# Package apps

Use this doc when authoring or debugging a package **app**, a community fork of
an app, or a hosted-app load. Package shape, README / AGENTS.md, Intent, and
export JSDoc stay in [Package authoring](/docs/package-authoring)
(`guide:package_authoring`). Proving the integration first stays in
[Integration bootstrap](/docs/integration-bootstrap)
(`guide:integration_bootstrap`).

A package app is a hosted **Worker entry**. `kody.app.entry` default-exports a
fetch handler (a function, `{ fetch }`, or a named `fetch` export). Anything
esbuild can bundle that answers `fetch` is a valid app. The host strips the app
mount before forwarding, so every entry sees `/notes` for
`/packages/<id>/notes`. Optional `kody.app.client` and `kody.app.assets` add a
browser module and static files under `/_assets`. `kody:runtime` exposes
`packageContext`, `packageStorage()`, and the rest of the run. Remix is
[Example A](#remix-recipe) — a recipe with its own boilerplate, not a host mode.

Open a heading with `search({ entity: "guide:package_apps#remix-recipe" })` (or
another slug below) when you need one recipe.

## After an integration smoke test

Once `integration_bootstrap` proves the integration works — or integration and
secret state are already clear enough to verify quickly — go straight to the
app. Do not spelunk the local repo first unless you specifically need repo
conventions, shared helpers, or an existing package to extend.

1. Discover integration and secret state with `search`. Read full integration
   metadata only when you need exact names, hosts, or the API base URL.
2. Verify the required connection exists. For OAuth, confirm the integration
   name, required hosts, and API base URL match the app you are about to build
   (tokens live on the connection). For secret-backed auth, confirm the secret
   names and allowed hosts match.
3. Run one cheap authenticated smoke test in `execute` — a small read-only
   request such as `GET /me`, `GET /viewer`, or `GET /v1/me`.
4. If it passes, build the app as a saved package with `package.json#kody.app`
   (start from a [fetch handler](#fetch-handlers); use the
   [Remix recipe](#remix-recipe) when you want Remix). Keep human `README.md`
   (including `## Intent`) and agent `AGENTS.md` aligned with the person's goal.
   Keep provider API calls and durable coordination in package-owned backend
   modules.
5. Save with `packageSave` (or push through the git lane), reopen the hosted
   package URL, and iterate there instead of pasting large inline HTML blobs
   back into model context.

### Default app shape

The host contract is the same for every app:

- **entry** — `kody.app.entry`, a Worker fetch handler. The host strips the
  mount (`/packages/<package-name>/notes` → `/notes`)
- **browser entry** — optional `kody.app.client`; the platform bundles it for
  the browser on publish (see
  [Browser client and static assets](#browser-client-and-static-assets))
- **static assets** — optional `kody.app.assets` directory, served as-is
- **exports** — reusable modules and callable default exports declared in
  `package.json#exports`
- **durable data** — `packageStorage()` for the shared package bucket
- **internal backend modules / Durable Objects / facets** — app-internal
  realtime and coordination details (integration lookups, provider calls,
  validation, mutations), not the persistence mechanism

A one-file fetch handler is a complete app (see
[Fetch handlers](#fetch-handlers)). Framework folder layouts belong in a recipe;
[Remix](#remix-recipe) is Example A.

## Session handoff

Production-hosted apps live at
`https://{username}.kody.run/packages/<package-name>/…`. Opening the app from
the signed-in kody.codes origin (**Open Package App**, the publish
`hosted_app_url`, or the equivalent package page control) attaches a short-lived
session, then the subdomain loads. Plan QA around that path: signed-in origin
first, then confirm the app on `*.kody.run/packages/…`.

`packageAppFetch` exercises the fetch handler without that browser session. Use
it for handler smoke tests. Use the handed-off URL for cookies, layout, OAuth
redirects, and websocket facets.

## Smoke with packageAppFetch

After publish, call `packageAppFetch` with the path, method, and body the
handler needs. Confirm `{ status, headers, body, truncated }` and any
`packageStorage()` side effects. Read
[Package app fetch](https://github.com/kentcdodds/kody/blob/main/docs/use/package-app-fetch.md) for the call shape.

Typical first probe:

```json
{
	"package_id": "550e8400-e29b-41d4-a716-446655440000",
	"path": "/"
}
```

Check status, content-type, and a small HTML or JS snippet in `body`. When
`truncated` is `true`, the handler ran; the MCP body is a size-capped sample
(about 100 KB). Side effects are real.

Copy-paste starting points land on `test_hints.app` after
`packagePublishExternalPush`.

## Interactive UI QA

Confirm the real user flow in a browser that already has the session, or in a
local harness that serves the **same** published client and assets:

1. Open the app from kody.codes so the handoff attaches, **or** serve the
   published entry, HTML, and asset routes locally with the same `appBasePath` /
   `hostedUrl` join the Worker uses.
2. Click, type, and submit the way a person would.
3. Confirm layout, redirects, and any websocket facet on that same client.
4. Then ping the owner.

`packageAppFetch` stays the handler smoke. Interactive QA is the handed-off
browser or that local harness.

## Large binaries

`packageAppFetch` is the lightweight smoke: status, headers, and a small body
sample. For a large download (WASM, WAD, video, zip), use a full download path —
`curl` against the handed-off or local harness URL, or the streamed app route
that serves those bytes — and confirm length, content-type, and that the file
opens in the client.

Treat `truncated: true` as “the handler answered,” then finish the proof on the
full stream.

## Remix recipe

**Example A.** Remix is a worked example, not a host mode. The platform supplies
`remix/<subpath>` at the version Kody's own UI ships (no npm install, no version
to pick) as an optional convenience. The host treats the entry as a fetch
handler: esbuild defaults, mount-stripped URLs. The recipe below adds the
boilerplate Remix needs under that contract — `tsconfig` JSX, per-file
`@jsxImportSource`, a remount wrapper, named islands with an explicit
`kody:app#Name` id, and a browser registry.

Kody's runtime is available as named exports from `kody:runtime`, and as the
`KodyRuntime` request-context key so controllers can `context.get(KodyRuntime)`
for `packageStorage()`, `packageSecrets`, `kody`, `createAuthenticatedFetch`,
`workflows`, and `packageContext` (`appBasePath`, `hostedUrl`, `assetBasePath`,
`clientModuleUrl`) without wiring a middleware.

