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 481–528 of 954 resources
3GitHub stars
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
Community
kylemclaren/jevpdfTypeScript
kylemclaren/jevpdfTypeScript7GitHub stars
Python agent that runs Discriminative MCTS with Jev judging and Gemini 3.8 Flash proposing. Choice supplies action priors and branching width, Score evaluates states on a 1-10 rubric, and Noul checks execution and ends the loop at 0.85 confidence, with a local web UI for following runs.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
lhemerly/mcts-agentPython
lhemerly/mcts-agentPython4GitHub stars
Claude Code CLI that ranks every skill installed on your machine against a session goal using Jev, then tells the agent which one to load. Three possible answers: load this skill, nothing you have installed fits, or no skill is needed, and nothing else runs for the rest of the session.
Jev Agents & MCP#community#jevbest#catalog-import
Community
lomeshdutta/skill-routerPython
lomeshdutta/skill-routerPython3GitHub stars
Python CLI that classifies a request into one of three tiers — local rule, structured decision or skill, or foundation model — using TypeSafe Jev, 20 bundled skill profiles with exclusion conditions, and local environment checks.
Jev Agents & MCP#community#jevbest#catalog-import
Community
maker-KK/todo-jevPython
maker-KK/todo-jevPython2GitHub stars
Local service for authoring versioned judgment functions on TypeSafe Jev in a browser, then publishing one immutable version that both your backend calls over HTTP and your coding agents call over MCP, using a scoped client token.
Jev Agents & MCP#community#jevbest#catalog-import
Community
molis-ai/jev-workbenchTypeScript
molis-ai/jev-workbenchTypeScript3GitHub stars
Plugin for Claude Code and native Codex that layers Jev-assisted task routing, evidence search, context compaction and readable tool output on top of the host, where typed judgments inform policy but the host keeps ownership of permissions and execution.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
MongLong0214/jev-gateTypeScript
MongLong0214/jev-gateTypeScript5GitHub stars
Python 3.12 CLI that drives real Chrome through Browser Harness and asks Jev to pick each next browser operation and target, while scenario fixtures, deterministic assertions and fresh persistence reads decide the actual contract verdict.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
Nainish-Rai/jev-frontend-qaPython
Nainish-Rai/jev-frontend-qaPython4GitHub stars
Open-source Electron computer-use agent for macOS and Windows that reads the apps you select through native accessibility with local OCR added for text targets, and asks Jev to choose concrete actions that it shows you before executing.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
NobleSpartan6/ottoTypeScript
NobleSpartan6/ottoTypeScript3GitHub stars
TypeScript guardrail that puts seven Jev checks in front of an AI SDK model or an OpenAI-compatible endpoint, blocks on high-confidence hard checks, downgrades low confidence to a flag, and logs every verdict as a PII-free JSONL row you can turn into an eval set.
Jev Integrations & Adapters#community#jevbest#catalog-import
Community
noelzappy/tripwireTypeScript
noelzappy/tripwireTypeScript2GitHub stars
Next.js service with a POST /api/migration-guard endpoint that asks Jev a SAFE or DANGER choice about a SQL statement plus target environment, returning HTTP 403 to halt a CI step or HTTP 200 to let Prisma migrations proceed against Postgres.
Jev Agents & MCP#community#jevbest#catalog-import
3GitHub stars
Unofficial .NET 10 HTTP client for TypeSafe Jev and the Jev-compatible local Laya server that posts the shared /v1/systemone body and returns typed Choice, Score and Noul answers, with no runtime package dependencies.
Jev Repos & SDKs#community#jevbest#catalog-import
Community
pinkroosterai/SystemOneSharpC#
pinkroosterai/SystemOneSharpC#6GitHub stars
CC0 curated list of Jev-based open-source projects where every entry links to the line of code that calls the API, and the marketing claims about accuracy, latency and cost are replaced with the author's own measurements.
Jev Guides & Articles#community#jevbest#catalog-import
3GitHub stars
pi extension that never summarizes: it asks Jev whether each old tool call and tool result is still needed, then drops or truncates only those, passing text, thinking and images through verbatim in a per-request view.
Jev Agents & MCP#community#jevbest#catalog-import
2GitHub stars
Next.js spectator demo in which two independent Jev agents drive separate Snake browsers through same-origin iframes, clicking indexed direction buttons only, with each board state streamed to a server-only endpoint that returns the chosen target.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
raihankhan-rk/jevarenaTypeScript
raihankhan-rk/jevarenaTypeScript2GitHub stars
A written agent skill, not code: it walks through where a system contains fuzzy semantic judgment that should become a small Jev decision primitive, and what the deterministic code around it should keep owning.
