Jev plays Pokémon

I wanted to see how Jev plays Pokémon.

Not a screenshot agent. Not a bot that mashes A. I wanted to know if it could look at a real FireRed fight the way a player does: HP, types, moves, stats, the other team's roster, and then pick something that makes sense.

So I pointed it at the Elite Four with a party that starts at level 40. Jolteon, Lapras, Alakazam, Charizard, Snorlax, Nidoking. Underleveled on purpose. Each turn the host reads the battle out of RAM, hands Jev the legal moves and switches, and waits. Then I watched it win.

That still gets me. Level 40 is the wrong side of Indigo Plateau. Jev is doing the notebook thing anyway: Thunderbolt here, Alakazam into the Fighting types, do not throw a punch at a Ghost. If a model can do that on a live cartridge, there is a lot more it can do. This repo is the demo.

_{The left side is the actual ROM. The right side is Jev's last choice, probabilities, and party HP.}

More on how the two runners share a brain: ARCHITECTURE.md

Numbers from the runs I kept: RESULTS.md

Why Showdown and PokéBot, and what I read first: RESEARCH.md

Try it

Grab a TypeSafe API key and put it in .env.

cp .env.example .env

Text battles, any computer. This is Pokémon Showdown. Fast. No ROM.

source "$HOME/.nvm/nvm.sh"
nvm install && nvm use
npm ci
cp .env.example .env
npm start -- --opponent all

Real FireRed, Mac with Apple Silicon. Drop Pokemon - Fire Red Version (U) (V1.1).gba next to this README.

brew install mgba ffmpeg
uv run --no-project --python 3.12 setup_emulator.py
./emulator.sh --prepare
./dashboard-service.sh start

That opens http://127.0.0.1:8765. Hit start and sit with it. Edit the party in the page. Speed it up. Scrub the replay after.

One fight, no browser:

./emulator.sh --run --opponent lorelei --speed 4

--opponent can be lorelei, bruno, agatha, lance, champion, or all.

npm start
npm start -- --agent human --opponent lance
npm test
./emulator.sh --check-custom

What Jev sees

Not the screen.

A JSON snapshot of the fight: who is out, remaining HP, status, stats, abilities, PP, weather, and only the legal moves and switches for this turn. Sometimes a rough damage estimate from the code. That is just math. It is not a recommended move.

Jev answers with one action and a probability for every option. If the answer is illegal, the battle stops. There is no backup brain.

On the ROM, a switch is the Pokémon's personality value, not "slot 3." The party menu moves around. Using the old slot would send out the wrong one. That note lives in AGENTS.md.

The team

Pokémon	Level	Moves
Jolteon	40	Thunderbolt, Bite, Thunder Wave, Double Kick
Lapras	40	Surf, Ice Beam, Thunderbolt, Confuse Ray
Alakazam	40	Psychic, Recover, Calm Mind, Reflect
Charizard	40	Flamethrower, Fly, Slash, Dragon Claw
Snorlax	40	Body Slam, Shadow Ball, Earthquake, Rest
Nidoking	40	Earthquake, Rock Slide, Ice Beam, Megahorn

Edit emulator-config.json or the dashboard. For Showdown, edit teams.js or pass --team team.json.

This is a demo

I wanted an answer to a simple question: can Jev look at a real FireRed fight and make the kind of call a player would make? At level 40, against the Elite Four, it could.

Fork it. Swap the party. Point it at Bruno first. Teach it items, or a whole campaign, or a different game. The interesting part is not this exact team. It is that a typed choice over honest game state is already enough to play.

The wiring is in ARCHITECTURE.md. The recorded fights are in RESULTS.md. The notes on other projects are in RESEARCH.md.

This build sits on Pokémon Showdown, PokéBot Gen3, libmgba-py, mGBA, and Jev's choice API. I also read poke-env, PokéLLMon, Clad3815's FireRed agent, NousResearch/pokemon-agent, Claude Plays Pokémon, and Gemini Plays Pokémon before settling here.