Client Config

import BaseDirEnvNote from './_baseDirEnvNote.md'

import { ShowForTs, ShowForJs } from '@site/src/components/TsJsHelpers'

You can configure the client using the client field inside the app declaration:

Root Component

Wasp gives you the option to define a "wrapper" component for your React app.

It can be used for a variety of purposes, but the most common ones are:

• Defining a common layout for your application.
• Setting up various providers that your application needs.

Defining a Common Layout

Let's define a common layout for your application:

```jsx title="src/Root.jsx"
import { Outlet } from 'react-router'

export default function Root() {
  return (
    <div>
      <header>
        <h1>My App</h1>
      </header>
      // highlight-next-line
      <Outlet />
      <footer>
        <p>My App footer</p>
      </footer>
    </div>
  )
}
```

```tsx title="src/Root.tsx"
import { Outlet } from 'react-router'

export default function Root() {
  return (
    <div>
      <header>
        <h1>My App</h1>
      </header>
      // highlight-next-line
      <Outlet />
      <footer>
        <p>My App footer</p>
      </footer>
    </div>
  )
}
```

You need to import the Outlet component from react-router and put it where you want the current page to be rendered.

Setting up a Provider

This is how to set up various providers that your application needs:

```jsx title="src/Root.jsx"
import { Outlet } from 'react-router'
import store from './store'
import { Provider } from 'react-redux'

export default function Root() {
  return (
    <Provider store={store}>
      <Outlet />
    </Provider>
  )
}
```

```tsx title="src/Root.tsx"
import { Outlet } from 'react-router'
import store from './store'
import { Provider } from 'react-redux'

export default function Root() {
  return (
    <Provider store={store}>
      <Outlet />
    </Provider>
  )
}
```

As long as you render the Outlet component, you can put what ever you want in the root component.

Read more about the root component in the API Reference.

Setup Function

setupFn declares a <ShowForTs>Typescript</ShowForTs><ShowForJs>JavaScript</ShowForJs> function that Wasp executes on the client before everything else.

Running Some Code

We can run any code we want in the setup function.

For example, here's a setup function that logs a message every hour:

Overriding Default Behaviour for Queries

:::info You can change the options for a single Query using the options object, as described here. :::

Wasp's useQuery hook uses react-query's useQuery hook under the hood. Since react-query comes configured with aggressive but sane default options, you most likely won't have to change those defaults for all Queries.

If you do need to change the global defaults, you can do so inside the client setup function.

Wasp exposes a configureQueryClient hook that lets you configure react-query's QueryClient object:

export default async function mySetupFunction() {
  // ... some setup
  configureQueryClient({
    defaultOptions: {
      queries: {
        staleTime: Infinity,
      },
    },
  })
  // ... some more setup
}
```

export default async function mySetupFunction(): Promise<void> {
  // ... some setup
  configureQueryClient({
    defaultOptions: {
      queries: {
        staleTime: Infinity,
      },
    },
  })
  // ... some more setup
}
```

Make sure to pass in an object expected by the QueryClient's constructor, as explained in react-query's docs.

Read more about the setup function in the API Reference.

Base Directory

If you need to serve the client from a subdirectory, you can use the baseDir option:

app MyApp {
  title: "My app",
  // ...
  client: {
    baseDir: "/my-app",
  }
}

This means that if you serve your app from https://example.com/my-app, the router will work correctly, and all the assets will be served from https://example.com/my-app.

API Reference

Client has the following options:

• rootComponent: ExtImport

  rootComponent defines the root component of your client application. It is expected to be a React component, and Wasp will use it as the root of the client application. It must render the Outlet component from react-router to render the current page.

  Here's an example of a root component that both sets up a provider and renders a custom layout:

  <Tabs groupId="js-ts"> <TabItem value="js" label="JavaScript"> ```jsx title="src/Root.jsx" import { Outlet } from 'react-router' import store from './store' import { Provider } from 'react-redux'
  Copy

  export default function Root() {
    return (
      <Provider store={store}>
        <Layout />
      </Provider>
    )
  }
  
  function Layout() {
    return (
      <div>
        <header>
          <h1>My App</h1>
        </header>
        // highlight-next-line
        <Outlet />
        <footer>
          <p>My App footer</p>
        </footer>
      </div>
    )
  }
  ```
  

  </TabItem> <TabItem value="ts" label="TypeScript"> ```tsx title="src/Root.tsx" import { Outlet } from 'react-router' import store from './store' import { Provider } from 'react-redux'
  Copy

  export default function Root() {
    return (
      <Provider store={store}>
        <Layout />
      </Provider>
    )
  }
  
  function Layout() {
    return (
      <div>
        <header>
          <h1>My App</h1>
        </header>
        // highlight-next-line
        <Outlet />
        <footer>
          <p>My App footer</p>
        </footer>
      </div>
    )
  }
  ```
  

  </TabItem> </Tabs>

• setupFn: ExtImport

  <ShowForTs> `setupFn` declares a Typescript function that Wasp executes on the client before everything else. It is expected to be asynchronous, and Wasp will await its completion before rendering the page. The function takes no arguments, and its return value is ignored. </ShowForTs> <ShowForJs> `setupFn` declares a JavaScript function that Wasp executes on the client before everything else. It is expected to be asynchronous, and Wasp will await its completion before rendering the page. The function takes no arguments, and its return value is ignored. </ShowForJs>

  You can use this function to perform any custom setup (e.g., setting up client-side periodic jobs).

  <Tabs groupId="js-ts"> <TabItem value="js" label="JavaScript"> ```js title="src/myClientSetupCode.js" export default async function mySetupFunction() { // Run some code } ``` </TabItem> <TabItem value="ts" label="TypeScript"> ```ts title="src/myClientSetupCode.ts" export default async function mySetupFunction(): Promise<void> { // Run some code } ``` </TabItem> </Tabs>

• baseDir: String

  If you need to serve the client from a subdirectory, you can use the baseDir option.

  If you set baseDir to /my-app for example, that will make Wasp set the basename prop of the Router to /my-app. It will also set the base option of the Vite config to /my-app.

  This means that if you serve your app from https://example.com/my-app, the router will work correctly, and all the assets will be served from https://example.com/my-app.

  <BaseDirEnvNote />