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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

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Showing 769–816 of 954 resources

1GitHub stars
CV review on localhost, built on TypeSafe System One (jev-latest): upload a PDF or DOCX, check the extracted text, and get whole-document judgments on work clarity, contribution, interpretability, outputs and scope, each expandable to the question, criteria, answer and probability distribution behind it.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
A one-commit TypeScript MCP server that exposes three TypeSafe System One judgments — noul, choice and score — as agent tools, with src, tests, docs, scripts and a knip config. No README, zero stars, no topics.
Jev Agents & MCP#community#jevbest#catalog-import
An eval that puts Jev two questions about shadcn-ui/lint: whether each finding is a real rule violation, and whether the linter's message tells you what to change. It runs the real linter over 131 rule test cases and scores both the detections and the messages.
Jev Practices & Patterns#community#jevbest#catalog-import
0GitHub stars
A native macOS push-to-talk voice orb that runs a direct Jev choice loop over the Accessibility tree: pure SwiftUI and AppKit, local Metal Whisper transcription, and Accessibility plus microphone permissions held by JevOrb.app instead of your terminal.
Jev Demos & Experiments#community#jevbest#catalog-import
A Turborepo proof of concept that replays a fictional ACME support call about once per second and schedules a real TypeSafe evaluation for every new turn, coalescing turns that arrive while a request is in flight and persisting evidence, confidence and score history to SQLite.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
A two-package collection of TypeSafe System One demos: jev_common is a shim for the API that loads .env and records results, and maze_lookahead checks spatial reasoning by testing how far the model can think ahead in a maze.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
A public X demo of TypeSafe Jev, in a repository named jev-ad-preflight. The README is one line - Typesafe/Jev public X demo - with no install steps, no description of the checks, no model choice and no recorded results.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A public X demo of TypeSafe Jev, in a repository named jev-should-i-apply. The README is one line - Typesafe/Jev public X demo - with no install steps, no description of the questions asked, no output format and no results.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
A public X demo of TypeSafe Jev, in a repository named jev-user-jury. The README is one line - Typesafe/Jev public X demo - with no install steps, no description of who the jury is, no questions and no results.
Jev Demos & Experiments#community#jevbest#catalog-import
A Next.js demo that sends one request of 36 independent questions to TypeSafe and renders a twelve-member council voting on your idea: each character answers approve, oppose or baffled, plus an enthusiasm score and a confusion probability.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
MCP server built on TypeSafe's official JavaScript SDK. One `ask` call batches choice, noul and score questions over a single state and returns per-option probabilities plus a separate confidence value.
Jev Agents & MCP#community#jevbest#catalog-import
Rust port of the Python system-one-adapter: a drop-in stand-in for TypeSafe's `system_one` evaluation API backed by LLM providers instead, so the same questions can be scored against an LLM on cost, speed and intelligence.
Jev Practices & Patterns#community#jevbest#catalog-import
3GitHub stars
Emoji autocomplete where every pause in typing triggers one Jev call answering eight typed questions in parallel: an emoji choice, an emotion choice, three scores and three booleans, in about 100 ms of model time.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
Local TypeScript library and CLI for exploratory browser testing: Jev picks actions and judges observed results while Playwright executes them in isolated sessions, with trace files, reports and replay that needs no model calls.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
Repository navigation tool that pairs a lexical index and reference graph with small typed Jev judgments: Find narrows to candidate files, Map locates a subject's members, and Explain builds an evidence-backed graph.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
Shared 1,000 by 1,000 emoji canvas where Jev paints alongside visitors: after each stroke it picks a keyword-matching emoji and a named position relative to that stroke, and answers whether the stroke is unfinished.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
Local stdio MCP server that lets an agent delegate a decision: send a decision, context and 2 to 64 choices, get back a recommended choice with per-choice percentages and an explicit statement of where those percentages came from.
Jev Agents & MCP#community#jevbest#catalog-import
Preprint plus reproducible experiments arguing that per-hop calibration does not compose across a decision pipeline: two lemmas, a Deferred Crispification design law, a BSF-S1 reference architecture, and two weight-free audit metrics.
Jev Practices & Patterns#community#jevbest#catalog-import
n8n community node for TypeSafe's System One API, exposing yes or no, choice and score questions as workflow nodes, with an Evaluate Questions operation that batches several over one state in a single request.
Jev Integrations & Adapters#community#jevbest#catalog-import
0GitHub stars
Registry of Jev question packs as data, with YAML questions, JSONL golden cases and recorded evidence, plus an offline-reproducible benchmark scoring TypeSafe, Anthropic and a local open-weights model on identical ground truth.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
Reference TypeScript integration for Jev that keeps thresholds in your code and confidence bands in the type: a decision builder, runtime response validation, a rule fallback, and an eval CLI that refuses thresholds from thin data.
Jev Tools & CLIs#community#jevbest#catalog-import
Experimental Minecraft Java bot driven by direct TypeSafe choices, one movement pulse, turn, aim, mine or place per decision, with the real API request and response shown beside a live third-person world view.
Jev Demos & Experiments#community#jevbest#catalog-import
A benchmark for browser-using agents hosted on Almond: one prompt, five timed events scored by the page, plus Almond-fastloop, a ~200-line Chrome DevTools loop where Jev picks one bounded action per tick.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
