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.
405 experiments · showing 121–180
A synthwave highway racer where Jev suggests lanes, tactics and nitro while a per-frame governor watches the moving road.
SOURCE SCREENSHOTEXPAND ↗
from the source
const questions = { recommended_lane: { type: "choice", instructions: "Select the safest forward lane that guarantees zero collision with oncoming traff...
A crisis-response simulation in which Jev helps decide where to send each team.
ACTUAL RECORDING12 SEC ↗
from the source
const response = await this.client.systemOne({ state: normalizeState(state), model: this.model, questions: toSdkQuestions(questions),});
A table-tennis game where Jev's answer is the paddle's target pixel and a tiny local servo simply moves there.
SOURCE SCREENSHOTEXPAND ↗
from the source
return {"place": { "type": "choice", "instructions": ("The ball is coming toward your face at x=%.0f. Where should the CE... "when the ball arrives, so that the ball hits your face? Work out w... "will be at x=%.0f, then pick the position closest to it. Your padd...
Turns Jev's judgments into conversation by compiling a semantic plan into an English sentence.
SOURCE SCREENSHOTEXPAND ↗
from the source
const CONFIDENCE: NoulQuestion = { id: "confidence", kind: "noul", prompt: "Can this message be responded to substantively, without inventing facts?",
A browser MuJoCo lab where Jev chooses instructions for individual robot ducks or a small swarm.
SOURCE SCREENSHOTEXPAND ↗
from the source
questions: { intent: { type: "choice" as const, instructions: { question: "Which ONE eligible group intention should the four-robot simulator execut...
Replays the same restaurant evening under hand-written rules or Jev-selected service tours for a fair side-by-side comparison.
SOURCE SCREENSHOTEXPAND ↗
from the source
return { model, state: { server: context.server, tasks }, questions: { service_tour: { t...
A ring-maze game that asks Jev for the best move from every cell, then colors each played or overruled step.
SOURCE SCREENSHOTEXPAND ↗
from the source
// A POLICY can be asked for in parallel questions, because a policy is a// function of the cell alone. So: one question per cell — "standing at ring R,// sector S, which move begins the optimal route to the centre?" — with that// cell's own doors listed as the options. Every question is self-contained, so
An AI player tackles Unreal Tournament 99 on a real Windows 98 machine.
SOURCE SCREENSHOTEXPAND ↗
from the source
move: choice("What movement should the player take right now?", { advance: "Move forward, toward the objective or nearest enemy.", retreat: "Move backward, away from danger.", strafe_left: "Strafe left.",
A self-running browser instrument that asks Jev which musical scene, harmony, phrase, riff and timbre should arrive next.
SOURCE SCREENSHOTEXPAND ↗
from the source
export const KINDS = { scene: { next: { type: 'choice', instructions: SET + 'Choose the scene that should come next so the set keeps developing over tens of m...
A 3D character whose movements, expressions and gaze are chosen by Jev.
SOURCE SCREENSHOTEXPAND ↗
from the source
for (const m of MOTIONS) { questions[m] = { type: 'noul', instructions: `The user just said to the robot: "${msg}". ` + doing
Two Jev brains perform a fixed piano piece, choosing hand and finger positions for each 100-millisecond slice ahead of time.
SOURCE SCREENSHOTEXPAND ↗
from the source
A hand has a fixed span and five fingers that never cross. A note sounds only if a finge...already resting on that exact key when its moment arrives. Every 100 ms slice of the pie...question to [TypeSafe's Jev](https://docs.typesafe.ai/introduction): where does this han...and which key does each of its fingers rest on. Jev answers with option ids from the lis...offered, never a key name or a coordinate.
Pitch an invention to three fictional judges and try to win their votes.
SOURCE SCREENSHOTEXPAND ↗
from the source
const result = await client.systemOne({ state, questions: Object.fromEntries( person.criteria.map((c) => [ c.id,
A pixel-art experiment that asks Jev to choose the colors from a short brief.
SOURCE SCREENSHOTEXPAND ↗
from the source
export const BRIEF_QUESTIONS = { boundary: { type: 'score', criteria: VERT, instructions: "Where, top to bottom, does the main boundary between the picture's tw... focal_present: { type: 'noul', instructions: 'Does the picture have one clear focal object that the eye goes to fir...
Three experiments in making color themes, photo grades and charts from Jev's decisions.
SOURCE SCREENSHOTEXPAND ↗
from the source
import { choice, score } from "@typesafe-ai/sdk";export const HUE_ANGLES: Record<string, number | null> = { red: 25, orange: 55, yellow: 95,
Turn a 3D Rubik’s Cube yourself while Jev decides when to coach you, stay quiet, or offer a demonstration.
