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.
Every category, from games and tools to repositories and writeups, traced to a primary source.
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.
380 experiments · showing 241–300
Watch Jev play both sides of chess, then replay each move’s probability distribution beside Stockfish’s grade.
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Play tic-tac-toe while Jev chooses its move from the cells that remain empty.
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A paper-trading loop for BTC and ETH that tests Jev's market judgments under explicit fees, latency and risk limits.
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Replays historical stock data to compare Jev-directed paper trades with moving-average and buy-and-hold baselines.
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A browser shooter with Jev directing the tanks and riflemen you face.
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from the source
const providerSchema = z.object({ model: z.string().min(1).max(100), answers: z.object({ tactic: z.object({ type: z.literal("choice"),
A retro platformer where Jev chooses maneuvers and detours while code keeps control of physics, jumps and pit-saving reflexes.
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from the source
import { choice, noul, score } from "@typesafe-ai/sdk";import type { Personality } from "@/lib/game/types";const MANEUVERS = { advance: {
Type a line and watch a 3D avatar choose one of fourteen performance styles and play the matching animation.
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from the source
const TS_URL = "https://api.typesafe.ai/v1/systemone";const KEY_ITEM = "jev-stage.typesafe.key";function buildQuestions(){ const crit = {};
A Clash Royale-style sandbox where one request chooses whether to play, which affordable card, which lane and how deep.
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from the source
const response = await client.systemOne({ state: { gameTimeRemaining: Math.round(state.timeLeftSeconds), myState: { playerId: 1,
A browser colony simulation where support tickets carry real text and Jev assigns the categories agents use to route them.
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from the source
var INSTRUCTIONS_PREFIX = 'Classify the support ticket in '; var CRITERIA = { incident: 'Something that was working is broken or degraded right now and a ' + 'user is blocked or impaired. The ticket reports a failure, an outage, an ' +
Play trivia by assigning probabilities, then compare your calibration with Jev and a coin flip.
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from the source
export const JEV_MODEL = "jev-1.13.0";const ENDPOINT = "https://api.typesafe.ai/v1/systemone"; state, questions: { verdict: { type: "noul", instructions } },
A top-down duel where Jev chooses among reachable positions and local code handles paths, leading aim and firing.
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from the source
const questions = { move: { type: "choice", instructions: { doctrine: DOCTRINE,
A three-level interrogation game where your statement receives a release probability, persuasiveness score and persuasion tactic.
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from the source
should_release: { type: 'noul', instructions: instruction, criteria: { true: 'Th... persuasiveness: { type: 'score', instructions: criteria.persuasivenessInstructio... tactic: { type: 'choice', instructions: criteria.tacticInstructions, criteria: c...
A collaborative story game where players write every line and Jev chooses the winner, screens content and senses an ending.
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from the source
questions[`dim_${d.key}`] = { type: 'choice', instructions: d.instructions, criteria... questions[`end_${c.id}`] = { type: 'noul', instructions: `If this sentence were added next, would the story feel finished, li...
Follows one Jev-controlled gambler through spins and shopping, while code owns the reels, bankroll and intentionally losing arithmetic.
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from the source
export function gamblingQuestions(s, ladder, { canSpend }) { const questions = { bet_size: choice('How much does Jev bet?', betCriteria(ladder, s.balance)), pace: score('How fast is Jev playing?', [
Play oversized tic-tac-toe against Jev, without a search algorithm rescuing its mistakes.
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from the source
export function buildJevRequest(snapshot) { const { size, board, currentPlayer, legalMoves } = jevState(snapshot); const opponent = otherPlayer(currentPlayer); const showReplies = board.filter((mark) => !mark).length <= MAX_REPLY_CONTEXT_EMPTY_CE... const criteria = [
A Portuguese platformer where typing a category changes which objects float, bridge, bounce or turn ghostly.
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from the source
test("API request asks one constrained Noul per object", () => { const request = makeRequest("madeira"); assert.equal(Object.keys(request.questions).length, 24); assert.equal(request.state.category, "madeira");});
A maze lab that reveals only local facts to Jev and measures the resulting path against breadth-first search.
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from the source
const DIRECTION_LABEL: Record<Direction, string> = { up: "Move one cell up (north)", down: "Move one cell down (south)", left: "Move one cell left (west)", right: "Move one cell right (east)",
Watch Jev play heads-up Hold'em against a heuristic bot, with the probabilities behind each move visible beside the table.
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from the source
ENDPOINT = "https://api.typesafe.ai/v1/systemone"CLIENT = httpx.Client(http2=True, timeout=30)POKER_RULES = ( "You are a top heads-up No-Limit Texas Hold'em player. Choose exactly one offered ac...
A Processing treasure hunt where each robot sees five sectors and Jev chooses its movement and turn size.
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from the source
"action": { "type": "choice", "choice": "forward", "probabilities": { "forward": 0.55, "backward": 0, "turn_left": 0.45, "turn_right"... "confidence": 0.4
Run a Mineflayer survival bot where Jev picks the next high-level action and code handles the execution knowledge.
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from the source
id: "next_action", type: "choice", instructions: "現在の状況(HP/満腹度と食料の所持有無/周辺の敵性エンティティとその種別/周辺の動... "夜間かどうか/装備/木材・道具のクラフト進行状況(crafting)/直近の行動履歴/周辺地...
A twenty-questions game that tries to guess a Japanese persona's home prefecture and age.
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from the source
export type NoulQuestion = { type: "noul"; instructions: string | object; criteria?: { true?: string; false?: string };};
An agent that predicts what actions will do, notices confident mistakes and rewrites its explicit model of the world.
