> ## Documentation Index
> Fetch the complete documentation index at: https://nango.dev/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Billit

> Connect to the Billit Access Point API with an API key

## Quickstart

Connect to the Billit Access Point API with Nango and make your first authenticated API request. This integration uses API key authentication, not the general Billit API's OAuth flow.

<Steps>
  <Step id="create-integration" title="Create the integration">
    In Nango, go to **Integrations**, select **Configure New Integration**, then select **Billit**.
  </Step>

  <Step id="authorize-billit" title="Authorize Billit">
    Go to **Connections**, select **Add Test Connection**, then enter the Billit environment, master account Party ID, and API key. See the [connect guide](/docs/api-integrations/billit/connect) for details.
  </Step>

  <Step id="call-billit-api" title="Call the Billit API">
    List the entities linked to the Billit master account. Replace the placeholders with your [Environment API key](/docs/reference/backend/http-api/api-keys), integration ID, and connection ID:

    <Tabs>
      <Tab title="cURL">
        ```bash theme={null}
        curl "https://api.nango.dev/proxy/v1/einvoices/registrations" \
          -H "Authorization: Bearer <NANGO-API-KEY>" \
          -H "Provider-Config-Key: <INTEGRATION-ID>" \
          -H "Connection-Id: <CONNECTION-ID>"
        ```
      </Tab>

      <Tab title="Node">
        Install Nango's backend SDK with `npm i @nangohq/node`. Then run:

        ```typescript theme={null}
        import { Nango } from '@nangohq/node';

        const nango = new Nango({ apiKey: '<NANGO-API-KEY>' });

        const response = await nango.get({
            endpoint: '/v1/einvoices/registrations',
            providerConfigKey: '<INTEGRATION-ID>',
            connectionId: '<CONNECTION-ID>'
        });

        console.log(response.data);
        ```
      </Tab>
    </Tabs>
  </Step>

  <Step id="implement-nango" title="Implement Nango in your app">
    Follow the [Auth implementation guide](/docs/guides/auth/auth-guide) to add the connection flow to your application.
  </Step>
</Steps>

## Environments

Billit provides isolated sandbox and production environments. API keys and master account Party IDs are not shared between them.

## Billit integration guides

* [How do I link my Billit account?](/docs/api-integrations/billit/connect): Find your API key and master account Party ID, then connect the appropriate environment.

Official docs: [Billit Access Point documentation](https://docs.accesspoint.billit.eu/), [authentication](https://docs.accesspoint.billit.eu/docs/authentication), and [sandbox versus production](https://docs.accesspoint.billit.eu/docs/sandbox-vs-production).

## Pre-built syncs & actions for Billit

*No pre-built syncs or actions available yet.*

<Tip>Not seeing the integration you need? [Build your own](/docs/guides/functions/functions-guide) independently.</Tip>