Skip to content
JJev AtlasField notes
The atlasStart hereClaimsProjectsPatternsIdeasMapEvidenceLibraryFor agents
Search⌘K

J Jev Atlas / Independent research

165 posts · 9 claims · 31 hypotheses

Back to top ↑
All ideas

Build blueprint

Decision Regression Harness

A test runner recording typed decisions and calibration metrics over versioned scenario suites.

Authored HypothesisVerification and guardrailsHIGH confidenceIndie fit 10/10
Problem
Teams cannot safely change prompts, thresholds, or Jev model versions without seeing behavior drift.
Why Jev
Typed outputs and probabilities make decisions unusually amenable to regression testing.
Architecture
Fixture states → batch Jev evaluation → schema/calibration/diff checks → CI report.
Current alternative
Ad hoc prompt snapshots and manual playground testing.
Jev advantage
Tests the machine-facing contract rather than brittle generated wording.
Unknowns
API support for deterministic comparison and expected probability variance.
1–7 day MVP
CLI with YAML fixtures, golden distributions, tolerance rules, and GitHub annotations.
Validation experiment
Use it on three sample decision apps and intentionally introduce prompt regressions.

Why this confidence: Typed decisions create a clear developer-tool opportunity independent of broad model adoption.

This is an authored hypothesis derived from the research corpus. Nothing here demonstrates product demand, or that Jev performs well on this particular workload. Run the validation experiment before building past the MVP.

Sources

  • officialhttps://docs.typesafe.ai/primitives
  • officialhttps://typesafe.ai/blog/introducing-system-one-models-and-jev
  • socialhttps://x.com/i/web/status/2099928060644749682

Limitations

  • API support for deterministic comparison and expected probability variance.
  • This is a research hypothesis, not evidence of product demand or Jev performance in this workflow.

Supporting research

  • Probabilistic predicate + deterministic action PlausibleJev supplies fuzzy predicates while TypeScript, policies, and workflows execute constrained actions.
  • Axon Work integration ObservedThe author states that Axon Work uses Jev-style model decisions with a skill/action harness.
  • Routing, classification, verification, and workflow control are the dominant early mental models. PlausibleThose categories recur in the collected launch discussion and align with the documented output primitives.
  • Confidence gate PlausibleAutomation proceeds above a threshold; ambiguous cases go to another check or a person.
Record
opportunity:decision-regression-harness
Canonical
/ideas/decision-regression-harness
Last verified
2026-09-18