A curated awesome list of public projects and practices built on Jev, TypeSafe AI's System One model for typed decisions.
This README is the homepage aggregate of the current category files, so the latest accepted entries are visible here without drilling into subpages.
Jev is not a chat model. It takes unstructured state plus a typed question and returns a typed decision — a choice, a score, or a boolean, each with a confidence. That makes it a drop-in decision layer for software: classification, routing, rubric scoring, verification, and agent guardrails. This list tracks who is actually building with it, and which patterns transfer across industries.
The repository treats all categories equally — each entry lives in exactly one category, chosen by its direct Jev application domain. A dedicated Related Practices / Discussions category captures credible public practice signals — X threads, Reddit discussions, and interviews — that describe real Jev usage even when no strong standalone case page exists yet.
Most Jev discussion is scattered across launch threads, model-gateway listings, and one-off prototypes. This list answers two practical questions quickly:
- Where is Jev already making real decisions in production workflows?
- Which decision patterns transfer across industries?
This is not a comprehensive database. It is a high-signal, fast-scanning field guide.
An entry should meet all of the following:
- The source is public and citable.
- The example uses Jev (or a documented Jev port/derivative) for a concrete decision task — not a generic classifier, router, or LLM judge with no Jev involvement.
- The source explicitly names
Jev/jev, cites TypeSafe AI's System One models, or shows a typed-decision loop (typed question → typed answer with confidence → accept/reject/escalate). - The summary explains the scenario, method, and value in one sentence.
We do not include:
- Generic classifiers, routers, or research agents that merely resemble the pattern without using Jev.
- Pure theory or opinion without a concrete practice.
- Launch-hype commentary with no working artifact or reproducible result.
- Long write-ups inside the list itself.
- Sources that are private, inaccessible, or too vague to classify.
- Classification & Routing — 14 entries
- Verification & Guardrails — 7 entries
- Scoring & Ranking — 5 entries
- Agent Decisions — 12 entries
- Data Labeling & Curation — 2 entries
- Evaluation & Benchmarking — 7 entries
- Calibration & Research — 7 entries
- Infra / SDKs / Integrations — 17 entries
- Game & Simulation — 5 entries
- Compliance & Legal — 1 entry
- Content Moderation — 2 entries
- Related Practices / Discussions — 21 entries
- Scientific Pipelines — 0 entries
Each entry lives in exactly one category. When a project could fit multiple categories, we choose the one closest to its direct application domain.
- Classification & Routing (source)
- Verification & Guardrails (source)
- Scoring & Ranking (source)
- Agent Decisions (source)
- Data Labeling & Curation (source)
- Evaluation & Benchmarking (source)
- Calibration & Research (source)
- Infra / SDKs / Integrations (source)
- Game & Simulation (source)
- Compliance & Legal (source)
- Content Moderation (source)
- Related Practices / Discussions (source)
Source file: categories/classification-routing.md
- Notra - Marketing analytics: production GEO platform whose
NOTRA_JEV_CLASSIFIERSflag routes brand-visibility classifiers off an LLM and onto JevBooleandecisions at a 0.5 threshold, targeting 300 ms p50. - jev-router - Developer tooling: routes Claude Code tasks to the cheapest capable model by asking Jev to choose among candidates.
- jev-router (prismhq) - LLM infrastructure: open-source LiteLLM-based router where a Jev decision picks which model serves each request.
- pi-jev-router - Coding agents: adds automatic per-request model routing to the Pi coding agent through Jev decisions on Vercel AI Gateway.
- jcm-router - Coding agents: local proxy that picks the Claude model and reasoning effort per message with a Jev decision while leaving the cached main chat untouched.
- jev-agent-skill-router - Agent infrastructure: routes agent skill selection through typed, confidence-aware Jev decisions so weak matches are declined instead of guessed.
- typesafe-jev CV screener - Recruiting: screens a folder of CVs with Jev typed judgments against an editable policy, re-scoring candidates for free when the policy changes.
- Jev email intent workflow - Back-office automation: async LangGraph workflow gets a typed Jev
Choice(invoiceorgeneral) and routes each inbound email to the matching handler. - unclutter - Browser tooli 8000 ng: WXT extension where Jev decides per page element whether it is clutter, removing it under reusable template rules.
- typesafe-adblock - Browser tooling: Chrome extension that asks Jev whether each DOM element is an ad, turning ad blocking into a stream of per-element typed questions.
- DiffJury - Code review: routes each pull request by risk with Jev before a human reviewer is assigned, doubling as a review coach.
