Read & learn
Written guides.
Understand Jev, one idea at a time. Walkthroughs, recipes, and writeups — our notes first, the original next.
Explore the Jev ecosystem.
Learn, build, and play with Jev — from deep technical guides to creative experiments.
Watch & learn
Video guides.
See an idea take shape. Tutorials, demos, and deep dives, organized by topic and credited to their creators.
Make & explore
Experiments.
See what builders made with Jev. Games, tools, repositories, articles, and more — traced to their sources.
The directory03 / 03 · Experiments
Find something worth exploring.Experiments
Every category, from games and tools to repositories and writeups, traced to a primary source.
Real-time research powered by
Same ideas.
Different paths.
This is the full registry, not just the featured picks. Figures like speed, cost, and stars are maker-reported or captured snapshots, not JevMade measurements.
2140 experiments · showing 481–540
An experiment in letting Jev review commands that Hermes would otherwise ask you to approve.
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from the source
hermes plugins install anpicasso/hermes-jev-approvals/plugin --no-enablehermes auth add jev-approval # paste your TypeSafe key when promptedhermes config set auxiliary.approval.provider jev-approvalhermes config set auxiliary.approval.model jev-latesthermes gateway restart # no hot reload for Python plugins
A Pi extension that asks Jev what context to retain verbatim during compaction.
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from the source
/fast-jev Show status, ledger size, and last-run stats/fast-jev status Same status output/fast-jev run Force one decision pass/fast-jev on Enable for this session/fast-jev off Disable for this session and abort an active pass
A shell client for asking Jev Noul, Choice, and Score questions and receiving numeric answers rather than prose.
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noul
Does the state request a refund?
A playful experiment that makes Jev compose a Grug-style reply one chosen word at a time.
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choice
Choose the next word in Grug reply.
How well does Jev understand Korean, including medical text? This benchmark publishes questions, results, runtime and cost.
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from the source
.venv/Scripts/python.exe -X utf8 -m jevbench.overview_figure
system-one-open recreates Jev-style calibrated decisions with small open Gemma models.
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from the source
modal run build_data.py # ~5 min, CPU onlymodal run typesafe_eval.py # secondsS1_GPU=H100 modal run train.py --name lite-270m --model unsloth/gemma-3-270m-it --tier l...S1_GPU=H100 modal run evaluate.py --run lite-270mS1_GPU=H100 modal run train.py --name e2b-full --model google/gemma-4-E2B-it --tier full...
LitJev wraps ordinary language models in a Jev-like layer for typed choices, scores, and binary judgments.
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choice
What does the customer want?
jevcal derives confidence thresholds, checks calibration, and watches typed decision models for drift against an LLM teacher.
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from the source
pip install "git+https://github.com/abhixhek/jevcal" # corepip install "jevcal[anthropic] @ git+https://github.com/abhixhek/jevcal" # + Claude a...
Race an F1 car against Jev as it picks racing lines, works the pedals, and learns where to push next lap.
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Watch Jev leave home, choose Charmander, and battle its rival in Pokémon Red by handling the game's real branch points.
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Play a MIDI keyboard and hear a Jev-driven partner answer on the next beat or bar.
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A Street Fighter II agent that reads the game state and asks Jev for Ryu's next move.
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Ask a coding model to create, test, and optionally evolve a Jev decision harness for a particular task.
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Type an ambiguous Chinese message and compare judgments about its meaning, anger level, and need for a caring response.
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Watch Kubernetes pods while Jev labels incident severity, suggests a remediation class, and flags cases for a human.
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Triage Gmail at a glance with badges for category, priority, spam likelihood, and whether a message needs a reply.
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Describe a Blender action in plain language, then review ranked operators before running or copying one.
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Searches a Rust codebase in two passes, first shortlisting paths and then returning relevant windows with line numbers.
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Checks changed hunks against editable standards packs before handing the findings to a coding agent.
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Gives Claude Code's reviews, debugging ideas, plans and searches a separate probabilistic second opinion.
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A language and runtime for budgeted agent programs whose declared decisions can be answered by Jev and replayed later.
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from the source
export const TYPESAFE_SYSTEMONE_URL = "https://api.typesafe.ai/v1/systemone" as const;export const JEV_DEFAULT_MODEL = "jev-latest" as const;export const JEV_CREDENTIAL_ENV = "TYPESAFE_API_KEY" as const;
An ad-free YouTube client whose Windows companion experiments with Jev recommendations and quality selection.