SOURCE SCREENSHOTEXPAND ↗
Enter a Korean name and see Jev choose the most likely age band for it in a small React experiment.
SOURCE SCREENSHOTEXPAND ↗
Explore numeric guessing with Jev choosing higher, lower or exactly while Python narrows the interval around each guess.
SOURCE SCREENSHOTEXPAND ↗
Compare decision models in simulated driving, airport and support-desk worlds, watching their choices or collecting results from the command line.
SOURCE SCREENSHOTEXPAND ↗
AutoTrust’s open-weight JEV-27B-VL turns images into fixed-answer decisions, with a sped-up Mario demonstration showing movement and jump choices.
ACTUAL RECORDING12 SEC ↗
Change a robot’s sorting rule, take over a game, or inspect Jev’s choices in DriftLoom’s eight-demo playground.
SOURCE SCREENSHOTEXPAND ↗
Jev chooses moves for a playable version of Tetris.
SOURCE SCREENSHOTEXPAND ↗
A small browser game challenges players to outguess Jev.
SOURCE SCREENSHOTEXPAND ↗
from the source
npm installnpx wrangler loginnpx wrangler secret put TYPESAFE_API_KEY # required before the first deploynpx wrangler deploy # → https://beatjev.<you>.workers.dev
Jev controls the paddle of a Next.js brick-breaker in real time.
SOURCE SCREENSHOTEXPAND ↗
Play either side of a browser chessboard while Jev chooses the opposing moves from structured board state.
SOURCE SCREENSHOTEXPAND ↗
An endless Three.js cyberpunk arena shooter uses Jev to drive combat decisions.
SOURCE SCREENSHOTEXPAND ↗
from the source
┌───────────────────────────┐ │ TypeSafe AI Jev Model │ │ (or Local RLCD Engine) │ └─────────────┬─────────────┘ │
A game about linking two seemingly unrelated things in as few steps as possible.
SOURCE SCREENSHOTEXPAND ↗
Arrive in a village of Jev-driven characters and earn their trust before nightfall—or try to get away with a lie.
SOURCE SCREENSHOTEXPAND ↗
A hundred AI residents go about their lives in a tiny town, with Jev choosing what each does next.
SOURCE SCREENSHOTEXPAND ↗
from the source
Jev Lab ├── Hundred 100 people, one town └── Jev Shogi human Sente, Jev Gote
Jev Arcade pairs an industrial duel with a neon survival game, both playable against live AI.
SOURCE SCREENSHOTEXPAND ↗
Play tic-tac-toe or Connect Four against Jev while conventional code enforces the rules.
SOURCE SCREENSHOTEXPAND ↗
A terminal tool races through Wikipedia links by asking Jev to rank each possible next page.
SOURCE SCREENSHOTEXPAND ↗
from the source
git clone https://github.com/komikat/jev-bfs.gitcd jev-bfsuv sync --lockeduv run jev-bfs --install-browseruv run python -m unittest discover -s tests -v
A visual lab runs Jev and scripted agents across several games and emulator platforms.
SOURCE SCREENSHOTEXPAND ↗
from the source
uv run jev-games play --game mario --policy scripted --decisions 20uv run jev-games play --game kungfu --policy scripted --decisions 20uv run jev-games play --game doom --policy scripted --decisions 20uv run jev-games play --game mario --policy jev --decisions 10
A MoonBit playground for trying Jev's Choice, Score and Noul question types.
ACTUAL RECORDING12 SEC ↗
noul
This message is spam.
Jev plays browser table tennis from structured telemetry and sends its choices through ordinary Chrome inputs.
ACTUAL RECORDING12 SEC ↗
Jev plays Snake by reading the board and picking a direction on every tick.
SOURCE SCREENSHOTEXPAND ↗
from the source
snake_game/├── game.py # pure game rules and state transitions├── jev_agent.py # typed Jev adapter├── state.py # game state -> JSON-compatible AI state├── config.py # defaults and environment overrides
Jev plays the Chrome dinosaur runner.
SOURCE SCREENSHOTEXPAND ↗
A playable Tetris asks Jev to choose each piece's rotation and column from the board state.
SOURCE SCREENSHOTEXPAND ↗
Spawn Minecraft bots and give them goals, with a planner choosing the task and Jev handling the immediate actions.
SOURCE SCREENSHOTEXPAND ↗
A cyberpunk game of bluffing your way past a border guard powered by Jev.
SOURCE SCREENSHOTEXPAND ↗
A cooperative platform shooter puts a Jev-controlled partner beside the player.
SOURCE SCREENSHOTEXPAND ↗
Jev plays Atari Pong by answering one movement question per frame without receiving raw coordinates.
