# Endpoints

Clerk provides helpers that allow you to protect your [Astro endpoints](https://docs.astro.build/en/guides/endpoints/#server-endpoints-api-routes), fetch the current user, and interact with the Clerk Backend API.

## Protect your endpoints

If you aren't protecting your endpoints using [clerkMiddleware()](https://clerk.com/docs/reference/astro/clerk-middleware.md), you can use the [auth() local](https://clerk.com/docs/reference/astro/locals.md) and check for the `isAuthenticated` value, as shown in the following example:

filename: src/pages/api/route.ts
```ts
export async function GET({ locals }) {
  const { isAuthenticated, userId } = locals.auth()

  if (!isAuthenticated) {
    return new Response('Error: No signed in user', { status: 401 })
  }

  // Add your Endpoint logic here

  return new Response(JSON.stringify({ userId }))
}
```

## Retrieve data from external sources

Clerk provides integrations with a number of popular databases.

To retrieve a token from a JWT template and fetch data from an external source, use the [`getToken()`](https://clerk.com/docs/reference/backend/types/auth-object.md#get-token){{ target: '_blank' }} method from the [auth() local](https://clerk.com/docs/reference/astro/locals.md), as shown in the following example:

filename: src/pages/api/route.ts
```ts
export async function GET({ locals }) {
  const { isAuthenticated, userId, getToken } = locals.auth()

  if (!isAuthenticated) {
    return new Response('Unauthorized', { status: 401 })
  }

  const token = await getToken({ template: 'supabase' })

  // Fetch data from Supabase and return it.
  const data = { supabaseData: 'Hello World' }

  return new Response(JSON.stringify(data))
}
```

## Retrieve the current user

In some cases, you might need the current user in your endpoint. Use the asynchronous [currentUser() local](https://clerk.com/docs/reference/astro/locals.md#locals-current-user) to retrieve the current [`Backend User`](https://clerk.com/docs/reference/backend/types/backend-user.md){{ target: '_blank' }} object, as shown in the following example:

> The [`Backend User`](https://clerk.com/docs/reference/backend/types/backend-user.md) object includes a `privateMetadata` field that should not be exposed to the frontend. Avoid passing the full user object returned by `currentUser()` to the frontend. Instead, pass only the specified fields you need.

filename: src/pages/api/route.ts
```ts
export async function GET({ locals }) {
  const user = await locals.currentUser()

  if (!user) {
    return new Response('Unauthorized', { status: 401 })
  }

  return new Response(
    JSON.stringify({ userId: user.id, email: user.emailAddresses[0].emailAddress }),
  )
}
```

## Interact with Clerk's Backend API

[`clerkClient`](https://clerk.com/docs/reference/backend/overview.md) is a wrapper around the [Backend API](https://clerk.com/docs/reference/backend-api){{ target: '_blank' }} that makes it easier to interact with the API **for JavaScript environments**. For example, here's how you can use `clerkClient` to update a user's first and last name:

filename: src/pages/api/route.ts
```ts
import { clerkClient } from '@clerk/astro/server'

export async function POST(context) {
  // Use the `auth()` local to access the `Auth` object
  // https://clerk.com/docs/reference/backend/types/auth-object
  const { isAuthenticated, userId } = context.locals.auth()

  // Protect the endpoint from unauthenticated users
  if (!isAuthenticated) {
    return new Response('Unauthorized', { status: 401 })
  }

  // Set the parameters for the `updateUser()` method
  const params = { firstName: 'Clerk', lastName: 'Cookie' }

  // Use the `updateUser()` method to update the user's first and last name
  const user = await clerkClient(context).users.updateUser(userId, params)

  // Return the updated user
  return new Response(JSON.stringify({ user }))
}
```

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