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.
- Repos & SDKs202Client libraries, adapters, and source code you can build on with Jev, from the official Python and TypeScript SDKs to community ports in Go, .NET, and PHP.
- Integrations & Adapters145Framework, platform, gateway, and database integrations that put Jev inside the stack you already run, from LangChain and Pydantic AI to Postgres and Home Assistant.
- Agents & MCP302Agent runtimes, coding-agent gates and routers, MCP servers, and skill or context tooling that hand an agent Jev's typed decisions.
- Tools & CLIs447Standalone Jev CLIs, desktop apps, playgrounds, and utilities you run directly, from shell history and semantic search to dashboards and meters.
- Cookbooks91Official, runnable Jev recipes that show what decision models are good at, each with its own datasets, latencies, and numbers.
- Demos & Experiments363Playable demos, games, simulators, and experiments that put Jev in the loop, from Mario and drones to moderation firehoses and trading bots.
- Practices & Patterns248How to design Jev states, questions, and confidence gates the right way, from the official patterns to the failure modes worth designing around.
- Guides & Articles224Documentation, write-ups, and community hubs for learning Jev, from the canonical docs to independent tutorials and reviews.
- Benchmarks & Evaluations55Benchmarks, calibration studies, independent evaluations, and observability write-ups that measure how Jev actually behaves.
- Models & Reimplementations99Open reimplementations of Jev, retrained heads on small models, and inference-time tricks that reproduce the System One shape with other weights.
- Media & Talks55Videos, talks, podcasts, and news coverage about building with Jev.
Browse Jev by use case or industry
The same directory, sliced by what you are building and who you are building it for.
All 2231 Jev resources
Search the full directory, or filter by category and tag.
Showing 577–624 of 736 resources
1GitHub stars
Yes/no decision site that asks Jev and a fair in-browser coin and shows whether they agree. One relay call returns a verdict, the probability behind it and how significant a decision Jev thinks it is, behind crisis and not-yes-or-no gates. Plain HTML, no build step, no sign-up.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
choxos/LetJevDecideJavaScript
choxos/LetJevDecideJavaScript3GitHub stars
Research notes on Jev plus a Cloudflare Worker demo you can paste a support ticket into. Useful for the failure modes rather than the pitch: no arithmetic, unreliable date comparison, scores that are not measurements, and speed and cost figures from TypeSafe's own evaluations.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
zeke/jevTypeScript
zeke/jevTypeScript1GitHub stars
pydecide is one Python client for typed System One decisions — Choice, Score and Noul — over hosted Jev, OpenRouter's Decisions endpoint, local laya on PyTorch or MLX, a sentence-transformers CrossEncoder, or a JSON-prompted LLM fallback.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
gopaljigaur/decidePython
gopaljigaur/decidePython3GitHub stars
A Go gateway that speaks the OpenAI and Anthropic APIs and handles model: "auto" by asking a decision model four typed questions about the prompt — topic, complexity, risk and private data — then scoring models in config.yaml and calling the cheapest one above the quality floor.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
mmornati/system-one-routerHTML
mmornati/system-one-routerHTML3GitHub stars
MEDJEV is an independent, JEV-inspired research implementation for typed evidence decisions: a clinical record or literature passage, a runtime question and a candidate set supplied at call time, scored into an explicit probability distribution plus calibration scope. Alpha research code, not clinical software.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
PAI-CUHK/MEDJEVPython
PAI-CUHK/MEDJEVPython1GitHub stars
PlotVeil is a Chrome extension that hides YouTube comments until a single typed Noul decision says the comment gives away the video you are on. The rule text travels from the extension to a Cloudflare Worker, which batches up to 20 comments per call and never sees the word spoiler.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
Dearest/plotveilTypeScript
Dearest/plotveilTypeScript1GitHub stars
jev-filter is a CLI that filters tool output before it reaches your agent and, since 0.3, drives web pages and desktop apps too. Jev picks the next operation and its target among controls the program enumerates itself; the program re-checks and executes, and irreversible steps stop for confirmation.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
apixly-ai/jev-filterPython
apixly-ai/jev-filterPython1GitHub stars
jevx is a Zig terminal agent that keeps Codex for code generation and confines Jev, reached through OpenRouter, to bounded choice, noul and score decisions for routing, hazard checks, impact and verification. The Zig side, not the model, holds the permissions and the final control flow.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
SupratimSircar05/jev-zig-cliZig
SupratimSircar05/jev-zig-cliZig2GitHub stars
jevXagent is a localhost proxy that sits in front of Claude Code, Codex, Kilo Code and Cline. It asks Jev to classify the prompt first, then injects that verdict into the agent's system context so the main model skips re-deriving the same classification.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
j1s4nn/jevXagentPython
j1s4nn/jevXagentPython1GitHub stars
XianHui for Windows screenshots the WeChat window, reads the other side's messages with local RapidOCR, and asks Jev which one has to be answered now, then shows up to five threads as a colour-coded overlay that jumps you to the right chat app. It ranks, it never replies.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
jeffyuysw/jev-xianhui-windowsPython
jeffyuysw/jev-xianhui-windowsPython0GitHub stars
Last Exit is a short cyberpunk checkpoint game where you type a cover story, present a manifest and offer a bribe to an inspector who decides whether to let you through. Each reply makes two Jev calls: one turns your statements into typed observations, the other picks his next action.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
0x963D/last-exitJavaScript
0x963D/last-exitJavaScript2GitHub stars
Jevegis wraps Jev into a single guardrail call for LLM apps: one request covering prompt injection, jailbreaks, credential and PII leaks, unauthorized actions, malicious code and indirect injection in retrieved documents, plus Trust & Safety moderation. It returns probabilities rather than booleans.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
0xArx/jevegisTypeScript
0xArx/jevegisTypeScript2GitHub stars
A Pi extension that catches the turn-ending "Continuing the run" reply and sends the agent back to it, gated on the latest user request actually containing a command to do work.
