BaseCity: a city built 24/7 by Blockies, the builders of Base

A live, watch-only voxel city tied to the $BLOCKY token on Base.

• Every $10 = 1 Blocky. Every $10 of $BLOCKY a wallet buys (added up per wallet) brings one Blocky to the city by blimp (usdPerBlocky in src/config.js; each buy counts at the price of its day, so changing it only affects later buys): Blocky #1, #2, ... with at most 10,000 in the city at once. A Blocky held 6 hours is a citizen: an NFT its wallet claims (BaseCity Blockies, BCB, see below). Only 10,000 NFTs can ever exist: first come, first claimed. Big buys arrive in batches. A single buy of $1,000+ also builds a Whale Fountain signed with the wallet, and jumps the build queue.
• Newcomers, opening day, citizens. Every Blocky starts as a newcomer: its wallet's $BLOCKY balance (tokens it had before count too) must cover it, so sell half of what it bought and the newest half of its newcomers leave (tokens moved away count as sold); freed places go to the next wallets in line (a waitlist once the city is full). Opening day is when unlockUsd has been bought in total (the HUD's "Bought"); it is 0, so trading opened at the first update after it was set: from then a Blocky held citizenDays (0.25: 6 hours) is a citizen for good, whatever the wallet does, and an NFT it can claim. Held tokens cover newcomers first, so citizens free the rest. Both settings can be lowered any time (lowering unlockUsd opens trading at the next update), never raised after launch.
• Basenames: buyers show up by their primary Basename (name.base.eth) instead of their address: in the city log, toasts and news, Blocky cards, whale fountains, the collection (search by name too) and the claim page (look a wallet up by its Basename). api/_names.js reads the primary name from ENS's L2 reverse registrar on Base (ENSIP-19, where names are set since 2025), else the older Basenames resolver, and only keeps names that resolve back to the wallet (the name's resolver from the Base registry, its Base address record, else its plain one). Contract addresses are in basenames in src/config.js. Names are cached in KV (new wallets right away, known ones re-checked daily) and sent with /api/colony as names.
• Base Avenue (plots: avenue in src/config.js; projects: src/projects.js): numbered plots kept for Base projects' headquarters. A free plot shows "BASE AVENUE · PLOT n · Your project's HQ here" (and adContact / xHandle, which its sign links to). Add a project with one line in src/projects.js (the file explains every field): its plot, its goal at (Blockies), the day it was added (its HQ is never built before then, so adding one never changes what the city already built), colours, style (tower, campus, spire, dome) and logo (one drawn in code, LOGOS in src/city.js, or a square image in public/logos/). Until its goal its plot shows COMING SOON; then the crew builds the HQ like a landmark, and its signs link to the project. The gallery (/gallery.html?only=hq) shows every style. Landmarks are spaced out (landmarkEvery: at most one in every 3 projects), so homes keep going up even when many goals unlock at once.
• Whale buildings (whaleTiers in src/config.js): one buy of $1k+ builds a Whale Fountain, $2.5k+ a Whale Tower, $5k+ a Whale Skyscraper, ahead of everything else; towers go downtown (a free lot within 3 rings of Town Square, else in place of the oldest home, shop or office there). Each carries its whale's Basename (or address) on its crown, clickable to the wallet. The name stays while the wallet keeps at least half the Blockies it had right after the buy (CitySim.whaleNames, from departure times); sell more and the building goes dark, FOR SALE, and the next whale of its size or bigger takes it over (a new tower on that lot). The log, toasts and ticker say so.
• Leaving leaves a mark (departures in src/config.js, CitySim.depart in src/sim.js): Blockies that leave take the blocks they placed on the current construction site with them (the HUD and the log say how many), so the site takes longer. A big exit, ruinAt (20) or more Blockies at the same moment, leaves the newest home, shop or office abandoned (one per 20, at most maxRuins): grey, dark, boarded up and taped off, until the crew rebuilds it as the same kind of building, ahead of everything but whale fountains. Landmarks, parks and fountains are never touched. All of it follows from the departure times, so every visitor sees the same city.
