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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 913–954 of 954 resources

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
A Python CLI that sorts GitHub stars into your existing GitHub Lists using README excerpts and repo metadata, writes a JSON classification report, and applies it only when you ask.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
A provider-agnostic TypeScript judgment layer for coding agents, with gates from PRD intake through release, a pluggable judge backend and a decision log you can replay.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
An alpha Python library that uses Jev to grade model responses for hallucination, correctness and instruction following, returning Noul probabilities and five-level severity Scores.
Jev Integrations & Adapters#community#jevbest#catalog-import
1GitHub stars
A Pokemon Red agent that boots a ROM, picks each move with Jev, and streams video plus a live decision panel from a small read-only local HTTP server.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
An experimental specification and offline evaluation kit for delegated coding work: evidence schemas, a gate protocol for PASS and BLOCKED reports, and a Jev integration contract.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
Manifest V3 Chrome extension that asks nine parallel Jev questions about the page you are on to separate advertising from first-hand account, across genre, stance, publisher, product and four Noul checks.
Jev Demos & Experiments#community#awesomejev#catalog-import
0GitHub stars
Decision Graph Protocol from Numerous ApS: the app publishes an immutable frame of evidence and offered decisions, an eligible assessor returns a typed assessment, and the app's own guards authorize the commit.
Jev Agents & MCP#community#awesomejev#catalog-import
0GitHub stars
Dependency-free Python 3 CLI that hands a JSON state plus 1 to 16 named Noul, Choice or Score questions to Jev and prints typed answers, usage and elapsed time without echoing the state back.
Jev Agents & MCP#community#awesomejev#catalog-import
0GitHub stars
Claude Code plugin with nine Jev-judged gates over edits, prompts, shell commands, stops and commits. Each one escalates to a permission prompt, and none of them can approve an action.
Jev Agents & MCP#community#awesomejev#catalog-import
1GitHub stars
MCP server that layers a reach tool onto chrome-devtools-mcp: Jev picks each click and typed value so your agent states a goal once, then makes one devtools call at the destination.
Jev Demos & Experiments#community#awesomejev#catalog-import
22GitHub stars
Local decision models that return Jev-shaped typed distributions instead of generated text: freeze a backbone, cache candidate features once, train a roughly 0.8M-parameter decision head, calibrate per primitive.
Jev Practices & Patterns#community#awesomejev#catalog-import
0GitHub stars
ACP stdio agent that evaluates explicit Choice, Score and Noul questions as typed Jev answers inside any Agent Client Protocol client or IDE, driven by a task picker rather than free-form chat.
Jev Integrations & Adapters#community#awesomejev#catalog-import
1GitHub stars
Unreleased Rails engine that turns Ruby-defined commands into voice and typed shortcuts, using Jev to interpret free-form phrasing while your own authorize callbacks keep the permission decision.
Jev Integrations & Adapters#community#awesomejev#catalog-import
0GitHub stars
Alpha OpenTelemetry Collector processor that scores operation metadata with three Jev noul questions, caches the result, and writes it onto later matching spans as jevtraces.operation annotations.
Jev Integrations & Adapters#community#awesomejev#catalog-import
19GitHub stars
Apache-2.0 router that runs inside Claude Code or Codex: Jev classifies the task, a local policy picks the model and reasoning effort, and the pair stays pinned for the whole conversation.
Jev Agents & MCP#community#awesomejev#catalog-import
9GitHub stars
Unofficial Kotlin Multiplatform client for Jev across JVM, Android and iOS. You declare the decision as an enum implementing Criterion and read back typed answers, distributions and confidence.
Jev Repos & SDKs#community#awesomejev#catalog-import
10GitHub stars
GPL-3.0 desktop app for Linux, macOS and Windows that gives every coding-agent task its own git worktree and its own terminal, with live diffs and optional Jev review of changed files.
