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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 241–288 of 625 resources

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
3GitHub stars
Browser agent where Jev makes every navigation decision and agent-browser performs clicks and typing, stopping when the named goal page is reached or blocked.
Jev Demos & Experiments#community#jevbest#catalog-import
3GitHub stars
TypeScript layer that binds a Standard Schema state to Jev Choice, Score, and Noul questions, validating locally before sending one parallel request with typed projections.
Jev Repos & SDKs#community#jevbest#catalog-import
5GitHub stars
Autonomous Pokemon Red demo where Jev reads a compact text state each turn and answers typed Choice and Noul questions that deterministic code maps to PyBoy button presses.
Jev Demos & Experiments#community#jevbest#catalog-import
Local three-panel playground for trying TypeSafe judgments, with 110 editable examples across 22 categories including A/B comparisons, running one request per Run without bulk automation.
Jev Demos & Experiments#community#jevbest#catalog-import
3GitHub stars
DeepSeek Harness bundle that registers a jev_ask tool plus a jev skill so a DSH agent can send mixed Noul, Choice, and Score questions to Jev.
Jev Agents & MCP#community#jevbest#catalog-import
6GitHub stars
Idiomatic Java 17 and later client for Jev with one-off evaluate calls, reusable JevRequest builders, async support, and structured rubric helpers.
Jev Repos & SDKs#community#jevbest#catalog-import
6GitHub stars
Go driver for native macOS apps where Jev picks the next Accessibility action from live app and window state, with code mapping typed answers to tool calls.
Jev Demos & Experiments#community#jevbest#catalog-import
9GitHub stars
Native C++ DuckDB extension that runs Noul, Choice, Score, and mixed judgments directly from SQL with batching, concurrent HTTP, and chunked streaming and no Python UDFs.
Jev Integrations & Adapters#community#jevbest#catalog-import
4GitHub stars
DuckDB table functions over a VGI worker that expose Jev Choice, Noul, Score, and multi-question ask for LATERAL joins with confidence-based routing.
Jev Integrations & Adapters#community#jevbest#catalog-import
7GitHub stars
MCP server exposing Jev Choice, Score, Noul, batched ask, file-reading triage, and model listing as typed tools with full probability distributions.
Jev Agents & MCP#community#jevbest#catalog-import
3GitHub stars
macOS window switcher that predicts the app you want on ⌘` from recent switching history, asking Jev to pick from the 10 most recently used running apps with a 1 s fallback.
Jev Tools & CLIs#community#jevbest#catalog-import
3GitHub stars
Independent browsable field guide to Jev 1.13.0 covering 11,621 text-study requests, Snake controllers, and a 3D-city driving lab with replays, token counts, and reports.
Jev Practices & Patterns#community#jevbest#catalog-import
Curated collection of 83 public projects using Jev for moderation, automation, routing, search, classification, experiments, and behavior studies, each linking to its original source.
Jev Guides & Articles#community#jevbest#catalog-import
6GitHub stars
Agent skill plus CLI that rebuilds a plain requirement, an existing prompt, or current LLM-call code as typed Jev choice, score, and noul questions with runnable code.
Jev Agents & MCP#community#jevbest#catalog-import
8GitHub stars
Local server emulating the Jev System One endpoint at POST /v1/systemone with typed noul, choice, and score questions, so the official SDK works with only base_url changed.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
Open-source System One scorer built on Gemma 3 270M with LoRA, where each option is scored in one batched forward pass and softmaxed into probabilities for choice, yes/no and ordered-scale questions.
Jev Practices & Patterns#community#jevbest#catalog-import
3GitHub stars
Autonomous Clash Royale agent on macOS through the native iPhone Mirroring app, with local deterministic pixel perception and Jev choosing between candidate plays that code has already scored.
Jev Demos & Experiments#community#jevbest#catalog-import
Shadow-mode validation of a pre-execution firewall that batches five typed Jev hazard questions plus a blast-radius score into one call, leaving ALLOW, APPROVE and BLOCK to auditable Python.
Jev Agents & MCP#community#jevbest#catalog-import
5GitHub stars
A Claude Code function hook that sends AskUserQuestion dialogs to Jev and draws a probability per option above the dialog, so you still choose while seeing how confident the model is.
Jev Agents & MCP#community#jevbest#catalog-import
30GitHub stars
Chat client over jev-latest, which cannot generate text: the transcript becomes the state and each step is a choice over a 20,000-word dictionary, so replies are built one word at a time.
Jev Practices & Patterns#community#jevbest#catalog-import
4GitHub stars
Browser-use layer for CLI coding agents: Jev picks the operation and target element in one round trip per step, exposed over MCP with a CLI, a Python API and an HTTP server.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
Writing evaluator that runs seven separate typed Jev checks, covering hedging, em dashes, clarity, filler phrases, tone, passive voice and actionability, and shows each verdict with its supporting sentence.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
Unofficial community component workspace for TypeSafe AI projects: a Turborepo and pnpm monorepo with a Next.js component browser, shiki-highlighted source previews and an interactive Lab, built on shadcn base-nova, Base UI primitives, Tailwind v4 and RTL-aware components.