Jev Agents & MCP#community#jevbest#catalog-import
Community
samtay32/jev-system-architect
samtay32/jev-system-architect3GitHub stars
A claim ledger for Jev that recomputes published calibration figures against their own noise floors and runs an 800-item difficulty gradient on jev-1.13.0.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
SamuelSacco/jev-explorationPython
SamuelSacco/jev-explorationPython2GitHub stars
Browser-use loop where a ~200 ms Jev call picks every step, run twice over the same site and model to isolate what a site map changes.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
sightmap/jev-turboGo
sightmap/jev-turboGo2GitHub stars
Chrome extension that labels Bluesky posts and drafts with tone classifiers as you read or type, hiding results the model is not confident about.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
sriganesh/jevibe-checkJavaScript
sriganesh/jevibe-checkJavaScript10GitHub stars
Playwright wrapper that routes natural-language operations and assertions through Jev while clicks, typing and waits stay deterministic, with verification provenance.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
tontoko/jev-browserJavaScript
tontoko/jev-browserJavaScript2GitHub stars
Model router that never names a model: Jev classifies the task family, then a cost-per-task Pareto walk picks the cheapest frontier point clearing its quality floor.
Jev Agents & MCP#community#jevbest#catalog-import
Community
tylerjharden/ailerixTypeScript
tylerjharden/ailerixTypeScript6GitHub stars
MCP layer that lets an agent harness ask Jev for a bounded choice from a candidate set it already allows, while permissions and execution stay with the host.
Jev Integrations & Adapters#community#jevbest#catalog-import
Community
typakon4/jev-layerJavaScript
typakon4/jev-layerJavaScript4GitHub stars
Manifest V3 ad blocker that scores candidate feed elements with Jev's noul primitive to collapse native ads, layered over network rules and a media engine.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
vmendes90/jev-shieldTypeScript
vmendes90/jev-shieldTypeScript5GitHub stars
Paper-only BTC experiment on Bybit data where code gates the market state and Jev picks a long-only spot policy or no trade, run on a Cloudflare cron.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
WebGrga/btc-jev-signalTypeScript
WebGrga/btc-jev-signalTypeScript7GitHub stars
Two committed benchmarks of Jev: chess, deliberately outside its lane, and NPC addressee detection, squarely inside it, with raw requests and a playground.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
wondertwins/jev-benchmarkPython
wondertwins/jev-benchmarkPython2GitHub stars
Game of Thrones roleplay where a narrator model writes each scene and Jev reads it back on five questions that drive the header, music and next prompt.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
phureewat29/jev-gotTypeScript
phureewat29/jev-gotTypeScript7GitHub stars
Four read-only MCP tools that rank files, cut a file down to the relevant part and pick from long lists, measured on a frozen SWE-bench Lite split.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
Bentlybro/siftrPython
Bentlybro/siftrPython2GitHub stars
Claude Code Stop hook that checks each factual claim in a finished answer against the tool output read during that session, blocking the turn on claims the evidence contradicts or does not support.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
VladyslavHontar/clear-headPython
VladyslavHontar/clear-headPython3GitHub stars
Claude Code plugin that scores your prompts against seven coding-agent habits on demand rather than on every keystroke, with a backfill so the first report covers prompts you have already written.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
CrowdLinker/JevPromptCoachTypeScript
CrowdLinker/JevPromptCoachTypeScript2GitHub stars
Describe the change you want in one sentence and it classifies every diff hunk as include, exclude or mixed, prints the plan, then stages the hunks you confirm. It never writes the commit.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
ibrahemid/git-jev-stageTypeScript
ibrahemid/git-jev-stageTypeScript2GitHub stars
Filters long command output for coding agents against a task description, keeping retained lines unchanged and in order, collapsing dropped runs into markers with a saved copy you can print back later.
Jev Agents & MCP#community#awesomejev#catalog-import
Communityibrahemid/jevpruneTypeScript
ibrahemid/jevpruneTypeScript4GitHub stars
Python library and CLI that moves bulk semantic judgments — ticket triage, stale-file tagging, bug or question routing — out of the agent's context into typed Jev questions, with a measured comparison against an in-context control.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
ddfeyes/jev-modePython
ddfeyes/jev-modePython2GitHub stars
Pi extension that uses Jev to judge which older session messages are still worth sending to the model, hiding low scorers from future requests while leaving the session transcript itself intact.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
kevinpita/pi-jev-contextTypeScript
kevinpita/pi-jev-contextTypeScript2GitHub stars
Three Python scripts that have Jev pick CVSS metric values from a vulnerability description while the numeric scores are computed in code, following the FIRST v3.0, v3.1 and v4.0 specifications.
