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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 289–336 of 954 resources

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
10GitHub stars
Unofficial Windows overlay that reads your own WeChat window with local offline OCR and drafts one to three replies for one-click fill, with auto-send off by default.
Jev Demos & Experiments#community#awesomejev#catalog-import
Starter kit putting Kinde identity plus Jev judgment in front of every agent tool call, with allow, hold-for-approval, or deny decided in code and written to a ledger first.
Jev Practices & Patterns#community#awesomejev#catalog-import
13GitHub stars
Three.js drone simulator where TypeSafe Jev flies a generated city from pad A to pad B through the AI SDK provider, with code turning telemetry into a situation report and probabilities into stick deflections.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
Python client and decision toolkit for the Jev System One endpoint with noul, choice, and score primitives, batched asks, composition helpers, concurrent evaluation, and an MCP server.
Jev Practices & Patterns#community#jevbest#catalog-import
9GitHub stars
MCP tool router for Codex that keeps large external tool inventories behind a small find_tool surface and asks Jev to select from names and descriptions at a 0.90 threshold, falling back to bounded search.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
Playful chat demo that makes Jev hold a conversation one word at a time by picking from a compact 979-word vocabulary through repeated Choice calls.
Jev Tools & CLIs#community#jevbest#catalog-import
11GitHub stars
Pre-commit and CI gate that turns each Markdown requirement into one Jev yes-or-no question over the paired code and fails the build when probabilities miss configured thresholds.
Jev Agents & MCP#community#jevbest#catalog-import
156GitHub stars
Community multimodal System One model in sizes from 0.8B to 27B that answers typed Noul, Choice, and Score questions over screenshots, photos, video, and text.
Jev Demos & Experiments#community#jevbest#catalog-import
5GitHub stars
OpenAPI compatibility gate that pairs deterministic structural checks with bounded Jev questions over changed prose to catch behavioral breaks that schema diffs miss.
Jev Agents & MCP#community#jevbest#catalog-import
4GitHub stars
TypeScript browser harness where an OpenRouter planner splits goals into subgoals, Jev picks each concrete action, OpenRouter fills text fields, and Playwright drives the page.
Jev Demos & Experiments#community#jevbest#catalog-import
4GitHub stars
Shell CLI that sends state plus noul, choice, and score questions to Jev in one request and prints probabilities, choices, and rubric positions for pipes and scripts.
Jev Tools & CLIs#community#jevbest#catalog-import
5GitHub stars
WordPress plugin that exposes Jev noul, choice, and score questions to PHP with settings-page and constant-based key, model, and endpoint configuration.
Jev Tools & CLIs#community#awesomejev#catalog-import
5GitHub stars
Inline verifier that checks LLM responses and agent plans with one Jev call across alignment heads and returns block, flag, or pass for gates and hooks.
Jev Practices & Patterns#community#awesomejev#catalog-import
5GitHub stars
Inference engine around Qwen2.5-1.5B-Instruct for classification, yes/no judgements, and rubric scoring with 100% schema-valid JSON, no fine-tuning required.
Jev Tools & CLIs#community#awesomejev#catalog-import
4GitHub stars
Semantic PR labeling with Jev through OpenRouter Decisions API, assigning type, area, platform, and conceptual-scope size from a fixed taxonomy.
Jev Tools & CLIs#community#awesomejev#catalog-import
4GitHub stars
Chrome extension that scores Gmail messages with Jev for category, priority, spam, and reply likelihood, inline as badges or in a sortable dashboard.
Jev Demos & Experiments#community#awesomejev#catalog-import
6GitHub stars
Terminal coding agent on Pi where Jev shortlists skills, ranks retrieved excerpts, and triages tool failures while the coding model handles reasoning and edits.
Jev Agents & MCP#community#awesomejev#catalog-import
5GitHub stars
CLI and agent commands that audit a git diff hunk-by-hunk against editable YAML standards packs, with Jev answering typed questions and the agent fixing flagged lines.
Jev Practices & Patterns#community#awesomejev#catalog-import
Windows Codex skill that installs and verifies user-level save-token-jev hooks, where PreCompact selects records with Jev before native compression and SessionStart restores them.
Jev Agents & MCP#community#awesomejev#catalog-import
19GitHub stars
Open-source Jev-compatible decision engine with a Claude Code style REPL, answering Choice, Score, and Noul questions in one forward pass over open models.
Jev Practices & Patterns#community#awesomejev#catalog-import
5GitHub stars
Open arena pitting Jev against a chosen opponent on your question, hiding identities until you vote, then revealing latency, cost, and confidence data.
Jev Practices & Patterns#community#awesomejev#catalog-import
Reproducible study of Jev 1.13 as reward model, judge, and process verifier across eight tracks and 40,940 examples with CSV data and an interactive report.
Jev Practices & Patterns#community#awesomejev#catalog-import
4GitHub stars
Natural-language code and text search where every match is a Jev judgement over supplied context, for cases when exact words or rule syntax are forgotten.
Jev Tools & CLIs#community#awesomejev#catalog-import
10GitHub stars
Commit-time design and code review that blocks AI slop on motion, copy tells, typography, and code patterns, with Jev probabilities for ambiguous cases.
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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