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All Jev resources

This is the full index of everything Jev: 2231 entries for TypeSafe AI's flagship System One model, from official documentation, SDKs, and cookbooks to community-built clients, MCP servers, agent tools, and write-ups. Every entry is tagged by category, format, and topic, and sorted newest first.

Filter by category or tag, or search titles, descriptions, authors, and repos. Open any card for its detail page — most entries carry a verified deep dive with highlights, caveats, and a quickstart snippet.

Entries
2231
Categories
11
Official
93
Community
2138
Source sites
148
Deep dives
2231

Last updated . Entries are added as they appear and re-checked when they are touched.

Browse Jev by category

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

All 2231 Jev resources

Search the full directory, or filter by category and tag.

Showing 25 of 2231 resources

46GitHub stars
Desktop and web live-call coach that sends transcript lines to TypeSafe Jev after each sentence and shows a 0-100 gauge with a suggested next step.
Jev Tools & CLIs#community#jevbest#catalog-import
40GitHub stars
Python decision client exposing Choice, Noul, and Score primitives with isolated order-invariant scoring, a deliberative flywheel that crystallizes hard cases into fast paths, and local or hybrid deployment.
Jev Demos & Experiments#community#jevbest#catalog-import
34GitHub stars
Local server for typed-decision models that answers many Jev questions in one forward pass with checkpoint routing and micro-batching.
Jev Demos & Experiments#community#jevbest#catalog-import
22GitHub stars
Browser extension that scores social hooks keystroke by keystroke with Jev curiosity, emotion, pattern and clickbait checks plus short fix tips.
Jev Demos & Experiments#community#jevbest#catalog-import
14GitHub stars
Browsable directory pairing 50 runnable judge-model evals with exact prompts against more than a thousand community builds, each linked to its project and source post.
Jev Guides & Articles#community#jevbest#catalog-import
13GitHub stars
Free starter that teaches turning one document into one small typed decision, built around a fictional travel agency where recorded observations meet inspectable application rules.
Jev Demos & Experiments#community#jevbest#catalog-import
16GitHub stars
Fifty minimal runnable demos pairing Jev's choice, score, and yes-no primitives against a structured-output language-model baseline, each with synthetic scenarios and a small 2D visual.
Jev Demos & Experiments#community#jevbest#catalog-import
10GitHub stars
Streaming caption page pairing append-only ASR with per-sentence Jev annotation for key points, emotion, and intent, with custom labels and optional DeepSeek discovery.
Jev Tools & CLIs#community#awesomejev#catalog-import
7GitHub stars
Local snake-arena demo where you steer a golden snake against four NanoJev AI snakes, with each AI snake showing its live direction-probability bars from a single forward pass.
Jev Practices & Patterns#community#awesomejev#catalog-import
7GitHub stars
Portable agent skill that guides a coding agent through choosing, designing, and testing Jev uses, including when plain code is the better answer.
Jev Agents & MCP#community#jevbest#catalog-import
7GitHub stars
Chinese-language demo contrasting Jev probabilities with a generative model on the same relationship message. Type a sentence, watch choice, score, and noul distributions move, then compare latency, cost, and output shape.
Jev Agents & MCP#community#awesomejev#catalog-import
25GitHub stars
Community gallery collecting thousands of Jev projects, demos, posts, and write-ups by scenario, with a searchable site, cheatsheet, and Chinese handbook built from the entries.
Jev Guides & Articles#community#awesomejev#catalog-import
3GitHub stars
Life-and-civilization sim where every voluntary action is a validated Jev Choice with ledger receipts, while optional LLM planners may only propose grounded intentions.
Jev Practices & Patterns#community#awesomejev#catalog-import
2GitHub stars
A teleprompter of talking points rather than a script: every open point is a Jev Score question, all scored in parallel against what you have said, and a point checks off once it passes a threshold.
Jev Demos & Experiments#community#awesomejev#catalog-import
4GitHub stars
A single-file host agent skill that reports what another skill's next closed decision would be, with a confidence and a probability over every outcome, by asking Jev to choose rather than by running the target skill at all.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
Python adapter that turns an existing LLM into a bounded decision function: define one question and its answers, get scores, optionally calibrate on your own examples, then abstain below a threshold you set.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
A static HTML dashboard, four commits deep, scoring Jev against two luna variants on Japan's 2026 Common Test. The repo is results only: CSV tables, one JSON file and two HTML pages, with no scripts to regenerate them.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
Single-file browser testbed that sends state plus boolean, choice and score questions to Jev through the Vercel AI Gateway and shows answers, probabilities, latency, token counts and estimated cost for every run.
Jev Demos & Experiments#community#awesomejev#catalog-import
2GitHub stars
A single-file browser client that fills Japanese PDF forms: it sends only OCR label fragments and your item names to Jev, gets a probability back for every field, and acts on the probability by filling, asking, or leaving it blank.
Jev Demos & Experiments#community#awesomejev#catalog-import
A benchmark for browser-using agents hosted on Almond: one prompt, five timed events scored by the page, plus Almond-fastloop, a ~200-line Chrome DevTools loop where Jev picks one bounded action per tick.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
A local Qwen3-Reranker-0.6B judge that returns choice, score and noul answers from yes/no scores rather than generated text, LoRA-tuned on JGLUE NLI and STS and served from a local FastAPI app.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
Static chart pages comparing Jev against 110 other language models on Thai standardized exams: cost and speed plotted against accuracy, plus a page on whether its stated confidence predicts correctness.
Jev Practices & Patterns#community#jevbest#catalog-import
A FastAPI app that turns a text prompt into 16x16 pixel art by asking Jev 256 parallel Choice questions, one per pixel over a 16-colour palette, then refining the grid.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
Tetris where Jev picks every move from the seven legal options, but the game pre-computes landings, holes, roughness and a best plan so the model only ever judges outcomes.
Jev Demos & Experiments#community#jevbest#catalog-import
6GitHub stars
A toy archipelago air-traffic demo where every in-flight judgment - divert or continue, declare an emergency, give way, and who lands first - is made live by Jev from each plane's local state in about 150 ms.
Jev Practices & Patterns#community#html#demo

Start here with Jev

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

Published evaluations of four automation workflows, security incidents, agent trace observability, invoice processing, and customer service, comparing Jev and frontier LLMs as structured workflows versus single prompts.
Jev Practices & PatternsDocs#official#benchmarks#evaluation
Official
6GitHub stars
.NET SDK for the System One API with typed question sets, HttpClientFactory and dependency-injection wiring, plus Microsoft.Extensions.AI guardrail, routing, tool, and evaluator adapters.
Jev Repos & SDKs#community#sdk#csharp
A NativeAOT-ready .NET SDK generated from TypeSafe's OpenAPI definition, with typed question sets, batching, dependency injection, and Microsoft.Extensions.AI integrations.
Jev Repos & SDKs#community#sdk#csharp

Watch: Jev in action

Walkthroughs, tests, and demos from the community.

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.

Discussions about Jev

Threads from Reddit and Hacker News about building with Jev.

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 hand-picked 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 Jev?

Jev is TypeSafe AI's first System One model. It 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, so 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 hand-picked, 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 2231 entries from 148 source sites, last updated Oct 12, 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. 2231 of the 2231 entries carry one today.

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

From the Jev community

Posts from builders shipping with Jev right now.

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