# Hovercard.setOpen

Sets hovercard visibility.

## Signatures

```ts
export declare function setOpen<E, R>(state: RefSubject.RefSubject<State, E, R>, open: boolean): Effect.Effect<State, E, R>;
```

## Why

Delayed focus/hover flows converge on one atomic state update.

## Ownership and lifetime

The Effect uses the existing RefSubject lifetime and acquires no resource.

## Examples

```ts
import { Effect } from "effect"
import * as Hovercard from "@typed/ui/Hovercard"

const program = Effect.gen(function* () {
  const state = yield* Hovercard.makeState({ id: "author-card" })
  yield* Hovercard.setOpen(state, true)
})
```