Jev Agents & MCP#community#awesomejev#catalog-import
0GitHub stars
A React and Three.js coffee-delivery arena shooter whose enemies score their own tactics locally, with a decision record explaining why Jev was retired from that job.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
Jev run against a community reconstruction of Indonesia's SNBT 2025 entrance exam: 159 remembered questions across seven subtests, 156 scored, with every request payload and response kept.
Jev Practices & Patterns#community#awesomejev#catalog-import
TypeSafe's official docs: the System One introduction, the three question primitives, confidence, composable patterns, cookbooks, and the HTTP API and SDK references.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A Hugging Face Space by drinkmoonshine for parallel constrained decoding. The captured page gives the name and owner only, with no Jev or System One detail anywhere.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A computer-use loop built on Jev: OCR the screen, attach bounding rects to text areas, then ask Jev which item moves the goal forward and click that item.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
Steve Krouse posted a playable hosted Jev demo and linked to it. The thread describes the demo not at all; a reply raises a $2 budget and a complaint about speed.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A developer rebuilt the same app on Cerebras with Qwen 3.8 27B and reports TypeSafe was cheaper and beat it on performance at similar quality. The benchmark itself is not shown.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A browser extension that hides or collapses individual posts on X from natural-language rules, using Jev to judge each post. The announcement names no install, code or rule syntax.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
An agentgateway example that scores prompts and responses for jailbreaks, harmful content and secret disclosure with Jev, rejecting anything scoring 2 or above with HTTP 403.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A browser tool where you paste a Telegram channel JSON export and each post gets four Jev labels: category, quality, sentiment and reaction tone, written out as result.json.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
DMX is a $19 macOS X client that embeds the real x.com interface for DMs and notifications while capping timeline browsing at five minutes an hour. No Jev integration is documented.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A CLI where you give it a task plus the AI subscriptions you already have, and Jev picks which agent or model should handle it, paired with Herdr to route from one terminal.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A small support ticket classifier where Jev decides category, urgency and whether a ticket needs a human, replacing a GPT-based version of the same flow.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A Japanese-language post where a game developer wired ConsoleChaosRacing to a typesafe system_one through a Python API and a display UI, letting the model supply driving decisions on a fixed course.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
kitze's skillbox serves a whole skills library over one MCP server, and adding Jev turns it into a router: the model reads the query and returns the relevant skills instead of the agent spending turns searching for them.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
An announced-in-progress PR review bot: Jev evaluates a pull request against rules you write in plain English, aimed at the review conditions that are awkward to express in TypeScript or linter configuration.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A merged TrainLCD pull request that adds a typesafe noul to re-select which stations the AI chat suggests, wired into the request path but inert by default until a KV threshold arrives.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A short demo post: StarCraft Brood War running in WASM is exposed as an MCP server, Jev is given the game as a tool, and the recorded run still loses to a Zerg rush.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A write-up of running a typesafe classifier against a Spanish legal corpus, replacing a hand-built regex with a probability, plus a thread arguing its best fit is as a pre-filter in front of an expensive model.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A developer mapping free-text player intent to typed server actions for a text MMORPG with tabletop-RPG freedom, reporting 96% run-to-run agreement at 317 ms median against a 6.52-second previous setup.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A 34-second video post from a design engineer who spent an evening reading up on Jev and condensed it into the clip, with the substantive examples appearing in the replies rather than the post.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
A page-by-page demo in which each wiki page yields a set of link candidates and Jev picks which one to click toward a stated goal, its author calling it simple and the speed the notable part.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
An open-source reproduction called Verdict: a post-trained 151M ModernBERT-base encoder with a GLiClass head, runnable in a browser tab, reporting its own calibration, order-invariance and failure numbers.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community
Milvus bootcamp notebooks pairing vector retrieval with typesafe judgments across nine search scenarios: reranking, context filtering, stopping criteria, routing, cache reuse, guardrails, curation and evaluation.
Jev Guides & ArticlesArticle#community#awesomejev#catalog-import
Community

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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