Branding & the website

Branding is app-owned: the engine ships none, because it has no app to ship. What it does do is make one set of source images serve everything: the app icon, the splash, the web assets, and the game's public website. Nothing is authored twice.

Author the marks in any vector tool and export the PNG sources below; every platform-specific size is generated from them.

Replacing the placeholder artwork

A scaffolded game ships with the EigenInteractive mark and seed colour, so it looks deliberate before you have drawn anything. Swapping in your own is these seven steps, in this order, because the later ones consume what the earlier ones write:

1. Replace the sources in app/assets/icon/: icon.png and icon_foreground.png at 1024 × 1024, and splash.png / splash_dark.png if your splash mark differs. See the app icon for what the foreground has to keep clear of.

2. Match the colours in app/pubspec.yaml: flutter_launcher_icons.adaptive_icon_background and every flutter_native_splash colour. These cannot read Dart, so nothing keeps them in step with your theme but you.

3. Regenerate, from app/:

   dart run flutter_launcher_icons
   dart run flutter_native_splash:create

4. Set the seed in app/lib/main.dart, Branding(seedColor: …), and, if you have configured a site, its primaryColor in server/src/index.ts. Material 3 rebuilds both schemes from the seed, so this one value is the app's whole palette.

5. Draw the share card: app/web/og-image.png at 1200 × 630, and fill in the OG tags in app/web/index.html. It is the only hand-made file in the pipeline.

6. Build the web bundle, from the repository root:

   pnpm run build:web

   This is the step that carries the regenerated icons into the Worker's public/, which is where the download page and the manifest read them from. Skip it and the website keeps showing the mark it had before.

7. Commit the generated files. Launcher icons, splash drawables and web icons are generated once and committed, not rebuilt on each build.

Everything below is the detail behind those steps.

The app icon

Two 1024 × 1024 PNGs in assets/icon/. They are build-time inputs, so they are not declared under flutter: assets:.

File	Notes
icon.png	Full square icon, artwork edge-to-edge, opaque. Used for iOS, macOS, web and the legacy Android icon. iOS rejects alpha, so set remove_alpha_ios: true if the source has any.
icon_foreground.png	Adaptive-icon foreground: the mark alone on transparent, inside the inner ~66%. Android masks it to a circle or squircle and parallaxes it, so anything near the edge is cropped. Also reused as the splash image.

dart run flutter_launcher_icons writes the Android mipmaps and adaptive XML, the iOS/macOS appiconsets, and the web favicon and icons plus the icons array in manifest.json. It never touches web/index.html, and it does not generate the notification icon.

The splash

flutter_native_splash: is a top-level pubspec key, not nested under flutter:. Reusing icon_foreground.png as the splash image keeps the splash mark and the home-screen icon the same file. Regenerate with dart run flutter_native_splash:create after any config or asset change.

Two things to know:

• On Android 12+ the image: key is ignored entirely. The platform builds the splash from the adaptive launcher icon, so the android_12: block only sets colours. And -v31 is a minimum-version qualifier: that block covers API 31 and everything after, not just Android 12.
• Colours cannot read Dart. color / color_dark must be kept in sync by hand with the theme surfaces derived from Branding.seedColor; changing the seed means editing them and regenerating.

For a splash mark that differs from the launcher icon, add assets/splash/logo.png (plus logo_dark.png) at 1152 × 1152 with artwork inside the inner 640 px, because the outer ring is cropped by Android 12's circular mask.

The app's web build

A fresh Flutter app ships template values that fail silently: <title> is the project name, the description is "A new Flutter project.", and manifest.json carries Flutter's default #0175C2. Replace all of them.

Flutter's web template also has no Open Graph tags, so a pasted link renders as a bare URL. Add og:* and twitter:* to <head>, with og:image an absolute URL at 1200 × 630 (web/og-image.png). A relative og:image is the usual reason a preview renders blank, since scrapers do not resolve them. Keep text centred; some clients crop to a square. Verify with the Facebook Sharing Debugger after deploying, and re-scrape after changes, since both it and Slack cache hard.

The game's website

The Worker's site block generates the rest of the game's public web presence, and it consumes exactly the files above, with no second icon set and no extra artwork:

Route	What it is
GET /	Landing page: app icon, name, tagline, screenshots, store buttons
GET /terms, /privacy, /delete-account	The legal documents
GET /sitemap.xml, GET /robots.txt	Crawler directives
GET /site.webmanifest	Web app manifest

site: {
  tagline: "A hidden-information battle of wits for two players.",
  primaryColor: "#1a237e",
  screenshots: ["1.png", "2.png"],   // under public/screenshots/
  operator: {
    name: "Your Company Ltd",
    jurisdiction: "India",
    contactEmail: "hello@example.com",
    effectiveDate: "1 July 2026",
  },
},

The point is that you get a complete, indexable, store-compliant site by configuration. The alternative is every game hand-rolling the same four pages and getting the store requirements subtly wrong.

