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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

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Showing 721–768 of 954 resources

1GitHub stars
C# client for Jev, TypeSafe AI's System One model. Typed Noul, Choice and Score questions go out with one state in a single round trip and come back with a value, a probability distribution and a confidence number. Choice questions can be built from an enum, so the compiler finds the switch branch you forgot.
Jev Repos & SDKs#community#awesomejev#catalog-import
5GitHub stars
Go client for the TypeSafe System One API and the Jev model. Send one state with named Noul, Choice and Score questions and read back a typed answer, a probability for every option and a confidence. Ships a token-bucket rate limiter, a JavaScript-SDK-style retry policy and a full set of error sentinels.
Jev Repos & SDKs#community#awesomejev#catalog-import
Communitykataras/jevGo
A Go repository around the TypeSafe System One API that also ships a released CLI and a VS Code extension. SysOneScript scripts run offline, semlint inspects source and proposes checks, Studio is the editor front end, and the typesafe subpackage talks to Jev from your own module.
Jev Repos & SDKs#community#awesomejev#catalog-import
A reproducible 100-case demo that runs TypeSafe's Jev decision model against OpenAI's Terra and Anthropic's Opus on identical synthetic security evidence, then renders the recorded JSON to a static dashboard with no credentials in the browser.
Jev Practices & Patterns#community#awesomejev#catalog-import
A Java and Maven framework that lets natural language route to existing tinystruct @Action methods: Jev picks the action and its arguments as a probability distribution over options you supply, and the dispatcher then runs, holds for confirmation, or refuses.
Jev Repos & SDKs#community#awesomejev#catalog-import
1GitHub stars
A TypeScript library that treats typed semantic judgments as React hooks or plain server programs: pass one judgment's result into the next and the runtime works out the dependency, waits for fresh answers and batches compatible questions.
Jev Demos & Experiments#community#awesomejev#catalog-import
3GitHub stars
A local, open-source System One API compatible with Jev, served by Qwen models over llama.cpp and Metal: Noul, Choice and Score answers with full probability distributions and native image input, with no paid inference API in the loop.
Jev Practices & Patterns#community#awesomejev#catalog-import
1GitHub stars
A zero-build Node server and static page for trying Jev: send a state plus choice, score and noul questions and read back options, scores and calibrated probabilities, with a beta browser agent that drives a real browser through Playwright.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
A Next.js Snake game where every move is a live System One Choice call: run it on Jev, on the wire-compatible Drex, or send the same state to both in parallel and watch the probabilities side by side.
Jev Demos & Experiments#community#awesomejev#catalog-import
2GitHub stars
A computer-use agent for the browser and for native macOS apps that puts a Jev guard in front of the driver: claimed completions are checked against observed state and the trajectory, irreversible actions pass a gate, and Jev can take the mechanical steps itself.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
An independent benchmark asking whether Jev can replace an LLM reranker, run over natural-language search across all 6,245 YC companies, plus the live search app it measures: Jev routes the query, BM25 and embeddings retrieve, Jev reranks.
Jev Practices & Patterns#community#awesomejev#catalog-import
2GitHub stars
A Windows MCP server for Codex and Claude Code that runs bounded UI Automation tasks and durable multi-source research jobs, letting Jev choose only among actions deterministic code created, and returns a compact typed trace instead of a stream of screenshots.
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
1GitHub stars
An async Rust client for models served through the System One API: typed Noul, Choice and Score questions go out with one state and typed answers come back, over a single multiplexed HTTP/2 connection with no vendor built in.
Jev Repos & SDKs#community#awesomejev#catalog-import
1GitHub stars
A Go harness for System One decision models, covering hosted Jev through the Vercel AI Gateway or the native API plus Kev running in-process on llama.cpp, with typed helpers for gating decisions and a CLI for trying a state and questions from a shell.
Jev Agents & MCP#community#awesomejev#catalog-import
1GitHub stars
Benchmark of Jev as a production reranker against Qwen3-Reranker-0.6B on BEIR SciFact and NFCorpus. Ranking quality is a wash, Jev runs about twice as fast with a much tighter tail, and the cross-encoder costs roughly a quarter as much. Every raw API response is committed, so the numbers recompute without an API key.