Jev Agents & MCP#community#jevbest#catalog-import
0GitHub stars
A short field note on playing Jev at chess: both sides keep proposing draws in positions that are far from balanced, then go on to win, with the loss probability much lower.
Jev Practices & Patterns#community#jevbest#catalog-import
1GitHub stars
An OpenAI-compatible proxy that spends one Jev call per request on injection, harm and PII checks plus a tier label, then routes to a small or large backend from pure code.
Jev Agents & MCP#community#jevbest#catalog-import
Community
aniruddh-krovvidi/switchboardPython
aniruddh-krovvidi/switchboardPython0GitHub stars
A pygame-ce river shooter whose AI pilot splits the river into 20 lanes and asks Jev one parallel System One request per decision for lane, fire and speed.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
ashaazami/river-run-typesafePython
ashaazami/river-run-typesafePython1GitHub 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
Community
awun8191/jev-resume-analyzerPython
awun8191/jev-resume-analyzerPython0GitHub 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
0GitHub stars
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
Community
blas0/jev-shadcn-lint-evalJavaScript
blas0/jev-shadcn-lint-evalJavaScript0GitHub stars
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
Community
Bud-ro/jev-demosDart
Bud-ro/jev-demosDart0GitHub 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
Community
cardotrejos/jev-ad-preflight
cardotrejos/jev-ad-preflight1GitHub 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
Communitycardotrejos/jev-should-i-apply
cardotrejos/jev-should-i-apply0GitHub 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
Communitycardotrejos/jev-user-jury
cardotrejos/jev-user-jury0GitHub stars
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
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
Community
colinmcdermott/emoji-jevTypeScript
colinmcdermott/emoji-jevTypeScript0GitHub 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
Community
CorieW/JevTestTypeScript
CorieW/JevTestTypeScript0GitHub 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
Community
cpaczek/s1sTypeScript
cpaczek/s1sTypeScript0GitHub stars
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
0GitHub stars
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
3GitHub stars
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
0GitHub stars
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
Community
eriestra/browser-use-olympicsHTML
eriestra/browser-use-olympicsHTML0GitHub 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
Community
Gaurav-Gosain/jev-alpha-benchGo
Gaurav-Gosain/jev-alpha-benchGo0GitHub 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
CommunityGaurav-Gosain/jev-headline-benchGo
Gaurav-Gosain/jev-headline-benchGo1GitHub 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
Community
HackSing/jev-reportPython
HackSing/jev-reportPython0GitHub 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
Community
Hardel-DW/jev.modsJava
Hardel-DW/jev.modsJava0GitHub 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
Community
heiwa4126/jev-bun1TypeScript
heiwa4126/jev-bun1TypeScript0GitHub 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
Community
hemanth/pkg-gateJavaScript
hemanth/pkg-gateJavaScript0GitHub 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
Community
Hexdigest123/typesafe-commentPython
Hexdigest123/typesafe-commentPython0GitHub 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
Community
hfiguera/typesafe_aiElixir
hfiguera/typesafe_aiElixir1GitHub 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
Community
iammusham/jev-snakePython
iammusham/jev-snakePython2GitHub 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
Community
Jevals/jevals-data
Jevals/jevals-data0GitHub stars
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
Community
juancamiloqhz/roverlabTypeScript
juancamiloqhz/roverlabTypeScriptStart 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
Community
Hawxy/TypeSafeAI.NetC#
Hawxy/TypeSafeAI.NetC#0GitHub stars
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
Community
tryAGI/TypeSafeAIC#
tryAGI/TypeSafeAIC#Newest Jev resources
The latest additions to the directory, newest first.
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 NewsReddit: 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 NewsHacker News: Decision Index 0.2.1 scores open reproductions of Jev on a frozen suite.
jackbravo4 pointsDecision Index 0.2.1 – 70 open reproductions of TypeSafe Jev's Decision ModelRead the thread on Hacker NewsHacker 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 NewsHacker 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 NewsHow 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.