Absolute URLs in canonical links, OG tags and the sitemap are built from the request origin, so there is no domain to configure. To keep one canonical host, disable the workers.dev route in production. Store buttons come from your deepLink block, so store URLs are configured once. The /download page emits SoftwareApplication JSON-LD with applicationCategory: "GameApplication".

Every page ends in a footer carrying your copyright, the three legal links, and a credit line, Built with EigenInteractive, where only the name is a link. Set madeByCredit to your own string, or to null to drop it:

site: { /* … */ madeByCredit: null },

A custom credit that still names EigenInteractive keeps the link on that word; one that does not renders as plain text. Every link the engine puts on these pages (legal, store buttons, the credit) opens in a new tab, so a visitor mid-download does not lose the page.

Before site is configured

/download serves without it, so a game has a working web/native handoff from the first deploy. What it does not have is the legal half: those routes are not mounted, so the footer carries only the credit until you fill in operator.

The page waits for a Flutter web build to reach public/ before it offers a "Play on the web" button, because / would otherwise bounce straight back to /download.

Icons are a separate question, and the answer is the same on every page the engine renders: the browser tab, the download page's logo, and the manifest. Until your game has icons of its own, all three use the EigenInteractive mark, served by the Worker and drawn in your primaryColor, exactly as the Flutter shell defaults to the EigenInteractive seed and credit. It is a placeholder, not a default. The moment favicon.png exists in public/ the engine links your icons everywhere and stops serving its own.

That check looks at the icons themselves rather than at the web build, so a game with no web build still gets its own. pnpm run build:web is the usual way they arrive; an Android-only game can copy the same files out of app/web/ into public/ and get the identical result.

A game with no web build and no store URLs in deepLink has nothing to offer at all, and the page says Coming soon. rather than trailing off after the tagline. That is the state a freshly scaffolded game is in, so seeing it on your first wrangler dev is correct, not a misconfiguration.

The web asset handoff

The root scaffold's build:web command writes Flutter's complete release bundle directly into the Worker's public/ directory. The engine's default paths match the filenames flutter_launcher_icons emits:

The app generates	Worker asset path	Used for
web/favicon.png	favicon.png	Browser tab
web/icons/Icon-192.png	icons/Icon-192.png	Manifest, apple-touch-icon
web/icons/Icon-512.png	icons/Icon-512.png	Manifest
web/icons/Icon-maskable-192.png	icons/Icon-maskable-192.png	Manifest (maskable)
web/icons/Icon-maskable-512.png	icons/Icon-maskable-512.png	Manifest (maskable)
web/og-image.png	og-image.png	Landing-page share card

Screenshots go under public/screenshots/. og-image.png is the only hand-made file in the whole pipeline, and the app's own share card already asks for it.

Legal documents

All three default to templates the engine ships. They take your operator block as typed props, so there are no placeholders to fill in and nothing to keep in sync, and a mistyped field is a compile error. They describe only what the engine itself collects: accounts, display names, optional avatars, game history, ratings, friend connections, push tokens and crash diagnostics.

Read them before you publish

They are a starting template, not legal advice, and you are the one on the hook for what they say. If you add analytics, advertising, payments, or any other processing, you must edit them. Two lines in particular assume things about your app: the privacy policy's "Diagnostics" bullet assumes crash reporting, and the delete-account steps describe the reference Flutter shell's Settings screen.

To supply your own prose, pass an HTML fragment, body content only, since the engine supplies the shell, styling and footer:

// wrangler.jsonc: lets you import .html files as strings
"rules": [{ "type": "Text", "globs": ["**/*.html"], "fallthrough": true }]

import terms from "./legal/terms.html";
// …
site: { /* … */ legal: { terms } },

Your fragment is inserted as-is, so write your own values into it directly.

Batteries included, batteries removable

The scaffold reserves legal and /download paths with run_worker_first, so Flutter's SPA fallback cannot shadow them. To replace generated legal prose, use the typed site.legal fragments above.

Checklist

• assets/icon/icon.png + icon_foreground.png at 1024 × 1024, foreground inside the inner ~66%
• flutter_launcher_icons: adaptive background matches the brand → regenerate
• flutter_native_splash: colours match the theme → regenerate
• (optional) ic_notification.xml declared to override eigen_firebase's default silhouette; notifications work without it
• web/index.html: real title, description and OG/Twitter tags, absolute og:image; web/og-image.png at 1200 × 630
• web/manifest.json: real name, short_name, description, background_color / theme_color
• pnpm run build:web places the complete Flutter bundle in Worker assets
• site.operator filled in, and the three legal documents actually read
• App Links <intent-filter> carries an android:pathPrefix for both /join and /game; see Deep links