Letopis

An idle civilization that lives on its own server. You just watch it grow.

Letopis (Bulgarian for chronicle) is a self-hosted idle simulation. A few families start in the Stone Age and, with nobody pressing a button, discover fire, tools, farming and everything after. Open the page whenever you like and see how far they got. The whole game runs in the browser; the world keeps living on the server while nobody is watching.

Features

• A generated world with relief, rivers, forests, mountains, seasons and snow, drawn in a cozy isometric pixel-art style.
• Every person has a name, parents, children and traits (strength, wit, curiosity, sociability, health, longevity) that are inherited with small mutations.
• Clans wander, split, meet, learn from each other, settle into villages and sometimes die out together with their knowledge.
• Trees grow and get cut for fires and huts; a clan moves on when the wood around its camp is gone.
• A living chronicle of everything that happens, with clickable people and clans, family trees back to the first humans and a list of first discoveries.
• English and Bulgarian, switchable at any time with the language button.
• Kids mode with bigger letters and simpler explanations.
• "While you were away": the highlights since your last visit.
• Tour mode: the camera wanders the world by itself and stops where something happens. Nice on a TV.
• 100 tiny secrets hidden around every world.

Pace

About three months of real time take the world from the Stone Age to the present day; after that it keeps going at the same pace. The Stone Age is the fastest (a year in about 3 minutes), the modern centuries the slowest (a year in about 1.5 hours). Each discovery has a target date, and its chance rises or falls when the world runs ahead of or behind history.

Running it

Docker

docker run -d --name letopis -p 2222:2222 -v /path/to/letopis-data:/data --restart unless-stopped ghcr.io/leppermesiah/letopis:latest

Then open http://<host>:2222/.

Unraid

Install Letopis from the Apps tab (Community Applications). The template lives in leppermesiah/unraid-templates. To add it by hand instead:

• Repository: ghcr.io/leppermesiah/letopis:latest
• Port: 2222 → 2222
• Path: /data → /mnt/user/appdata/letopis

The world is saved every 2 minutes and when the container stops, and continues where it left off after a restart. If humanity dies out, the world is archived in /data/archive/ and a new one begins a minute later.

Settings (environment)

Building from source

Requires Node.js 22.

npm ci
npm run dev     # runs at x200 speed with data in ./data, http://localhost:2222
npm run build   # production build into dist/

Graphics

The sprite sheets live in art/sheets/. After changing or adding a sheet (needs Python, Pillow and NumPy):

python3 -I tools/slice_sprites.py   # cuts the sheets into single sprites in art/cut/ and cleans the halos
python3 -I tools/build_atlas.py     # builds public/sprites/atlas*.png and atlas.json

The finished atlas is in git, so Python is not needed to build the game.

API

/api/health, /api/world, /api/snapshot, /api/chronicle?before=&after=&min=&limit=, /api/since?after=, /api/person/:id, /api/tree/:id, /api/band/:id, /api/heroes, /api/discoveries, /api/stats, /api/worlds, WebSocket /ws. /api/health works well as a sensor for Home Assistant or any uptime monitor.

Roadmap

1. World and people (now): terrain, people, clans, the Stone Age up to the first villages, isometric view, chronicle.
2. Settlements and discoveries up to the Iron Age, richer villages.
3. States, trade, wars without on-screen violence, diseases, disasters.
4. Middle Ages to modern times, portraits, more for kids.
5. Space and colonies on other worlds.

Credits

Everything taken from outside, with its author and license, is listed in CREDITS.md.

License

MIT. The third-party libraries keep their own licenses, listed in CREDITS.md.