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 289–336 of 625 resources
7GitHub 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-benchmarkPython7GitHub stars
A single-page Rubik's cube playground where jev rates your scramble, then solves it one move at a time: each turn is judged from the live cube state, streamed to a 3D cube over SSE, and verified against a reference model before it animates.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
0xtrou/rubikjevTypeScript
0xtrou/rubikjevTypeScript3GitHub stars
A Node CLI, MCP server and local web app that scores document drafts against a context file and a list of questions, so an agent can rewrite against per-question scores.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
a-Fig/jev-scoreJavaScript
a-Fig/jev-scoreJavaScript4GitHub stars
Four small Pydantic AI demos that put a Jev question at a fixed hook, before the model runs, before a tool runs or after the run ends, and act on the number.
Jev Integrations & Adapters#community#jevbest#catalog-import
1GitHub stars
An unofficial Go client that keeps Jev answers in your own types, so a choice over your enum yields that enum and the compiler checks the switch you write on it.
Jev Repos & SDKs#community#jevbest#catalog-import
Community
anilsenay/jevGo
anilsenay/jevGo2GitHub stars
GitHub issue triage that classifies a new issue as bug, feature, documentation, question or other, applies the matching label when thresholds pass, and asks for only the details it judged missing.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
Ayush0054/metisPython
Ayush0054/metisPython6GitHub stars
A per-prompt capability router for coding agents: a local BM25 shortlist of installed skills, MCP servers, subagents and commands, then one Jev request injects at most one suggestion plus two runner-ups.
Jev Agents & MCP#community#jevbest#catalog-import
Community
bestagentkits/jev-skillfulTypeScript
bestagentkits/jev-skillfulTypeScript3GitHub stars
An MCP server built around measuring questions rather than asking them: jev_ask prototypes wording, jev_eval sweeps thresholds against labeled data, jev_map applies the winner over a workload.
Jev Agents & MCP#community#jevbest#catalog-import
Community
BYK/jev-mcpTypeScript
BYK/jev-mcpTypeScript1GitHub stars
A Letta agent skill that wraps TypeSafe System One (Jev) as a cheap external judge for texts and decisions, plus a paragraph scanner that maps where a document argues, lists, asks, or admits uncertainty. The README is in Russian.
Jev Integrations & Adapters#community#jevbest#catalog-import
2GitHub stars
A Next.js workbench that converts OpenAI-compatible Chat Completions requests into Jev state and typed questions, compares chat output against structured judgments, and publishes saved question packs as proxy routes. The interface is mainly in Chinese.
Jev Integrations & Adapters#community#jevbest#catalog-import
Community
Chandler-Sun/chat2jevTypeScript
Chandler-Sun/chat2jevTypeScript1GitHub stars
An evidence and reproduction package for a Jev decision study: the original fixed-split result on DBLP to ACM entity matching and SciFact relation verification, a later fresh repeat that did not resolve it, and the graph-synthesis work that followed.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
CompleteDotTech/paper-packagePython
CompleteDotTech/paper-packagePython1GitHub stars
An Oh-my-pi extension that asks Jev which parts of large tool results are worth keeping before they enter the main model's context, and can also trim earlier plain-text assistant messages, keeping the original text locally for exact recovery.
Jev Agents & MCP#community#jevbest#catalog-import
Community
d3d0n/omp-statifyTypeScript
d3d0n/omp-statifyTypeScript4GitHub stars
A single-file host agent skill that reports what another skill's next closed decision would be, with a confidence and a probability over every outcome, by asking Jev to choose rather than by running the target skill at all.
