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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 145–192 of 736 resources

7GitHub stars
Chrome extension that scores YouTube cards with Jev from title, channel, duration, and search intent, then covers likely time-wasters with a dimmed shield. Every cover has a click to reveal that lasts for the tab.
Jev Demos & Experiments#community#awesomejev#catalog-import
8GitHub stars
Line-oriented semantic search that adds a Jev meaning pass over your own shortlisted files next to exact search. Real search is the default with a key, while dry-run previews the payload offline with no network or credentials.
Jev Practices & Patterns#community#awesomejev#catalog-import
13GitHub stars
Curated list of Jev and System One ecosystem projects across agents, browser use, SDKs, tools, research, and demos, with news tracked separately. Independent typed-decision alternatives are listed apart, not as official or compatible.
Jev Guides & Articles#community#awesomejev#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
8GitHub stars
Compiler that turns ignored markdown rules into testable Jev gates: typed questions answered with probabilities plus a reducer computing allow, ask, or deny in code. Ships with offline replay fixtures and Claude Code hook wiring.
Jev Integrations & Adapters#community#awesomejev#catalog-import
6GitHub stars
Local Windows gateway that fronts agent loops with stop, extract, and scan endpoints plus a System One-shaped typed decision path. Runs a small coder model over llama.cpp at localhost with telemetry and self-tests.
Jev Agents & MCP#community#awesomejev#catalog-import
WeChat reply helper that reads the visible chat with local OCR, drafts three DeepSeek candidates, and optionally adds TypeSafe pre-judgment plus review sorting. Fill-in never auto-sends unless Windows countdown is explicitly enabled.
Jev Tools & CLIs#community#awesomejev#catalog-import
11GitHub stars
Decision layer for coding agents that triages test failures deterministically before spending frontier tokens. Offline heuristics handle missing packages, flaky transients, and loop breaking, with optional Jev micro-decisions and CLI, MCP, hook, and SDK use.
Jev Demos & Experiments#community#awesomejev#catalog-import
11GitHub stars
Community runner that adds a strict jevAct step to Midscene Test plus a direct runJev helper for Playwright scripts, with caller-owned browser control and optional completion checks.
Jev Demos & Experiments#community#awesomejev#catalog-import
9GitHub stars
Curated list of open-source projects that use Jev for typed decisions, grouped into coding agents, browser automation, search, integrations, alternatives, and applied cases.
Jev Guides & Articles#community#awesomejev#catalog-import
16GitHub stars
Free hands-on course of 12 notebooks that pairs Jev decisions with LLM writing across 13 small tools, needing one OpenRouter key and printing cost and self-checks per lesson.
Jev Practices & Patterns#community#awesomejev#catalog-import
7GitHub stars
Research code that tackles dimensional sentiment scoring with Jev typed Score, Choice, and Noul calls plus small corpus statistics, without generation, fine-tuning, or GPU.
Jev Tools & CLIs#community#awesomejev#catalog-import
5GitHub stars
Community Agent Zero plugin that exposes one typesafe_query tool for combined Choice, Noul, and Score questions over the same evidence, with probability cards in chat.
Jev Integrations & Adapters#community#jevbest#catalog-import
22GitHub stars
Independent open-source local decision model inspired by Jev, with a spark-s1 family plus smaller control models for agent gates, served locally with probabilities and policy actions.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
MCP server exposing one evaluate tool for Jev Choice, Noul, and Score questions, plus a separate eval harness that compares Jev against LLMs on shared labeled sets.
Jev Agents & MCP#community#jevbest#catalog-import
42GitHub stars
Server-authoritative browser FPS where one queued player fights a Jev-driven opponent to five kills, with spectators, killcam replay, and heuristic fallback when the API is down.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
Benchmark harness that tests whether models can forecast federal motion-to-dismiss outcomes from the written record, scored per claim-defendant pair with micro-Brier and clustered intervals.
Jev Practices & Patterns#community#jevbest#catalog-import
8GitHub stars
Shadcn registry search block that shows lexical hits instantly then re-ranks the top candidates with Jev intent scoring in one request, with keyword fallback on failure.
Jev Integrations & Adapters#community#jevbest#catalog-import
Frozen 100-question-per-cell check of TypeSafe Jev on Korean versus English reading, paraphrase, and medical exam items, with recorded responses and uncertainty intervals.
Jev Practices & Patterns#community#jevbest#catalog-import
7GitHub stars
Tournament engine that ranks texts by pairwise or cohort duels judged with Jev or local open-weight models, using Elo and TrueSkill ratings with a live web dashboard.
Jev Tools & CLIs#community#jevbest#catalog-import
7GitHub stars
Prose linter that combines millisecond static Python checks with per-judgement Jev probability calls, reporting ruff-style rule codes with tunable thresholds.
Jev Agents & MCP#community#jevbest#catalog-import
5GitHub stars
Independent Jev-inspired decision API with choice, score, and noul primitives, shipping a local mock server plus Python and JavaScript SDKs for interface prototyping.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
Word-level language model experiment that uses Jev as its output layer, with explicit tokenizer, sampler, repetition mask, stop rules, and chunk verification.
Jev Practices & Patterns#community#jevbest#catalog-import
Curated collection of 139 independent Jev robustness tests on wording, order, repetition, language, injected text, and calibration, each grouped by the property measured.