• Builds take time, on several sites at once: the city opens one construction site per 40 Blockies it has had (at most 6, sites in src/config.js) and splits the crew between them. A crew's speed grows with the square root of its skill (4× the skill = 2× faster), so smaller crews on more sites build more in total, and bigger buildings take longer by tier (buildTime in src/config.js: ×3 small, ×4 mid, ×5 large, ×6 towers and skyscrapers; landmarks, fountains, land and the metro have their own). With ~100 Blockies a cottage takes ~9 min, apartments ~1.5 h, a skyscraper ~13 h. A new city gets a head start (launchBoost): its first project takes 8% of the time and each next one a bit more, up to the full time from the 80th, so with the 100 reserve Blockies the first buildings are up in minutes and ~50 in the first day. The HUD shows the time left, the next community goal and how many of the 10,000 Blockies are left. Land expansions and landmarks unlock at Blocky counts (10, 30, 75, … for land; 15 for Builder HQ, 100 for the airport, 1,000 for the metro, …). Up to ~120 Blockies walk the streets at once (the founder, the Base Builders, the first 20 OGs, every Legendary and the newest arrivals); all of them build.
• The city starts from empty land: grass, forest, a river. The founder builds the first garage, then the town square, then the city grows outward, roads appearing next to every new lot.
• ~30 building types by district: cottages, family houses, townhouses, apartments, villas, shops, cafés, offices, dev hubs, a school, GPU farms, towers, skyscrapers, wind turbines, water towers, farms, gardens, and leisure: a roller coaster, Ferris wheel and carousel (all animated), lake parks with ducks, flower gardens, playgrounds, skate parks, a public pool, soccer field, basketball court, concert stage and ice cream stand. Plus cars, buses and boats.
• Base Builders: real Base builders you add by hand build the city from day one with hand-made looks: the Founder, then Jesse (Builder 001), Nibel, Xen, Poet, Brian (CEO), Saumya Saxena, Jerry Pan, Ahaan Raizada, Jeremy Grinberg, Jon Roethke, Kien Nguyen, Toady Hawk, mleejr, deployer, David Tso, mrtdlgc, Quigley, DonJohnson, everythingempty, Cobie, statuette, Oxxbid and Joey. Add one line per builder to legends in src/config.js (joined: 'YYYY-MM-DD' to start later). gallery.html?only=legends shows them all, ?only=Jesse,Ahaan Raizada just those. Each one is in the Blocky viewer too, by name (/b/jesse).
• Rare Blockies: every Blocky rolls a rarity from its number and the block hash of the buy that brought it (rollSeed in src/ledger.js), so nobody can know or snipe a rare number before buying and anyone can check it afterwards: Common 70%, Uncommon 22% (Shades, Base Cap), Rare 7% (Gold Hard Hat, Laser Eyes, Astronaut), Legendary 1% (Diamond Skin, Crown). Rare ones walk the city, get a toast and fireworks when they arrive, and show on their card and PFP. Odds live in rarity in src/config.js; gallery.html?only=rare shows them.
• Base Builders page (/builders.html, linked from the HUD): every Base Builder's profile with a voxel PFP, title, live stats (hours building, blocks placed, share of the city, skill, building since) in a profile you can link to (/builders.html#jesse) and share on X, and a Download PFP button (1024×1024 PNG with a small BaseCity tag). Clicking any Blocky in the city shows its PFP too, so every buyer can download the Blocky their buy brought. Add x (handle) or bg (PFP colour) to a legend in src/config.js.
• Every other Blocky role has its own look: Founder (blue cap, gold badge), Smart Contract Dev (hard hat, hoodie, backpack), Frontend Dev (headphones), Designer (beret, scarf), Community (backwards cap, megaphone), Researcher (glasses, lab coat, clipboard).
• gallery.html shows every design and Blocky side by side; ?only=blockies or ?only=coaster,ferris to zoom in.
• Watching live: the city page shows how many people are watching now and how many have visited (api/live.js). Each open tab checks in every 2 minutes while it's visible; visitors are a hash of their IP in Redis HyperLogLogs (one per 2 minutes, one for all time), so no address is stored, a reload counts once and random ids can't inflate it. About one KV command per viewer per 2 minutes.