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from the source
private const string JevEndpoint = "https://api.typesafe.ai/v1/systemone";
A Rust query language that mixes ordinary analytics with row-by-row semantic judgments from Jev.
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from the source
"questions": { "is_urgent": {"type": "noul", "instructions": "Does this convey urgency?... "department": {"type": "choice", "instructions": "Which team should hand... "criteria": {"billing": "Payments, invoicing, refunds", "... "frustration": {"type": "score", "instructions": "How frustrated is the...
Jev helps Pi choose skills, rank source files and understand failed commands.
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from the source
export type Question = | { type: "noul"; instructions: string; criteria?: { true: string; false: string } } | { type: "choice"; instructions: string; criteria: Record<string, string | null> };export type Questions = Record<string, Question>;export type Answer =
Surveys evidence on Jev and compatible decision models, separating calibration claims, selective control, and open implementations.
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Lets people test which memories Jev would admit, comparing editable cases through an inspectable web interface.
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Uses Jev to keep useful Codex tool output while replacing low-value bulk with bounded excerpts.
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Tracks an imaginary brain budget for Codex using local Laya scores through a Jev-compatible request shape.
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Reviews code against plain-language team rules, using Jev to turn each rule into a probability-backed finding.
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Lets Codex prepare browser goals and text while Jev repeatedly selects the next allowed action, target, and prepared input.
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Flags OpenAPI changes whose schemas still match but whose descriptions imply different behaviour.
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Labels pull requests by type, area, platform, risk, and conceptual scope from their title, body, and diff.
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Overlays Jev judgements on live WeChat messages and publishes the experiment’s failed accuracy tests.
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Test whether Jev can choose compiler optimisation passes from program features, with its decisions compared against measured outcomes.
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A Pi extension masks stale tool output after Jev review while retaining paged access to the original session evidence.
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An Agent Skill and CLI convert decision prompts or calling code into validated Jev requests and runnable integration scripts.
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Review changed code for stylistic warning signs before it ships, with Jev mapping findings to a small verdict set.
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Filter MySQL rows with natural-language conditions through an AILIKE plugin backed by TypeSafe Jev.
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Run tool-using agents where Jev makes bounded decisions, deterministic code executes, and an LLM handles language when needed.
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JevGate reviews code, tests and documentation with small typed questions, then turns the answers into located findings.
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from the source
let first: Vec<_> = plan.requests.iter().map(Task::unit).collect();self.dispatch(report, first, |file, asked, body| { crate::units::record(file, &asked, body)})?;compose_files(&plan, report);
Paste JSON, a JWT, cron, stack trace, code, or prose and watch the page become the tool that content needs.
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Let a group-chat assistant consider useful untagged questions, then recheck whether its reply is still wanted before sending.
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Explore an Enigma codebreaking machine whose local search produces candidate decryptions for Jev to judge.
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An unofficial Ruby client for the TypeSafe AI API.
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from the source
client.system_one( state: { message: "I was charged twice." }, questions: { billing: { type: "noul", instructions: "Is this about billing?", weight: 2 }, tone: Typesafe::SDK::Choice.new(criteria: { calm: nil, angry: nil })
An idiomatic Java SDK for TypeSafe AI's Jev decision model.
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Use Zod schemas to check your data before asking Jev questions about it.
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from the source
import { z } from "zod";import { choice, noul, score, semantics } from "@mateonunez/jod";const Ticket = z.object({ message: z.string(), policy: z.string(),
An independent Rust SDK for the TypeSafe System One API with asynchronous and blocking clients.
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from the source
cargo add typesafe-ai-rs --git https://github.com/gilljon/typesafe-ai-rs --tag v0.1.0
An unofficial Java client for the TypeSafe System One API.
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A Neon Function proxy that routes TypeSafe Jev through the Neon AI Gateway.
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from the source
export SITE_URL="https://safer-with-jev.com"export API_URL="https://api.safer-with-jev.com"
A Jev-powered pull-request risk router and code-review coach.
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A Hermes plugin for typed decisions, ranking, verification, and optional tool gating with Jev.
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from the source
hermes config set plugins.entries.hermes-jev.settings.jev_model typesafe/jev-1.13 --forc...hermes config set plugins.entries.hermes-jev.settings.timeout_seconds 15 --force
A Python command-line agent that uses Jev while working through file-based questions.
