# usePermissions API

> Auto-generated API reference for `usePermissions` from @vuetify/v0 (Vuetify0).
> Source of truth: https://0.vuetifyjs.com/api/use-permissions

## Related

- https://0.vuetifyjs.com/composables/plugins/use-permissions
- https://0.vuetifyjs.com/composables/plugins/use-features
- https://0.vuetifyjs.com/composables/registration/create-tokens

## Functions

### createPermissions

Creates a new permissions instance.

```ts
(_options?: PermissionOptions) => PermissionContext<PermissionTicket>
```

### createPermissionsContext

```ts
<_E>(_options?: PermissionContextOptions | undefined) => ContextTrinity<_E>
```

### createPermissionsPlugin

```ts
(_options?: PermissionContextOptions | undefined) => Plugin
```

### usePermissions

```ts
<_E>(namespace?: string) => _E
```

## Options

| Name | Type | Default | Required | Description |
|---|---|---|---|---|
| `events` | `boolean \| undefined` | `false` | no | Enable event emission for registry operations |
| `reactive` | `boolean \| undefined` | `false` | no | Enable reactive behavior for registry operations |
| `flat` | `boolean \| undefined` | `false` | no | Whether to flatten nested token structures. |
| `prefix` | `string \| undefined` | — | no | An optional prefix to prepend to each token ID during registration. |
| `adapter` | `PermissionsAdapter \| undefined` | — | no | — |
| `permissions` | `Record<ID, [string \| string[], string \| string[], (boolean \| ((context: Record<string, unknown>) => boolean) \| undefined)?][]> \| undefined` | — | no | — |

## Methods

| Name | Type | Description |
|---|---|---|
| `clear` | `() => void` | Clear the entire registry |
| `has` | `(id: ID) => boolean` | Check if a ticket exists by ID |
| `keys` | `() => readonly ID[]` | Get all registered IDs |
| `browse` | `(value: E["value"]) => readonly ID[] \| undefined` | Browse for an ID(s) by value |
| `lookup` | `(index: number) => ID \| undefined` | Lookup a ticket by index number |
| `get` | `(id: ID) => E \| undefined` | Get a ticket by ID |
| `upsert` | `(id: ID, ticket?: Partial<Z>, event?: string) => E` | Update or insert a ticket by ID |
| `values` | `() => readonly E[]` | Get all values of registered tickets |
| `entries` | `() => readonly [ID, E][]` | Get all entries of registered tickets |
| `register` | `(ticket?: Partial<Z & RegistryTicket>) => E` | Register a new ticket |
| `unregister` | `(id: ID) => void` | Unregister a ticket by ID |
| `reindex` | `() => void` | Reset the index directory and update all tickets |
| `move` | `(id: ID, toIndex: number) => E \| undefined` | Move a ticket to a new index position |
| `reorder` | `(ids: ID[]) => void` | Reorder the registry to match a canonical permutation of ids in one pass. |
| `seek` | `(direction?: "first" \| "last", from?: number, predicate?: (ticket: E) => boolean) => E \| undefined` | Seek for a ticket based on direction and optional predicate |
| `on` | `<K extends Extensible<RegistryEventName>>(event: K, cb: RegistryEventCallback<E, K>) => void` | Listen for registry events |
| `off` | `<K extends Extensible<RegistryEventName>>(event: K, cb: RegistryEventCallback<E, K>) => void` | Stop listening for registry events |
| `emit` | `<K extends Extensible<RegistryEventName>>(event: K, data: EventPayload<E, K>) => void` | Emit an event with data |
| `dispose` | `() => void` | Clears the registry and removes all listeners |
| `onboard` | `(registrations: Partial<Z & RegistryTicket>[]) => E[]` | Onboard multiple tickets at once |
| `offboard` | `(ids: ID[]) => Partial<Z>[]` | Offboard multiple tickets at once, returning the input shapes that were removed. |
| `batch` | `<R>(fn: () => R) => R` | Execute operations in a batch, deferring cache invalidation and event emission until complete |
| `isAlias` | `(token: unknown) => token is string` | Checks if a token is an alias |
| `resolve` | `<T = unknown>(token: string \| TokenAlias) => T \| undefined` | Resolves a token or alias to its value. |
| `can` | `(id: ID, action: string, subject: string, context?: Record<string, unknown>) => boolean` | — |

## Properties

| Name | Type | Description |
|---|---|---|
| `collection` | `ReadonlyMap<ID, E>` | The collection of tickets in the registry |
| `size` | `number` | The number of tickets in the registry |