Two studies on whether Jev can be turned into a trading signal: Nasdaq-100 headlines and price candles. Publication-day rank IC is +0.24; the window you can actually trade is flat and the long-short loses 18 bps a trade.
Jev Practices & Patterns#community#jevbest#catalog-import
0GitHub stars
Upworthy's randomized headline A/B tests, filtered to variants that shared an image: Jev picks the click winner 64.5% of the time on a held-out confirmatory split, and 74.7% when the real gap was decisive.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
An independent Chinese-language report auditing where Jev's headline numbers come from, plus a reproducible 50-sample Chinese evaluation: 86 of 90 judgments right, ECE 0.070, run for a fraction of a cent.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
A reference app for Jev's typed primitives: three use cases — support routing, compare-and-choose and content triage — behind one server-side SDK boundary, with a developer view of every question, threshold and token count.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
A French-language design note for a Minecraft agent: deterministic world code, an LLM strategist called at most twice a minute, and Jev picking among movement primitives each tick while a structured journal holds what neither model remembers.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
A Codex plugin that asks Jev which conversation passages still matter, lets Codex compact normally, then restores the selected excerpts verbatim afterwards with labels for their original role and tool source.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
A Choice-only decision framework around Jev: a local rule engine answers reject, short-circuit, route and constrain cases with no remote call, and only misses reach a Choice request on TypeSafe, Cloudflare, Vercel or a self-hosted host.
Jev Integrations & Adapters#community#jevbest#catalog-import
0GitHub stars
A minimal Japanese walkthrough of calling Jev through the TypeScript SDK on Bun: install, set the key, run the SDK's own sample, then extra scripts covering Noul, placeholders, parallel calls and Japanese prompts.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
A pre-install gate for npm lifecycle scripts: pkgGate() pulls the preinstall, install and postinstall hooks from a package name, a path or a raw command, judges them with System One, and returns allow, warn or block.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
A Python linter that scores code comments with System One on five heuristics — usefulness, readability, accuracy, redundancy, coverage — and fails the pipeline when a comment falls under a threshold.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
Elixir client for the TypeSafe AI System One API: supervised Mint HTTP/1 and HTTP/2 connections, bounded concurrency, request deadlines, retries and telemetry, with typed Choice, Score and Noul answers.
Jev Repos & SDKs#community#jevbest#catalog-import
3GitHub stars
Fifteen independent local plugins for the Paseo desktop app, two of which use Jev: an evaluator exposed to Codex and Claude agents over MCP, and an orchestrator that routes a task to one model profile and effort level.
Jev Integrations & Adapters#community#jevbest#catalog-import
An empty GitHub repository named jev-finance-benchmark. The page shows no description, no topics, no commits, no files and no license — there is nothing published here to read, run or evaluate.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
Experimental Snake environment where the engine owns the deterministic rules and Jev picks every direction from structured state, with a browser human baseline and a pygame client sharing one fixed server clock.
Jev Demos & Experiments#community#jevbest#catalog-import
2GitHub stars
Jev plays the hosted RALLY browser game live: structured telemetry in, typed Choice decisions out, executed through ordinary Chrome input by a dependency-free Node controller that records every decision it made.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
Upload a PDF and get an understandability and completeness judgment back in seconds: the browser extracts passages, a Cloudflare Worker judges each one in parallel with typed System One questions and visible rubric arithmetic.
Jev Demos & Experiments#community#jevbest#catalog-import
1GitHub stars
Ground-truth benchmark data for Jev and six LLMs answering the same typed questions on PubMedQA, Banking77 and HelpSteer2, published as a board plus per-decision JSONL logs so every number can be recomputed.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
Plugin for Claude Code and Codex CLI that turns project rules into typed Jev questions a lifecycle hook uses to block a tool call or a final response, instead of trusting the agent to remember them.
Jev Agents & MCP#community#jevbest#catalog-import
A read-only market demo that pulls Coinbase trades for BTC, ETH and XRP, folds the last 60 seconds into up to twelve five-second OHLC samples, and asks one shared Jev request for a buy/wait call per coin.
Jev Demos & Experiments#community#jevbest#catalog-import
7GitHub stars
The Chromium offline T-Rex Runner extracted into a standalone ES6 Runner class with no circular dependencies, plus an optional Jev controller that picks a maneuver and jump profile per obstacle.
Jev Demos & Experiments#community#jevbest#catalog-import
0GitHub stars
A browser-based planetary rover sandbox with a keyless local 3D baseline and an optional selectable TypeSafe controller, where every decision can be inspected, held in teaching mode, saved, replayed and compared against the baseline.
Jev Demos & Experiments#community#jevbest#catalog-import
An unaffiliated, API-only audit of Jev calibration built on roughly 7,000 public HTTP calls, covering abstention, Korean, probabilistic coherence, option order, question interference, caching and latency, with a drift ledger.
Jev Practices & Patterns#community#jevbest#catalog-import
0GitHub stars
A Python workspace plus Manifest V3 Chrome extension that turns a rough opinion into a draft in your own voice, with an OpenAI clarity pass and Jev as the style judge, and per-phrase accept or dismiss.
Jev Tools & CLIs#community#jevbest#catalog-import
0GitHub stars
A Pi extension that keeps your existing coding model as the only agent and adds Jev as a coprocessor for search reranking, a pre-edit semantic gate, and a diff review against the task's starting commit.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
A local Qwen3-Reranker-0.6B judge that returns choice, score and noul answers from yes/no scores rather than generated text, LoRA-tuned on JGLUE NLI and STS and served from a local FastAPI app.
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.

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