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from the source
uv sync --group devcp .env.example .env# Fill in TYPESAFE_API_KEY and OPENAI_API_KEY in .env.uv run jevex 'Read prices.md. How much do three notebooks cost?' --trace run.jsonl
Give the Pi coding agent a way to ask Jev for decisions while it works.
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Slidepilot advances Slidev presentations by matching live speech to the next slide with Jev.
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from the source
pnpm installcp apps/worker/.dev.vars.example apps/worker/.dev.vars# Uncomment TYPESAFE_API_KEY in apps/worker/.dev.vars for real Jev inference.# Terminal 1pnpm dev:worker
Ask Jev questions from the command line, with answers as choices, scores or yes-or-no probabilities.
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from the source
typesafe info # endpoints; does not print the keytypesafe modelstypesafe smoke # docs quickstart exampletypesafe ask --state "…" --noul is_urgent="Does this convey urgency?"typesafe ask --state-file s.json --questions-file q.json --json
A Pi extension that checks risky tool calls and notices when a coding agent gets stuck.
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A browser harness where an LLM plans verifiable subgoals, Jev selects actions and fields, and Playwright executes them.
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from the source
npm start -- --goal 'register a user on example.com' \ --value 'name=Test User' \ --value 'email=user@example.com' \ --value 'password=a-test-password' \ --headed
A browser agent for Ego Lite that asks Jev or another agent to choose one action per observed page state.
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from the source
pnpm exec jev-ego serve --url https://en.wikipedia.org/wiki/Main_Page \ --goal 'Find and open the Wikipedia article about Gödel’s incompleteness theorems.'pnpm exec jev-ego observepnpm exec jev-ego suggestpnpm exec jev-ego act CLICK 4
An MCP browser agent that lets Jev choose each click and map supplied text values to form fields.
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from the source
claude mcp add jev-browse -e TYPESAFE_API_KEY=YOUR_API_KEY -- npx -y -p github:kyrylosyz...
In this browser stealth game, Jev judges the guards' actions while deterministic code runs the world.
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Jev, briefly
A decision model, not a chatbot.
A chat model generates text token by token and hopes you parse it. Jev never generates a word. Your code sends the state of the world plus typed questions; Jev returns every answer in one parallel pass — typed values with calibrated probabilities and a confidence score your code can trust. About 70–500 ms end to end, $0.042 per million input tokens, output free. Trained with what TypeSafe calls Reinforcement Learning for Calibrated Decisions.
choice Pick one of these.
You define the options. Jev returns the chosen option, a probability for every option, and a confidence. The workhorse of routing, agents, and games — the answer space is always legal, so there is nothing to parse and nothing to hallucinate.
score Rate this on a rubric.
You describe ordered levels — say trivial / normal / critical. Jev returns the level, the probability of each, and a confidence. Scores turn fuzzy judgment (“how severe is this log line?”) into a number-free decision your code can branch on.
noul Is this statement true?
You assert a statement; Jev returns the probability that it is true — a noul. Moderation, verification, guardrails, “does this diff actually fix the bug?”: one question, one calibrated probability.
Official material lives at typesafe.ai and docs.typesafe.ai. JevMade is an independent community registry — not affiliated with or endorsed by TypeSafe AI.
Recurring lessons
Patterns that keep showing up.
One decision per tick
Games, drones, trading bots, and browser agents all converge on the same loop: serialize the state, ask one decisive question, act, repeat. Jev’s latency makes the loop feel instant — the model lives inside the control loop, not outside it.
Confidence as a gate
The answer says what; the confidence says whether to act. The most reliable entries threshold on confidence to route edge cases to a slower model or a human — automation with an honest escape hatch.
Shrink the choice space in code
Makers rarely ask Jev to pick from everything. Local tactics prune 225 gomoku moves to ~40; DOM filters turn a page into an element table; code narrows options, Jev judges within them.
Jev judges, LLMs talk
A recurring split: Jev makes every decision cheaply and instantly, and a small LLM is only invoked when a human-facing string must actually be written. Decision and generation are separate budgets.
Made something with Jev?
Send the link — repo, live demo, post, or video — plus a line on what it does and which primitives it uses. Every entry is verified against its primary source before it ships.
Submit your experimentSign in first so we can reply to you. Submissions are reviewed, not published automatically.