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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 625 resources

3GitHub stars
A Home Assistant Assist conversation agent that sends each command to Jev as one request with a speculative fan-out of questions, then hands the typed answers to Home Assistant's own intents to do the device control.
Jev Integrations & Adapters#community#jevbest#catalog-import
1GitHub stars
A small stdio MCP server that exposes three Jev-backed tools to coding agents: structured judgments, ranking supplied candidates by relevance, and checking claims against evidence you provide.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
An unofficial async Rust client for the TypeSafe System One API in which each question hands back a key typed by its answer, so reading a choice answer as a probability fails to compile.
Jev Repos & SDKs#community#jevbest#catalog-import
3GitHub stars
A CLI that sends state plus typed questions to Jev and prints structured JSON, with boolean, choice and score question types, a documented exit-code contract for CI, and an optional Vercel AI Gateway transport.
Jev Tools & CLIs#community#jevbest#catalog-import
4GitHub stars
A CLI and agent skill that asks plain-English questions across a repository, sends each in-scope chunk to the provider, returns scored source locations to investigate, and runs recurring review rules on diffs.
Jev Agents & MCP#community#jevbest#catalog-import
3GitHub stars
An experiment that composes TypeSafe Jev Choice decisions into free-form text: every next character becomes one typed decision over 98 options, with branch backtracking and a final complete/incomplete check.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
A Python search command for terminals and agents: Parallel Search seeds queries, a local Chromium fetches pages concurrently, and Jev scores the evidence to expand a breadth-first link queue. Ships readable output, JSON and an MCP server.
Jev Demos & Experiments#community#jevbest#catalog-import
10GitHub stars
A research reproduction of the Jev question shape — Choice, Score and Noul answered in one forward pass — trained and measured side by side on encoder backbones and a diffusion LLM, with accuracy, calibration, latency and training cost in one table.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
A FastAPI plus React lab where Jev picks each 2048 move through one choice decision per turn, running many games in parallel with a live best score and a browser editor for the exact state payload Jev sees.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A minimal Next.js workbench for Jev: paste a state, mix noul, choice and score questions, and see the typed answers, probability distributions and confidence returned from a single parallel request.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
A TypeScript decision layer for agent loops that reads yes/no, one-of-n and rubric answers off one token's probabilities from a local logprobs model, with a permission gate shipped as a Claude Code plugin.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
A LangChain agent where Jev routes intent as a typed choice over four fixed criteria, with confidence below 0.6 falling back to local keyword rules, and each route carrying exactly one tool and one prompt.
Jev Agents & MCP#community#jevbest#catalog-import
6GitHub stars
An unofficial Java 21 client for the Jev decision API that replaces maps with records and sealed types, so a malformed choice, score or noul question fails to compile instead of coming back as a 422.
Jev Repos & SDKs#community#jevbest#catalog-import
1GitHub stars
A Rust filter that reads JSONL security alerts on stdin and asks five Jev questions per alert — disposition, severity, false positive, escalation, ATT&CK class — then applies the routing policy in ordinary code you control.
Jev Tools & CLIs#community#jevbest#catalog-import
A Rust CLI of Jev experiments, led by a PHI screener that judges four separate 45 CFR 160.103 metrics per file and an English part-of-speech tagger that batches only the unresolved words into one request.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
An agent tool and MCP call gate: paste a planned call plus its context and it returns allow, ask_human or deny with risk scores derived from a TypeSafe Jev decision call.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A Bun and Next.js moderation demo that screens text with one systemOne call — seven hazard Nouls plus a severity Score in parallel — and computes the verdict in code from policy thresholds.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A CLI that reads the comments in your JS/TS files with the code around them and scores each one for accuracy and usefulness out of 100, weakest first, using Jev.
Jev Tools & CLIs#community#jevbest#catalog-import
1GitHub stars
A PowerShell hook for Codex that intercepts your prompt turn and asks Jev to audit the conversation recorded so far, answering with typed probabilities rather than prose.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
A Game of Thrones roleplay where a narrator model writes each scene and Jev answers five typed questions about it, with the location, music, artwork and next prompt all following from those answers.
Jev Demos & Experiments#community#jevbest#catalog-import
Screens MEDLINE titles and abstracts for an ADHD systematic review with Jev, scored against the Cohen 2006 Abstract Triage gold labels, with a published rule rather than a bare model verdict.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
An unofficial MCP server exposing one ask tool: your agent hands Jev some material and a list of plain questions, and gets typed answers with probabilities back in one round trip.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
A TypeScript client for Jev where every decision must handle an unsure branch, so a low-confidence answer escalates instead of collapsing silently into a boolean.
