also receive assumed latency adjustments. This page therefore preserves the measured Jev components and does not present the composite as “Jev accuracy.”

Latency was measured from one server in Germany at one time. The standard+judge run was serial. Public tasks may be known to models; held-out tasks were still sent to evaluated services. The suite is English-only and continues to add systems without changing the frozen task set.

Why two honest benchmark numbers can disagree

The Banking results are a useful example. The BTZSC pilot reports 87% Jev accuracy on 100 approximately class-balanced examples with 72 candidate labels. Dhruv Mehra’s run reports 76.4% on a different seeded sample of 500 examples with all 77 Banking77 labels. Different sample, label space, descriptions, and transport mean these are not replications of one another.

01Match task shape. A Choice classifier, a probability-calibration study, and a multi-step workflow answer different questions.
02Keep sample and labels attached. Accuracy over 4 labels is not comparable with accuracy over 72 or 77 labels.
03Read calibration by dataset. Low ECE on one task does not validate confidence thresholds on another.
04Do not merge latency or cost. Region, provider, concurrency, hardware, request size, and pricing basis differ.

What Jev FYI has not measured yet

Jev FYI has not published its own Jev benchmark, calibration study, latency run, cost comparison, or reproduced failure ledger. Category E—Jev FYI first-party evidence—is empty. Every number on this page is attributed to its original publisher.

No result here establishes a global Jev accuracy rate, universal calibration, provider-independent latency, or expected production savings. A deployment decision still needs a labeled sample from the actual task, the exact Jev version and provider path, and thresholds selected on validation data before one held-out test.

Not affiliated with, endorsed by, or operated by TypeSafe AI. Vendor claims are cited and attributed.