**Do not depend on `@remix-run/*` or npm `remix`.** The platform supplies every
`remix/<subpath>` import at the version Kody's origin ships (`3.0.0-rc.2`);
publish **rejects** any `@remix-run/*` entry in `package.json#dependencies`, and
a `remix` entry there is ignored. No `esm.sh`, no vendored browser build in
`public/`, no `client.externals` / import map for Remix: `remix/ui` is inlined
into the browser module from the platform copy. Put `remix` in `devDependencies`
only, for editor types. A kit or recipe that installs `@remix-run/ui` from npm
or maps it through an import map is describing the
[island pattern](#migrating-an-island-app); see
[What the platform supplies](#what-the-platform-supplies) for the surface and
version rules.

The layout below is what `create-package-app` scaffolds. Keep it: routes and
router at the root of `app/`, controllers, middleware, data, and UI in their own
folders, the browser entry under `app/assets/`, static files in `public/`. The
[scaffolder contract](#scaffolder-contract) spells out what a kit emits.

### Recipe

`package.json` — `remix` goes in `devDependencies` for local types only: publish
installs `package.json#dependencies` and nothing else, so a types-only `remix`
dev dependency is inert and the bundle uses the platform copy. There is no
runtime field: the default export is the app.

```json
{
	"name": "@you/notes",
	"exports": { ".": "./src/index.ts" },
	"devDependencies": { "remix": "3.0.0-rc.2" },
	"kody": {
		"id": "notes",
		"description": "Notes with a hosted Remix app",
		"app": {
			"entry": "./app/router.ts",
			"client": "./app/assets/entry.ts",
			"assets": "./public"
		}
	}
}
```

`app/routes.ts` — the typed URL contract. Hosted apps live under a mount
(`/packages/<package-name>` on the subdomain), so the contract is prefixed with
`packageContext.appBasePath`: every `href()`, redirect, and form action then
stays inside the mount, and the router matches the URL the browser requested.
This module is server-only (it imports `kody:runtime`); pass URLs to islands as
props instead of importing it from browser code.

```ts
import { packageContext } from 'kody:runtime'
import { form, route } from 'remix/routes'

export const routes = route(packageContext?.appBasePath ?? '', {
	home: '/',
	notes: form('notes'),
	health: '/healthz',
})
```

`tsconfig.json` — the host maps root `compilerOptions.jsx` / `jsxImportSource`
onto the esbuild bundle (no graph sniff). The editor reads the same file.

```json
{
	"compilerOptions": {
		"jsx": "react-jsx",
		"jsxImportSource": "remix/ui",
		"allowImportingTsExtensions": true,
		"module": "esnext",
		"moduleResolution": "bundler",
		"target": "es2022",
		"strict": true,
		"noEmit": true
	}
}
```

`app/router.ts` — `kody.app.entry`. Default-export a fetch handler. The host
strips the mount, so remount the Request before `router.fetch` when the route
contract includes `appBasePath`. Do not default-export the router object:
`router.fetch` takes `(input, init?)`, and the Worker `env` is not
`RequestInit`.

```ts
import { packageContext } from 'kody:runtime'
import { createRouter } from 'remix/router'
import { formData } from 'remix/middleware/form-data'
import { requestId } from './middleware/request-id.ts'
import { routes } from './routes.ts'
import home from './controllers/home.tsx'
import notes from './controllers/notes.tsx'

const router = createRouter({ middleware: [requestId(), formData()] })

router.map(routes.home, home)
router.map(routes.notes, notes)
router.get(routes.health, () => Response.json({ ok: true }))

function remountRequest(request: Request) {
	const appBasePath = String(packageContext?.appBasePath ?? '').replace(
		/\/+$/,
		'',
	)
	if (!appBasePath) return request
	const url = new URL(request.url)
	url.pathname = url.pathname === '/' ? appBasePath : appBasePath + url.pathname
	return new Request(url, request)
}

export default {
	fetch(request: Request) {
		return router.fetch(remountRequest(request))
	},
}
```

`app/middleware/request-id.ts` — middleware sets typed context the usual Remix
way.

```ts
import { createContextKey, type Middleware } from 'remix/router'

export const RequestId = createContextKey<string>()

export function requestId(): Middleware {
	return async (context, next) => {
		context.set(RequestId, crypto.randomUUID())
		const response = await next()
		response.headers.set('x-request-id', context.get(RequestId) ?? '')
		return response
	}
}
```

`app/data/notes.ts` — durable data through `KodyRuntime`. `get(KodyRuntime)` is
the `kody:runtime` module for the current request; nothing installs it, it is
the key's default value.

```ts
import { KodyRuntime } from 'kody:runtime'
import type { RequestContext } from 'remix/router'

export type Note = { id: string; text: string }

export async function listNotes(context: RequestContext): Promise<Array<Note>> {
	const stored = await context.get(KodyRuntime).packageStorage().get('notes')
	return Array.isArray(stored) ? (stored as Array<Note>) : []
}

export async function addNote(context: RequestContext, text: string) {
	const storage = context.get(KodyRuntime).packageStorage()
	const notes = await listNotes(context)
	await storage.set('notes', [...notes, { id: crypto.randomUUID(), text }])
}
```

`app/controllers/notes.tsx` — a `form()` route: GET renders, POST validates with
`remix/data-schema`, persists, and redirects inside the mount. JSX needs no
pragma: the bundle compiles against `remix/ui`. `context.get(FormData)` uses the
**global `FormData` constructor** as the context key — that is the key the
`formData()` middleware stores the parsed body under.
`remix/middleware/form-data` exports only `formData` and `FormDataParseError`;
an `import { FormData } from 'remix/middleware/form-data'` has no matching
export and fails publish.

```tsx
/** @jsxImportSource remix/ui */
import type { Controller } from 'remix/router'
import * as s from 'remix/data-schema'
import * as f from 'remix/data-schema/form-data'
import { redirect } from 'remix/response/redirect'
import { addNote, listNotes } from '../data/notes.ts'
import { routes } from '../routes.ts'
import { render } from '../ui/render.tsx'

const noteSchema = f.object({ text: f.field(s.string()) })

export default {
	actions: {
		async index(context) {
			const notes = await listNotes(context)
			return render(
				context,
				<main>
					<ul>
						{notes.map((note) => (
							<li key={note.id}>{note.text}</li>
						))}
					</ul>
					<form method="post" action={routes.notes.action.href()}>
						<input name="text" />
						<button type="submit">Add</button>
					</form>
				</main>,
			)
		},
		async action(context) {
			const parsed = s.parseSafe(noteSchema, context.get(FormData))
			if (!parsed.success || parsed.value.text.trim() === '') {
				return render(context, <p>A note needs some text.</p>, { status: 400 })
			}
			await addNote(context, parsed.value.text.trim())
			return redirect(routes.notes.index.href(), 303)
		},
	},
} satisfies Controller<typeof routes.notes>
```