Jev Integrations & Adapters#community#jevbest#catalog-import
3GitHub stars
Proxy that sits between any MCP client and any stdio MCP server and screens tool calls, tool results and tool descriptions with Jev probabilities, layering deterministic allowlists, semantic checks and session taint tracking over a JSONL audit trail.
Jev Agents & MCP#community#jevbest#catalog-import
Local-first app that extracts document text on the machine and files it into configured category folders using typed Jev decisions for category, confidentiality, prompt-injection risk and subject, with a per-run audit that previews and undoes every move.
Jev Tools & CLIs#community#jevbest#catalog-import
One-file Mastra input processor that screens the last user message with Jev instead of an LLM verdict: a typed yes/no gate plus a log-only category label, in a single request that fails open behind a circuit breaker.
Jev Agents & MCP#community#jevbest#catalog-import
3GitHub stars
Unofficial Rust client for the TypeSafe AI System One API, matching the Python SDK 0.6.0 contract: named noul, choice and score questions, a typestated builder, per-call overrides, and a `wire` module for serving the same shape.
Jev Repos & SDKs#community#jevbest#catalog-import
1GitHub stars
Unofficial, independently maintained Go client for the TypeSafe AI System One API with no third-party dependencies: choice, score and noul questions, typed accessors that error instead of returning zero, and per-call timeout, retry and header overrides.
Jev Repos & SDKs#community#jevbest#catalog-import
5GitHub stars
React library on npm where Jev judgments choose presentation: `Branch` picks a subtree, `Rank` orders or truncates a candidate set, `Gate` shows an affordance, and `useScore` returns a number you can use as an ordinary prop.
Jev Integrations & Adapters#community#jevbest#catalog-import
Task plugin that puts TypeSafe's System One endpoint behind a QuantumNous/new-api channel, so clients keep posting `/v1/systemone` while new-api handles auth, routing, model mapping and token billing against either TypeSafe or the Vercel AI Gateway.
Jev Integrations & Adapters#community#jevbest#catalog-import
2GitHub stars
Community Go client for the TypeSafe AI System One API covering the same surface as the official Python and TypeScript SDKs, using functional options, context cancellation, sentinel errors, `log/slog`, no dependencies outside the standard library, and optional Langfuse tracing.
Jev Repos & SDKs#community#jevbest#catalog-import
Communityfgn/jevgoGo
3GitHub stars
Go MCP server exposing Jev through OpenRouter or TypeSafe as five tools: decide, classify, verify, rerank and list_models. Each tool call is one paid inference request, answers are validated against the question asked, and the unchanged provider response is returned with its usage cost.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
Agent skill that pushes a coding agent to try Jev before it writes another regex or prompt, then writes down what happened. Four reference files, an eval set of 20 trigger prompts, and three stdlib Python scripts for running questions, scoring agreement against labels you already have, and keeping a decision lab.
Jev Agents & MCP#community#jevbest#catalog-import
5GitHub stars
Python terminal app that puts Jev on both sides of an OpenAI answer. A LangGraph pipeline asks Jev for response mode, clarification and depth, has OpenAI draft, then has Jev score whether the draft answers the question and whether it carries unsupported claims before approving or sending it back.
Jev Demos & Experiments#community#jevbest#catalog-import
Cloudflare Pages site that asks Jev every ten minutes whether AI should kill humanity, from a state built out of live headlines, and shows the typed answers next to the exact request payload. The same ruling is served as JSON from /api/verdict, and the standing answer is held in KV rather than recomputed.
Jev Demos & Experiments#community#jevbest#catalog-import
3GitHub stars
Model router that asks Jev eleven questions in one call and lets a YAML policy turn the answers into a tier. Every request starts on the fast tier and only escalates on evidence such as multi-step reasoning, hard difficulty, high stakes or safety, and every decision is logged without the message text.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
Rust client that lets Jev choose the model and privacy tier for NEAR AI Cloud calls. A client-controlled monthly cap in cents is combined with Jev scores for complexity and sensitivity and nouls for private TEE, risk and urgency, then the NEAR catalog is filtered to what survives that choice.
Jev Agents & MCP#community#jevbest#catalog-import
7GitHub stars
Two TypeScript monorepo products that keep the rules in the engine and ask Jev exactly one question: what should this person or this shogi side do next. Hundred runs a hundred NPCs with hunger, money, jobs, relationships and memories; Jev Shogi picks Gote's reply from engine-legal USI moves.
Jev Demos & Experiments#community#jevbest#catalog-import
12GitHub stars
Backtest harness that asks Jev for a BUY, SELL or HOLD call every 15 seconds on NQ L10 order-book data and trades one contract against hold, random and imbalance baselines. Runs cost money; replays of stored answers under new settings are free, and a local web app replays any mix of runs live.
Jev Practices & Patterns#community#jevbest#catalog-import
Recorded experiments on how Jev reports probability rather than whether it predicts well. On a hidden fair die it picked an option with a mean reported probability of 82.9% while accuracy stayed at 19.0% over 400 trials, and Choice lost a stated 45% versus 55% distinction in an input document.
Jev Practices & Patterns#community#jevbest#catalog-import
7GitHub stars
PDF search that asks Jev one noul per line, does this line answer the query, and ranks the lines by the returned probability, so matches highlight without embeddings, a vector index or a chunking strategy. Text is extracted locally with pdf.js and the key stays on the server.
Jev Tools & CLIs#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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