Cathnivore

A free, cooperative, engine-building strategy game set in the fictional Republic of Marrow. One or two producers — played by humans, or by one human and an AI teammate — build up small farms and push two satirical corporations, Hollowell Group and Candor Health, out of the country one region at a time. A six-chapter story campaign doubles as the tutorial; Quick Game is a standalone full game once you know the rules.

Cathnivore is a work of satire. All places, companies and people in it are fictional. There is no tracking, no accounts and no ads — every save stays on your device.

How to play

• Campaign teaches the game a chapter at a time, starting from a single producer with very few rules switched on and building up to the full game. Start here if this is your first time.
• Quick Game is the full game (two producers, the full rulebook) from a fresh board. Recommended once you've finished at least chapter 3.
• Each round: Harvest (gain resources), then each producer takes 3 actions (Open Stall, Supply, Rebut, Invest, Sell, Scheme or Graft, plus a free once-per-round role ability), then the enemy turn (Agenda card, Squeeze, Expand, Scout). The enemy plan strip at the top of the game screen always shows which regions Squeeze and Expand will hit next — reading it is the core of every decision.
• You win the moment 5 regions are liberated, including Kingsmarket. You lose if Public Trust hits 0, the Lost Land token pool runs out, or the Pressure deck runs out.
• The full rules are generated from the same data the game plays with, and are always available in-game under How to Play, so they can never drift out of sync with how the game actually behaves.

Playing it

The live web version is at cathnivore.com. It works offline after the first visit and can be added to your home screen like an app. An iPhone app is in progress; see PROGRESS.md for its current status.

Running it locally

Requires Node.js (LTS) and npm.

npm ci                # install dependencies
npm run dev            # start a local dev server

Other useful commands:

npm run check          # typecheck, lint, unit tests, a quick fuzz run, and a production build
npm test               # unit and property tests only
npm run e2e             # the Playwright end-to-end suite
npm run sim -- --games 1000 --bot heuristic --difficulty normal --pairs all   # balance simulations
npm run gates           # the full quality-gate suite (SPEC 11.4's gates 1-8)

How it was built

Cathnivore was built end to end by unattended Claude Code sessions, one per hour, following a fixed build specification (SPEC.md) and visual style guide (STYLE.md) with no human approval in the loop while it ran. Every session's decisions and reasoning are logged in DECISIONS.md; build progress, balance-loop results and known issues are tracked in PROGRESS.md and BALANCE.md.

Stack

• TypeScript (strict mode), Vite and React. src/engine is pure, deterministic TypeScript (a seeded random number generator, no DOM or timers) — it's the single source of truth for the rules, and both the UI and the AI bots play through the exact same API.
• Three bots (src/ai): a random baseline, a greedy heuristic bot, and an MCTS bot that simulates many possible futures per decision. A headless simulation harness (sim/) runs thousands of self-played games to measure win rates and tune balance, logged in BALANCE.md.
• Plain CSS using design tokens from STYLE.md — no UI component library, no external image assets. Every piece, icon and portrait is drawn in code as SVG.
• vite-plugin-pwa for offline play and home-screen install on the web; Capacitor for the iPhone app (ios/), which bundles every asset so it runs fully offline.
• Vitest and fast-check for unit and property tests, Playwright for end-to-end tests, axe-core for accessibility checks and Lighthouse for a performance budget — all wired into npm run gates, which every change has to pass before it can ship.

Process

Each hourly session read the spec fresh, picked up the next unfinished task from PROGRESS.md, worked for about 50 minutes, and committed and pushed its progress before releasing a lock file so the next session could pick up cleanly. When the spec was silent or ambiguous, the session made a call and logged it in DECISIONS.md rather than stopping to ask — there was no one to ask.