Jev Agents & MCP#community#jevbest#catalog-import
3GitHub stars
A local markdown mirror of the TypeSafe documentation plus Lume, a Rust search tool that indexes it with BM25 and a tag graph, so pattern-style queries such as intent routing can walk to the right page without a network round trip.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
DeepBlueDynamics/typesafe-arenaRust
DeepBlueDynamics/typesafe-arenaRust2GitHub stars
A Chrome extension that asks Jev closed yes/no questions about the pages you browse and hangs a label on each item from a rule pack, with per-site sensitivity, read-ahead, optional fading or hiding, and a tuning mode that shows how every judgment was reached.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
elpumberto/barruntoTypeScript
elpumberto/barruntoTypeScript1GitHub stars
Two frozen open-weight Qwen3.5 models read each task four ways, a letter and a pair readout each, and a fit-free fusion plus an agreement router turn those readings into calibrated decisions, with no fine-tuning and no distillation anywhere in the pipeline.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
FeiLiuEM/tetrajevPython
FeiLiuEM/tetrajevPython9GitHub stars
An SRT translator and subtitle QC tool: cue numbers, order and timestamps are preserved locally, missing translations are retried by ID, and Jev flags each source and translation pair that may deserve human review. Web UI or CLI.
Jev Tools & CLIs#community#jevbest#catalog-import
1GitHub stars
A Claude Code plugin that verifies every tool call before it runs, asking Jev five parallel questions about the plan, scope, prior action and stated intent, then allowing, asking or blocking. Fresh installs ship in audit mode.
Jev Agents & MCP#community#jevbest#catalog-import
Community
getexcited/stepwardenTypeScript
getexcited/stepwardenTypeScript2GitHub stars
A .NET 10 and React 19 support-ticket triage application: one batched Jev call yields five typed decisions, a deterministic rule engine makes the final call, and every field reports whether the model or a rule decided it. Accepts Persian and English.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
GhrezaKh74/JevTicktRouterC#
GhrezaKh74/JevTicktRouterC#1GitHub stars
Python adapter that turns an existing LLM into a bounded decision function: define one question and its answers, get scores, optionally calibrate on your own examples, then abstain below a threshold you set.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
grishahq/decisionbridgeHTML
grishahq/decisionbridgeHTML1GitHub stars
Unofficial Go SDK for TypeSafe AI's System One API, kept deliberately minimal: one client, a state map, a map of typed questions, and answers read back by question id.
Jev Repos & SDKs#community#jevbest#catalog-import
Community
guillemus/jev-goGo
guillemus/jev-goGo10GitHub stars
An independent typed-decision server built on Google's DiffusionGemma and SGLang: it reads image pixels as well as text, returns choice, noul and score answers, and ships a drawing playground and local evaluation artifacts.
Jev Demos & Experiments#community#jevbest#catalog-import
Community
Hangzhi/diffusion-jev-sglangPython
Hangzhi/diffusion-jev-sglangPython1GitHub stars
A stunt build where C is compiled and run on a simulated SERV RISC-V CPU whose logic gates are lookup tables of 22 boolean answers that Jev fills in, with the clock, trace and cost on screen.
Jev Practices & Patterns#community#jevbest#catalog-import
Community
i2cjak/RISC-jeVPython
i2cjak/RISC-jeVPython1GitHub stars
A pre-release .NET decision library that keeps the domain in a dependency-free Core assembly and reaches Jev through a pluggable provider, so changing vendors does not mean rewriting your application model.
Jev Repos & SDKs#community#jevbest#catalog-import
Community
iamjonatha/decisionkit-dotnetC#
iamjonatha/decisionkit-dotnetC#10GitHub stars
Two pi extensions driven by Jev judgments: one replaces summary-based context compaction with keep, drop and shorten calls, the other scores each prompt for difficulty and switches pi's model before the turn runs.
Jev Agents & MCP#community#jevbest#catalog-import
Community
iefnaf/pi-jevTypeScript
iefnaf/pi-jevTypeScript2GitHub stars
A Tauri desktop workspace for running coding agents side by side: parallel task queues in isolated Git worktrees, your existing agent sign-ins, and a review step before anything is merged.
Jev Tools & CLIs#community#jevbest#catalog-import
Community
Jackalope-Dev/jackalopeRust
Jackalope-Dev/jackalopeRustStart 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.