Jev Tools & CLIs#community#awesomejev#catalog-import
Community
Red5d/jev-cvssPython
Red5d/jev-cvssPython2GitHub stars
A Playwright agent that lets TypeSafe's Jev decision model play a real online 2048 site, one API call and one keypress per move, printing calibrated probabilities for all four directions as it goes.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
erhanmeydan/jev2048Python
erhanmeydan/jev2048Python3GitHub stars
A Jev demonstration that pulls live company profiles and headlines from yfinance and reads them into ranked, grounded, routed trade ideas, where every number in the UI is a typed answer from one request.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
0xnairb/research_deskPython
0xnairb/research_deskPython2GitHub stars
Pi package that uses Jev to decide, call by call, which old tool results can leave model context, with a savings gate that rejects prunes too small to be worth the prompt churn and bounded excerpts from status documents.
Jev Agents & MCP#community#awesomejev#catalog-import
2GitHub stars
Web chat where Jev picks the LLM for each message: one Choice question over four priced tiers, then the chosen model replies through the same Vercel AI Gateway key.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
az9713/jev-model-routerJavaScript
az9713/jev-model-routerJavaScript2GitHub stars
A teleprompter of talking points rather than a script: every open point is a Jev Score question, all scored in parallel against what you have said, and a point checks off once it passes a threshold.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
finetuningsingh/intelliprompterHTML
finetuningsingh/intelliprompterHTML2GitHub stars
TypeScript chess library where Jev resolves natural-language move intent against verified legal moves, scores sharpness, strategic theme and king risk in one call, and drives persona opponents.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
hemanth/jev-chessTypeScript
hemanth/jev-chessTypeScript3GitHub stars
Cucumber-style browser tests with no step definitions: Playwright opens the page, Jev picks among the controls actually present what each Gherkin step means, and a lockfile makes reruns deterministic.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
RubyBrewsday/jevcumberTypeScript
RubyBrewsday/jevcumberTypeScript2GitHub stars
Framework-agnostic PHP client for TypeSafe's System One API: send state plus typed Noul, Choice and Score questions in one call, get back probabilities, scores and confidence you can route on.
Jev Repos & SDKs#community#awesomejev#catalog-import
Community
mzainzulifqar/jev-php-sdkPHP
mzainzulifqar/jev-php-sdkPHP3GitHub stars
Hermes plugin that puts an agent's plans, drafts and claimed completions up for review — plan_review, evidence_review, action_verify — plus local approval rules that make no model request.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
bojansandhaus/jev-decisionsPython
bojansandhaus/jev-decisionsPython4GitHub stars
A 3D football match where each of the 22 players is a separate decision-maker: the simulation generates typed move candidates locally and Jev only picks among them, returning a probability per option.
Jev Demos & Experiments#community#awesomejev#catalog-import
Community
atarikcaliskan/jevballJavaScript
atarikcaliskan/jevballJavaScript2GitHub stars
A runtime authorization gateway for agent tool calls: deterministic policy plus six narrow Jev questions produce evidence, then a single-use grant bound to the exact approved action is consumed at execution.
Jev Agents & MCP#community#awesomejev#catalog-import
2GitHub stars
A local chess workbench for measuring Jev as a move chooser: the code enumerates legal moves with chess.js, Jev picks from them, and Stockfish grades every pick without its evaluations reaching the model.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
Dimesio/typesafe-chessJavaScript
Dimesio/typesafe-chessJavaScript22GitHub stars
A calibrated tool-call firewall for coding agents: seven typed risk questions plus one question about whether the task authorized the call decide whether a Bash, Write or MCP action runs, asks, or is denied.
Jev Practices & Patterns#community#awesomejev#catalog-import
Community
RiskAverseTech/toolgateTypeScript
RiskAverseTech/toolgateTypeScript2GitHub stars
A Python library that routes each prompt to the cheapest OpenRouter model that can handle it: Jev classifies domain and complexity, then a deterministic scoring function ranks OpenRouter's live catalog against that classification.
Jev Agents & MCP#community#awesomejev#catalog-import
Community
lucianfialho/jev-model-routerPython
lucianfialho/jev-model-routerPythonStart 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.