Jev Practices & Patterns#community#awesomejev#catalog-import
2GitHub stars
An open System One decision model on small fine-tuned backbones, served locally through Apple MLX and speaking Jev's request/answer shape. Two model tiers with identity-bound temperatures, calibration fitted to your own labeled decisions, and a comparison ladder that includes the misses. A research prototype.
Jev Practices & Patterns#community#awesomejev#catalog-import
1GitHub stars
Vendor-neutral Python SDK for System One decision models. One ask(state, questions) call over noul, choice and score, with provider choice expressed as a config class rather than a string. Hosted backends, a Fastino GLiDE preset, and an in-process ONNX path needing no torch at runtime.
Jev Repos & SDKs#community#awesomejev#catalog-import
1GitHub stars
Spanish-language demo running Jev over Spain's official gazette (BOE) daily. One call per disposition scores relevance 0-3, probes 13 policy categories with Noul, and picks the paragraph explaining the change, so the summary is selected rather than written. Astro on GitHub Pages, JSON data, no login.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
Cross-platform assistant that ranks pending messages by urgency with one Jev call per item, shown in a draggable overlay that snaps to the screen edge. Android reads system notifications via NotificationListenerService; Windows screenshots the WeChat window and OCRs it locally. It judges, never replies.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
TypeScript runtime that keeps Jev's probabilities out of the decision path. YAML policies declare preconditions, typed questions and ordered rules; it returns a decision plus an audit trace, records fingerprinted signals as JSONL, and replays offline without calling the provider. Ships shadow evaluation.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
Experiment scoring Jev's decisions on a game with a known right answer: a fair die, exact payouts, one Bet-or-Skip call per offer, judged by expected value rather than by whether the roll wins. Across 12,000 decisions it accepts profitable bets but rarely refuses bad ones.
Jev Practices & Patterns#community#awesomejev#catalog-import
3GitHub stars
Bilingual static catalogue of work touching TypeSafe's Jev decision model, split into papers, projects and online materials. Every record carries its relationship to Jev, an evidence level and a verification date in plain JSON, readable without a database or an account.
Jev Practices & Patterns#community#awesomejev#catalog-import
1GitHub stars
Free Chrome extension that scores tweets already loaded on your X page against criteria you write yourself, showing the probability as a badge. The substance is the prompts library of goals, judgment subjects and counter-examples; the extension is a no-build sideload with no store listing.
Jev Demos & Experiments#community#awesomejev#catalog-import
2GitHub stars
OpenCode extension putting a Jev-backed judgment layer between a coding agent and its tools. Four controllers, AEGIS, METIS, NIKE and EPISTEMICS, emit GO, DELIBERATE, VERIFY or BLOCK, and a tool router predicts the smallest useful capability set. Observe mode is the default.
Jev Agents & MCP#community#awesomejev#catalog-import
1GitHub stars
Yes/no decision site that asks Jev and a fair in-browser coin and shows whether they agree. One relay call returns a verdict, the probability behind it and how significant a decision Jev thinks it is, behind crisis and not-yes-or-no gates. Plain HTML, no build step, no sign-up.
Jev Practices & Patterns#community#awesomejev#catalog-import
3GitHub stars
Research notes on Jev plus a Cloudflare Worker demo you can paste a support ticket into. Useful for the failure modes rather than the pitch: no arithmetic, unreliable date comparison, scores that are not measurements, and speed and cost figures from TypeSafe's own evaluations.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
pydecide is one Python client for typed System One decisions — Choice, Score and Noul — over hosted Jev, OpenRouter's Decisions endpoint, local laya on PyTorch or MLX, a sentence-transformers CrossEncoder, or a JSON-prompted LLM fallback.
Jev Practices & Patterns#community#awesomejev#catalog-import
3GitHub stars
A Go gateway that speaks the OpenAI and Anthropic APIs and handles model: "auto" by asking a decision model four typed questions about the prompt — topic, complexity, risk and private data — then scoring models in config.yaml and calling the cheapest one above the quality floor.
Jev Practices & Patterns#community#awesomejev#catalog-import
3GitHub stars
MEDJEV is an independent, JEV-inspired research implementation for typed evidence decisions: a clinical record or literature passage, a runtime question and a candidate set supplied at call time, scored into an explicit probability distribution plus calibration scope. Alpha research code, not clinical software.
