Open
Independent reproductions and public eval surfaces — clearly labeled.
What is Jev? (open field guide)
Independent mental model: schema-first System One, dual Py/TS, jaggedness, myth FAQ — not a rival what-is clone.
Why use Jev?
Use Jev when code must branch on messy language. FAQ atoms for GEO — not nine thin rival FAQ clones.
When to use Jev
Use Jev for snap language judgments; compose with LLMs (decide then draft). When not to use System One.
How Jev decides
State in, parallel typed questions, code out. Dual Py/TS. Independent mental model — not a docs mirror.
Jev learning path (curious → Pro)
Independent sequence from mental model to operate loops. Not a course landing page. Confirm on docs.typesafe.ai.
About jev.pro
Who runs this independent Jev field guide — not TypeSafe, not a key shop. Editorial rules and what Pro means.
TypeSafe AI
Company context for Jev builders: what TypeSafe is, public seed facts, official team. Not a brand-bait microsite.
Jev founders
TypeSafe founders behind Jev: Almeida, Gafni, Sheng — public bios, why RLCD/System One, link to the official team.
Jev review
Independent Jev review: methodology, vendor claims vs public tests, jagged edges, when to try. No invented scores.
Jev testimonials
Public developer quotes about Jev from press — named, sourced, not endorsement theater. No invented reviews.
Jev reviews roundup
Index of third-party Jev reviews and hands-on notes with outbound links. No cloned write-ups, no invented scores.
Jev quick reference
One-screen primitives, pins, and floors. Unofficial cheat sheet — not a docs dump. Confirm on docs.typesafe.ai.
Jev playbook
Production playbook: design → implement → launch checklists, plus operate loops. Beats a narrative-only “build with System One” guide.
Jev best practices
Operate-pillar practices: pin, contract, harness, fail-closed. Methodology over review blogs. Confirm on docs.typesafe.ai.
Jev common mistakes
Production mistakes: aliases, 0.5 Nouls, warehouse dumps. Unofficial — not a FAQ clone. Confirm on docs.typesafe.ai.
Jev anti-patterns
Named architectures that fight System One. Unofficial — distinct from the mistakes list. Confirm on docs.typesafe.ai.
Jev documentation map
Map official docs → our pillars. Outbound to docs.typesafe.ai; no mirrored IA.
Jev API reading guide
How to read TypeSafe’s API ref: one evaluation POST, aliases, errors. We do not republish OpenAPI.
Jev glossary guide
How to use our glossary cluster — term-first pages, not a cloned 26-term SOM hub.
Jev design checklist
Design gates before you write clients: action space, atomic questions, state filter, unofficial stance. Not a TypeSafe build guide clone.
Jev implementation checklist
Wire the client: pin jev-1.13.0, door-specific model ids, retries, traces, eval harness. Unofficial production gates.
Jev launch checklist
Ship gates: pinned model, fitted floors, handoff SLA, labeled vendor claims, docs.typesafe.ai outbound. Unofficial.
Jev cost planning
Worked token math per channel, dated 2026-09-21. Vendor prices only — no invented volumes.
Jev latency planning
Plan p95 with timeouts and 429/529. Vendor speed claims are not your SLO.
Jev evaluation guide
Score policy actions on a dated harness. Vendor 193× stays vendor. Methodology > review-blog voice.
Jev testing guide
Reproducible tests: pin jev-1.13.0, freeze questions, date your notes. Methodology over opinion blogs.
Jev monitoring guide
Monitor aliases, 429s, and floors. Outbound status — not a cloned “is Jev down” page.
Jev observability guide
Log model, usage, probabilities, and actions. Jev is not your APM.
Jev operating model
Who owns questions, floors, and traces. Unofficial RACI — not a Gartner OM. Confirm on docs.typesafe.ai.
Jev success metrics
Measure policy actions, not a fake leaderboard. Unofficial metrics — vendor 193× stays vendor.
Jev reference architecture
A practitioner reference: doors, questions module, traces, HITL — known boxes only.
Jev architecture patterns
Known patterns (gate, fan-out, compose) vs unknown internals. Cite TypeSafe only — no speculation as fact.
Jev workflow examples
Worked shapes: triage, gate, compose. Not a rival recipe-hub clone — pointers into our usecases.
Jev decision templates
Copy-ready question shapes: Choice, Score, Noul. Fill criteria; keep math in code.
Jev policy templates
Map Noul/Score bands onto act/review/block. Policy stays in code, not in a mega-prompt.
Jev evidence templates
Workpaper fields for a Jev decision: questions SHA, model, probabilities, human.
Jev review templates
Reviewer UI copy: show questions, not fake rationales. Capture override reason codes. Unofficial HITL notes.
Questions for Jev builders
Engineering interrogation: primitives, doors, retries, traces. Production craft, not a tutorial clone.
Questions for Jev buyers
Procurement list: doors, pin, ZDR, limits, no key resale. Independent — not TypeSafe sales.
Jev for startups
Ship one pinned decision loop, not an AI platform. Hybrid gates beat a mega-prompt.
Jev for product teams
Product owns action space and UX of abstain. Jev is not a feature flag and not a chatbot.
Jev for platform teams
Production habits for a shared Jev decision layer: skill install, constants file, LangChain hooks. Jev routes; agents act.
Public TypeSafe evals
TypeSafe points at a workflow-evals site for examples and full queries. Use that — not invented leaderboards.
OpenJev (now SemIf) is not Jev
OpenJev / SemIf is an independent open-source project that reproduces a Jev-like interface on open models. Not TypeSafe, not this site.
Jev adoption roadmap (unofficial)
Your adoption stages — not TypeSafe’s product roadmap. Unofficial. Confirm on docs.typesafe.ai.
Jev feedback guide
Human overrides become gold — not a TypeSafe fine-tune. Close the loop in your harness.
Jev for data teams
Jev outputs are features and labels — not a warehouse. Pin, isolate hops, measure calibration yourselves.
Jev for enterprises
Procurement, pinning, traces, ZDR questions — short TypeSafe context, no brand-bait microsite.
Jev for operations
Ops owns queues, SLAs, and fail-closed defaults. Jev only labels; it does not page or refund.
Jev governance guide
Who may change questions and floors. Treat criteria like code. Jev is not the control owner.
Jev migration guide
Migrate prompts or classifiers to questions + code. Dual-run, pin, don’t big-bang irreversible auto-act.
Jev privacy guide
Minimize state, read TypeSafe Legal, myth FAQ on training. We are not your DPA.
Jev security guide
Keys, injection, least state, fail closed. Jev is not a WAF or EDR.
Jev team roles
Who edits criteria vs who owns floors. Unofficial roles — not TypeSafe job posts. Confirm on docs.typesafe.ai.
Jev versioning guide
Pin jev-1.13.0 in prod; aliases move. Not a cloned changelog microsite.
Questions for analysts
Measurement questions: actions not argmax, calibration, no invented vendor multiples. Unofficial analyst brief.
Questions for legal
Counsel list: unofficial site, DPA, high-risk uses, schema ≠ truth. Not legal advice.
Questions for security reviewers
Threat questions: keys, injection, data egress, fail closed. Jev is not your SIEM.