the short answer
Jev can score or select retrieved passages for a query and check whether a specific claim is supported by cited evidence. Retrieve candidates first, keep source identity intact and ask one bounded question per candidate or claim. Benchmark against the current lexical/vector pipeline because an extra semantic stage does not guarantee better retrieval, and retain citations for human inspection.
- Semantic decision
- Judge candidate relevance or whether a cited passage supports one extracted claim.
- Likely primitive
- Choice or Score for candidate relevance; Noul or Choice for bounded support status.
- Relevant state
- the query or claim, candidate passage, source metadata and only essential surrounding context.
- Keep deterministic
- Code retrieves candidates, preserves citations, deduplicates, applies access control and constructs the final answer.
The Useful Jev Decision
Judge candidate relevance or whether a cited passage supports one extracted claim. Jev should receive only the state needed for that judgment: the query or claim, candidate passage, source metadata and only essential surrounding context. The application defines the possible answers before inference and consumes the typed result; Jev does not own the surrounding workflow.
A verification stage can check each answer claim against its cited passage without asking Jev to write a replacement answer. This is a design pattern, not evidence that every implementation will perform well. Test the exact state, question, model version and action against representative outcomes.
Architecture: Evidence in, Judgment Out, Action in Code
The source record and projected state are not interchangeable. If decisive evidence never enters state, the model cannot recover it; if irrelevant or adversarial text is copied wholesale, it can move the result. Give the projection its own version and test it with the question. The state-design guide shows how to separate trusted fields, untrusted content and derived values.
What Remains in Code
Code retrieves candidates, preserves citations, deduplicates, applies access control and constructs the final answer. Exact checks should run before the model when they can narrow or reject candidates. After Jev returns, code applies thresholds, permissions, fallbacks and the final action. Store the raw distribution rather than only the selected label so later evaluation can distinguish a close decision from a concentrated one.
Version the Complete Decision Instrument
A final label alone is not enough to investigate a regression. The same label can come from a clear distribution or a near-tie, and it may have been produced by a different candidate set or projection. Keep the record append-only so a later threshold change can be replayed without rewriting history. The evaluator scorecard defines validity, robustness, calibration and utility checks for this complete instrument.
| Component | What to record |
|---|---|
| Evidence unit | The source record and projection used for: the query or claim, candidate passage, source metadata and only essential surrounding context. |
| Question contract | Judge candidate relevance or whether a cited passage supports one extracted claim. |
| Primitive and criteria | Choice or Score for candidate relevance; Noul or Choice for bounded support status. |
| Inference identity | Requested model, resolved model, provider, timestamp and request ID |
| Raw result | Selected answer, complete distribution, confidence where defined, latency and failure state |
| Application outcome | Threshold branch, review or fallback, final action and later ground truth |
How to Evaluate This Use Case
- Collect representative examples and define the observable outcome before tuning the question.
- Split broad quality into independently useful Choice, Score or Noul judgments.
- Pin the Jev model, question, criteria and state projection.
- Measure class-level errors, calibration, coverage, latency and cost against the simplest baseline.
- Add review or fallback behavior, then monitor drift and real downstream outcomes.
Run a Decision-Level Baseline Experiment
Compare the Jev design with the simplest credible existing method: deterministic rules, a keyword or embedding classifier, the current LLM prompt, or human-only handling. Hold the evidence unit and outcome definition constant, but allow each method to use its native interface. Include invalid responses, timeouts, retries and review work in the result instead of scoring only successful model calls.
The primary metric should reflect the cost of getting “Judge candidate relevance or whether a cited passage supports one extracted claim.” wrong. Report class or rubric errors by important slice, calibration where the output supports it, automation coverage at the proposed threshold, p50/p95 latency and total workflow cost. Use grouped or time-based splits when related records could leak across train and test. The benchmark methodology gives a reproducible protocol.
Main Failure Mode
Long irrelevant passages hurt accuracy, and community evidence includes a reranking workload where Jev did not beat vector retrieval. Jev 1.13 can also read instructions literally, lose accuracy in irrelevant long state and be steered by adversarial content. Keep state narrow, define boundary cases and never treat model confidence as authorization.
FAQ
Is Jev a good fit for a RAG pipeline?
Jev can score or select retrieved passages for a query and check whether a specific claim is supported by cited evidence. Retrieve candidates first, keep source identity intact and ask one bounded question per candidate or claim. Benchmark against the current lexical/vector pipeline because an extra semantic stage does not guarantee better retrieval, and retain citations for human inspection.
Which Jev primitive should I start with?
Choice or Score for candidate relevance; Noul or Choice for bounded support status. Start from what the answer means: Choice for one option, Score for ordered levels and Noul for one independent yes/no condition.
What should not be sent to Jev?
Do not send fields irrelevant to the decision. Code retrieves candidates, preserves citations, deduplicates, applies access control and constructs the final answer. Keep secrets and regulated data within the deployment's approved data-handling design.
How do I know whether the integration works?
Compare it with a deterministic or existing baseline on held-out outcomes. Report errors and coverage at the operating threshold, not only average accuracy or a demo result.
Sources
Checked against the sources below on September 22, 2026. Model versions, prices and limits change.
- TypeSafe AI docs: Example use cases
- TypeSafe AI docs: How to build with System One
- TypeSafe AI docs: Primitives
- TypeSafe AI docs: Confidence
- TypeSafe AI docs: Jev 1.13 jaggedness
- Community index: awesome-jev