Page Script

Page Script is Nenu’s browser-safe execution profile for a page or library component.
It keeps local state and UI behavior close to the visual page while durable work stays behind APIs.
Some full-language constructs are intentionally unavailable in the browser profile.

What Page Script Owns

Page Script is embedded before the visual content of a page or reusable library component. It owns the typed values and behavior that the visual editor binds to: loading data through APIs, filtering a displayed expense list, opening a form, and navigating to an expense detail page.

Page Script owns	Backend runnable owns
Page-local state	Durable entity reads
Input and callback contracts	Saves, transactions, and deletes
Event handlers	Cache and backend logging
Load and change effects	Domain failures through `throw`
Imported API calls	Request-to-Response implementation
Navigation, modals, and toasts	Scheduled and event-listener work

The Supported Language Surface

Supported	Not supported in Page Script
Typed and inferred local declarations	Entity and default definitions
Functions and browser-safe expressions	Backend entity-fetching `need`
`if`, `loop`, `with`, `without`	`save` and `delete`
Non-destructuring `match`	`cache`, `log`, and `throw`
`return`, `continue`, `break`	Container fallback declarations
Top-level reference `alias` declarations	`alias` inside handlers or effects
`use api` and `use library`	JavaScript async, await, promises, or raw fetch
`on load` and `on change`	Nested effects or backend runtime statements
`goto`, `modal`, and `toast`	Direct public `api(...)` calls

A Small Room Page

pages/room.page.nenu — Page Script

1use api/expenses/list as ListExpensesApi23need {4  room_id: string5}67Expense[] expenses = []8bool loading = false910fn refreshExpenses() {11  loading = true12  result = ListExpensesApi({ room_id })13  expenses = result.expenses14  loading = false15}1617on load() {18  refreshExpenses()19}

use api gives the backend route a callable local alias.
need says the page must receive room_id.
expenses and loading are page state.
refreshExpenses is ordinary reusable behavior.
on load runs the initial page effect.

How Visual Elements Use It

The visual page binds element values to state and binds events to top-level handler names. Repeated visual content can supply its current row to a compatible typed handler. Page Script remains source code; element layout and event wiring remain App Marché visual configuration.

Expose the state the visual element needs, such as expenses or loading.
Expose a top-level function for each interaction, such as openExpense.
Bind the bare handler name rather than a JavaScript arrow or call expression.
Keep the durable mutation in an API and update page state from its typed response.

Common Mistakes

Wrong	Correct
Fetch `Expense[](...)` directly on the page	Import and call an API alias.
`save(expense)` in a click handler	Call a mutation API.
Use JavaScript `let` or an arrow function	Use Nenu declarations and `fn`.
Treat Page Script `need` as storage	Treat it as a page/component input contract.

Continue Learning

Page State And Inputs Declare typed state and component contracts.API Runnables Implement the durable work that Page Script calls.