Chainle

Russian daily math puzzle game. Draw a chain through a 5×5 grid so the sum of numbers equals the daily target.

Play now: chainle.ru

Game mechanics

• Connect adjacent cells (up/down/left/right) in a continuous chain
• No cell can be visited twice
• The sum of all cells in the chain must exactly equal the daily target (~45–60)
• Backtrack by returning to the previous cell
• ⭐⭐⭐ — optimal path length
• ⭐⭐ — one cell longer than optimal
• ⭐ — solved, but can be improved

Stack

• Vanilla JS ES modules, no framework
• Single HTML file + style.css + js/app.js + js/engine.js
• Game state and stats persisted in localStorage
• Daily puzzle: pre-generated JSON for all of 2026, selected by date

Project structure

index.html              Single-page app entry point
style.css               All styles: CSS variables, dark mode, responsive
js/
  app.js                UI, touch/mouse input, SVG path overlay, modals
  engine.js             Pure functions: DFS solver, path validation, star rating
data/
  puzzles.json          327 pre-generated puzzles for 2026
tests/
  engine.test.js        Unit tests for game logic (vitest, 38 tests)
scripts/
  generate_puzzles.py   Puzzle generator
  build.js              Replaces __BUILD_HASH__ with git short hash
  deploy.sh             Initial server provisioning script
docker/
  nginx.conf            nginx config inside container (gzip, 30d cache)
Dockerfile              Multi-stage build: node → nginx
docker-compose.yml      Port 127.0.0.1:8082:80
.github/workflows/
  deploy.yml            CI/CD: push to main → tests → SSH deploy

Local development

python3 -m http.server 3457
# open http://localhost:3457

No build step required for local dev. __BUILD_HASH__ is replaced automatically during Docker build.

Tests

npm ci
npm test

Build

npm run build

Replaces __BUILD_HASH__ in index.html and js/app.js with the current git short hash for cache busting.

Deployment

Push to main triggers GitHub Actions → tests → SSH into production server → sudo chainle-update (git pull + docker compose up).

Server: Ubuntu, nginx reverse proxy, Docker, Let's Encrypt SSL
Webroot: /var/www/chainle.ru

Puzzles

327 puzzles pre-generated for 2026-01-02 through 2026-12-31.
Each puzzle: date, grid[25] (values 1–9), target, optimal (shortest path length).
To regenerate: python3 scripts/generate_puzzles.py

Sister project

Не вордли (source) — a Russian Wordle variant by the same author, same infra.