> For the complete documentation index, see [llms.txt](https://react-observatory.js.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://react-observatory.js.org/api-reference/applyasyncepics.md).

# applyAsyncEpics

A function that takes a stream of [Epics](https://redux-observable.js.org/docs/basics/Epics.html) and returns a [store enhancer.](https://redux.js.org/glossary#store-enhancer) for dynamic Epic injection.

### Arguments

1. `epic$` ([`BehaviorSubject`](http://reactivex.io/rxjs/manual/overview.html#behaviorsubject)[\*\[\`Epic\`\](https://redux-observable.js.org/docs/basics/Epics.html)\*](https://github.com/react-observatory/react-observatory/tree/b7fec29590e82061bdb66717128488ad0c66f5d0/docs/API-Reference/*\[%60Epic%60]\(https:/redux-observable.js.org/docs/basics/Epics.html\)*)): a stream of all epics in the runtime.

### Returns

(`Function`): (`Function`): A store enhancer that is used as an argument for [createStore.](https://redux.js.org/api-reference/createstore) to enable dynamic Epic injection.

### Example: Setting-up The dynamic Epic Injection

## `./src/epics`

```javascript
import { createRootEpic } from '@react-observatory/inject-epic'

const logger = action$ =>
  action$
    .ofType('Up')
    .do(console.log)
    .ignoreElements()

const { epic$, rootEpic } = createRootEpic(logger)

export { epic$, rootEpic }
```

## `./src/configureStore`

```javascript
import { createStore, compose, applyMiddleware } from 'redux'
import { applyAsyncEpics } from '@react-observatory/inject-epic'
import { createEpicMiddleware } from 'redux-observable'
import reducers from './reducers'
import { rootEpic, epic$ } from './epics'

const epicMiddleware = createEpicMiddleware(rootEpic)

export default function configureStore(initialState = {}) {
  const store = createStore(
    reducers,
    initialState,
    compose(
      applyAsyncEpics(epic$),
      applyMiddleware(epicMiddleware)
    )
  )

  return store
}
```