`app/controllers/home.tsx` — a page with a hydrated island. `packageContext`
comes from the same key.

```tsx
/** @jsxImportSource remix/ui */
import type { BuildAction } from 'remix/router'
import { KodyRuntime } from 'kody:runtime'
import { listNotes } from '../data/notes.ts'
import { routes } from '../routes.ts'
import { Counter } from '../ui/counter.tsx'
import { render } from '../ui/render.tsx'

export default {
	async handler(context) {
		const { packageContext } = context.get(KodyRuntime)
		const notes = await listNotes(context)
		return render(
			context,
			<main>
				<h1>Notes at {packageContext?.appBasePath}</h1>
				<Counter initialCount={notes.length} label="Notes" />
				<a href={routes.notes.index.href()}>Add a note</a>
			</main>,
		)
	},
} satisfies BuildAction<'ANY', typeof routes.home>
```

`app/ui/render.tsx` — SSR through `remix/ui/server`. The document renders the
platform module URL from `packageContext.clientModuleUrl`; no
`resolveClientEntry` is needed (see [Hydration](#hydration)).

```tsx
/** @jsxImportSource remix/ui */
import type { RequestContext } from 'remix/router'
import { KodyRuntime } from 'kody:runtime'
import type { Handle, RemixNode } from 'remix/ui'
import { renderToStream } from 'remix/ui/server'
import { createHtmlResponse } from 'remix/response/html'

function Document(
	handle: Handle<{
		appBasePath: string
		assetBasePath: string
		clientModuleUrl: string | null
		children?: RemixNode
	}>,
) {
	return () => (
		<html lang="en" data-app-base={handle.props.appBasePath}>
			<head>
				<meta charset="utf-8" />
				<link
					rel="stylesheet"
					href={`${handle.props.assetBasePath}/styles.css`}
				/>
			</head>
			<body>
				{handle.props.children}
				{handle.props.clientModuleUrl ? (
					<script type="module" src={handle.props.clientModuleUrl}></script>
				) : null}
			</body>
		</html>
	)
}

export function render(
	context: RequestContext,
	children: RemixNode,
	init?: ResponseInit,
) {
	const { packageContext } = context.get(KodyRuntime)
	const stream = renderToStream(
		<Document
			appBasePath={packageContext?.appBasePath ?? ''}
			assetBasePath={packageContext?.assetBasePath ?? ''}
			clientModuleUrl={packageContext?.clientModuleUrl ?? null}
		>
			{children}
		</Document>,
		{ frameSrc: context.url.href },
	)
	return createHtmlResponse(stream, init)
}
```

`app/ui/counter.tsx` — a `clientEntry` island, shared by the server render and
the browser bundle. Use a **named** function and an explicit id
(`kody:app#Counter`): workerd leaves `import.meta.url` empty, and the host does
not pin it or keep export names.

```tsx
/** @jsxImportSource remix/ui */
import { clientEntry, on, type Handle } from 'remix/ui'

export const Counter = clientEntry(
	'kody:app#Counter',
	function Counter(handle: Handle<{ initialCount: number; label: string }>) {
		let count = handle.props.initialCount
		return () => (
			<button
				type="button"
				mix={on('click', () => {
					count += 1
					handle.update()
				})}
			>
				{handle.props.label}: {count}
			</button>
		)
	},
)
```

`app/assets/entry.ts` — `kody.app.client`. One browser module, so `loadModule`
resolves islands by export name from a registry instead of importing a URL.

```ts
import { run } from 'remix/ui'
import { Counter } from '../ui/counter.tsx'

const clientEntries: Record<string, unknown> = { Counter }

const app = run({
	async loadModule(_moduleUrl, exportName) {
		const component = clientEntries[exportName]
		if (typeof component !== 'function') {
			throw new Error(`Unknown client entry "${exportName}"`)
		}
		return component
	},
})

void app.ready().then(() => {
	document.documentElement.dataset.hydrated = 'true'
})
```

`public/styles.css` — served as-is under `<appBasePath>/_assets/styles.css`.

Save with `packageSave`, open the hosted URL, add a note, and confirm the
counter increments after hydration (`<html data-hydrated="true">`).

### Kody in the request context

`KodyRuntime` (from `kody:runtime`) is a frozen `{ defaultValue }` object.
Remix's `context.get(KodyRuntime)` returns the `kody:runtime` module for the
current request when nothing called `set()`:
`{ kody, packageStorage, packageSecrets, packageContext, createAuthenticatedFetch, workflows, events, packages, email }`
plus package-app extras such as `realtime`. It is the same object as
`import runtime from 'kody:runtime'`. Other entries import named exports
directly. Modules that come from another saved package (static
`kody:@scope/package` imports) get their own stamped key, so their
`packageStorage()` resolves to the declaring package.

### Mount and URLs

The host strips the mount before the entry runs. This recipe remounts in
`app/router.ts` so `context.url` matches the address bar and `routes.x.href()`
produces mount-prefixed paths when the contract is built with
`route(packageContext.appBasePath, …)`. A contract without the prefix 404s on
every hosted path; a missing remount does the same. `hostedUrl`, `appBasePath`,
and `assetBasePath` never end with a slash, and the mount root is served with or
without a trailing slash.

The route contract reads `packageContext.appBasePath` at module scope. That is
safe: the app module is first evaluated inside the request that loads it, and
each hosted mount gets its own isolate, so the prefix is stable for the life of
the worker.