• Blocky viewer (blocky.html, src/viewer.js, at /b/N, or /b/jesse for a Base Builder): any Blocky by its number, or a Base Builder by name (suggested as you type), head to toe in 3D (drag to turn it) doing what Blockies do in the city (src/dance.js: Idle, Walk, Run, Carry a block, Build, Wave) or a dance (Bounce, Sway, Spin, Cheer), each a loop posed on the Blocky's rig; with its rarity, trait, role, status, owner, arrival and blocks placed (a Base Builder: office, who they are, building since, blocks placed). ◀ ▶ (arrow keys) and Random. Downloads: one loop of the move as a 480 px GIF (gifenc), a 2048 px full-body PNG, the same without background, the PFP and a 1500×500 X header. Numbers not reached yet say how to bring the next one.
• Daily recap (recap.html, src/recap.js): what the city did each day (24 h from its start), replayed from the same ledger: Blockies in the city and the day's change, arrivals (Legendary and Rare), departures, buildings finished, blocks placed, landmarks, whale builds and land, the day's rarest arrivals and its hardest-working buyer's Blocky. A 16:9 card to screenshot, a prefilled post for X, ?day=N for any day (the last full day by default). The post links to /r/N (vercel.json rewrites it to api/recap.js): a page whose X card is that day's recap as a 1200×675 PNG, drawn on the server from the same numbers (src/recap-data.js, satori + resvg), and that sends people on to the recap. ⬇ Save image makes the image from the card on the page (html-to-image, 2400×1350); on phones, Share attaches it to the post.
• Share cards: every page has its Open Graph and X card (title, description, og:url, a 1200×630 image with absolute URLs from siteUrl, twitter:site from xHandle): public/og.png for the city, og-builders.png, og-blockies.png and og-claim.png for the Builders, Blockies and Claim pages. In the pages, %SITE% and %X% are filled in at build time (vite.config.js).
• Zones, like SimCity: buildings follow rings around Town Square: Downtown (towers, offices), Midtown (apartments, shops, parks), Suburbs (Suburban Homes: four houses with yards; family houses, villas, schools), Outskirts (farms, wind, solar). Industry gathers in a park on the east bank; some lots from ring 3 out stay forest for good (isReserve in src/sim.js) and get named woods districts. Weights per zone live in CATALOG (w: [downtown, midtown, suburbs, outskirts]).
• Never finished: when the land is full and there aren't enough Blockies for the next ring, the crew redevelops: the oldest home, shop or office comes down and something at least as big for its zone goes up (cottages downtown become apartments, then towers; top-tier buildings are only renewed once nothing else can grow). New land, landmarks and whale fountains still come first. CitySim.redevelop in src/sim.js; npm test checks the crew never runs out of work.
• The land is a square that expands: when every lot is built, the Blockies reclaim a new ring of land, but only once enough Blockies live in the city (10, 30, 75, 150…, expandNeeds in src/config.js). Until then the city waits, which is where new buys come in.
• Landmarks are built as the crew grows: Founder's Garage → Town Square → Statue of Blockerty (the city icon, on a riverside point, unlocked by the first buy) → gm Café → Builder HQ → … → Onchain Beacon.
• The city sits in open countryside (crop fields, farms, woods, the river running on past the city limits, highways into town) that fades into haze; no floating island.
• Day/night cycle, clouds drifting high over the countryside, flocks of birds and river gulls (they sleep at night), a city log with exact completion times, and a "while you were away" recap.
• Market weather: the sky follows $BLOCKY's 24h price change: storm with lightning (≤ -15%), rain, cloudy, sunny, and a fireworks bull run (≥ +15%). Buys of 10+ Blockies fire a volley over the Statue of Blockerty, whales fire three. ?weather=storm forces a look for recording.
• Named districts: 3×3-lot neighbourhoods are named after what was built there (Downtown, GPU Valley, Fun Pier, Builder Heights…) and labelled on the map.