SOURCE SCREENSHOTEXPAND ↗
from the source
bridge/pong_bridge.py ALE/Pong-v5 behind a JSON step APIsrc/core.ts arithmetic, wording, the question, the baseline policysrc/jev.ts TypeSafe System One client, one POST, no SDKsrc/bridge.ts HTTP client for the environmentsrc/agent.ts the play loop, emits ticks and never prints
An autonomous agent plays PlayStation 2 games while a live HUD shows Jev's visual telemetry.
SOURCE SCREENSHOTEXPAND ↗
from the source
export TYPESAFE_API_KEY="your_api_key_here"export TYPESAFE_MODEL="jev-latest"export EMULATOR_WINDOW_TITLE="PCSX2"export TARGET_FPS="30"
Jev supplies the decisions for non-player characters living in a simulation of River Oaks, Houston.
SOURCE SCREENSHOTEXPAND ↗
A Jev pilot flies through a Python river shooter inspired by Atari's River Raid.
SOURCE SCREENSHOTEXPAND ↗
from the source
.venv/bin/python -m typesafe_pilot # watch it play in r....venv/bin/python -m typesafe_pilot --lockstep # game waits for eac....venv/bin/python -m typesafe_pilot --headless --frames 3000 # no window, prints....venv/bin/python -m typesafe_pilot --record play.mp4 --seconds 60 # save a video with....venv/bin/python -m typesafe_pilot --human # fly it yourself (n...
A 3D planetary rover sandbox tests autonomous choices made with TypeSafe AI.
SOURCE SCREENSHOTEXPAND ↗
Jev moderates a living-room social-deduction game designed for a shared television.
SOURCE SCREENSHOTEXPAND ↗
Two hundred people try to break an agent's defenses while a defender uses each breach to improve them.
SOURCE SCREENSHOTEXPAND ↗
Jev considers several questions about the board at once to choose Snake's next move.
SOURCE SCREENSHOTEXPAND ↗
from the source
git clone https://github.com/siroccomask/snake-jev.gitcd snake-jevuv synccp .env.example .env
Jev presses the controls of a small virtual creature while deterministic code runs its world.
SOURCE SCREENSHOTEXPAND ↗
Play either side of a 3D chessboard against Jev, or watch two Jev players face off.
SOURCE SCREENSHOTEXPAND ↗
Two Jev agents play chess, choosing every move through a typed Choice question.
SOURCE SCREENSHOTEXPAND ↗
Jev controls a Minecraft Java player through tasks such as gathering lumber and building a Canadian flag.
SOURCE SCREENSHOTEXPAND ↗
from the source
{ "model": "jev-latest", "state": { "scenario": "lumber", "goal": "Find trees, collect 10 new logs, then return to the starting position.",
CartShield assigns a fraud disposition to checkout activity for small online shops.
SOURCE SCREENSHOTEXPAND ↗
Crowdcheck simulates how 10,000 AI readers might react to a post before publication.
SOURCE SCREENSHOTEXPAND ↗
Twelve deliberately unqualified AI councillors vote on unusually specific questions.
SOURCE SCREENSHOTEXPAND ↗
from the source
TYPESAFE_API_KEY=your-key-hereTYPESAFE_MODEL=jev-latest
Harness Judge labels each agent step as acceptable, worth retrying, needing escalation or ready to stop.
SOURCE SCREENSHOTEXPAND ↗
HireSignal gives resumes a first-pass fit assessment and an interview recommendation.
SOURCE SCREENSHOTEXPAND ↗
Human Compiler turns prose into compiler-style diagnostics for traits such as passive aggression and corporate jargon.
SOURCE SCREENSHOTEXPAND ↗
from the source
Compiling input.txt (--mode corporate) Lexing 0.4ms 4 paragraphs, 7 sentences, 62 words Analyzing 812ms jev-1.13.0, 45 questions, 1203 tokensPASSIVE_AGGRESSION ████████░░ 0.82CORPORATE_BULLSHIT █████████░ 0.94
Upload a dataset, pose a question and watch Jev classify every row.
SOURCE SCREENSHOTEXPAND ↗
from the source
CONVEX_URL=https://<deployment>.convex.cloudCONVEX_WRITE_SECRET=<operator-provisioned-secret>CONVEX_DEPLOY_KEY=<Convex production deploy key, Vercel Production only>OPENROUTER_KEY=<operator-provisioned-secret>JEV_API_KEY=<operator-provisioned-secret>
A 3D robot companion reacts through typed Jev decisions rather than generated dialogue.
SOURCE SCREENSHOTEXPAND ↗
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.