Jev Practices & Patterns#community#awesomejev#catalog-import
1GitHub stars
PlotVeil is a Chrome extension that hides YouTube comments until a single typed Noul decision says the comment gives away the video you are on. The rule text travels from the extension to a Cloudflare Worker, which batches up to 20 comments per call and never sees the word spoiler.
Jev Demos & Experiments#community#awesomejev#catalog-import
1GitHub stars
jev-filter is a CLI that filters tool output before it reaches your agent and, since 0.3, drives web pages and desktop apps too. Jev picks the next operation and its target among controls the program enumerates itself; the program re-checks and executes, and irreversible steps stop for confirmation.
Jev Practices & Patterns#community#awesomejev#catalog-import
1GitHub stars
jevx is a Zig terminal agent that keeps Codex for code generation and confines Jev, reached through OpenRouter, to bounded choice, noul and score decisions for routing, hazard checks, impact and verification. The Zig side, not the model, holds the permissions and the final control flow.
Jev Practices & Patterns#community#awesomejev#catalog-import
2GitHub stars
jevXagent is a localhost proxy that sits in front of Claude Code, Codex, Kilo Code and Cline. It asks Jev to classify the prompt first, then injects that verdict into the agent's system context so the main model skips re-deriving the same classification.
Jev Agents & MCP#community#awesomejev#catalog-import
1GitHub stars
XianHui for Windows screenshots the WeChat window, reads the other side's messages with local RapidOCR, and asks Jev which one has to be answered now, then shows up to five threads as a colour-coded overlay that jumps you to the right chat app. It ranks, it never replies.
Jev Demos & Experiments#community#awesomejev#catalog-import
0GitHub stars
Last Exit is a short cyberpunk checkpoint game where you type a cover story, present a manifest and offer a bribe to an inspector who decides whether to let you through. Each reply makes two Jev calls: one turns your statements into typed observations, the other picks his next action.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
Jevegis wraps Jev into a single guardrail call for LLM apps: one request covering prompt injection, jailbreaks, credential and PII leaks, unauthorized actions, malicious code and indirect injection in retrieved documents, plus Trust & Safety moderation. It returns probabilities rather than booleans.
Jev Tools & CLIs#community#jevbest#catalog-import
1GitHub stars
Jev RPS is rock-paper-scissors against TypeSafe's Jev with a commit-then-reveal protocol: the server seals Jev's move with a salted SHA-256 commitment and AES-256-GCM encryption before your buttons unlock, and the browser recomputes the hash after the reveal.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
Tiltmeter records the probabilities Jev returns for every question your app asks and alerts when one moves: a version change behind jev-latest, drift away from baseline, too many answers sitting next to your threshold, or an estimated accuracy drop computed without labels.
Jev Integrations & Adapters#community#jevbest#catalog-import
1GitHub stars
Pong where the ball advances one segment per model decision, run as four lanes so you can watch a typed-decision model keep up with a court that structured-output chat models cannot.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
A Python decision layer for browser and desktop automation: your code observes the surface, builds the candidate list and verifies the result, and the model only picks one id per step.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
A Pi extension that catches the turn-ending "Continuing the run" reply and sends the agent back to it, gated on the latest user request actually containing a command to do work.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
A short field note on playing Jev at chess: both sides keep proposing draws in positions that are far from balanced, then go on to win, with the loss probability much lower.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
An OpenAI-compatible proxy that spends one Jev call per request on injection, harm and PII checks plus a tier label, then routes to a small or large backend from pure code.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
An experimental bench for writing a game ruleset and immediately watching it played: Jev is both the tool that explores the rules and the first player, one typed boolean per legal cell.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A Jev-protocol model gateway: a Rust and axum daemon turns an editable routing DAG into the actual call path, with a React console, a Tauri desktop shell and a Docker image.
Jev Integrations & Adapters#community#jevbest#catalog-import
0GitHub stars
A pygame-ce river shooter whose AI pilot splits the river into 20 lanes and asks Jev one parallel System One request per decision for lane, fire and speed.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
An npm package that supervises a running agent: one Jev systemOne call per check returns six semantic signals about recent steps, and a deterministic policy in your own code turns them into CONTINUE, WARN, REPLAN or HALT.
Jev Agents & MCP#community#jevbest#catalog-import

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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