@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 extends XEvent, Metadata extends boolean>(event: Event, withMetadata: Metadata) => {
        subscribe: (callback: (payload: Metadata extends true ? SubjectPayload<EventPayload<XEventsTypes, Event>, WireMetadata> : EventPayload<XEventsTypes, Event>) => void) => void;
    };
    emit: <Event extends XEvent>(event: Event, payload?: XEventPayload<Event>, metadata?: Omit<WireMetadata, "moduleName">) => Promise<import("../x-bus").EmittedData<XEventsTypes, Event, WireMetadata>>;
};
```
**Returns:**

{ on: &lt;Event extends [XEvent](./x-components.xevent.md)<!-- -->, Metadata extends boolean&gt;(event: Event, withMetadata: Metadata) =&gt; { subscribe: (callback: (payload: Metadata extends true ? [SubjectPayload](./x-components.subjectpayload.md)<!-- -->&lt;[EventPayload](./x-components.eventpayload.md)<!-- -->&lt;[XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Event&gt;, [WireMetadata](./x-components.wiremetadata.md)<!-- -->&gt; : [EventPayload](./x-components.eventpayload.md)<!-- -->&lt;[XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Event&gt;) =&gt; void) =&gt; void; }; emit: &lt;Event extends [XEvent](./x-components.xevent.md)<!-- -->&gt;(event: Event, payload?: [XEventPayload](./x-components.xeventpayload.md)<!-- -->&lt;Event&gt;, metadata?: Omit&lt;[WireMetadata](./x-components.wiremetadata.md)<!-- -->, "moduleName"&gt;) =&gt; Promise&lt;import("../x-bus").[EmittedData](./x-components.emitteddata.md)<!-- -->&lt;[XEventsTypes](./x-components.xeventstypes.md)<!-- -->, Event, [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.