### Hydration

`clientEntry('kody:app#Name', function Name…)` is the recipe's island id.
workerd leaves `import.meta.url` empty, and the host does not define it or set
`keepNames`. The explicit `#Name` fragment is the export the browser registry
must list. Remix then emits `{ moduleUrl: "kody:app", exportName: "Name" }` and
`run({ loadModule })` looks `Name` up in that registry. Rules that follow from
that:

- Islands are **named functions** (`function Counter(handle) {}`); an arrow
  function has no name and fails at render with Remix's own error. Put the
  export name in the id: `clientEntry('kody:app#Counter', …)`.
- Every island is listed in the browser entry's registry and shared with the
  server through a module that imports neither `kody:runtime` nor DOM-only
  packages at module scope.
- The document renders `<script type="module" src={clientModuleUrl}>` from
  `packageContext`; the URL is fingerprinted and changes on every publish.
- Islands receive serializable props only. Give an island the URL it needs
  (`routes.api.href()`) as a prop rather than importing `app/routes.ts` into the
  browser graph; that module imports `kody:runtime`, which the browser bundle
  rejects at publish.
- **Server-only modules stay out of the island graph.** `app/routes.ts` reads
  `kody:runtime`, so anything that imports it — a layout or nav component that
  renders `routes.x.href()`, `app/ui/render.tsx`, controllers, `app/data/*` — is
  server-only. That is fine for SSR: a layout may import `routes` freely. It
  must not be reachable from `app/assets/entry.ts` or any `clientEntry` island
  it registers. Publish enforces the boundary: the browser bundle fails with
  `imports server-only modules that cannot run in the browser (<file>: "kody:runtime")`
  naming the offending module, and the message points at the fix (pass hrefs as
  props). Keep islands in their own files under `app/ui/` that import only
  `remix/ui` and other islands.
- `<Frame>` and `handle.frame.reload()` work with Remix's default frame
  resolver; frame sources are mount-prefixed hrefs like every other URL.

### Default export

`kody.app.entry` default-exports a fetch handler (a function, `{ fetch }`, or a
named `fetch` export). Every entry receives the mount-stripped path (`/` at the
app root). Publish rejects `kody.app.runtime`: there is no configured runtime
mode. A leftover field on a published snapshot is ignored.

The host uses esbuild's JSX defaults unless the root `tsconfig.json` sets
`compilerOptions.jsx` / `jsxImportSource`. A Remix recipe sets
`"jsx": "react-jsx"` and `"jsxImportSource": "remix/ui"` there (and can repeat a
`@jsxImportSource remix/ui` pragma per file). A handler that only borrows
`remix/headers` or `remix/html-template` needs neither.

### What the platform supplies

Import Remix as `remix/<subpath>`; the version is the platform's and matches
Kody's own UI. The Workers-safe surface is available: `router`, `routes`,
`route-pattern/*`, `headers/*`, `response/*`, `html-template`, `ui`, `ui/*`
(primitives, `animation`, `server`, `jsx-runtime`), `data-schema/*`,
`data-table` (core, `operators`, `sql-helpers`, `migrations`), `cookie`,
`session`, `session-storage/cookie` and `/memory`, `middleware/*` (`form-data`,
`method-override`, `session`, `async-context`, `auth`, `compression`, `cors`,
`cop`, `csrf`, `logger`), `auth`, `form-data-parser`, `multipart-parser`,
`file-storage` and `/memory`, `fetch-proxy`, `mime`, `lazy-file`, `tar-parser`,
`spa`, `multiple-import-maps-polyfill`, `assert`. Subpaths that need a Node
process, a filesystem, a TCP database driver, or a dev server (`assets`, `cli`,
`fs`, `node-fetch-server`, `session-storage/fs`, `file-storage/fs`,
`data-table/sqlite`, `middleware/static`, `middleware/render`, `test`, the HMR
family) are not, and fail publish as an unresolved bare import that names the
specifier. Durable data is `packageStorage()`; there is no D1 driver in the
isolate.

`package.json#dependencies` must not list `@remix-run/*` packages — publish
rejects them, because a second copy from npm would not share the platform copy's
component runtime. A `remix` entry there is inert; put it in `devDependencies`
for editor types. Publish reads `dependencies` only (the runtime bundler
installs with `dev: false`, and the repo dependency check lists `dependencies`
only), so a types-only `remix` dev dependency never reaches the bundle and the
runtime always uses the platform copy.

**Version pin.** There is exactly one Remix version per platform deploy: the
origin's `remix@3.0.0-rc.2`. A package never selects it. When the platform
upgrades Remix, a **republish** picks the new version up for both the server
bundle and the browser module; artifacts already published keep the Remix they
were built with until then (they are sticky, not rebuilt behind your back). A
`devDependencies` pin is for editor types only; keep it on the platform version
so the types match what publish compiles. Older kit pins such as
`@remix-run/ui@0.9.0` are obsolete — `remix/ui` comes from the platform.

Local development: `npm i -D remix@3.0.0-rc.2` and a `tsconfig.json` with
`"jsx": "react-jsx"`, `"jsxImportSource": "remix/ui"`, and
`"allowImportingTsExtensions": true` gives editors the same types the bundle
compiles against. `kody:runtime` types come from the repo's generated
declaration (`KodyRuntime`, `packageContext`, `packageStorage`, …).

### Conventions that keep agents out of trouble

- **Read Kody through `get(KodyRuntime)` in controllers, actions, and
  middleware.** Direct `import { packageStorage } from 'kody:runtime'` still
  works, but mixing the two in one app hides which requests touch Kody; the
  context key is the Remix-shaped door. The one module-scope read the recipe
  keeps is `packageContext.appBasePath` in `app/routes.ts`.
- **Every URL comes from the mount-prefixed contract.** Build
  `route(packageContext?.appBasePath ?? '', …)` once and use `routes.x.href()`
  for links, `redirect()`, `<form action>`, `<Frame src>`, and fetch targets. A
  root-relative literal such as `/about` or `/api/notes` leaves the mount and
  404s on the host.
- **TSX compiles against `remix/ui` only when you set it.** Put
  `"jsxImportSource": "remix/ui"` in `tsconfig.json` and a
  `@jsxImportSource remix/ui` pragma on each TSX file. No React, no
  `jsx-runtime` dependency.
- **Islands are named functions listed in the browser registry.** The server id
  is the explicit `kody:app#Name` string, and `run({ loadModule })` resolves by
  export name. If hydration misses, the id, the function name, or the registry
  key drifted — see the troubleshooting entries for `Unknown client entry` and
  `clientEntry() requires …`.

