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The full directory

All Jev AI model resources

Entries for TypeSafe AI's flagship System One model — official docs and SDKs alongside community clients, tools, and write-ups.

Entries
3,739
Categories
11
Official
102
Community
3,637
Source sites
292
Deep dives
3,739

By format

3739
  • Docs169
  • Repos & sites2980
  • Videos73
  • Posts103
  • Articles344
  • Playgrounds70

Updated

Browse the Jev AI model by category

11 ways into the ecosystem. Each category page leads with its own shortlist of starting points.

All 3739 Jev AI model resources

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Showing 145–161 of 161 resources

HAL-X AI's 322M non-autoregressive decision model returns calibrated answers in one forward pass of about 10 ms, with native number, excerpt and citation outputs beyond Jev's choice, noul and score types. Apache-2.0, post-trained in 18 languages.
Jev Models & Reimplementations#community#catalog-import#madewithjev
Community
A fork of Laya that answers choice, yes/no and score questions about an image plus optional text in one forward pass. This 201M checkpoint is SmolVLM-256M cut to 20 of 30 language layers and trained for two hours, with no text generation.
Jev Models & Reimplementations#community#catalog-import#madewithjev
Community
vagmi's QLoRA adapter turns Gemma 4 E4B into a System One model: it reads the answer from the logits at the option letters, so it cannot answer outside your options, and returns choice, score and yes/no from one forward pass.
Jev Models & Reimplementations#community#catalog-import#madewithjev
Community
Ian Nuttall's free internal linking tool crawls up to 2,000 pages, maps every internal link, and uses Jev to classify each page and its search intent before recommending link placements with anchors. Runs up to 100 pages are free.
Jev Tools & CLIs#community#catalog-import#madewithjev
Community
A magic eight ball answered by Jev: ask a question and the decision model picks an answer in the shape of the classic toy. Built by sarreph and listed on madewithjev, the community directory of Jev builds.
Jev Demos & ExperimentsPlayground#community#catalog-import#madewithjev
Community
An adaptive onboarding demo by Tamir where Jev picks the next question instead of following if-then branches. The sample flows include project planning, fitness coaching, travel, learning, and ecommerce.
Jev Demos & ExperimentsPlayground#community#catalog-import#madewithjev
Community
Kitsuno's engineering write-up on training an open-weight Laya model to take over parts of its Jev usage: eight days of work, run in shadow beside Jev on every job-side request, without training on Jev's outputs.
Jev Practices & PatternsPost#community#catalog-import#madewithjev
Community
A syntax highlighter where code does the tokenizing and Jev does the judging: paste a file and typesafe-ai/jev names the language, colours every word, and reports which of nine lint rules the file breaks.
Jev Tools & CLIs#community#catalog-import#madewithjev
Community
LangChain's post on putting Jev inside agent loops: it introduces System One models, shows TypeSafeClassifier calls in Python, and demonstrates a model-routing middleware, with tool output kept out of the classifier's input.
Jev Guides & ArticlesPost#community#catalog-import#madewithjev
Community
A marketplace for paid services credited to Georgios Konstantopoulos: give Mercator an outcome-shaped task and it finds the right services, composes the workflow, and pays per call through MPP or x402, with Jev credited in the listing.
Jev Tools & CLIs#community#catalog-import#madewithjev
Community
A free Chrome extension for LinkedIn, built by Tom Frazier, that scores posts with Jev and folds suspected slop into a 44px strip you can unfold in one click. The nine-tell Slopprint shows which writing habits triggered the verdict.
Jev Tools & CLIs#community#catalog-import#madewithjev
Community
The Strands Agents team's 2B open-source decision model: it swaps Qwen3.5-2B's language-model head for a roughly million-parameter pointer head that scores offered options, runs on local CPU or GPU, and placed third of 33 in its JevBench class.
Jev Models & ReimplementationsArticle#community#catalog-import#madewithjev
Community
A free, no-signup tool from SuperX: pick a niche and Jev reads the last three days of X posts, asks five questions per post in one pass, and sorts each one into Read, Skim or Pass with a clarity percentage.
Jev Tools & CLIs#community#catalog-import#madewithjev
Community
A Beam-hosted playground for comparing open-source alternatives to Jev and running any of them as an API. You edit a state and typed questions in the browser, then call the same model through an OpenAI-compatible endpoint with a workspace token.
Jev Demos & ExperimentsPlayground#community#catalog-import#madewithjev
Community
A hands-on write-up of swapping an LLM routing call for System One decisions in a Quarkus LangChain4j app: a custom Planner asks one Choice question to pick the specialist agent, and an OutputGuardrail asks a Noul question to reject bad replies.
Jev Practices & PatternsPost#community#catalog-import#madewithjev
Community
Vals AI's independent benchmarks of Jev: it ties frontier models on 400 claim-verification items drawn from SEC filings at about 1/500th of GPT-6 Astra's cost, but finishes last of twelve on a preregistered 12-subtask LegalBench slice.
Jev Benchmarks & EvaluationsPost#community#catalog-import#madewithjev
Community
A daily word game where you describe a word and Jev guesses it. Rohan Mahtani built it in the spirit of charades and taboo: you circle the word without saying it and the model has to land on it.
Jev Demos & Experiments#community#catalog-import#madewithjev
Community

Start here with the Jev AI model

Hand-picked entries the maintainers recommend first, from official primitives to community tools.

