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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 97–144 of 625 resources

Self-hosted Google Apps Script that classifies Gmail by meaning with Jev Choice over your own dozen-label taxonomy, checking metadata first and full content only when confidence demands it.
Jev Tools & CLIs#community#jevbest#catalog-import
22GitHub stars
Offline evaluator that checks whether classifier confidences match reality and converts mistake costs into a deployable threshold, emitting an HTML report plus machine-readable threshold files.
Jev Practices & Patterns#community#jevbest#catalog-import
18GitHub stars
Turkish Next.js app that classifies transcript passages with Jev instead of rewriting them, finding chapters, heatmap moments, claim types and topic matches while showing original wording.
Jev Tools & CLIs#community#jevbest#catalog-import
35GitHub stars
Rust terminal tool that asks Jev noul, choice and score questions about piped text or files and returns calibrated probabilities with stable exit codes for shell scripts, CI jobs and agents.
Jev Agents & MCP#community#jevbest#catalog-import
22GitHub stars
Runnable agent harness that moves pick, score and yes-no loop choices to Jev or Laya in milliseconds while reserving the language model for writing, compiling DECISION.md into executable questions.
Jev Agents & MCP#community#jevbest#catalog-import
64GitHub stars
LangGraph deep-research agent that plans, searches, reads pages, aggregates evidence, checks gaps, and writes a Markdown report with sources, built as a runnable tool and a staged learning reference.
Jev Agents & MCP#community#jevbest#catalog-import
21GitHub stars
Community catalog of real Jev use cases, working architectures, and hard-won guidance, organized by decision shape with runnable examples and a ready-made question catalog.
Jev Guides & Articles#community#jevbest#catalog-import
23GitHub stars
Memory-maintenance library that checks every stored memory against each new event with Jev yes-or-no votes, then marks stale facts superseded or contradicted instead of editing them.
Jev Integrations & Adapters#community#jevbest#catalog-import
35GitHub stars
Diff-aware test selector that sends the git diff to Jev with one question per test, then prints the native filter flags and hands them to vitest, jest, node, bun, Playwright, cargo, or go test.
Jev Agents & MCP#community#jevbest#catalog-import
23GitHub stars
Chrome extension that sends each X post to Jev with six typed questions in one call near the viewport, then renders a behavior chip under the post plus a session cost and latency panel.
Jev Demos & Experiments#community#jevbest#catalog-import
20GitHub stars
Permissions plugin for coding agents that reviews unresolved shell approval requests with Jev and auto-approves only harmless ones, leaving everything else in the normal permission flow.
Jev Agents & MCP#community#jevbest#catalog-import
16GitHub stars
Python kit pairing a Jev CLI for verify, screen, classify, extract, match, route, ask, find, rerank, compact, and batch with an MCP server exposing the Jev ruleset over stdio.
Jev Demos & Experiments#community#jevbest#catalog-import
50GitHub stars
Android WeChat assistant that analyzes visible text and voice transcripts for emotion and intent, then drafts分条 reply options and topic openers you copy and send yourself.
Jev Tools & CLIs#community#jevbest#catalog-import
15GitHub stars
Isolated multi-reviewer code review as CLI, CI gate, and agent skill, running fresh read-only Pi sessions singly or as a consensus panel with structured verdicts and exit codes.
Jev Agents & MCP#community#jevbest#catalog-import
Independent community Next.js playground for Jev experiments: editable typed questions, A/B input comparisons, conversation routing, document extraction, code-policy review, plus game and simulation workspaces.
Jev Demos & Experiments#community#jevbest#catalog-import
19GitHub stars
Ruby control-flow helper that asks plain-English questions about text or app data via a System One model and returns probabilities, picks, or ordered ratings for use directly in code.
Jev Integrations & Adapters#community#jevbest#catalog-import
16GitHub stars
Vendor-neutral harness that tests whether Jev reranking improves a small RAG stack, using frozen hybrid BM25 plus BGE-M3 candidates and isolating retrieval, rerank, and generation stages.
Jev Practices & Patterns#community#jevbest#catalog-import
21GitHub stars
Turkish-language local-first memory starter that keeps preferences, decisions, jobs, and sources in your own Markdown vault and points Claude Code, Codex, and Antigravity at the same files.
Jev Tools & CLIs#community#jevbest#catalog-import
25GitHub stars
Python inference-time loop that lets a separate judge score one greedy answer and, when uncertain, samples extra thought paths in parallel and returns the best-scored path.
Jev Agents & MCP#community#jevbest#catalog-import
14GitHub stars
Python library for schema-enforced JSON extraction into Pydantic models, with provider-native JSON mode fallback, auto-repair, token and cost tracking, plus agents, RAG, and eval helpers.
Jev Integrations & Adapters#community#jevbest#catalog-import
13GitHub stars
Pi extension that classifies each task with Jev over OpenRouter and routes it to a Pareto-optimal model balancing measured quality, cost, and latency under a role policy.
Jev Agents & MCP#community#jevbest#catalog-import
15GitHub stars
PHP 8.2+ client for Jev that sends a state with typed noul, choice, and score questions and returns one typed answer per question ID with probabilities and usage.
Jev Repos & SDKs#community#jevbest#catalog-import
37GitHub stars
Minimal Python recipe that turns any causal LLM into a Jev-style classifier by prefilling choice_index and constraining sampling to legal indexes in one forward pass.