Jev Tools & CLIs#community#jevbest#catalog-import
3GitHub stars
An MCP server with a single evaluate_decision tool that returns noul, choice or score probabilities over a diff, log or plan, with output tokens set to zero on every call.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
Ten runnable JavaScript experiments on agent decisions, each pairing a small Jev judgment with visible application policy code, plus authored fixtures so the whole set runs offline.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A zero-dependency Node proxy that sits in front of Jev, forwards every request unchanged, and reports whether a local decision model would have made the same call on your own traffic.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
A directory of projects built on Jev, grouped into SDKs, integrations, agent tooling, applications and research, where each repository is classified by the model itself.
Jev Guides & Articles#community#jevbest#catalog-import
5GitHub stars
An inference-only prototype of a Jev-style decision model on a sub-billion-parameter hybrid backbone, returning typed probability distributions in one forward pass, with its architecture treated as an explicit guess.
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
14GitHub stars
Claude Code hook that asks Jev which installed skill fits each prompt and logs the answer, plus the script that joins that log to session transcripts and the negative result the author got from a week of running it.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
omp plugin that runs Jev batteries over tool results, assistant messages and turn ends, gathers deterministic git evidence before each judgment, and can score stale tool output out of later model requests.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
Unofficial catalog of public projects that use Jev, grouped by what each project does with the answer, with every entry labelled code-inspected or demo-inspected and the counts backed by a JSON catalog.
Jev Guides & Articles#community#jevbest#catalog-import
4GitHub stars
Python library that maps Jev's Choice, Score and Noul onto verbs like classify, score, check, where, extract, verify and rank, keeping data shape in and out, batching one request per distinct row and caching answers.
Jev Integrations & Adapters#community#jevbest#catalog-import
2GitHub stars
TypeScript build of hunch for Node 20 and up, mapping Jev's Choice, Score and Noul onto classify, score, check, where, extract, verify, rank and route over arrays and row objects.
Jev Integrations & Adapters#community#jevbest#catalog-import
7GitHub stars
A local MCP server that gives Codex a few cited excerpts instead of a whole noisy search result, with a deterministic default selector that needs no Jev account or key.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
A research agent where GPT picks what to look for and Jev judges many document regions in one call, so the code can hand back verbatim passages for verification.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
A small Next.js demo that sends the same input to GPT and Jev side by side, showing generative text next to three fixed Noul probabilities.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
A directory of projects actually shipped with Jev, filtered by what each one replaces, whether it was benchmarked, and whether there is code to copy.
Jev Guides & Articles#community#jevbest#catalog-import
Runs Jev as an LLM router over two public benchmarks, with a no-Jev ablation and RouterArena's own scorer so the numbers sit next to the public leaderboard.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
A decision board that sends one System One request describing eleven stream ideas, then lets code gate and weight Jev's answers into a single pick for what to build next.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
An unofficial Elixir SDK for TypeSafe's System One endpoint, built on Req and Finch, with per-call retry policies, a shared connection pool and status-mapped errors.
Jev Repos & SDKs#community#jevbest#catalog-import
3GitHub stars
A gomoku lab that runs nine 15x15 games at once with two Jev players, holding the rules fixed while you vary how much tactical detail reaches the model.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A DeepSeek Harness plugin that exposes System One decisions as agent tools and adds an opt-in auto-guard, with a labeled benchmark it re-runs against the live API.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
A Python layer over a small decision-provider contract that adds validated distributions, batching, budgets, ranking and exportable records, with Jev as the first provider.
Jev Repos & SDKs#community#jevbest#catalog-import
2GitHub stars
A Chrome extension that runs title and abstract screening for systematic reviews inside a shared Google Sheets project, with Jev offered beside Gemini and OpenRouter as the judging model.
Jev Tools & CLIs#community#jevbest#catalog-import
1GitHub stars
A Pi extension that sends each new unit of work to a Jev client as a paid classification request and routes it to one of four configured Pi models, failing open to your baseline.
Jev Agents & MCP#community#jevbest#catalog-import
1GitHub stars
A single self-contained Python script around AlexWortega/openjev, a Qwen3.5-4B cross-encoder that answers contradiction, entailment or neutral, exposing pair classification, multiple-choice rerank, a library API and a CLI.
Jev Practices & Patterns#community#jevbest#catalog-import
3GitHub stars
An unofficial, dependency-free Go client for the TypeSafe v1 API: System One calls built from Noul, Choice and Score questions, per-request model overrides, typed answers with a request ID, and retries that honor Retry-After.
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.

Follow @typesafeai