The Jev Day release post: Jev 1.14.0 under jev-preview plus three danger-zone features — composable images on both models, the box question type on 1.14 only, and opt-in 262k context.
Jev Guides & ArticlesArticle#official#release#vision
Official
The box question type: one bounding box per question, returned as four edges that are fractions of the image, plus confidence, with no criteria field and no not-found value.
Jev Practices & PatternsDocs#official#docs#vision
Official
LiteLLM's Day 0 post for TypeSafe Jev 1.14: the proxy adds box questions, image input and long-context mode on both POST /v1/systemone and POST /v1/decisions, forwarding TypeSafe-Danger-Zone headers only to TypeSafe deployments.
Jev Integrations & AdaptersArticle#community#litellm#gateway
Community

From the Jev community

Watch walkthroughs, read the threads, and see what builders are posting.

YouTube: KodeKloud's three-minute primer: what a System One model decides, and why it answers in milliseconds.

YouTube: Caleb Writes Code explains what Jev is and how to call it, in seven minutes.

YouTube: Greg Isenberg and Ryan Vogel on the businesses Jev unlocks, and a path in through the Vercel AI Gateway.

YouTube: CJ from Syntax demos browser use, classification, code review, a model router, and a chat bot with no LLM.

YouTube: Ryan Vogel runs Jev on 100 and then 1,000 emails: category, priority, spam, and reply predictions.

YouTube: AICodeKing tests support routing, refund detection, prompt-injection resistance, and browser automation.

Hacker News: Show HN: Ad Spend Guard gates budget before the auction, not the creative after.

Show HN: Gating ad budget with a decision modelRead the thread on Hacker News

Reddit: Reranking rebooking options with a decision model, ranked with reasons.

Hacker News: Pick Verify: a single decision at the warehouse pick station catches confusable picks.

Show HN: Verifying robot picks with a decision modelRead the thread on Hacker News

Hacker News: Software Bombe and live Enigma demo where Jev ranks cribs and judges plaintext.

ag_212 pointsShow HN: Jev as the Bletchley Park Analyst: A Software Bombe on EnigmaRead the thread on Hacker News

Hacker News: Show HN for the decide CLI: brew install, file context, and multi-question shell scripts.

vsekhar2 pointsShow HN: Decide – Jev decisions in the shell, scripts, and agent skillsRead the thread on Hacker News

How entries are chosen

Every entry is reviewed against the same bar, whether it comes from TypeSafe or the community.

  • Public and working — no paywalls, sign-up walls, or dead links.
  • Concrete — it has to be about Jev and the System One API, not generic LLM content.
  • Useful today — something a developer can learn from or use right now.
  • Distinct — if a similar entry exists, the description has to say what makes this one different: a different runtime, a cheaper path, a measured result, or a narrower focus.
  • Documented — repos state their license, and docs are in English or carry an English summary.

Spam, affiliate links, and thin AI-generated content are rejected. New entries are expected to ship with a deep dive: two to five highlights, caveats, a quickstart snippet where one helps, and a verification date. Star counts are refreshed when an entry is touched.

Common questions

Short answers about Jev and how this directory works.

What is the Jev AI model?

Jev is TypeSafe AI's first System One model — an AI model that takes a state plus typed questions and returns one structured answer per question: a choice, an ordered score, or the probability of yes, with calibrated confidence on Choice and Score answers. Code can branch on the result without parsing generated text.

What is the difference between Choice, Score, and Noul?

They are the three question primitives. Choice picks one of up to 255 options, Score rates on 2 to 10 ordered levels, and Noul answers yes or no. Choice and Score answers carry a confidence between 0 and 1; a Noul answer is the probability of yes.

Which Jev SDKs and client libraries are available?

TypeSafe maintains official JavaScript/TypeScript and Python SDKs plus a Python adapter. The community has built clients for Go, .NET, PHP, Laravel, Rust, Elixir, Ruby, and Scala, along with framework integrations such as DSPy, LlamaIndex, and Home Assistant. All of them are listed in the Repos & SDKs category.

Is the directory free, and is it affiliated with TypeSafe AI?

The directory is free to browse: every entry is reviewed, and spam, affiliate links, and sign-up walls are rejected. JevDirectory.org is community-run and not affiliated with TypeSafe AI — Jev and System One are TypeSafe AI trademarks.

How often is the directory updated?

Entries are added as new resources appear and re-checked when they are touched. The directory currently holds 3739 entries from 292 source sites, last updated Oct 25, 2026.

What is a verified deep dive?

Most entries include a deep dive: two to five highlight bullets someone would only know from using the resource, a caveats note about limits and requirements, an optional quickstart snippet, and the date the link was last checked. 3739 of the 3739 entries carry one today.

For the canonical details, read the official TypeSafe docs and the API reference.