A little aquarium you can hold: feed the fish, wipe the glass, and let a tiny language model decide when they eat, explore or rest.

StratoBuilds / mediacutlet's Pocket Tank runs its fish decisions on an ESP32-S3, using a roughly 14-million-parameter model stored on the board. A separate layer handles movement and the aquarium's rules, so the fish can keep swimming while a new decision is being made. The fish brain works without a cloud connection.

The October 24–25 updates add a strawberry crab, a bubble volcano and better decoration controls. The crab digs up in-game sand dollars and shoos shrimp away from its food. Those additions are part of the aquarium simulation; the language model's role is guiding the fish.

The attached clip is the creator's aquarium loop. This is an ongoing open-source hardware project, with alpha firmware, supported boards and recent changes here:
pocketank.com/

Code and model:
github.com/mediacutlet/pocket-tank