## Remix troubleshooting

- **Every hosted path returns `Not Found: /packages/<name>/…`** — the route
  contract has no mount prefix, or `app/router.ts` does not remount the Request.
  Build the contract with `route(packageContext?.appBasePath ?? '', …)` and
  remount before `router.fetch`.
- **A link or redirect lands on the host root (`/about` → 404)** — a
  root-relative literal bypassed the contract. Add the route and use
  `routes.about.href()`.
- **Browser console `Unknown client entry "Counter2"`** — the island's export
  name drifted from the registry key; keep islands named functions or put
  `#Counter` in the entry id, and register that exact name.
- **`clientEntry() requires either an export name in the entry ID …`** — the
  island is an anonymous function, or the id is `import.meta.url` (empty in
  workerd). Name the island and pass an explicit id:
  `clientEntry('kody:app#Counter', function Counter…)`.
- **Island renders on the server but never hydrates, no console error** — the
  document does not render `<script type="module" src={clientModuleUrl}>`, or
  `kody.app.client` is missing so `clientModuleUrl` is `null`. Check the
  `#rmx-data` script in the page for `"moduleUrl":"kody:app"`.
- **Publish fails with
  `No matching export in "…/middleware/form-data.js" for import "FormData"`** —
  `FormData` is not a Remix export. Drop the import and use the global:
  `context.get(FormData)`.
- **Publish fails with
  `imports server-only modules that cannot run in the browser (app/routes.ts: "kody:runtime")`**
  — an island or the browser entry imports `app/routes.ts`, usually through a
  layout/nav module that renders `routes.x.href()` (the check names the file
  that imports `kody:runtime`). Keep that module server-side and pass the hrefs
  it needs to the island as props.
- **Publish fails with `unresolved bare package imports … "remix/assets"`** — a
  Node-only subpath. Serve files from `kody.app.assets` instead.
- **Publish fails with
  `package.json#dependencies must not list "@remix-run/…"`** — import
  `remix/<subpath>` and delete the entry (and any import map that pointed at
  it).
- **Browser console `Failed to resolve module specifier "remix/ui"`** — the
  bundle left it external because `client.externals` lists `remix/ui` or
  `@remix-run/ui`. Remove the external and the import-map entry; the platform
  inlines it.
- **JSX compiled to `React.createElement`** — missing
  `"jsxImportSource": "remix/ui"` in `tsconfig.json` and no
  `@jsxImportSource remix/ui` pragma. The host does not sniff the graph.

## Migrating an island app

An app built on the island pattern — `src/app.ts` rendering an HTML string,
`kody.app.client` with `externals: ["@remix-run/ui"]`, an import map pointing at
`esm.sh` or a vendored build in `public/`, and a hand-written Navigation API
router in the client — moves to a Remix router in one publish:

1. **Dependencies.** Delete `@remix-run/*` from `dependencies` (publish rejects
   them), drop the `client.externals` entry and the `<script type="importmap">`
   for Remix, and remove the vendored `public/vendor/remix-ui.js` (or the
   `esm.sh` URL). Add `"remix": "3.0.0-rc.2"` to `devDependencies` for types.
2. **Manifest.** Point `entry` at `./app/router.ts` and `client` at
   `./app/assets/entry.ts`. `assets` stays `./public`. Do not set
   `kody.app.runtime`.
3. **Server.** Replace the fetch handler with the Remix recipe: remount in
   `app/router.ts`, render a `Document` through `renderToStream`
   (`app/ui/render.tsx`), turn each path into a route in `app/routes.ts`
   (prefixed with `packageContext.appBasePath`) with a controller in
   `app/controllers/`, and replace `appUrl()` / manual URL joins with
   `routes.x.href()`. Reads of `packageContext`, `packageStorage()`, and secrets
   move to `get(KodyRuntime)`.
4. **Client.** The custom SPA router goes away: `run({ loadModule })` in
   `app/assets/entry.ts` hydrates `clientEntry` islands, real anchors and forms
   navigate, and `<Frame>` covers partial reloads. Interactive pieces become
   named `clientEntry` components registered in the entry; page-level state that
   lived in the SPA router becomes server-rendered props.
5. **Service worker and `__version.json`.** Unchanged — see
   [Service worker and PWA files](#service-worker-and-pwa-files).

Router apps and fetch handlers serve `/_assets/*` the same way, so
`assetBasePath`, `clientModuleUrl`, and `__version.json` keep their meaning
across the move.

## Service worker and PWA files

The Remix recipe does not change where PWA files live: `public/sw.js`,
`public/manifest.webmanifest`, and icons are static files in the
`kody.app.assets` directory, served under `<assetBasePath>/…` with
`Service-Worker-Allowed: <appBasePath>/` on JavaScript. Those product assets
stay in the app tree. The catalog / list mark is `.kody/icon.png` — see
[Package icon](/docs/package-authoring#package-icon). Registration belongs in the
browser entry next to `run()`:

```ts
// app/assets/entry.ts, after run()
const { appBase } = document.documentElement.dataset
if (appBase && 'serviceWorker' in navigator) {
	void navigator.serviceWorker.register(`${appBase}/_assets/sw.js`, {
		scope: `${appBase}/`,
	})
}
```

`public/sw.js` discovers the current fingerprinted module through
`<assetBasePath>/__version.json` exactly as in
[Service worker precache](#service-worker-precache) — the document's
`data-app-base` attribute and the version endpoint are the same for router apps
and fetch handlers, so a worker written for a fetch handler keeps working.

## Scaffolder contract

`create-package-app` (the `@kentcdodds/package-app-kit` scaffolder) emits the
Remix recipe layout for a new app, not `src/app.ts`. The host contract is a
fetch handler; this recipe is the source of truth for remount, JSX, and island
ids.

```text
package.json            entry ./app/router.ts, client ./app/assets/entry.ts, assets ./public
tsconfig.json           jsx react-jsx, jsxImportSource remix/ui
app/routes.ts           route(packageContext?.appBasePath ?? '', …)
app/router.ts           createRouter + remount wrapper, default export { fetch }
app/controllers/        one file or folder per route area
app/middleware/         request-lifecycle context keys
app/data/               packageStorage() access through get(KodyRuntime)
app/ui/render.tsx       Document + renderToStream
app/ui/*.tsx            islands (clientEntry, named functions)
app/assets/entry.ts     run({ loadModule }) + service-worker registration
public/                 styles, sw.js, manifest, icons
src/index.ts            package export (unchanged)
```

- The **starter** a kit scaffolds is the Remix recipe above. A kit **demo** may
  emit a fetch handler for a script-only page; it does not set a runtime field,
  and it does not install `@remix-run/*`.
- Kits must not add `@remix-run/*` to `dependencies`, `remix/ui` or
  `@remix-run/ui` to `client.externals`, or an import map for Remix; the
  `client.externals` + import map pair is valid for other browser packages.
- `data-app-base` on `<html>` and `__version.json` are the two runtime discovery
  points kits may rely on; `data-client-module` is optional because the document
  already renders `clientModuleUrl`.
- `kody:runtime` types (`KodyRuntime`, `packageContext`) come from the
  platform's generated declaration, so a kit ships only `remix` in
  `devDependencies` and the `tsconfig.json` from
  [What the platform supplies](#what-the-platform-supplies).
- Common kit pieces map onto the layout without platform help: a **toast** or
  **double-check confirm** is a named `clientEntry` island fed by props; an
  **update check** is an island (or the service worker) that polls
  `<assetBasePath>/__version.json` and compares `publishedCommit`; **icons**
  live in `public/icons/` and are linked from the document via
  `${assetBasePath}/icons/…` (one path — no fetch-runtime `/icons/` handler
  route is needed); shared **nav/layout** components import `routes` and stay
  server-only.