• BaseCity News: a SimCity-style ticker with buys, completions, weather, City Hall notices and the builder of the day.
• Base Airport (community goal at 100 Blockies): runway, terminal, control tower, and a plane that lands and takes off on a loop.
• What Base is building: AI agents and onchain stocks.
  • Base Stock Exchange (community goal at 25 Blockies): columns, a live LED ticker on the frieze and a big board on the roof showing $BLOCKY's price and 24h move, the token it trades against (NVDAc, priced from the pool) and any STOCK_TOKENS. A gold bull stands out front while $BLOCKY is up over 24h, a bear when it is down.
  • AI Agent Hub (community goal at 40 Blockies): a dark glass tower with glowing floors, server racks and a holographic agent head. It launches the city's AI agent drones, which pick up parcels and fly them over the rooftops to other buildings; every AI Startup adds two more. Brokerages carry the same live ticker.
  • The news ticker adds MARKETS (live quotes) and AGENTS (drones flying, parcels delivered) lines.
• Cat Town (@cattownbase): voxel cats stroll the sidewalks around the parks, and Cat Town Plaza on Base Avenue (plot 14) has the town cat as a statue, with more cats strolling and napping around it (src/cats.js, HQ style cats).
• City services: a Fire Station, Police Station, Hospital, Recycling Center and Solar Farm arrive early in every city (more as it grows). Each sends its vehicles out on the roads with flashing light bars: fire trucks, police cars, ambulances and garbage trucks.
• BaseCity Metro (community goal at 1,000 Blockies, once the land is 13×13 lots, so it circles a real city): an elevated loop over the ring road, on pillars between the car lanes. It rises piece by piece while the crew builds it, then a three-car train runs the loop and stops at a station on every side. The loop grows with the land. Set it in metro in src/config.js.
• Billboards on the Town Square, Builder HQ, the airport and some rooftops show Base projects (Coinbase Wallet, o1.exchange, Virtuals, bankrbot, Aero, logos drawn in code) plus one "YOUR PROJECT HERE" slot that sells the space. Edit sponsors in src/config.js ({ name, tagline, color, logo?, url, sponsored? }); clicking a board opens its link.
• Camera: drag to rotate, scroll or pinch to zoom, shift+drag / right-drag / two fingers to move around the city; the view stays where you leave it.
• Photo mode for screenshots and recordings: 📷 button or P hides the panels and holds the camera still (Esc to exit); The camera holds still by default; R or ⟳ turns a slow auto-rotate on (remembered). ?photo starts in photo mode, ?spin / ?still force rotation on / off.
• City Council (offices in src/config.js): every Base Builder holds a city office (office on each legend): Jesse (founder of Base) is the Mayor, Brian (CEO of Coinbase) the Governor, then the Speaker, Treasurer, Chief Architect, Fire Chief, Night Mayor and more. Offices show on the Blocky card (★ MAYOR · CITY COUNCIL), the leaderboard, the Base Builders page (ordered by rank), cinematic captions and the news ticker (each office has a duty line). Each office has a home (landmarks or building types): once one stands, its holder spends most breaks there ("At Town Square").
• Cinematic mode (src/cinematic.js): 🎬 Cinematic (or F, or 🎬 Film on a Blocky's card) swaps the isometric view for a film camera: a perspective lens, a real sky with the sun and moon, bloom (the windows glow at night) and depth of field on the subject. Shots change by themselves (Auto) or with ◀ ▶: a close-up of a Blocky, a high tracking shot following one, the construction site from above, the skyline from out of town, a drone flyover, a crane shot up the tallest building, the river. A spring-arm camera keeps buildings, trees, the metro and other Blockies from blocking the star, and cuts away if they do. Light presets (Golden hour, Night, Noon, Live; only your view, the city keeps its clock), frames for every feed (2.39:1, 16:9, 1:1, 9:16), and captures with the caption and the BaseCity watermark: 📸 a photo (2400 px on the long edge) and ⏺ a 10-second clip (MP4 where the browser can, else WebM), with Share (the phone's share sheet) and Save.
• Same city for every visitor. No wallet needed to watch. The buys are real, read onchain; nothing is faked.

