@empathyco/x-components/docs/API-reference/api/x-components.usexbus.md

Empathy X Components

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[Home](./index.md) &gt; [@empathyco/x-components](./x-components.md) &gt; [useXBus](./x-components.usexbus.md)

## useXBus() function

Composable which injects the current location, returns the `on` and `emit` functions using the bus and applying component metadata. Also unsubscribe from events when components is unmounted.

**Signature:**

```typescript
export declare function useXBus(): {
    on: <Event_1 extends keyof XEventsTypes, Metadata extends boolean>(event: Event_1, withMetadata: Metadata) => {
        subscribe: (callback: (payload: Metadata extends true ? SubjectPayload<EventPayload<XEventsTypes, Event_1>, WireMetadata> : EventPayload<XEventsTypes, Event_1>) => void) => void;
    };
    emit: <Event_2 extends keyof XEventsTypes>(event: Event_2, payload?: XEventPayload<Event_2> | undefined, metadata?: Omit<WireMetadata, 'moduleName'>) => Promise<import("@empathyco/x-bus").EmittedData<XEventsTypes, Event_2, WireMetadata>>;
};
```
**Returns:**

{ on: &lt;Event\_1 extends keyof [XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Metadata extends boolean&gt;(event: Event\_1, withMetadata: Metadata) =&gt; { subscribe: (callback: (payload: Metadata extends true ? SubjectPayload&lt;EventPayload&lt;[XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Event\_1&gt;, [WireMetadata](./x-components.wiremetadata.md)<!-- -->&gt; : EventPayload&lt;[XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Event\_1&gt;) =&gt; void) =&gt; void; }; emit: &lt;Event\_2 extends keyof [XEventsTypes](./x-components.xeventstypes.md)<!-- -->&gt;(event: Event\_2, payload?: [XEventPayload](./x-components.xeventpayload.md)<!-- -->&lt;Event\_2&gt; \| undefined, metadata?: Omit&lt;[WireMetadata](./x-components.wiremetadata.md)<!-- -->, 'moduleName'&gt;) =&gt; Promise&lt;import("@empathyco/x-bus").EmittedData&lt;[XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Event\_2, [WireMetadata](./x-components.wiremetadata.md)<!-- -->&gt;&gt;; }

An object with the `on` and `emit` functions.

## Remarks

This composable tries to use the `XPlugin` bus and catches the exception thrown by the `XPlugin` if it was not instantiated and uses the default `xBus` as fallback.