Docs

How Capo City is built, what the numbers actually are, and how to run your own copy. For the player-facing guide see How to play.

Overview

Capo City is a real-time isometric city rendered on a single HTML canvas. The whole game — renderer, pathfinding, economy, UI — lives in one self-contained file, city.html, with no build step and no runtime dependencies. It works offline and from a file:// URL.

• Grid: 48 × 48 tiles, 2:1 isometric projection (64 × 32 px tiles).
• Rendering: every static object is baked once into its own offscreen canvas and blitted; the ground is a single pre-composited layer. A frame is a few dozen drawImage calls.
• Pathfinding: 4-directional A* over the walkable mask, Manhattan heuristic.
• Depth: painter's algorithm sorted on gx + gy, with entities merged into the same sorted list each frame.
• Persistence: localStorage under the key capocity.v1.

Economy reference

Every tunable number in one place.

City generation

The city is deterministic: the turf name is hashed (FNV-1a) into a seed for a mulberry32 PRNG, so the same turf always produces the same city on every device.

• Roads run every 6 tiles on both axes, giving an 8 × 8 grid of blocks.
• Each block is 5 × 5 inside the roads: a walkable pavement ring around a 3 × 3 buildable core.
• Building cores are filled from six footprint templates, heights 3–12 storeys, taller toward the centre.
• Tiles 18–29 on both axes are cleared for Vault Plaza; the 4 × 4 vault sits at its centre.
• Ten blocks in the ring around the plaza are reserved for boss towers, 14–32 storeys by rank.
• Rows 43+ are water, 41–42 are the dock strip, and one block is Lantern Park.

Seasons and the pot

A season runs 7 days from launch. The pot splits across the top ten by rank weight (11 − rank)^1.45, normalised — so rank 1 takes roughly a quarter of the pot and rank 10 takes a few percent.

Token

Architecture

frontend/                 static, deploy anywhere
  index.html              landing page
  how-to-play.html        player guide
  docs.html               this page
  city.html               the game (self-contained, no build)
  js/config.js            single source of truth: name, launch, CA, API URL
  js/site.js              nav, countdown, CA copy
  js/api.js               backend client — no-ops when API_URL is empty
  css/site.css            shared site styles
  assets/                 wordmark, badge, banner, OG, favicons

backend/                  optional — the city runs fully without it
  src/server.js           Express + WebSocket, server-authoritative payouts
  supabase/schema.sql     tables, indexes and row level security
  Dockerfile              Railway deploy target

The frontend degrades cleanly. With API_URL empty the city is single-player: local save, simulated leaderboard, local wire. Set API_URL and the same build switches on live chat, presence, a shared leaderboard and server-checked payouts — no code changes.

Backend setup

1. Supabase

Create a project, open the SQL editor and run backend/supabase/schema.sql. It creates the tables, indexes and row level security policies. Copy the project URL, the anon key and the service role key.

2. Railway

Point Railway at backend/. It builds from the Dockerfile. Set these variables:

SUPABASE_URL=https://xxxx.supabase.co
SUPABASE_SERVICE_KEY=eyJ...        # service role — server only, never ship to the browser
ALLOWED_ORIGINS=https://capocity.fun,https://www.capocity.fun
PORT=8080

3. Point the frontend at it

Set API_URL in frontend/js/config.js to your Railway URL and redeploy the frontend. That is the whole switch-over.

API reference

Payouts are never trusted from the client. /api/job/start records a server timestamp and /api/job/claim refuses anything that comes back faster than the job's real duration, or that would push the player past the daily cap.

Run it yourself

# frontend — any static server
cd frontend
python3 -m http.server 4173

# backend — optional
cd backend
cp .env.example .env      # fill in your Supabase keys
npm install
npm run dev

The frontend has no build step, so whatever is in frontend/ is exactly what ships. Deploy it to Vercel, Netlify, Cloudflare Pages, GitHub Pages or an S3 bucket — set the output directory to frontend and there is nothing else to configure.

Launch checklist

1. Frontend deployed to capocity.fun, DNS pointed, HTTPS live.
2. Open Graph images resolving — check with the X card validator before the day.
3. X and Telegram bios pointing at capocity.fun.
4. Mint on pump.fun at 5:00 PM UTC on 12 August.
5. Paste the address into CA in js/config.js and upload that one file. Every page loads it with a timestamp, so it is picked up immediately — no cache purge needed.
6. Pin the CA post on X. Confirm the site and the pinned post match, character for character.

Disclaimers

Capo City is a browser game and a memecoin. It is not an investment product, it is not a security, and nothing on this site is financial advice.

In-game CASH, XP and $CAPO points exist only inside the game. They have no monetary value, they are not tradeable, and they are not redeemable for the token or anything else.

Leaderboard figures, PnL and pot values shown while the DEMO SEASON badge is visible are simulated and do not describe any real trader or any real money.

Crypto assets are volatile and you can lose everything you put in. Only ever risk what you are happy to lose, and always verify the contract address against the pinned post on X before you buy.

Enter the city