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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 337–384 of 954 resources

5GitHub stars
Local agent observability stack that scores chains of tool events with Jev, Sentinel rules, and SafetyDrift, then sets escalate-only incident levels with graph forensics.
Jev Demos & Experiments#community#awesomejev#catalog-import
7GitHub stars
Local SEO tool that scores a page separately for search, answer, and generative engines, using fixed code rules plus 25 Jev judgment questions in one request with ranked fixes.
Jev Demos & Experiments#community#awesomejev#catalog-import
4GitHub stars
Unofficial Rust client for the System One API with a fluid request builder for noul, choice, and score questions, typed answers, and client-side cost math.
Jev Repos & SDKs#community#awesomejev#catalog-import
23GitHub stars
Browser extension for Chrome and Firefox that scores X, LinkedIn, Reddit, and YouTube items on AI-writing tells and collapses posts over your threshold.
Jev Demos & Experiments#community#awesomejev#catalog-import
Desktop paper-trading app for stocks and crypto where Jev answers narrow market questions each second and code turns the answers into orders under your stops and targets.
Jev Practices & Patterns#community#awesomejev#catalog-import
6GitHub stars
Claude Code routing mod that asks Jev which model tier and effort each turn needs, then directs that turn to haiku, sonnet, opus, or fable with visible route lines.
Jev Agents & MCP#community#awesomejev#catalog-import
6GitHub stars
macOS menu-bar voice app where speech is transcribed on-device and Jev routes each clause to open, close, dictate, search, system, or UI actions with typed decisions.
Jev Tools & CLIs#community#awesomejev#catalog-import
5GitHub stars
Zero-dependency extraction library that numbers the words in your text, offers those numbers to Jev as choices, and maps the picks back to exact substrings with offsets.
Jev Demos & Experiments#community#awesomejev#catalog-import
5GitHub stars
Resume review app that takes a PDF, DOCX, or TXT plus a target role and optional job description, then returns an overall score, criteria, bullet scores, and ordering.
Jev Demos & Experiments#community#awesomejev#catalog-import
5GitHub stars
Community quickstart and FAQ that explains Jev as a called-by-software System One model returning choice, score, or yes-no probability over one API call.
Jev Demos & Experiments#community#awesomejev#catalog-import
5GitHub stars
Pluggable browser-automation decision layer that replaces per-step large-model calls with one Jev request for operation plus target, leaving observation and guards in code.
Jev Demos & Experiments#community#awesomejev#catalog-import
8GitHub stars
Kotlin UI-agent SDK for Android where Jev or DeepSeek picks actions from live on-screen controls and an accessibility service executes them under host policy.
Jev Repos & SDKs#community#awesomejev#catalog-import
5GitHub stars
Local grid tactics arena and NanoJev experiment field where each turn offers real candidate actions across 2-AP rounds, enemies, hazards, ammo, cooldowns, and staged bosses.
Jev Demos & Experiments#community#awesomejev#catalog-import
5GitHub stars
CLI that routes a task to one specialist skill from a Tink library using TypeSafe Jev, verifies the winner with tink mount, then prints it inline or as a mounted path.
Jev Agents & MCP#community#awesomejev#catalog-import
5GitHub stars
R client for TypeSafe Jev that asks typed noul, choice, and score questions about text or structured rows and returns probabilities ready for code and aggregation.
Jev Repos & SDKs#community#awesomejev#catalog-import
6GitHub stars
Self-hosted Feishu bot plus web workbench where a text model proposes 2-5 candidate answers and TypeSafe Jev picks among them with probabilities.
Jev Practices & Patterns#community#awesomejev#catalog-import
7GitHub stars
Independent open-source agent runtime where Jev makes typed tool decisions, an LLM authors text only when needed and reviews low-confidence calls, and code owns execution.
Jev Practices & Patterns#community#awesomejev#catalog-import
5GitHub stars
Android decision aid that reads the active chat window through Accessibility and returns typed judgments on reply timing, intent, tone, and risk without sending anything.
Jev Demos & Experiments#community#awesomejev#catalog-import
6GitHub stars
Independent harness grading System One decision models on the same sealed manifest and seed with byte-identical inputs, pitting closed Jev against open Laya and constrained Qwen.
Jev Practices & Patterns#community#awesomejev#catalog-import
11GitHub stars
Native C++ inference for Dohnuts on llama.cpp that runs the Qwen3.5-based decision model on CPU, scoring candidate markers with a scalar head in one forward pass.
Jev Tools & CLIs#community#awesomejev#catalog-import
9GitHub stars
Local bridge where TypeSafe Jev picks the model and reasoning effort for Codex Desktop and CLI sessions, reusing the existing Codex login.
Jev Agents & MCP#community#awesomejev#catalog-import
4GitHub stars
Experiment turning Jev into a sampler: DeepSeek proposes top-k next tokens with logprobs and Jev picks each token, also judging when to stop or cut rambling.
Jev Tools & CLIs#community#awesomejev#catalog-import
4GitHub stars
Semantic code search that scores every function against a plain-language predicate with a calibrated Jev probability, then hands back file-line hits for an agent to open.
Jev Tools & CLIs#community#awesomejev#catalog-import
4GitHub stars
OpenAI-compatible proxy that holds streamed tokens in a sliding buffer and scores the full criteria matrix before release, cutting the stream before a violating token reaches the client.