## Fetch handlers

`kody.app.entry` default-exports a function or an object with
`fetch(request, env, ctx)`, receives the **mount-stripped** path (`/` for the
app root), and builds URLs itself (see [Asset URLs](#asset-urls)). Everything
below about `packageContext`, `client`, `assets`, and `/_assets` applies to
every package app.

## Asset URLs

Build every in-app asset URL, link, redirect, share/email URL, and OAuth
callback from `packageContext.appBasePath` plus `hostedUrl` (or
`new URL(path, origin)` with a trailing-slash-safe origin). Kody strips the
mount before the handler runs, so every entry sees `/<path>` only. Absolute
`/audio/123` links leave the mount; mount-prefixed URLs stay under
`/packages/<package-name>/…` (or `/@username/packages/<package-name>/…` when
served inline). A Remix recipe that prefixes its route contract remounts the
Request in the entry (see [Mount and URLs](#mount-and-urls)).

```ts
import { packageContext } from 'kody:runtime'

function appUrl(path: string) {
	if (!packageContext?.hostedUrl) {
		throw new Error('This module must run as a package app.')
	}
	const relative = path.replace(/^\/+/, '')
	const mount = packageContext.appBasePath.endsWith('/')
		? packageContext.appBasePath
		: `${packageContext.appBasePath}/`
	return new URL(`${mount}${relative}`, packageContext.hostedUrl)
}

const sprite = appUrl('assets/sprite.png')
const callback = appUrl('oauth/callback')
```

`hostedUrl` is the public mount URL. `appBasePath` is the origin-relative mount
(`/packages/<package-name>` on a subdomain). Both come from the current serving
username and package name leaf, including after a rename or fork. When you pass
a relative path to `new URL(path, origin)`, give `origin` a trailing slash so
`assets/sprite.png` stays under the mount.

Files the platform serves for you (the bundled browser client and the
`kody.app.assets` directory) live under `packageContext.assetBasePath`; see the
next section.

## Browser client and static assets

Declare a browser entry and Kody compiles it on publish, so the repo holds
TypeScript source instead of checked-in `.js`. Every app shares this surface: a
Remix recipe's `client` is its `run()` entry ([Remix recipe](#remix-recipe));
the example below is a page that only needs a script.

### Minimal fetch recipe

Three files plus an optional directory: Worker code under `src/`, browser code
under `src/client/`, static files under `public/`.

`package.json`:

```json
{
	"name": "@you/counter",
	"exports": { ".": "./src/index.ts" },
	"kody": {
		"id": "counter",
		"description": "Counter with a platform-built browser client",
		"app": {
			"entry": "./src/app.ts",
			"client": "./src/client/index.ts",
			"assets": "./public"
		}
	}
}
```

`src/app.ts` (Worker fetch handler; renders the page). Runtime config rides on
`<html>` data attributes rendered from `packageContext`: `data-app-base` (the
mount), `data-client-module` (the fingerprinted module URL), and
`data-pak-config` (any JSON your client needs):

```ts
import { packageContext } from 'kody:runtime'

export default {
	async fetch() {
		const { appBasePath, assetBasePath, clientModuleUrl } = packageContext ?? {}
		const pakConfig = JSON.stringify({ theme: 'dark' })
		return new Response(
			`<!doctype html>
<html lang="en"
	data-app-base="${appBasePath}"
	data-client-module="${clientModuleUrl}"
	data-pak-config='${pakConfig}'>
<head>
	<meta charset="utf-8" />
	<link rel="stylesheet" href="${assetBasePath}/styles.css" />
</head>
<body>
	<button id="inc" type="button">Clicked 0 times</button>
	<script type="module" src="${clientModuleUrl}"></script>
</body>
</html>`,
			{ headers: { 'content-type': 'text/html; charset=utf-8' } },
		)
	},
}
```

`src/client/index.ts` (browser; TypeScript is fine, relative imports are
inlined):

```ts
const config = JSON.parse(document.documentElement.dataset.pakConfig ?? '{}')
let count = 0
const button = document.querySelector<HTMLButtonElement>('#inc')!
button.addEventListener('click', () => {
	count += 1
	button.textContent = `Clicked ${count} time${count === 1 ? '' : 's'}`
})
console.log('theme', config.theme)
```

`public/styles.css` (optional `assets` directory, served as-is).

`remix/ui` and the other `remix/…` subpaths are inlined from the platform copy,
so a Remix client needs no import map. Using another browser package from the
client? Either add it to `package.json#dependencies` to inline it, or switch
`client` to the object form and pair it with an import map — see
[Import maps and externals](#import-maps-and-externals) for the copy-paste pair.

### Two graphs, not one

`kody.app.entry` and `kody.app.client` are **separate module graphs**. The
Worker bundle rewrites `kody:` imports into runtime proxies and runs in an
isolate; the client bundle targets the browser. Publish fails when the Worker
graph imports the client entry (directly or through a helper), or when both
fields point at the same file. Shared helpers imported from both sides are fine
— keep them free of `kody:` and DOM APIs. The Worker renders the
`<script type="module">` tag; the two sides talk over fetch or the realtime
facet.

Browser-only packages (a component library, a DOM polyfill) therefore never
reach the Worker bundle as long as the Worker graph does not import them. To
keep them out of the client bundle too, declare them as
[externals](#import-maps-and-externals) and resolve them with an import map.