Jev Practices & Patterns#community#jevbest#catalog-import
14GitHub stars
Manifest V3 Chrome extension in TypeScript that sends each LinkedIn post to Jev and collapses bait, self-promo, off-topic, and sponsored posts into a one-line bar with reasons and scores.
Jev Demos & Experiments#community#jevbest#catalog-import
15GitHub stars
Node CLI that lints a file tree against fuzzy natural-language rules in one Markdown file, judging each matched file with a swappable TypeSafe-backed judge.
Jev Agents & MCP#community#jevbest#catalog-import
22GitHub stars
Local server running Jev-style typed decisions on a Mac GPU through Metal, with a demo page, a latency benchmark, and tunable memory modes around one FP32 model.
Jev Demos & Experiments#community#jevbest#catalog-import
14GitHub stars
Browsable directory pairing 50 runnable judge-model evals with exact prompts against more than a thousand community builds, each linked to its project and source post.
Jev Guides & Articles#community#jevbest#catalog-import
14GitHub stars
Tiered agent memory keeping compact summaries with source links over searchable raw history, where a router decides per query whether notes suffice or raw pages must be recovered.
Jev Agents & MCP#community#jevbest#catalog-import
19GitHub stars
MCP server where one browser_goal call hands a URL, a goal, and code-checked assertions to a server-side loop driven by a decision model over live page elements.
Jev Demos & Experiments#community#jevbest#catalog-import
41GitHub stars
Gateway-side admission control judging incoming requests with a typed decision model, layering cheap rules, synchronous judgment, and an async side path that never blocks responses.
Jev Integrations & Adapters#community#jevbest#catalog-import
14GitHub stars
Recursive language-model layer holding full inputs in a local evaluator and exposing a small working surface, with optional typed semantic judgments alongside generative calls.
Jev Agents & MCP#community#jevbest#catalog-import
21GitHub stars
Discord bot forcing a textless decision model to speak by repeatedly picking the next word through vocab tournaments, a completeness check, and reuse penalties.
Jev Demos & Experiments#community#jevbest#catalog-import
45GitHub stars
Go SDK plus a pipeline-friendly CLI for typed decisions, covering single questions, batched question maps, retries, and line-oriented filtering over stdin.
Jev Repos & SDKs#community#jevbest#catalog-import
39GitHub stars
Open replica of the typed decision API on openly available base models, answering choice, score, and true-probability questions in one forward pass with no decoding.
Jev Practices & Patterns#community#jevbest#catalog-import
26GitHub stars
Open-source browser extension filtering feed posts by local keywords and, with your own model key, labeling ads, chosen topics, and likely AI-generated share directly on the page.
Jev Tools & CLIs#community#jevbest#catalog-import
33GitHub stars
Split-screen demo pitting Rust plus Jev against Python plus DeepSeek on the same Portuguese scam messages, with fund tracing over a simulated graph of 10 million transactions.
Jev Demos & Experiments#community#jevbest#catalog-import
20GitHub stars
Embeddable C99 runtime for one-pass typed decisions that returns one probability per option with no token loop, plus a 66 KB WebAssembly build for browsers and Node.
Jev Demos & Experiments#community#jevbest#catalog-import
16GitHub stars
Shell wrapper that intercepts unknown subcommands, reads the target CLI help output, and asks Jev which documented subcommand matches the intent behind the typo.
Jev Agents & MCP#community#jevbest#catalog-import
72GitHub stars
Open training and deployment stack for System 1 decision models: one state-plus-question-plus-options API that returns a choice with probabilities for tickets, tools, or robot actions.
Jev Demos & Experiments#community#jevbest#catalog-import
275GitHub stars
Self-rebuilding Jev index organized by evidence grade, with one ranked pick per category, multilingual guides, and links through to full cards and sources.
Jev Guides & Articles#community#jevbest#catalog-import
19GitHub stars
Windows desktop aid that reads the local WeChat database for the foreground chat, strips identifiers, and asks Jev for stage, intent, tension, suggested moves, and a reply review.
Jev Tools & CLIs#community#jevbest#catalog-import
48GitHub stars
Next.js dashboard plus Python feed that streams market data, computes indicators across timeframes, sends enabled states to Jev, and applies the judgments to a SQLite paper portfolio.
Jev Tools & CLIs#community#jevbest#catalog-import
23GitHub stars
Coding-agent plugin that routes prompt classification, subagent tiering, edit rule checks, and fast Jev-backed compaction through small typed judgments.
Jev Agents & MCP#community#jevbest#catalog-import
15GitHub stars
Prompt-first symbolic music studio where a live Jev model decides plan, instruments, harmony, groove, and each bar, rendering every pick into an editable multitrack piece.
Jev Tools & CLIs#community#jevbest#catalog-import
15GitHub stars
Uncertainty-aware semantic control flow and routable procedures for Effect, with type-safe patterns and policies over Effect Decision and DecisionModel where uncertain answers stay explicit branches.
Jev Integrations & Adapters#community#jevbest#catalog-import
13GitHub stars
Free starter that teaches turning one document into one small typed decision, built around a fictional travel agency where recorded observations meet inspectable application rules.
Jev Demos & Experiments#community#jevbest#catalog-import
14GitHub stars
Small skill that grills a plan as a design-tree interview, using Jev ad hoc for typed judgments during the session.
Jev Demos & Experiments#community#jevbest#catalog-import
46GitHub stars
Pixel-art simulation engine where agents pick structured next actions through Jev while a separate language model handles dialogue, memory, and beliefs, all running in one browser tab.
Jev Demos & Experiments#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