Jev Practices & Patterns#community#awesomejev#catalog-import
macOS computer-use kit exposing an 18-tool stdio MCP server plus CLI that drives apps through the accessibility tree, posting input in the background without moving the user cursor.
Jev Demos & Experiments#community#awesomejev#catalog-import
9GitHub stars
Code-review gate that parses a repo locally, asks TypeSafe Jev short typed questions per unit of evidence, and lets deterministic code combine answers into findings with locations and fix steps.
Jev Agents & MCP#community#awesomejev#catalog-import
4GitHub stars
JVM SDK for the TypeSafe System One API with a pure-Java core, Kotlin DSL, Spring Boot starter, and Spring AI bridge, speaking the System One wire contract across hosted and self-hosted backends.
Jev Repos & SDKs#community#awesomejev#catalog-import
4GitHub stars
Self-hosted trading intelligence platform pairing a Python scoring and risk engine with a Claude plus Jev analyst, where the analyst answers only through fetched data tools and the user confirms every action at their broker.
Jev Tools & CLIs#community#awesomejev#catalog-import
9GitHub stars
Cookbook of runnable Jev examples, reusable composition patterns, and theory notes showing how to put a fast typed classifier in front of slower LLM fallbacks.
Jev Agents & MCP#community#awesomejev#catalog-import
11GitHub stars
NPM package and Ink TUI for asking Jev small typed questions stored as jevel files, mapping confidence to act, mark, or fall_back decisions with every decision kept in a local log.
Jev Agents & MCP#community#awesomejev#catalog-import
10GitHub stars
Claude Code plugin that re-checks each reply and file edit against CLAUDE.md or AGENTS.md rules with one batched Jev request, quoting broken rules back so the model fixes them in the same turn.
Jev Agents & MCP#community#awesomejev#catalog-import
6GitHub stars
Provider-neutral benchmark and harness for typed System One decisions, freezing corpora, manifests, and scoring so engines are compared on identical rows across accuracy, calibration, and robustness axes.
Jev Practices & Patterns#community#awesomejev#catalog-import
4GitHub stars
Context manager where Jev scores tool output into keep, pointer, or quarantine classes while kept lines stay verbatim and anything moved out can be expanded back byte for byte.
Jev Demos & Experiments#community#awesomejev#catalog-import
26GitHub stars
Explainable day-trip planner where an LLM drafts the itinerary, Jev screens candidates and reviews choices with typed decisions, and deterministic controller code owns routes, timing, validation, and repair.
Jev Demos & Experiments#community#awesomejev#catalog-import
4GitHub stars
Proof-of-concept dispatcher that discovers an MCP server's tools at runtime with list_tools() and routes plain-language commands using only Jev Choice and Noul, with no general-purpose LLM calls.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
Research decoder that treats Jev as if it were a language model, assembling replies in code from Choice distributions over a hierarchical codebook instead of generated tokens.
Jev Practices & Patterns#community#jevbest#catalog-import
Recruiter dashboard that applies calendar date math plus visa, tenure, license and clearance gates, then a Jev decision step, sorting resumes into disqualified, advance or manual review.
Jev Tools & CLIs#community#jevbest#catalog-import
9GitHub stars
Hermes Agent plugin exposing Jev as four coding-workflow tools for parallel judgments, binary checks, option routing and rubric scoring, with a bundled question-design skill.
Jev Agents & MCP#community#jevbest#catalog-import
3GitHub stars
Approval gate for Claude Code where hooks send each tool call to Jev and a local policy returns allow or deny without changing the harness model, provider or sandbox.
Jev Agents & MCP#community#jevbest#catalog-import
27GitHub stars
Local typed-decision models that answer Choice, Noul and Score in one forward pass on your own machine, with a Python API, local HTTP server and System One request shape.
Jev Demos & Experiments#community#jevbest#catalog-import
3GitHub stars
Open local classifier that reproduces a hosted Jev job-posting decision with a frozen CPU encoder plus small per-question heads, answering the same posting questions offline at zero marginal cost.
Jev Practices & Patterns#community#jevbest#catalog-import
LangChain deepagents middleware that replaces SkillsMiddleware with per-turn judging, loading only the SKILL.md files a turn needs so large catalogs stay out of the prompt.
Jev Agents & MCP#community#jevbest#catalog-import
18GitHub stars
TypeScript library adding plain-English browser control to an existing Playwright page, where Jev picks numbered nodes and fixed operations and Playwright executes them.
Jev Demos & Experiments#community#jevbest#catalog-import
3GitHub stars
Stdlib-only Python CLI and agent skill that evaluates a state against typed Choice, Score and Noul questions over the System One API without generating prose.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
Community Swift SDK for TypeSafe with a dependency-free client that sends state plus typed questions and returns inferred answers for Apple platforms.
Jev Repos & SDKs#community#jevbest#catalog-import
4GitHub stars
Curated Jev project list grouping models, agent tooling, guardrails, search, apps, trading, benchmarks and games, with a ranked top section and framework integration notes.
Jev Guides & Articles#community#jevbest#catalog-import
3GitHub stars
Experiment where Jev controls the tool loop and a LangChain chat model only fills argument values and final prose, using 12 local read-only MCP tools across documents, math, and calendar.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
Community Go client for the TypeSafe System One evaluation API with raw structs and a builder that produce the same EvaluationRequest, defaulting to jev-latest.
Jev Repos & SDKs#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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