Jev Snake — watch the AI play Snake live
Jev, TypeSafe AI's decision model, plays Snake by itself — every tick it reads the board and picks the next turn in a real API call, chasing the food without crashing. Watch the live latency, cost and confidence. No key, just press play.
Jev plays Snake by itself: every tick the board goes to the live decision API as one typed choice over the legal turns, and Jev picks. It's a visible demo of a fast, bounded decision — not a strong Snake AI.
The same demo is one Jev call
- Read the board — snake head, heading, food, body
- List the safe, non-reverse directions this tick
- Send it to Jev as one
choicequestion - Jev returns the direction (with confidence)
- Move one cell, then decide again next tick
const res = await fetch("https://jevtypesafeai.com/api/v1/decide", {
method: "POST",
headers: { Authorization: `Bearer ${process.env.JEV_API_KEY}` },
body: JSON.stringify({
state: `Head (7,7) heading RIGHT. Food (7,10). Safe: up, right, down.`, // the board, as text
questions: {
move: { type: "choice", instructions: "Best direction? Head for food, don't hit a wall or yourself.",
criteria: { up: "toward nothing", right: "toward the food", down: "safe" } },
},
}),
});
const { answers } = await res.json();
step(answers.move.choice); // → "right" (0.82)See a real decision RIGHT · 190ms
Head at (7,7) heading RIGHT. Food at (7,10). Safe: UP, RIGHT, DOWN (LEFT reverses).
How Jev plays Snake
Nothing here is scripted. On every tick the current board — a 15×15 grid with the snake's head, its body and the food — is sent to the Jev API as a single request carrying one typed choice question. The options are only the snake's currently-legal, non-reverse turns, and each one is labelled honestly: 'toward the food, safe', 'into the wall — game over', 'into the snake's own body — game over', or 'onto the food — grow'. Jev reads that situation and returns one direction with a calibrated probability, in roughly 100–300ms, and the snake turns that way.
Because each tick is an ordinary API request, you watch exactly what a developer wiring an LLM into real game logic would see: the latency, the cost — a fraction of a cent — and the confidence behind each chosen turn, live above the board. The snake grows one tile every time Jev steers it onto the food, and the run ends the moment it decides its way into a wall or its own tail.
What is Jev?
Jev is TypeSafe AI's first System One model. Instead of writing prose like a chatbot, it reads a situation and returns a typed, calibrated decision — a choice between options, a score on a scale, or a yes/no probability — in tens to hundreds of milliseconds, with no hallucinations. Picking which way a snake should turn to reach the food without crashing is exactly the kind of small, fast, bounded decision it is built for, which is why it can play in real time.
The same model powers ticket routing, content moderation, lead scoring, agent tool-call guardrails and model routing in real products. Snake is just a visible, fun way to watch it decide — here it is deciding every turn, and the confidence readout shows how sure it was about each move.
Why watching an AI play Snake is a good decision demo
- The move set is tiny and typed — up, down, left or right — so every tick is one clean choice call, the exact shape you'd use for routing or a tool-call guardrail.
- The stakes are legible: one wrong turn ends the game, so you can literally watch a good or bad decision play out on the board.
- The state stays small — a compact grid plus the food's relative position — so the input token cost per decision is tiny, and the running total shows just how cheap a bounded decision is.
- It runs live against the real API, so the latency and confidence you see are the same numbers you'd get wiring Jev into your own product.
FAQ
Is Jev Snake free to watch?
Yes. It runs in your browser with no API key and no signup — press play and every turn the snake makes is a free, rate-limited call to the live Jev decision API.
Does Jev really decide each move, or is it scripted?
Jev really decides. On each tick the board is sent to the Jev API as one choice question over the snake's legal, non-reverse turns, and it returns the direction to move with a calibrated probability. If the API is rate-limited the game pauses briefly and resumes — the turns are genuine API calls, not a hard-coded pathfinder.
What happens when the snake crashes?
The run ends. If Jev steers the head into a wall or into the snake's own body the game is over, and the page shows how many decisions it made, how long it survived, how long the snake grew, and the total cost. Hit Play again to start a fresh board.
How fast and how expensive is each decision?
Each turn is a single API call that typically returns in about 100–300ms and costs a fraction of a cent in input tokens. The page shows the live latency, the running cost, and the confidence behind each chosen turn.
More: Jev 2048 — watch the AI play · Jev Pac-Man — outrun the AI · Jev Trading Bot · All decision games · Jev API docs