- HA-Jev - Smart home: Home Assistant integration that answers questions about the house as a probability, a choice, or a score.
- secondlayer - Fault triage: self-hosted Stacks data service whose Slack gate and fault-triage paths both run on Jev decisions.
- new-api-typesafe-plugin - LLM gateway: adds a native
/v1/systemoneendpoint to new-api so typed decisions sit behind the same gateway as chat models.
Source file: categories/verification-guardrails.md
- jev-review - Software engineering: staged code-review workflow and local dashboard where Jev gates each review stage before a change advances.
- pi-jev - Agent safety: adds a measured tool-call gate to the Pi coding agent so risky calls are checked by Jev before execution.
- OpenWork - Engineering workflow: wires Jev into its eval testkit as a verification judge so agent-produced work is gated by typed verdicts rather than a text model.
- jev-guard - Agent security: prompt-injection and dangerous-action guard for Claude Code, Codex, Pi, and ACP agents, with Jev deciding what to block.
- Foreman - Software factory: sits above Codex workers and has Jev independently judge whether an implementation is complete, its tests sufficient, or a human is needed.
- jev-code - Coding agents: bounded Jev workflows that keep agent judgments typed instead of free-form.
- opencompany - Agent workspace: runs its approval review through Jev so workspace actions are gated by a typed decision.
Source file: categories/scoring-ranking.md
- Clean Code Judge - Code quality: scores every file of a pull request on 31 boolean Clean Code smells plus function size and nesting, then hands the verdicts to a writing model for the review prose.
- citation-verifier - Academic publishing: checks whether each cited paper actually supports the sentence citing it, with Claude locating the quote, Jev scoring the support, and a human making the final call.
- jev-bfs - Search tooling: finds link paths between English Wikipedia articles by having Jev rank each page's outgoing links while Python controls the search.
- Jev Search - Web search: uses Jev Noul judgments on result titles and snippets to rank Search1API results by relevance, with application code merging duplicate URLs and grouping lower-scoring matches separately.
- pagegrade - Content quality: grades page sections for clarity, writing, and on-page SEO with Jev and returns per-section scores.
Source file: categories/agent-decisions.md
- Jev Ultrafast - Browser automation: browser-use's ultrafast agent where Jev decides each next action and element to click, calling a language model only when text must be typed.
- pi-typesafe-jev - Coding agents: exposes System One judgments as five Pi tools so a model makes narrow semantic judgments while code and users keep control of thresholds, weights, and actions.
- jev-judgment - Coding agents: agent skill that sends closed coding-agent judgments to Jev so verdicts stay typed, cheap, and comparable across runs.
- limpet - Coding agents: Stop hook that keeps an agent from finishing too early by judging plain-language completion rules with Jev.
- robo-harness - Robotics: SO-101 arm workbench where a Jev decision runner picks bounded joint steps from typed candidate actions under a spend budget.
- dsh-auto-mode - Coding agents: DeepSeek Harness permission preset whose end-prompt step has Jev answer the open questions an agent leaves in its final message, steering them back only when a choice clears 0.6 confidence and an autonomy-safety Noul clears 0.5, and returning the turn to the human otherwise.
- augustus - Coding agents: agent skill that maps Choice, Score, and Noul onto classical methods so an agent can place typed judgment in software, with a composition algebra, question-design diagnosis, and a validation gate that requires a falsifying experiment.
- yoshi - Context management: proxy for Claude Code and Codex where Jev judges which conversation history is still needed before pruning.
- pi-jev (TheoOliveira) - Coding agents: semantic tool routing and typed System One decisions for the Pi coding agent.
- pi-quiet-ask - Coding agents: gives the Pi agent a quiet Jev decision layer for judgments it would otherwise hand to a chat model.
- fastbrowse - Browser agents: Jev picks each action from what is on the page while an LLM reads and plans.
- super-jev - Decision harness: turns a Jev answer into a bounded action instead of leaving the caller to interpret it.
Source file: categories/data-labeling-curation.md
- jev-curate - Dataset engineering: sifts synthetic JSONL and Parquet rows using Jev Noul checks and calibrated confidence scores, streaming passed records and rejections straight to disk.
- typeful-triage - Open-source maintenance: multiplayer triage dashboard where Jev answers a fixed set of typed questions per issue — kind, severity, urgency, duplicate, and next step — and every human correction is kept and shown back to the model on later runs.
