Run it · Terrarium

In your browser

Watch a world right now. It runs entirely on your machine; nothing is sent anywhere. Pick a world by its name in the address, or press W in the viewer to move to the next one:

World
Great Valley	120 people, 80 × 50	Valleys, uplands and ten lakes. A big enough world for generations.
First Winter	10 people, 10 × 10	A small band and a hard winter.
Kepler-442b	12 people	An Earth-like exoplanet colony.
Antarctica	6 people	A polar station through the long night.
Mars Colony	8 people	Hydroponics bays and nothing outside.
Orbital Station	6 people	A station in orbit.

Keys

Key
`Space`	Pause and resume
`N`	One day at a time, while paused
`+` `−`	Faster, slower
`Tab`, `1`–`9`, arrows	Follow someone else (the map follows them)
`E` `T` `A` `F`	Events, trades, person, full details
`W` `R`	Next world, start over
`?`	All keys

In a terminal

You’ll need Rust.

git clone https://github.com/raskell-io/terrarium
cd terrarium
cargo build --release

# Watch, in the same viewer as the browser
./target/release/terrarium --scenario scenarios/great_valley.toml --tui

# Or run without a screen, then read what happened
./target/release/terrarium --scenario scenarios/first_winter.toml
less output/chronicle.md

A run writes its full event log (events.jsonl), a readable chronicle (chronicle.md) and snapshots of the world (states/) to output/.

With Claude thinking for them

Set an Anthropic API key and every person deliberates their days through Claude instead of acting on instinct:

export ANTHROPIC_API_KEY=sk-ant-...
./target/release/terrarium --scenario scenarios/first_winter.toml --tui

Each person makes one call a day, so a ten-person world makes about a thousand calls a year. The model and its settings are in the scenario’s [llm] section.

Make your own world

A world is a TOML file: its size and land, its people, its seasons and weather, illness, and everything in between. Copy one from scenarios/; every setting is listed there with its default.