Pages

Page	What
/	The city, live. Click any Blocky for its card, PFP and NFT page.
/collection.html	The Blockies: every Blocky with filters (rarity, trait, in the city / left), search by #number, name or wallet, top holders, and a card per Blocky (/collection.html#206) with its NFT portrait, stats, PNG download and OpenSea / Basescan links.
/claim.html	Claim: connect the wallet that bought (browser wallets via EIP-6963, Coinbase Smart Wallet / Base App via the Coinbase Wallet SDK), see its Blockies, claim them 50 per transaction. The buyer pays the gas. ?address=0x… opens a wallet.
/builders.html	Base Builders: profiles, live stats and downloadable voxel PFPs.
/about.html	How it works: the rules, rarity odds, goals, contracts, FAQ.
/deploy.html	Owner tool (not linked): deploys the NFT contract from your browser wallet.

The NFT: BaseCity Blockies (BCB)

contracts/BaseCityBlockies.sol: ERC-721 + ERC-2981 (5% royalty to the treasury) + ERC-4906, OpenZeppelin 5.

• Token id = Blocky number. The ledger (src/ledger.js, run by api/colony.js) decides which wallet brought which Blocky and when it becomes a citizen (citizenAt: not before opening day, L.openedAt). api/claim.js signs an EIP-712 claim for the wallet's citizens not claimed yet; the wallet sends claim(ids, deadline, signature) itself and pays the gas. Only the wallet named in the signature can use it; signatures last 30 minutes.
• Only citizens are minted, so nothing is locked or burned. A citizen never leaves the city, so the contract is a plain ERC-721: every Blocky trades on OpenSea from the moment it's claimed, no lock to lift later. An NFT costs holding $10 of $BLOCKY for 6 hours, which keeps instant buy-and-dump from farming them. The contract mints at most MAX_SUPPLY (10,000), ever.
• Max 10,000 (MAX_SUPPLY, set at deploy, the same as the city's cap); the claim API never signs a claim the contract can't mint.
• Team reserve: Blockies #1 to #100 belong to the team wallet from day one (nft.reserve in src/config.js, or TEAM_RESERVE_WALLET / TEAM_RESERVE_COUNT): citizens from opening day, never sent away by the hold rule, counted in the 10,000, disclosed on the About page and as Origin: Team reserve in their metadata. Set the count to 0 for none.
• Metadata from api/nft/[id].js: /api/nft/206 (name, rarity, trait, role, status: Newcomer / Citizen / Left the city, citizen since, blocks placed, arrival date), /api/nft/206.svg (the portrait, drawn from the same 3D model by src/voxel-svg.js, cached for a year), /api/nft/collection (contractURI).
• Owner functions: setSigner (rotate the claim key if it ever leaks), setBaseURI (also asks marketplaces to refresh, ERC-4906: call it if the domain changes after deploy), setContractURI, setRoyalty.
• Build and test: cd contracts && npm install && npm test compiles (solc 0.8.26, Cancun), runs the contract tests on an in-memory Base and an end-to-end test of the claim and metadata APIs against it. contracts/out/ holds the artifact (ABI + bytecode, used by /deploy.html) and the Standard JSON Input for Basescan verification.

Run

npm install
cp .env.example .env.local
npm run dev                  # http://localhost:5173, also serves /api/colony, /api/claim, /api/live and /api/nft/* locally
                             # (installs any dependency a git pull added before it starts)
npm run build

Locally the API reads trades from GeckoTerminal like production; without KV the ledger lives in memory and starts empty. If the live API is unreachable, the pages fall back to demo data.

URL flags: ?demo fakes 3 days of history and then a trade every 30s (a $1,000 whale at 2 minutes, a seller at 3.5 minutes); ?speed=600 fast-forwards the city clock for timelapse videos; ?weather=bull forces the weather; ?photo starts in photo mode. Combine them: /?demo&speed=600&photo.

Go live (fresh city, 0 / 10,000)

1. Storage: add Upstash Redis from the Vercel Marketplace (sets KV_REST_API_URL / KV_REST_API_TOKEN). Required in production.
2. Fresh start: set KV_KEY to a new name (e.g. basecity-v1): a new key means a fresh ledger, so the city starts from empty land with only the team reserve (100 / 10,000, or 0 with no reserve) and only buys from now on count. Optionally set LAUNCH_TIME_MS (ms timestamp) to the launch moment. Do not set BACKFILL_HOURS.
3. RPC: set BASE_RPC_URL to your own Base RPC (Alchemy, QuickNode, …): the API reads every trade's receipt (the real wallet, and the block hash that seeds rarity) and checks holders' balances. A trade whose receipt can't be read yet waits, with every trade after it, for up to 10 minutes rather than count for the bundler; and one serverless instance at a time updates the ledger (a KV lock), so a Blocky number never goes to two wallets.
4. Deploy and open the site once so the ledger starts (/api/colony).
5. Contract: open /deploy.html with the dev wallet (0x8eBA…C34D), click Generate a signer key, copy the key, deploy. Then in Vercel set NFT_CONTRACT (the new address), CLAIM_SIGNER_KEY (the key) and SITE_URL (your domain), and redeploy: claims open. Claims stay closed on Vercel without KV (every instance must sign from the same ledger).
6. Verify on Basescan with the Standard JSON Input the deploy page links (compiler and constructor arguments are printed there too).
7. OpenSea lists the collection after the first claim; set its links and creator earnings there.
8. Keep it ticking: point a free uptime pinger (cron-job.org, UptimeRobot) at /api/colony every minute. The ledger only updates when the API runs, and the trade feed keeps just the last 300 trades of the pool, so a quiet night without visitors must not drop buys.