Source file: categories/evaluation-benchmarking.md
- Jev Playground - Model evaluation: benchmarks Jev against Luna, Haiku, and Gemini at choosing validated legal moves in explicit-state games, scoring decision quality and consistency across a sequence of moves.
- Jev vs Mistral and Gemini for event validation - Event discovery: head-to-head test of Jev against Mistral Small and Gemini Flash-Lite at validating local event listings.
- jev-research-eval - Research automation: reproducible eval harness plus field note for Jev Ultrafast research-browser tasks, with QC'd cases, a suite runner, and a report generator.
- Jev judge call vs dimension scores - Model evaluation: tests one direct Jev question per row against 12–14 Jev-scored dimensions with locally fitted weights on three classification tasks, reaching 0.9076 against 0.8373 on Japanese NLI but flagging about 25× more hard benign rows as attacks.
- Jev Pong - Model comparison: Pong where the ball advances one step per model decision, putting Jev head-to-head with LLMs through Vercel AI Gateway.
- Jev reranking is not a free win - Search reranking: a measured run over 33,047 catalog entries, 164 real queries, and 9,831 graded pairs reports that Jev reranking alone did not beat vector retrieval.
- An early-access test of TypeSafe's Jev - Independent trial: measures calibrated judgments on early-access Jev and reports the resulting cost per decision.
Source file: categories/calibration-research.md
- decider - Open models: reproduces the System One shape with a Qwen3.5-2B fine-tune that emits typed decisions with calibrated probabilities in one pass.
- openjev - Open research: independent local preview that answers bilingual probability questions from context, questions, and candidate answers, inspired by TypeSafe Jev.
- Parallel Constrained Decoding (Qwen2.5-1B-RLCD) - Open research: RLCD-trained Qwen2.5-1B demo exploring open-source parallel constrained decoding as an alternative to Jev.
- NanoJev - Open replica: a 0.6B parallel decision model that returns full probability distributions with no output-token decoding, shipped with its training pipeline, weights, and dataset.
- open-alternative-jev - Open alternative: runs a Jev-shaped decision model locally on your own GPU.
- mini-jev - Local reproduction: implements Jev's typed-decision interface on top of a local LLM.
- Jev-compatible public API - Open research: a public Jev-shaped API backed by an open Qwen3.6-35B-A3B model so anyone can try the typed-decision interface.
Source file: categories/infra-sdks-integrations.md
- eve - Agent frameworks: Vercel's eve engine ships Jev as the default evaluation model (
typesafe-ai/jev) in its experimental evaluate path. - AI CLI - Developer tooling: Vercel Labs CLI that can run Jev as the evaluation model for its
evaluatecommand. - jev-mcp (jkudish) - MCP ecosystem: proof-of-concept MCP server that puts Jev claim verification, content screening, and candidate ranking behind standard MCP tools.
- jev-mcp (blakestone-x) - MCP ecosystem: MCP server exposing Jev classify, score, check, match, and screen as tools for any agent, with confidence on every answer.
- zio-typesafe-ai - Scala ecosystem: ZIO client for TypeSafe AI with a typed DSL over Jev decisions.
- laravel-typesafe-jev - PHP ecosystem: unofficial Laravel integration for Jev with typed responses, async requests, scoped dependency injection, and testing fakes.
- advocaat - Data tooling: small type-safe client for asking Jev questions about a dataset.
- jevclient - Python ecosystem: async client for Jev published on PyPI.
- typesafe-on-neon - Cloud infrastructure: Neon Function proxy for the Neon AI Gateway that routes decisions with Jev.
- typesafe-ai/skills - Official tooling: installable agent skills package (
npx skills add typesafe-ai/skills) that teaches agents the Jev workflow. - Smithers - Agent frameworks: TypeScript workflow framework with a Jev session checker wired into its workflows.
- skillbox - Skills infrastructure: self-hosted versioned skills library that adds optional Jev recommendations using your own TypeSafe or Gateway key.
- Jevbridge - Agent bridges: ACP and MCP adapter that exposes Jev typed decisions to Codex, Claude, Grok, and other LLMs.
- jev (Elixir) - Elixir ecosystem: GenServer client that replies with Jev's answer so callers can pattern match on it directly.
- jev-go - Go ecosystem: community Go SDK for Jev.
- jev-cli - Developer tooling: small dependency-free CLI for Jev.
- decide-mcp - MCP ecosystem: configurable decision server with percentage scores and bias-profile routing on top of Jev.
Source file: categories/game-simulation.md
- typesafe-mario - Gaming: TypeSafe/Jev agent that plays Super Mario Bros. from structured emulator state, choosing each action from emulator-derived features.
