Jev glossary
Core ConceptsSystem 2 task
System Two task
Work that needs extended, multi-step reasoning; the docs treat it as a signal to decompose rather than a job for Jev.
- Category
- Core Concepts
- Also known as
- System 2 task
- Reading time
- 1 min
- Related terms
- 4
- Directory entries
- 2
- Docs
- docs.typesafe.ai
- Added
- 2026-09-24
Definition
The jaggedness page lists System Two tasks (more layers of indirection, extended reasoning) among the things to avoid. Jev is built for fast, focused judgments, and its accuracy falls as a question requires multiple hops.
The remedy is not a longer prompt but a different decomposition: split the reasoning into judgments code can sequence, or hand the genuinely deliberative step to a generative model.
Tagslimitationsdesign
Related terms
Definitions that connect to this one.
Atomic questionA question that asks one specific, well-scoped thing, the kind of judgment a knowledgeable person makes in a few seconds.Core ConceptsIndirectionQuestions about a property of a property, or with double negatives, cost accuracy; write instructions as directly as possible.Evaluation & TrainingJaggednessThe documented set of jev-1.13 failure modes (literal reading, counting, dates, indirection, context rot), each with a guardrail.Evaluation & TrainingAgent loopA control pattern where the model chooses its next step repeatedly; TypeSafe's guidance is to prefer a code-owned workflow instead.Core Concepts
From the Jev directory
Directory entries that go deeper on this term.
A maintained list of jev-1.13's known failure modes, literal reading, unreliable counting, dates as text, indirection, context rot, and contradictory criteria, each with a guardrail.
Jev Practices & PatternsDocs#official#docs#evaluation
Official
Design AI-powered software by keeping code in control and giving System One narrow, structured decisions to make.
Jev Practices & PatternsDocs#official#patterns#architecture
Official
From the Jev AI model community
Posts from builders shipping with Jev right now.