### What each field does

- `entry` — the server fetch handler. Every entry gets the mount-stripped path
  (see [Default export](#default-export)).
- `client` — one `.ts`, `.tsx`, `.js`, or `.jsx` file bundled for the
  **browser** (ESM, `es2022`, relative imports and `package.json` npm
  dependencies inlined). The output is served at
  `<appBasePath>/_assets/client.<hash>.js` with
  `Cache-Control: private, max-age=31536000, immutable` (browser-cached for a
  year; `private` because the owner's session gates every package-app response);
  the hash changes with the content, so never hardcode the file name. Use the
  object form `{ "entry": "./src/client/index.ts", "externals": [...] }` when
  the page supplies an [import map](#import-maps-and-externals).
- `assets` — a subdirectory of static files served as-is at
  `<appBasePath>/_assets/<path inside the directory>` with a content type
  inferred from the extension (`.css`, `.png`, `.wasm`, `.woff2`, …), a
  commit-scoped `ETag`, and `Cache-Control: private, max-age=300`. No TypeScript
  compile, no bundling. Two root names are reserved because the platform answers
  them first: `__version.json` (see
  [Service worker precache](#service-worker-precache)) and, when `client` is
  declared, anything shaped like the compiled module
  (`client.<16-char-hash>.js`). Publish rejects a root asset with either name;
  nest it or rename it.

### Stable `packageContext` fields

These names are part of the package-app contract and stay stable; kits and
scaffolders can depend on them.

- `packageContext.clientModuleUrl` — absolute URL of the current fingerprinted
  client module (`<hostedUrl>/_assets/client.<hash>.js`), or `null` when the
  manifest declares no `client`. Drop it straight into
  `<script type="module" src="…">` and `data-client-module`.
- `packageContext.assetBasePath` — origin-relative `<appBasePath>/_assets`,
  mount-aware like `appBasePath`. Join `assets` files onto it
  (`${assetBasePath}/styles.css`).

`/_assets/*` is reserved: the platform answers it before the fetch handler runs,
and the handler never sees those paths. A client hash from an older publish
returns 404 rather than a stale module, so always render the URL from
`packageContext`.

None of `appBasePath`, `assetBasePath`, `hostedUrl`, or `clientModuleUrl` ends
with a slash, so `${assetBasePath}/styles.css` is always a single-slash join.
When you resolve relative to a URL that does end with a slash (a service worker
scope, `new URL('x', base)`), pass the relative path without a leading slash.

#### Detecting support

Kits that must run on hosts with and without this feature probe the platform
version endpoint — it answers on every host that serves client assets, whether
or not the manifest declares `client`:

```ts
const version = await fetch(`${assetBasePath}/__version.json`)
// 200  → the host serves /_assets (clientModuleUrl may still be null when the
//        manifest has no `client`)
// 404  → the host does not serve client assets yet; fall back
```

In the fetch handler the same distinction is `packageContext.clientModuleUrl`:
`null` means the host supports client assets but this manifest declares no
`client`; `undefined` (field absent) means the host predates the feature. A host
that returns 200 from `__version.json` also builds the declared client at
publish, so a declared `client` with a `null` URL does not happen there.

### Browser-safe graph

The client graph must be browser-safe. Publish fails, naming the file, when the
client (or anything it imports) pulls in `kody:runtime`, a `kody:@…` package
import, `cloudflare:*`, or `node:*`; keep those in `entry` and expose data over
fetch or the realtime facet. `import './styles.css'` is rejected too — put CSS
in the assets directory and link it. Full `https://` URL imports stay external
and load in the browser as written.

### Import maps and externals

By default every bare import is inlined from `package.json#dependencies`, and a
bare import the bundler cannot resolve fails publish. To let the **page** decide
where a package comes from, declare it under `client.externals` **and** map it
in the page's import map. The two lists must match: an external with no import
map entry is a bare-specifier error in the browser; an import map entry with no
external is simply unused (the bundler inlines or fails on the specifier).

Recommended vendor story: ship the browser build of the package in the `assets`
directory and map to it. It is same-origin, versioned with your publish, and
needs no third-party CDN. One copy-paste pair:

`package.json`:

```json
{
	"kody": {
		"app": {
			"entry": "./src/app.ts",
			"client": {
				"entry": "./src/client/index.ts",
				"externals": ["preact"]
			},
			"assets": "./public"
		}
	}
}
```

`src/app.ts` (the import map goes in `<head>`, before the module script; keys
are exactly the `externals` entries):

```ts
const importMap = JSON.stringify({
	imports: {
		preact: `${assetBasePath}/vendor/preact.js`,
	},
})
// <script type="importmap">${importMap}</script>
// <script type="module" src="${clientModuleUrl}"></script>
```

`public/vendor/preact.js` — the package's browser ESM build, copied into the
assets directory.

Externals are bare specifiers only (no relative paths, URLs, or `kody:` /
`cloudflare:` / `node:` schemes); each covers its subpaths (`preact` also covers
`preact/hooks`; map subpaths with a trailing-slash prefix entry such as
`"preact/": "${assetBasePath}/vendor/preact/"` next to the bare `"preact"`
entry). The bundled module keeps them as `import … from "preact"`. A CDN URL
(`https://esm.sh/preact@10`) works as the map target too when you accept the
third-party dependency.

Undeclared bare imports that survive bundling fail publish; the error names the
specifier and offers the fix: add it to `package.json#dependencies` to inline
it, or to `kody.app.client.externals` and the import map to load it from the
page.

### Service worker precache

`clientModuleUrl` is content-addressed and immutable, so a service worker can
precache it on install and serve it from cache forever. **Never hardcode the
hash in the worker's source** — it changes on every publish. Discover the URL at
runtime instead; the platform gives you two ways:

- `<html data-client-module="…">`, rendered by your fetch handler from
  `packageContext.clientModuleUrl` (the page reads it and posts it to the
  worker, as in the recipe above).
- `GET <assetBasePath>/__version.json` — served by the platform, never cached
  (`Cache-Control: private, no-cache`), always the current publish:

```json
{
	"clientModuleUrl": "https://you.kody.run/packages/counter/_assets/client.83T6UIqNQEvueSq_.js",
	"assetBasePath": "/packages/counter/_assets",
	"publishedCommit": "0f3c…"
}
```

Ship the worker script from the `assets` directory and register it with the
slash-terminated app mount as its scope. The canonical pair is:

- scope: `` `${appBasePath}/` `` (always with the trailing slash)
- header the platform sends on JavaScript under `/_assets/`:
  `Service-Worker-Allowed: <appBasePath>/` (the same value)