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from the source
model: this.opts.model ?? 'jev-latest', state: { world: stateText(state), action: actionText(action), ...(withRules ? { co... questions: Object.fromEntries(questions.map(q => [q.id, { type: 'noul', instructio... }
A pinball table that keeps moving while Jev chooses flipper states, applying only answers fresh enough to matter.
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from the source
questions: { flippers: { type: 'choice' as const, instructions: 'Choose the flipper buttons to hold NOW to keep this moving ball in play... criteria: { left: 'Press left flipper; release right.',
A Factorio agent loop where Jev picks the macro goal and next action while deterministic code owns rules and actuation.
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from the source
def evaluate(self, state: dict, questions: dict) -> dict: """One system-one call. Returns the `answers` map keyed by question id.""" resp = requests.post( headers={"Authorization": f"Bearer {self.api_key}"}, json={"state": state, "model": self.model, "questions": questions},
A Magic 8-Ball that first checks whether your question is askable, then judges which way the outlook leans.
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from the source
askable: noul( "Is `question` a yes-or-no question about the future or the unknown, the kind a Magi... { true: { meaning: "A question that can be answered yes or no",
Type a word or phrase and see Jev spread it across sixteen fixed colors in a bar chart.
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from the source
const QUESTIONS = { colour: { type: 'choice', instructions: 'A person typed a word or phrase. If they had to paint it using only these sixteen...
Pick a question or type your own, and Jev answers it twice: once alone, once with six live Exa results in its state.
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choice
Six Exa results, each `Title — domain (date): highlights`, sit in `state.search_results` beside the typed question · yes / no
Fifty HR tool logos sit in a pile at the bottom of the page. Type an HR problem and the ones that fit rise into rows; Jev scores all fifty at once.
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from the source
POST /api/jev/search {"q":"payroll for a small startup with eight employees"}{"picks":[{"id":"gusto","noul":0.91},{"id":"payfit","noul":0.71}],"ms":191}{"scale":{"choice":"smb","confidence":1}}
Four models play parallel Pong lanes; Jev chooses a paddle move whenever the ball needs another decision.
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Watch Jev and a fly-connectome player race across separate Minesweeper boards, one move at a time.
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Steer a Chicago traffic simulation with Jev choosing citywide priorities and bounded corridor policies.
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Play a mahjong hand while Jev recommends a discard and rates its efficiency, safety and wait.
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Solve a bilingual lateral-thinking mystery by asking questions while Jev plays the keeper of the hidden answer.
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Take penalty kicks against a Jev goalkeeper in a 3D football shootout.
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Tour a graphical Jev dojo with Tetris stacking, task routing, swarm reactions and other decision scenes.
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Race Jev through ten snap-judgment rounds, deciding whether reviews, messages, and other prompts are genuine, sarcastic, urgent, or invented.
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A zero-dependency Node playground whose four tabs send typed questions to Jev through OpenRouter and draw the probabilities.
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from the source
upstream = await fetch(ENDPOINT, {
A zero-dependency local playground for Jev with a structured question editor and three presets: browser operation, intent routing and agent context trimming.
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from the source
const API_URL_PRESETS = {official: 'https://api.typesafe.ai/v1/systemone',openrouter: 'https://openrouter.ai/api/v1/systemone',
A single-page app that classifies BANKING77 support queries with Jev and streams the results one ticket at a time.
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from the source
const res = await fetch(`${baseUrl}/systemone`, {
A smart-home assistant demo that recreates TypeSafe's own: one request carries every question the app might need, and low-confidence answers get a confirmation step.
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from the source
const r = await fetch("https://api.typesafe.ai/v1/systemone", {
Ten runnable examples plus more than 120 use cases, four composition patterns and a theory write-up for building with Jev.
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from the source
ENDPOINT =
Guide a World of Warcraft character through leveling decisions while reserving expensive generation for harder moments.
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Paste a URL to check its design and copy against dozens of AI-slop signals.
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Ask a short question, let Jev judge it, then watch a routed model stream an answer to a shared wall.
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Ask a question and let Jev turn judgment and chance into a Magic 8-Ball-style answer.
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Paste code and watch Jev classify its language, every token, and nine lint rules.
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Run a browser ecosystem where Jev or fixed rules choose each animal’s next move.
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Describe a product and follow an adaptive onboarding path that asks one question at a time.
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Disrupt simulated New York and London transit networks, then watch Jev choose how to respond.
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Play the card game Cheat against three opponents that ask Jev whether a claim is plausible.
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Survive an isometric dead zone while two Jev decision streams steer and aim your companion Ruby.
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Watch Jev agents control Overcooked players in real time while a generative model plans the team strategy.
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Play Heist and Chess against Jev, or ask it for a second opinion in Minesweeper.
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Explore six runnable demos of Choice, Score, and Noul, from bluffing cards to Sentence Jenga.
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Abol gave a Jev-driven trading experiment a simulated $10,000 balance and let it choose trades.
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Kengo Nonaka’s 3D character changes its face and body while listening to conversation or watching YouTube.
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Pitofui combined Jev with Sonnet Fast so game agents can choose actions during real-time battles.
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Max Blade’s always-listening assistant uses Jev probabilities to distinguish computer commands from ordinary speech.
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TactiX used Jev in an automated scalper tested against one-minute market charts on testnet.
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GOGOGO’s chess experiment first let Jev move freely, then filtered moves for attack and defense before Jev chose one.
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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 experiment → hello@JevMade.com