Deploy (Vercel)

Import the repo; Vercel detects Vite and serves api/*.js as serverless functions.

Environment variables (see .env.example):

Var	What
KV_REST_API_URL / KV_REST_API_TOKEN	Upstash Redis (Vercel KV). Required in production: stores the ledger (every Blocky, its wallet and seed, departures, the waitlist) so every visitor sees the same city.
KV_KEY	Name of the stored ledger (default blocky:colony). A new name starts a fresh city at 0 / 10,000.
LAUNCH_TIME_MS	When the city starts from empty land and buys start counting. Default: the first time the API runs.
BASE_RPC_URL	Base RPC for receipts, balance checks and the NFT contract (default: the public mainnet.base.org, rate limited).
NFT_CONTRACT	The BaseCity Blockies contract (from /deploy.html). Claims open when this and CLAIM_SIGNER_KEY are set.
CLAIM_SIGNER_KEY	Private key that signs claims; its address is the contract's signer. Server only, never commit it.
OPENSEA_API_KEY / OPENSEA_SLUG	Optional: reads the collection's floor and listings on OpenSea for the claim page's suggested prices and low-listing warnings (src/pricing.js; slug default nft.openseaSlug). Without a key, suggestions use a fixed $15 of ETH. The key also lets holders list on OpenSea from the claim page (src/listing.js, OpenSea's SDK; api/opensea.js relays only BaseCity Blocky listings, at /api/os/*, so the key never reaches the browser).
SITE_URL	Your domain, e.g. https://basecity.xyz: NFT metadata links, share links and share images.
USD_PER_BLOCKY / MAX_SUPPLY / WHALE_USD / UNLOCK_USD / CITIZEN_DAYS	Optional overrides of usdPerBlocky (10), supply (10000), whaleUsd (1000), unlockUsd (0: open) and citizenDays (0.25: 6 hours) in src/config.js; keep them in sync.
MIN_BUY_USD	Ignore dust buys (default $1).
HOLD_CHECK_MINUTES

Customize

• src/config.js: city name, ticker, token links, $ per Blocky, supply, rarity odds, Base Builders, billboards, blocksPerHour, day length, land size and expansion thresholds, landmark milestones.
• src/sim.js: Blocky roles and work rates, the river, the building catalog and the deterministic build plan (landmarks, buildings, land expansions).
• src/city.js: voxel designs, land/river/bridges, progressive roads, construction sites, day/night.
• src/vehicles.js: cars, buses, boats and service patrols; src/fleet.js: the service vehicles.
• src/metro.js: the elevated metro loop, its stations and the train.
• src/pfp.js: voxel PFP renderer (WebGL); src/voxel-svg.js: the same Blocky as an SVG (NFT images, collection pages).
• src/ledger.js: the Blocky ledger (buys, the hold rule, the waitlist, rarity seeds), shared by the API and demo mode.
• Pages: builders.html, collection.html, claim.html, about.html with src/site.js + src/site.css (nav, footer, shared styles).
• src/agents.js: the AI agent drones.
• src/cats.js: Cat Town's cats and the plaza's statue.
• src/music.js: the city's lo-fi music, played live with the Web Audio API (no audio files): ♪ Music or M. It gets darker at night and quieter in the rain.
• src/votes.js, api/vote.js, /vote.html: the citizens' vote. Holders of BaseCity Blockies NFTs pick what the city builds next, 1 NFT = 1 vote (the team's reserve and grants don't vote), signed for free (smart wallets too), counted per NFT in KV. The round lives in vote in src/config.js; the winner goes into src/projects.js by hand when it ends.
• src/citizens.js: builders walking the roads, hauling and placing blocks.

How "24/7, same for every visitor" works

No game server. The crew's speed only changes when a builder arrives (blocksPerHour × √(total skill)), so total blocks placed is a piecewise-linear function of time. The city plan is a fixed, seeded sequence of buildings; each starts when the previous one is done and finishes once the crew has placed its cost in blocks. Any browser that knows every Blocky's arrival and departure (from /api/colony + KV) computes the exact same skyline, including when each building was completed.