# Jev Plays Pokémon Red — a decision model makes every move, live

> A typed-decision model plays a full RPG, one probability-scored choice at a time.

- Org: Frigade
- Date: 2026-09-25
- Category: showcase
- Source: https://jev-pokemon.vercel.app/
- Canonical page: https://ai-tldr.dev/releases/frigade-jev-plays-pokemon-red/

## In short

Jev Plays Pokémon Red is an open-source live stream where TypeSafe's Jev decision model makes every menu, route and battle choice in the game and shows its odds for each one.

## What it is

Jev Plays Pokémon Red is a project by Christian Mathiesen at Frigade in which the Jev decision model plays the Game Boy game on a live stream. Jev picks menu answers, starter and team choices, where to go, when to heal or train, and every battle action. A side panel shows each decision and Jev's odds.

## How it works

A Node.js harness runs a Game Boy emulator, reads game memory, and turns the current situation into a list of legal options with context. Jev is called through Vercel AI Gateway to pick one, and the harness only presses buttons — it never writes to game memory. The README counts 800 to 1,300 calls an hour, about 1,200 tokens each, at roughly $1 to $1.70 a day.

## Why it matters

The project is a long, public stress test of the typed-decision idea behind Jev: can one-shot choices from a fixed list carry an agent through hours of play? It reached 221 points as a Show HN, and every call is logged with its probabilities and latency, so anyone can study where the approach gets stuck.

## Who it's for

developers experimenting with decision models and game agents

## Try it

git clone https://github.com/christianmat/jev-pokemon && cd jev-pokemon && npm install

## Links

- [Live Stream Page](https://jev-pokemon.vercel.app/)
- [Repository](https://github.com/christianmat/jev-pokemon)
- [HN Discussion](https://news.ycombinator.com/item?id=49845172)