Jev Guides & Articles#community#jevbest#catalog-import
21GitHub stars
Local offline pipeline that converts open Jev reproductions to ONNX, applies quantization, and serves typed decisions on CPU with a protocol-compatible endpoint.
Jev Demos & Experiments#community#jevbest#catalog-import
5GitHub stars
Browser automation loop with no LLM where code enumerates page actions and Jev only picks, verifies, and stops, including a live viewer and QA regression mode.
Jev Demos & Experiments#community#awesomejev#catalog-import
7GitHub stars
Claude Code plugin that routes code review, debugging, planning, and search triage through typed Jev judgements with fixed thresholds applied in code.
Jev Practices & Patterns#community#awesomejev#catalog-import
10GitHub stars
Plugin suite pairing Jev decision primitives with DeepSeek Harness for tool pruning, loop blocking, risk guarding, skill routing, and result shaping.
Jev Agents & MCP#community#awesomejev#catalog-import
12GitHub stars
Kotlin Multiplatform DSL and client for Jev covering JVM, Apple platforms, Linux, Windows, and Node.js, declaring noul, choice, and score questions in one request.
Jev Repos & SDKs#community#awesomejev#catalog-import
6GitHub stars
Watch Jev play chess against OpenRouter LLMs or Stockfish, or play Jev yourself, with every weighed move, likelihood, clock, and finished game saved for replay.
Jev Practices & Patterns#community#awesomejev#catalog-import
Pi extension that judges context units with Jev before each model call, keeping what a future response needs and omitting the rest without editing the stored session.
Jev Agents & MCP#community#awesomejev#catalog-import
335GitHub stars
Chinese Jev Cookbook with runnable Jupyter notebooks covering the three question primitives, 18 official recipes, a voice-driven 3D smart home, eval discipline, and local Laya fine-tuning.
Jev Tools & CLIs#community#awesomejev#catalog-import
5GitHub stars
Grok Build wrapper that asks Jev one noul per tool before the first model call of a turn, then holds the shortened tool list so the prompt cache survives.
Jev Agents & MCP#community#awesomejev#catalog-import
5GitHub stars
Static web tool that finds bounded decisions in GPT, Claude, or Gemini prompts and proposes Jev Choice, Score, and Noul questions with SDK exports.
Jev Tools & CLIs#community#awesomejev#catalog-import
22GitHub stars
Callable Python collection implementing most documented Jev decisions, where each module builds state, asks typed questions, and returns a UseCaseResult for code to execute.
Jev Agents & MCP#community#awesomejev#catalog-import
10GitHub stars
Curated discovery index for Jev launch posts and demos, browsable by application with original video frames and links back to every X source post.
Jev Demos & Experiments#community#awesomejev#catalog-import
6GitHub stars
Type up to 40 characters and get many related emojis scored by Jev, with category score traces and a keyword hits shortlist on a hosted Worker demo.
Jev Demos & Experiments#community#awesomejev#catalog-import
6GitHub stars
Skill and CLI that helps Codex, Claude Code, and other agents add bounded Jev judgments for routing, ranking, classification, and next-step choice.
Jev Agents & MCP#community#awesomejev#catalog-import
Pre-compaction advisor for DeepSeek Harness that asks Jev which tool results can be pruned in the 70-80% lookahead band, keeping the log intact and leaving real compaction to the backend.
Jev Agents & MCP#community#awesomejev#catalog-import
5GitHub stars
Go gateway exposing the Jev POST /v1/systemone contract over Ollama Cloud, llama.cpp, vLLM, SGLang, and OpenAI-compatible servers by scoring one label token per question.
Jev Tools & CLIs#community#awesomejev#catalog-import
8GitHub stars
Reproducible harness comparing Jev, Laya, two LLMs, and two BERT variants on SST-2, AG News, and Banking77 for accuracy, calibration, latency, throughput, and cost.
Jev Practices & Patterns#community#awesomejev#catalog-import
12GitHub stars
Research pilot pairing an LLM-authored support ontology with Jev classification, testing 78 synthetic tickets over 190 passes and 380 calls plus a 3-iteration convergence check.
Jev Tools & CLIs#community#awesomejev#catalog-import
14GitHub stars
DeepSeek Harness plugin that routes long tool outputs, web content, skill choice, and delivery checks through Jev before they reach context, with a local metadata-only ledger.
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
7GitHub stars
Go proof of concept routing support tickets with three parallel TypeSafe questions for urgency, six-way department, and five-level frustration, plus deterministic auto, review, and human paths.
Jev Demos & Experiments#community#awesomejev#catalog-import
6GitHub stars
Free Jev-style multimodal decision API that takes images plus state and returns a choice, score, or yes-no answer with probabilities in a few hundred milliseconds.
Jev Demos & Experiments#community#awesomejev#catalog-import
6GitHub stars
Claude Code Stop hook that sends the final message to Jev to catch empty stops, unbacked action claims, unwatched background promises, and wrong-language replies.
Jev Agents & MCP#community#awesomejev#catalog-import
14GitHub stars
Shared routing contract connecting OpenCode, Claude Code, Hermes, and pi to Jev for per-message skill choice, per-step tool subsets, and browser moves over the Decisions API.
Jev Agents & MCP#community#awesomejev#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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