A scope that does not start with that header value is rejected by the browser
with a `SecurityError`, so register exactly `${appBase}/`. The trailing slash
matters: scope matching is a string-prefix check, so a scope of `/packages/app`
would also claim the sibling mount `/packages/app-secret`; `/packages/app/`
cannot.

```ts
// in the page (src/client/index.ts)
const { appBase } = document.documentElement.dataset
navigator.serviceWorker.register(`${appBase}/_assets/sw.js`, {
	scope: `${appBase}/`,
})
```

```js
// public/sw.js — no hash anywhere: read the current module URL on install.
self.addEventListener('install', (event) => {
	event.waitUntil(
		(async () => {
			const version = await (
				await fetch(new URL('_assets/__version.json', self.registration.scope))
			).json()
			const cache = await caches.open(`app-${version.publishedCommit}`)
			if (version.clientModuleUrl) await cache.add(version.clientModuleUrl)
		})(),
	)
})
```

Scope boundary: the bare mount URL (`hostedUrl`, `/packages/app` with no
trailing slash — where the handoff lands) sits outside a `/packages/app/` scope,
so the worker controls every page under the mount but not a document loaded at
that exact URL. Link and redirect to slash-terminated paths inside the app
(`${appBase}/`, `${appBase}/settings`) so the pages people spend time on are
controlled; the root visit still gets the module straight from the platform with
its immutable cache header.

Static `assets` paths are not fingerprinted (they carry a commit-scoped `ETag`
and a five-minute max-age), so precache them keyed by `publishedCommit` and drop
old caches on activate.

### Troubleshooting

- **404 on `<assetBasePath>/__version.json`** — the host does not serve client
  assets yet. This is the support probe, not a broken fetch handler; nothing
  under `/_assets/` will answer on that host, and
  `packageContext.clientModuleUrl` is `undefined` there.
- **`clientModuleUrl` is `null` on a host where `__version.json` returns 200** —
  the published manifest declares no `client`. Check the manifest that actually
  published (the `client` key, path or object form).
- **404 on `<assetBasePath>/client.<hash>.js`** — the hash is from an older
  publish. Re-read the URL from `packageContext`, `data-client-module`, or
  `__version.json`; never store it in code.
- **Publish fails with "unresolved bare package imports"** — the client imports
  a package that is neither installable from `package.json#dependencies` nor
  listed in `kody.app.client.externals`. Pick one and, for an external, add the
  matching import map entry.
- **Browser console: "Failed to resolve module specifier"** — the module kept an
  external import that the page's import map does not cover. Add the entry (keys
  must match the `externals` strings exactly).
- **Publish fails with "imports the browser client entry"** — the Worker graph
  reaches `kody.app.client`. Move the shared code into a helper both sides
  import and keep the client entry out of `src/app.ts`.
- **`packageAppFetch` returns HTTP 500 `"Package app could not be prepared"`** —
  host-setup failed before package code ran (manifest load, worker build, or
  asset prep). The JSON body includes `cause` on synthetic fetches. Publish
  rejects `kody.app.runtime`; a leftover field on a published snapshot does not
  brick serve.

Checked-in browser-ready `.js` served from the fetch handler with an explicit
`Content-Type` is valid; `client` is the pit-of-success path for source you want
compiled.

## Same-origin proxy

When the browser needs third-party bytes reliably (WASM, media, a vendor
script), add an app route that streams the upstream body from the Worker. The
page then fetches a same-origin `appUrl('…')` instead of a foreign host.

```ts
export default {
	async fetch(request: Request) {
		const path = new URL(request.url).pathname
		if (path === '/vendor/engine.wasm') {
			const upstream = await fetch('https://cdn.example.com/engine.wasm')
			return new Response(upstream.body, {
				status: upstream.status,
				headers: {
					'content-type':
						upstream.headers.get('content-type') ?? 'application/wasm',
				},
			})
		}
		return new Response('ok')
	},
}
```

Point the client at `appUrl('vendor/engine.wasm')`. The Worker holds the
upstream `fetch`; the browser stays on the package-app origin.

## Lean forks

Keep the package source cheap to `communityFork`: modest raw assets in the repo
(icons, small sprites, HTML/JS). Serve heavy runtime payloads from a CDN or a
streamed [same-origin app route](#same-origin-proxy). Forks copy default-branch
HEAD; a smaller tree finishes faster and stays under isolate limits.

A fork that dies on memory or CPU returns a capability error that the listing
was unchanged. Lean the tree, then fork again.

## Compiled clients

This section is about third-party compiled engines, not the `kody.app.client`
bundle above. When the app ships a compiled engine (WASM plus JS glue), read the
**shipped** glue and match its startup contract. Typical Emscripten-style glue
accepts `Module.arguments` plus a normal `run()`, and `wasmBinary` or
`instantiateWasm` when you supply the bytes:

```js
const Module = {
	arguments: ['--fullscreen'],
	wasmBinary: engineBytes,
}

document.querySelector('#engine-script').addEventListener('load', () => {
	Module.run?.()
})
```

Load a one-shot engine script **once** per page life (a single `<script>`
element, or one dynamic import). After a failed boot, recover with a full page
reload when the glue is not re-entrant.

## Fork failures

When `communityFork` or one-click install fails, read the **capability error
text** first, then the run or delivery logs on [Activity](https://github.com/kentcdodds/kody/blob/main/docs/use/activity.md)
(`runs` domain). Match the next step to that failure:

- “too large to finish forking” — slim the listing source
  ([Lean forks](#lean-forks)), then retry
- repo `docs` or check failures — add README / AGENTS.md or fix the named check,
  then publish
- secret or host approval — send the owner the approval URL, then smoke-test

The error text is the source of truth for which of those paths you are on.

## Listing verification

After `communityPublish` (or `packageUpdate` with
`changes.visibility: "public"`), call `communityGet` with the listing id and
confirm the card matches intent:

| Field           | Confirm                                                            |
| --------------- | ------------------------------------------------------------------ |
| `license`       | The license string you meant to show                               |
| `pinned_commit` | The commit you just published                                      |
| `description`   | Short tagline (`kody.description`)                                 |
| `tags`          | Search keywords                                                    |
| `category`      | `integrations`, `examples`, `productivity`, `apps`, or `utilities` |
| `name`          | Scoped package name (`@username/leaf`)                             |
| `public_url`    | `/@username/{package-name}` (share this URL with people)           |
| `version`       | `package.json#version` when you set one                            |

Share `public_url` with humans. Hygiene before going public stays in
[Package authoring](/docs/package-authoring#personal-details-hygiene-before-going-public).