- jev-drone - Robotics simulation: camera-only autonomous drone in MuJoCo that puts a Jev judgment model in the control loop at 2.5 Hz.
- tsai-sc - Gaming: drives original StarCraft shareware through keyboard and mouse with Jev action probabilities recorded per decision.
- jev-plays-pokemon - Gaming: reads Pokémon Red game state as text, answers typed questions each turn, and lets deterministic code turn the answers into moves.
- typesafe-jev-drone-demo - Simulation: Three.js drone simulator with a Python backend where Jev drives the navigation decisions.
Source file: categories/compliance-legal.md
- LegalForecast-MTD - Legal forecasting: benchmark that asks Jev to predict federal motion-to-dismiss rulings from the judge's written record and scores the calibrated probabilities with claim-defendant micro-Brier metrics.
Source file: categories/content-moderation.md
- Jev Moderation Bot - Community moderation: Discord bot that scores incoming messages for phishing, spam, and social engineering with Jev and drives a four-stage escalation ladder, injecting pardoned messages back into context as verified-safe precedent.
- jev-spam-eval - Spam filtering: zero-shot spam classification with Jev
Booleanquestions, benchmarked against TF-IDF baselines.
Source file: categories/related-practices-discussions.md
- Introducing System One Models and Jev (Hacker News) - Hacker News: 1,800-point launch thread whose ~480 comments debate whether typed decisions replace LLM calls for classification, routing, and verification.
- Launch thread by Diogo Almeida - X: the 63k-like announcement from TypeSafe's founder arguing RLCD-trained decision models are a shorter path to economic value than chat models.
- Model router built with Jev - X: 948-like demo where Jev decides which model should serve a request before it is forwarded.
- MLP on Qwen 4B mimicking Jev - X: builder reports that a small MLP trained on top of Qwen 4B already reproduces Jev-like decision behaviour.
- Running a local Typesafe Jev - X (Japanese): attempt at running a Jev-style decision model locally, with speed noted as still improvable.
- Jev as an AI agent safety monitor - X: test report using Jev to check each agent action first, reportedly catching most attacks with almost no false blocks and much lower latency.
- Rethinking security engineering with Jev - X: argues that purely engineering decisions in security work belong to Jev rather than a chat model.
- Ask Jev anything, it will judge - X: public Convex-backed demo inviting one million judged questions instead of generated answers.
- First Jev use case in a Mac app - X: a shipped Mac app routes setup and troubleshooting questions to Jev when no language model is loaded.
- Jev 中文解读 - X (Chinese): explains the System One category to Chinese readers as a calibrated, typed decision layer for code.
- TypeSafe AI releases Jev (r/singularity) - Reddit: launch thread framing Jev as a low-hallucination, low-cost decision model for software rather than chat.
- Testing Jev for Pi extensions (r/PiCodingAgent) - Reddit: builders describe using Jev as an agent tool-use safety layer and planning a prompt-complexity model router.
- Jev "playing" Minecraft (r/accelerate) - Reddit: work-in-progress demo of Jev driving Minecraft, including fleeing zombies at night, as a test of fast structured decisions.
- Awesome Jev by TypeSafe - Curated list: a peer collection of Jev use cases, patterns, prompts, and starter code, with a video walkthrough of eight projects people already built.
- Jev on OpenRouter - X: OpenRouter ships Jev in beta, exposing the System One model through its routing layer.
- Jev on Cloudflare AI Gateway - X: Jev goes live on Cloudflare's AI Gateway, callable from Workers.
- Jev for instant compaction - X: argues agent context compaction should be a Jev decision rather than a summarization prompt.
- Reviewing unnecessary tool calls with Jev - X: a Claude plugin asks Jev to review redundant tool calls, running in about a second.
- 19 open-source Jev projects - X (Chinese): tallies 19 open-source Jev projects totalling more than 6,800 stars.
- Jev is the fish at the poker table - Blog: plays poker with Jev and uses the table to probe where a fast decision model helps and where it does not.
- Jev is about to change the AI economy - Substack: argues that cheap calibrated decisions move where inference spend goes.
Use exactly one line per entry:
- [Name](URL) - Industry: one-sentence description of the Jev use case.- Pick the category that best matches the direct Jev application domain.
- Add a single-line entry in the required format to the category file, not directly to the README aggregate.
- Keep the summary concrete and scannable.
- Prefer examples that clearly show scenario + typed decision + value.
See CONTRIBUTING.md for details.
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