# useClerk()

> This hook should only be used for advanced use cases, such as building a completely custom OAuth flow or as an escape hatch to access to the `Clerk` object.

The `useClerk()` hook provides access to the [Clerk](https://clerk.com/docs/tanstack-react-start/reference/objects/clerk.md) object, allowing you to build alternatives to any Clerk Component.

## Returns

[Clerk](https://clerk.com/docs/tanstack-react-start/reference/objects/clerk.md) — The `useClerk()` hook returns the `Clerk` object, which includes all the methods and properties listed in the [Clerk reference](https://clerk.com/docs/tanstack-react-start/reference/objects/clerk.md).

## Example

The following example uses the [useClerk()](https://clerk.com/docs/tanstack-react-start/reference/hooks/use-clerk.md) hook to access the `clerk` object. The `clerk` object is used to call the [openSignIn()](https://clerk.com/docs/tanstack-react-start/reference/objects/clerk.md#sign-in) method to open the sign-in modal.

filename: app/routes/index.tsx
```tsx
import { useClerk } from '@clerk/tanstack-react-start'
import { createFileRoute } from '@tanstack/react-router'

export const Route = createFileRoute('/')({
  component: Home,
})

export default function Home() {
  const clerk = useClerk()

  return <button onClick={() => clerk.openSignIn({})}>Sign in</button>
}
```

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## Sitemap

[Overview of all docs pages](https://clerk.com/docs/llms.txt)