Question 1

What does one tick actually cost me?

Accepted Answer

One API call per tick, carrying one choice question per AI snake, all answered in parallel. That means the price tracks tick rate times snake count times rounds played. The engine limits the exposure: Jev is only called while a round is actually playing, never on the start screen, the win screen, while paused, or while the tab is hidden.

Question 2

Can Jev steer a snake into an illegal move or a wall?

Accepted Answer

Not an illegal one. Each tick the game computes the legal moves for every snake along with the hard facts, and only those legal options are put to the model, so an out-of-bounds choice is never on the menu. What the model does affect is which of the legal moves gets taken, and how good that is depends on the criteria you wrote into each question.

Question 3

Do the eight snakes actually behave differently, or is it one prompt repeated?

Accepted Answer

They behave differently because personality is fed into each question. A Psycho hunts, a Greedy chases food, a Coward avoids fights, and each snake gets its own description alongside the same computed facts, so identical inputs produce different decisions per snake. The resulting probabilities are shown floating over each head and can be toggled with O.

Question 4

What is worth stealing from this if I am not building a game?

Accepted Answer

The shape of the call. The engine computes everything deterministic and hands the model a small set of pre-filtered options plus one choice question per decision point, then reads a probability back. That is the same pattern as routing or triage: keep legality in code, let the model only pick among what you already computed.

Question 5

How do I run the game on my own machine?

Accepted Answer

Run npm i, copy .env.example to .env and add your TYPESAFE_API_KEY, then node server.js and open http://localhost:3000. The frontend is vanilla JS and canvas with a small Express server acting as the Jev bridge, and there is no build step or framework.

Question 6

How does a single tick work?

Accepted Answer

Each tick the game computes every snake's legal moves and hard facts about them: distance to the nearest food, distance to the nearest enemy head, and how much open space each move leads to. All of it goes to Jev as one call with one choice question per AI snake, and Jev answers each in parallel with a move and a probability.

Question 7

Can I watch without playing, or record it?

Accepted Answer

Add ?watch=1 to skip the start screen and run eight Jev snakes with no human, and ?rec=1 to hide the cursor for recording. Arrow keys steer your snake in play mode, Space or P pauses or resumes, O toggles the odds tags over each head, and R restarts. Jev is only called while a round is actually playing.

Slither-Me-Jev

About this project

Highlights

Questions about this entry

More Jev resources like this

From the Jev guides

From the Jev community